Glossary of technical terms for the use of metallurgical engineers Terms starting with alphabet ‘W’
Glossary of technical terms for the use of metallurgical engineers
Terms starting with alphabet ‘W’
Wackenroder solution – It is a dilute aqueous solution created by reacting hydrogen sulphide (H2S) with sulphur di-oxide (SO2). This reaction yields a mixture of various sulphur oxy-acids, including polythionic acids, and colloidal sulphur
Wadell shape factor – It is also known as sphericity. It is a dimensionless number which quantifies how closely a particle’s shape resembles a sphere. It is defined as the ratio of the surface area of a sphere with the same volume as the particle to the actual surface area of the particle. A perfect sphere has a sphericity of 1, while more irregularly shaped particles have sphericity values closer to 0.
Wafer – It is a reinforcement for motor-case port openings. In electronics, a wafer (also called a slice or substrate) is a thin slice of semi-conductor, such as a crystalline silicon (c-Si, silicium), used for the fabrication of integrated circuits and, in photovoltaics, to manufacture solar cells. The wafer serves as the substrate for micro-electronic devices built in and upon the wafer. It undergoes several micro-fabrication processes, such as doping, ion implantation, etching, thin-film deposition of different materials, and photo-litho-graphic patterning. Finally, the individual microcircuits are separated by wafer dicing and packaged as an integrated circuit.
Wages – These are payments made by an employer to an employee for work done in a specific period of time. Some examples of wage payments include compensatory payments such as minimum wage, prevailing wage, and yearly bonuses, and remunerative payments such as prizes and tip payouts. Wages are part of the expenses which are involved in running an organization. It is an obligation to the employee regardless of the profitability of the organization.
Wake hackle (ceramic, glassy materials) – It is a hackle line extending from a singularity at the crack front in the direction of cracking, such as on encounter with an inclusion.
Wald-Wolfowitz test – It is a non-parametric statistical test used to test the hypothesis that a series of numbers is random. It is also known as the runs test for randomness.
Walking-beam furnace – It is a continuous-type heat treating or sintering furnace consisting of two sets of beams, one stationary and the other movable, which lift and advance parts inside the hearth. With this system, the moving rails lift the work from the stationary rails, move it forward, and then lower it back onto the stationary rails. The moving rails then return to the starting position and repeat the process to advance the parts again.
Walking beam reheating furnaces – Initially these furnaces have been e designed with alloy steel walking beams which were exposed directly to the furnace heat and were also subjected to heat corrosion. Hence these furnaces were operated at maximum temperatures of 1,065 deg C. These furnaces were not suitable for heating steels where the temperature of reheat is up to 1,320 deg C. Presently the walking beam is made of water-cooled steel members lined with refractories so that only the refractories are exposed to the heat of the furnace. Alternatively, the beams and supports are constructed of water-cooled pipe sections with buttons on the top surfaces to keep away the hot material from direct contact with the water-cooled pipes. Walking beam furnaces are now used to reheat billets, blooms and slabs. These furnaces have two sets of beams. The steel stock rests on the stationary or fixed beams. For moving forward, the steel stock is lifted by moving beams which move forward at a preset distance and placed the stock to the next step on the hearth. After placing the stock on the hearth, the moving beams comes back to the original position. These furnaces are normally designed with end or side charging and discharging. The beams can be actuated either hydraulically or mechanically. Cross firing with side wall burners above and below the material stock being heated are being used. In some furnaces, the material is heated with radiant type roof burners or with burners placed in the roof and below the material.
Walking beam type cooling bed – They are normally used in modern large capacity long product rolling mills. Walking beam type of cooling bed utilizes two sets of rakes, one moving and one fixed, to carry the bars across the cooling bed. The hot side of the cooling bed begins with grid castings to absorb much of the initial heat from the hot bars while offering additional support as the steel bar is still in malleable state. The moving rake lifts, traverses, and lowers the bar several times so that where it touches continually changes permitting the entire length of the bars to cool at the same rate. The bar walks its way to the end of the bed where it is placed on a set of roller tables. Aligning rolls are used close to the cool side of the cooling bed to align the product which is needed for the finishing side of the mill. Walking beam cooling bed has a saw tooth pattern which is why it is also known as a walking rake type cooling bed. The mechanism ensures that the bars are uniformly positioned over the toothed rakes. The cooling bed is normally designed considering the smallest and the maximum size of the bars being rolled, delivered from the finishing rolling stand of the mill, and the cooling time needed for the different sizes of the bars. Waking beam cooling bed increases the production efficiency. However, the structure of the walking beam cooling bed is complex and needs extra efforts in its production and installation.
Walking hearth reheating furnaces – These are similar to the walking beam reheating furnace with regards to the passage of steel stock through the heating chamber. The difference lies in the method of conveyance in these two furnaces. In the walking hearth reheating furnace, the steel stock rests on the fixed refractory piers. These piers extend through openings in the hearth and their tops are above the hearth surface during the time when the material is stationary in the furnace. The furnace gases can hence circulate between most of the bottom surface of the work and the hearth. For movement of the material toward the discharge end of the furnace, the hearth is raised vertically to first contact the material and then raised further for a short distance above the piers. The hearth then moves forward to a preset distance, stops, lowers the material on to its new position on the piers, continues to descend to its lowest position and then moves backward to its starting position toward the charging end of the furnace to await the next stroke. The advantages and disadvantages of a walking hearth furnace are similar to those of a walking beam furnace.
Wallner line – It is a rib mark with wavelike contour caused by temporary excursion of the crack front out of plane in response to a tilt in the axis of principal tension induced by an elastic pulse. Such marks frequently appear as a series of curved lines, indicating the direction of propagation of the fracture from the concave to the convex side of a given Wallner line, and are sometimes observed when viewing brittle fracture surfaces at high magnification in an electron microscope. Wallner lines are attributed to interaction between a shock wave and a brittle crack front propagating at high velocity. Sometimes a Wallner line is misinterpreted as a fatigue striation.
Wallner lines – It is a distinct pattern of intersecting sets of parallel lines, sometimes producing a set of V-shaped lines, sometimes observed when viewing brittle fracture surfaces at high magnification in an electron microscope. Wallner lines are attributed to interaction between a shock wave and a brittle crack front propagating at high velocity. Sometimes Wallner lines are misinterpreted as fatigue striations.
Wall rocks – These are rock units on either side of an orebody. These are hanging wall and footwall rocks of an orebody.
Wall thickness – It refers to the distance between the inner and outer surfaces of a structure, normally applied to pipes, tubes, and containers. It is a critical measurement which impacts the strength, durability, and functionality of the object, as per the design and construction resources. In several fields like construction, and manufacturing, understanding wall thickness is essential for ensuring structural integrity and optimal performance.
Wall thickness tolerance – It refers to the acceptable variation in the thickness of a material, typically a pipe or tube, from its nominal or specified thickness. It defines the allowable range above and below the nominal value within which the actual wall thickness can fluctuate while still being considered acceptable. This tolerance is crucial for ensuring the structural integrity, functionality, and safety of components and systems that rely on specific wall thicknesses.
Ward Leonard control – It is a speed control system for direct control (DC) machines using an interconnected generator and motor.
Warehouse – It is a large building where commercial goods, or wares, are stored before they are sold. Over the years, warehouses have evolved to be an important part of the supply chains.
Warehouse management system (WMS) – It enables enterprises to gain control and visibility over inventory, which streamlines supply chain operations across locations. With automated warehouse management system, organizations can manage warehouse operations and limit manual intervention during the movement of inventory from the point of origin to delivery. Advanced warehouse management systems can cut inventory liabilities and tighten inventory control by providing real-time visibility across locations and controlling supply chain fluctuations.
Warehousing – It is the process of storing goods, frequently in large quantities, before they are sold, distributed, or used in manufacturing. It involves the physical storage of inventory, along with associated activities like receiving, organizing, and preparing goods for their next stage in the supply chain. Essentially, warehousing bridges the time gap between production and consumption. The core function is to provide a safe and secure space for goods. Warehouses track the quantity, location, and duration of storage for inventory. They handle the receipt of goods from suppliers and the subsequent dispatch to customers or other locations.
Warm compaction – It is a powder metallurgy process where metal powder is compacted at high temperatures, typically above 100 deg C, to achieve higher density and improved mechanical properties in the resulting part. This method combines the benefits of thermally activated deformation of the powder with the stable, higher-temperature lubricant system, leading to denser parts with improved performance and more uniform properties.
Warm extrusion – It is a metal forming process where the material is heated to a temperature above room temperature but below its recrystallization temperature. This temperature range typically falls between 424 deg C and 975 deg C. It is a method used to achieve a balance between the needed forces during extrusion and the desired final properties of the extruded product.
Warm forging – It is a metal forming process where a work-piece is heated to a temperature between its recrystallization temperature and the temperature at which it starts scaling (around 800 deg C to 1,200 deg C for steel), allowing for easier deformation while maintaining some of the benefits of cold forging.
Warm heading – It is a variation of the cold heading process. In it, the work metal is heated to a temperature high enough to increase its ductility yet still below the recrystallization temperature. A rise in work metal temperature normally results in a marked reduction in the energy needed for heading the material, with tooling loads reduced by as much as 50 % compared to cold forming. These lower tool forces normally reduce die breakage, but the higher contact temperatures can result in increased wear. Temperatures for warm heading typically range from 175 deg C to 650 deg C but can be as high as around 980 deg C, depending on the characteristics of the work metal. Warm heading is occasionally used to produce an upset which needs a larger machine than if the upsetting is done cold, but by far the most extensive use of warm heading is for the processing of difficult-to-head metals, such as stainless steels, titanium alloys, and nickel-base alloys. Warm heading allows for high-speed production of parts which otherwise are to be forged on vertical presses, frequently eliminating the need for reheating and relubricating the workpiece.
Warm peening – It is a surface treatment process where shot peening is performed at high temperatures, typically above room temperature, to improve the beneficial effects of compressive residual stress on a material’s surface. This technique combines the benefits of shot peening, which improves fatigue resistance and reduces crack initiation, with the advantages of high temperatures, such as increased plastic deformation and potential for dynamic strain aging.
Warm rolling – It is a metalworking process performed at temperatures between hot and cold rolling, typically ranging from 600 deg C to 900 deg C for steel. It offers a balance of advantages from both hot and cold rolling, resulting in a material with improved mechanical properties and dimensional accuracy compared to hot-rolled products, while still allowing for considerable plastic deformation. like closer tolerances and better surface finish.
Warm working – It is the deformation of metals at high temperatures below the recrystallization temperature. The flow stress and rate of strain hardening are reduced with increasing temperature. Hence, lower forces are needed than in cold working.
Warp – It is the yarn running lengthwise in a woven fabric. It is a group of yarns in long lengths and approximately parallel. It is a change in dimension of a cured laminate from its original molded shape.
Warpage – It consists of deformation other than contraction which develops in a casting between solidification and room temperature. It is also the distortion which occurs during annealing, stress relieving, and high temperature service. In refractories, warpage is the deviation of a plane surface on a refractory from being flat. In compacts, it is the dimensional distortion in a composite part. It is the distortion which can occur in a compact during sintering.
Warping – It refers to the unintentional bending, twisting, or deformation of a part or material away from its intended shape. It is a defect that often arises during processes like injection molding, casting, or even woodworking because of uneven cooling, stress distribution, or moisture absorption.
Warranty – It is a guarantee or promise made by a manufacturer or similar party regarding the condition of their product. A warranty also refers to the terms and situations in which repairs, refunds, or exchanges will be made if the product does not function as originally described or intended.
Warrington type wire rope construction – it has two layers of wires around a centre with one diameter of wire in the inner layer, and two diameters of wire alternating large and small in the outer layer. The larger outer-layer wires rest in the valleys, and the smaller ones on the crowns, of the inner layer. In the Warrington type, the number of wires of each layer is shown as 1+n+(n+n) and there are two types of wires for the outer layers, one being large and the other being small. The number of wires of the outer layer is double that of the inner layer and through a combination of the inner and outer layers the spaces between the wires are kept small. The Warrington type rope is not being used to a great extent these days.
Wash – It is a coating applied to the face of a mould prior to casting. It is also an imperfection at a cast surface similar to a cut.
Washer – It is a thin plate, typically disk-shaped, with a central hole. It is used with threaded fasteners like screws and bolts to distribute the load of the fastener and prevent damage to the material being fastened. Washers can also prevent loosening, or provide a seal. Other uses are as a spacer, spring (Belleville washer, wave washer), wear pad, preload indicating device, locking device, and to reduce vibration (rubber washer).
Wash metal – It is the molten metal used to wash out a furnace, ladle, or other container.
Washout – It is the sudden erosion of soft soil or other support surfaces by a gush of water, normally occurring during a heavy downpour of rain (a flash flood) or other stream flooding.
Wash primer – It is a thin, inhibiting paint, normally chromate pigmented with a polyvinyl butyrate binder.
Waspaloy – It is a nickel-based superalloy known for its excellent high-temperature strength and good corrosion resistance, particularly oxidation resistance, making it suitable for demanding applications like gas turbine components. It maintains its strength at temperatures up to 980 deg C.
Wastage – It is the materials produced which do not meet a needed quality standard.
Waste – In a nuclear facility, it consists of the products of nuclear power generation and other applications of nuclear fission or nuclear technology, such as research and medicine. Radioactive waste is hazardous to most forms of life and the environment, and is regulated by government agencies in order to protect human health and the environment. In mining, waste is unmineralized, or sometimes mineralized, rock which is not minable at a profit.
Waste acceptance criteria (WAC) – It consists of the conditions which are to be met before radioactive waste is accepted at a Repository. Waste acceptance criteria describe the nature, form, physical, chemical, radiological characteristics which can be accepted for onward management and disposal by a waste management operator or waste management site.
Waste acid – It refers to any acidic substance which is discarded as unwanted, no longer useful, or considered hazardous. This includes expired acids, byproducts from chemical reactions, and unused or contaminated acids. Waste acids can be generated in different settings, such as industrial processes, laboratories, and even households, and frequently need specific disposal methods because of their corrosive nature.
Waste container – It is a vessel used for the purposes of containing a waste form for disposal.
Waste disposal – It is the process of eliminating waste by means of dumping in a landfill, combustion in an incinerator, dumping at sea, or eliminating waste in some other way which is not recycled or reused.
Waste energy – It refers to energy which is produced but not used, or is used inefficiently and dissipated into the surroundings. It is essentially energy which is not transferred to a useful output. This can include energy used for unimportant, unnecessary, or unsuccessful tasks.
Waste-form – It is the waste which is in the final chemical and physical form in which it is to be disposed of (but excluding the waste container and any capping material).
Waste gases – It refers to waste materials in the form of gases which are released into the atmosphere as byproducts of different processes, mainly from industrial / human activities. These gases can be harmful to the environment and human health.
Waste gas analysis – Gases emitted by the process in the furnace can be analyzed either in the furnace itself (in order to assess process efficiency, for example) or as they are discharged from the furnace stack (above all, for pollution control purposes). Furnace gas testing can be performed with Orsat equipment (gases are absorbed selectively as they pass through a series of specific solvents) or by means of instrumental analysis. Paramagnetic detection can be used for oxygen analysis, and infrared absorption for carbon di-oxide analysis. Mass spectrometry or gas chromatography are also used to analyze gas mixtures.
Waste heat – It is intrinsic to all manufacturing processes. During the industrial manufacturing processes, around 20 % to 50 % of the energy consumed is ultimately lost via waste heat contained in streams of hot exhaust gases and liquids, as well as through heat conduction, convection, and radiation from the surface of the hot equipments as well as from the heated products. It is heat which is generated during industrial or energy production processes but is not used for any productive purpose and is instead released into the environment. It is essentially the unused portion of energy which can potentially be harnessed for other applications. In the definition of waste heat, it is implicit that the waste streams carrying the heat eventually mix with atmospheric air or groundwater and that the energy contained within these streams becomes unavailable as useful energy. The absorption of waste energy by the environment is often termed as thermal pollution.
Waste heat boiler – It is a normal water tube boiler in which the hot exhaust gases from a furnace pass over a number of parallel tubes containing water. Waste heat boiler normally uses medium to high temperature exhaust gases to generate steam. Waste heat boilers are available in a variety of capacities allowing for gas intakes ranging from 30 cubic meters per minute to 25,000 cubic meters per minute. In cases where the waste heat is not sufficient for producing desired levels of steam, auxiliary burners or an afterburner are normally added for getting higher output of steam. The steam can be produced for process purpose or for generation of power. Generation of superheated steam normally needs addition of an external super heater to the boiler.
Waste-heat recovery – It consists of the capture and reuse of the waste heat of the industrial processes for heating or for generating mechanical or electrical work. Typical uses include combustion air preheating, preheating of fuel gas, boiler feed water preheating, raw material preheating, generation of process steam, and production of steam for power generation etc. The basic idea behind the recovery of the waste heat is to try to recover maximum amounts of heat in the plant and to reuse it as much as possible, instead of just releasing it into the environment (air or a nearby river). It is an economy measure whereby the heat of exhaust gases is used in a cyclic process to pre-heat combustion air and / or fuel-gas.
Waste heat recovery devices (WHRDs) – These devices recover part of the heat of the exhaust gases. As the name implies, waste-heat recovery boiler is a boiler where heat, generated in different processes, is recovered and used to generate steam or boil water. The main purpose of this boiler is to cool down flue gases produced by metallurgical or chemical processes, so that the flue gases can be either further processed or released without causing harm. The steam generated is only a useful by-product. A waste-heat recovery boiler is a heat exchanger which recovers heat from a gas stream and in turn produces steam which can be used in a process or to drive steam turbines. Waste-heat recovery boiler uses excess or waste heat from a process to produce steam. This boiler has two functions namely (i) to produce steam and to provide cooling for a process in order for it to proceed or to recover heat which otherwise is released to the atmosphere, losing a tremendous quantity of usable energy. Methods for waste heat recovery include (i) transferring heat between exhaust gases and combustion air for its preheating, (ii) transferring heat to the load entering furnaces, (iii) generation of steam and electrical power, or (iv) using waste heat with a heat pump for heating or cooling facilities. Waste heat recovery devices work on the principle of heat exchange. During heat exchange the heat energy of the exhaust gases gets transferred to some other fluid medium. This exchange of heat reduces the temperature of the exhaust gases and simultaneously increases the temperature of the fluid medium. The heated fluid medium is either recycled back to the process or utilized in the production of some utilities such as steam or power etc. The benefits of Waste heat recovery devices are multiple namely (i) economic, (ii) resource (fuel) saving, and (iii) environmental. The benefits of these devices include (i) saving of fuel, (ii) generation of electricity and mechanical work, (iii) reducing cooling needs, (iv) reducing capital investment costs in case of new facility, (v) increasing production, (vi) reducing greenhouse gas emissions, and (vii) transforming the heat to useful forms of energy.
Waste heat recovery (WHR) technologies – These are the technologies for the recovery of waste heat. These technologies provide valuable energy sources and reduce the overall energy consumption. There are several waste heat recovery technologies which are available and which can be used for capturing and recovering the waste heat. Waste heat recovery technologies consist of capturing and transferring the waste heat from a process with a gas, liquid, or solid back to the system as an extra energy source. The energy source can be used to create additional heat or to generate electrical and mechanical power. Waste heat can be rejected at any temperature. Normally, the higher the temperature of the waste heat, the higher is the quality of the waste heat and the easier is the optimization of the waste heat recovery technologies. An increased use of waste heat recovery technologies also serves to mitigate greenhouse gas (GHG) emissions.
Waste incineration – It is the process of burning waste materials, typically at high temperatures, to reduce their volume and potentially recover energy. It is a form of thermal treatment which converts waste into ash, flue gas, and heat.
Waste liquids – It refers to any waste material in a liquid form which is no longer needed or is contaminated and need safe disposal. This can include wastewater, used oils, and other fluids from various sources like industrial processes, households, or commercial activities. It is important to manage liquid waste properly to prevent environmental pollution and health hazards.
Waste management – It is the process of managing, treating and storing radioactive waste pending its final disposal.
Waste material – It refers to any materials which are considered unwanted, unusable, or worthless after their main use or purpose has been fulfilled. It encompasses a broad range of discarded items, including garbage, refuse, and byproducts from different processes.
Waste package – It is the total waste product including the waste, waste-form and the waste container.
Waste plastic – It refers to discarded plastic materials, including objects and substances, which are no longer needed or have become unsuitable for their intended use and are hence disposed of or intended for disposal. These materials can include discarded plastic products, manufacturing byproducts, or any other plastic-containing items which are no longer wanted. The accumulation of plastic waste in the environment can have detrimental effects on ecosystems and human health.
Waste plastics injection (WPI) – It consists of the injection of waste plastic as a solid in the blast furnace through the tuyeres in a similar way to pulverized coal (PC). Normally it is done as a co-injection of waste plastic and coal into the blast furnace. The quality of the waste plastic injectants is important not only in terms of their utilization in the blast furnace itself, but also in the preparation, handling and distribution of the materials to the furnace. Waste plastics injectant is prepared and conveyed to a storage hopper. It is then pneumatically transported through individual pipelines or through a distributor to the individual tuyeres. Two of the most critical requirements for the successful use of waste plastics in blast furnace are their availability and processing costs. The waste plastics are frequently highly heterogeneous and frequently mixed with other materials. Hence, the collection and sorting of these wastes containing plastic residues is expensive. The aim of the processing plant is to provide a feedstock of consistent quality with the requisite particle size and in sufficient quantity. The extent of processing required depends on the condition in which these wastes are received.
Waste plastic processing – It refers to the methods and technologies used to manage and transform plastic waste into reusable materials or energy, reducing its environmental impact. This includes recycling, where plastic is transformed into new products, and waste-to-energy processes, where plastic is used to generate heat, electricity, or fuel.
Waste reduction – It is also known as waste minimization. It refers to the practice of minimizing the quantity of waste generated in the first place, rather than focusing on managing or disposing of it after it’ has been created. It is a proactive approach aimed at preventing waste at its source through different strategies and practices.
Waste solids – It refers to any discarded material, including garbage, refuse, or other discarded material, which is in a solid, semi-solid, or contained gaseous state. It encompasses a wide range of materials from different processes. Essentially, if something is unwanted or unusable and exists in a solid or similar form, it can be considered solid waste.
Waste sorting – It is also known as waste segregation or separation. It is the process of dividing different types of waste materials into separate categories. This separation is crucial for effective recycling, resource recovery, and proper disposal of waste materials.
Waste-to-energy-facilities – These are specially designed waste management facilities where waste is burned to create energy, which is captured for use in generating electricity.
Wastewater – It is any water which has been adversely affected in quality by human influence. It encompasses liquid and solid waste discharged from domestic, commercial, and industrial sources. Wastewater can contain a wide range of pollutants, including physical, chemical, and biological contaminants.
Wastewater engineering – It is a branch of environmental and civil engineering focused on the collection, treatment, and safe disposal of wastewater from different sources like industries. It encompasses the design, construction, and operation of systems that remove pollutants from wastewater, making it suitable for discharge into the environment or for reuse.
Wastewater sludge treatment – It refers to the processes used to manage and treat the solid or semi-solid residue (sludge) generated during wastewater treatment. The main objective is to reduce the volume and potential hazards of sludge, making it suitable for disposal, reuse, or recycling. This process is crucial for protecting human health and the environment from potential risks associated with untreated sludge.
Wastewater treatment -It consists of the mechanical or chemical processes used to modify the quality of waste water in order to make it more compatible or acceptable to the environment. It is carried out in three stages namely (i) primary treatment, (ii) secondary treatment, and (iii) tertiary treatment.
Wastewater treatment plant – It is a structure, thing, or process used for the physical, chemical, biological, or radiological treatment of wastewater before it is returned to the environment. The term also includes any structure, thing, or process used for wastewater storage or disposal, or sludge treatment, storage, or disposal.
Wastewater treatment sludge – It is the solid or semi-solid material which remains after wastewater has been treated. It is a by-product of both primary and secondary treatment stages. Primary sludge comes from the initial settling of solids in wastewater, while secondary sludge is generated during biological treatment processes. Sludge contains organic and inorganic solids, water, and sometimes harmful contaminants.
Watch glass – It is a circular, concave piece of glass normally used in chemistry laboratories as a working surface for different purposes, such as evaporating liquids, holding solids while they are being weighed, heating small quantities of a substance, or as a cover for a beaker.
Water – It is a polar inorganic compound with the chemical formula H2O. It is a tasteless, odourless, and normally colourless liquid at standard temperature and pressure, though it also occurs naturally as a solid and a gas at the earth’s surface. It is the most abundant substance on earth and hence an integral component of virtually all chemical and biological systems. Water is frequently described as the ‘universal solvent’ for its inherent ability to dissolve several substances. Depending on the use and the quality of water, water carry different terminology in different places of the industrial plant These are (i) raw water, (ii) intake water, (iii) rain water, (iv) treated water, (v) process water, (vi) recirculating water, (vii) direct cooling water, (viii) indirect cooling water, (ix) boiler feed water, (x) DM (demineralized) water, (xi) soft water, (xii) distilled water, (xiii) make up water, (xiv) water condensate, (xv) drinking water, (xvi) fire- fighting water, (xvii) domestic water, (xviii) contaminated water, (xix) phenolic water, (xx) waste water, and (xxi) water effluent etc.
Water absorption – It is the ratio of the weight of water absorbed by a material to the weight of the dry material.
Water atomization – It is a process where liquid water is forced through a nozzle at high pressure, breaking it into fine droplets, or atomizing it, to create a spray. This technique is used in various applications, including the production of metal powders and in spray drying. In the context of powder metallurgy, water atomization involves using high-pressure water jets to break down molten metal into small droplets, which then solidify into powder particles.
Water atomized particles – These are small, solid particles produced by breaking a molten material into droplets using high-pressure water jets, which then solidify. This process is a normal method for producing metal powders, including those used in powder metallurgy and other applications. The resulting particles can vary in size and shape, with higher water pressures normally leading to finer particles.
Water balance – It is a measure of the quantity of water entering and the quantity of water leaving a system.
Water-based graphite dispersion – It is a suspension of finely ground graphite particles in water, where water acts as the carrier liquid. It’s essentially a mixture where graphite, a form of carbon, is dispersed throughout the water, rather than dissolved. This dispersion is frequently stabilized by additives which prevent the graphite particles from settling or clumping together.
Water-based hydraulic fluids – These are hydraulic fluids where water is a significant component, frequently mixed with additives like glycols or esters, to improve performance and safety. These fluids are typically used when fire resistance is crucial, as water provides inherent fire-retardant properties. These fluids are also known for being biodegradable and less toxic than traditional petroleum-based fluids.
Water bath – It is a piece of laboratory equipment consisting of a container of heated water, used to incubate samples at a constant temperature over a period of time. It provides a gentle and controlled way to heat samples without direct exposure to a flame or hot surface, making it suitable for a variety of applications like warming reagents, melting substrates, or incubating cell cultures.
Water body – It is a significant accumulation of water, either on the earth’s surface or underground. It can refer to a variety of features, including oceans, seas, lakes, rivers, streams, ponds, and even groundwater aquifers.
Water boxes – These boxes are essentially cooling units in a wire rod mill. They help to quickly reduce the temperature of the hot wire rod after it has been rolled to its final dimensions. These boxes are specialized cooling systems designed to rapidly cool hot-rolled wire rod as it exits the finishing mill stands. These boxes are strategically placed along the rolling line and use water sprays or immersion to control the temperature profile of the wire rod, which is crucial for achieving desired mechanical and metallurgical properties.
Water break – It is the appearance of a discontinuous film of water on a surface signifying non-uniform wetting and normally associated with a surface contamination.
Water break test – It is a test to determine if a surface is chemically clean by the use of a drop of water, preferably distilled water. If the surface.
Water circulation – The circulation of boiler water is based on the principle of convection. A fluid which is heated expands and becomes less dense, moving upward through heavier, denser fluid. Convection and conduction transfer heat through pipe walls and water currents, resulting in unequal densities. Cold water flows through the downcomer to the bottom of the mud drum and then flows upward through the riser (water wall tubes) as it is heated.
Water column – It is a vertical tubular member connected at its top and bottom to the steam and water space respectively of a boiler, to which the water gauge, water level controls, and fuel cut-off can be connected.
Water condensate – It is that water which is produced during the condensation of steam in an industrial application. If there is no contamination of water condensate then the water condensate can be directly added to the boiler feed water.
Water conservation – It is the practice of using water wisely and efficiently to reduce unnecessary water waste. It involves strategies and actions to protect, preserve, and manage water resources, ensuring their availability for current and future needs. This includes both reducing water consumption and preventing water pollution.
Water contamination – It refers to the introduction of harmful substances into bodies of water like rivers, lakes, and oceans, making them unsuitable for their intended uses. These harmful substances, called pollutants, can include chemicals, microorganisms, and even heat or radioactive materials, and can negatively impact human health and ecosystems. Water contamination occurs when the natural composition of water is changed, making it unsafe for drinking, and several industrial uses.
Water cooling – It is a method of heat removal which utilizes water as a cooling medium. It is normally used in several applications, including computer systems, industrial processes, and even in engines, to dissipate heat and maintain optimal operating temperatures. In essence, it involves circulating water to absorb heat from a component or fluid and then transferring that heat to another location for dissipation.
Water cycle – It is also hydrologic cycle. It is a biogeochemical cycle which involves the continuous movement of water on, above and below the surface of the earth across different reservoirs. The mass of water on earth remains fairly constant over time.
Water demand – A plant uses huge quantities of fresh water for a variety of usage which includes cooling, dust suppression, cleaning, temperature control (heat treatment), transport of waste materials (ash, sludge, and scale etc.), and other usages. For example, in a steel plant, water is an essential part of some of the plant processes such as water addition for controlling the moisture content of the coking coal blend, pelletizing of sinter mix, making of green pellets during the production of iron ore pellets, production of steam and hence power, and granulation of blast furnace slag etc. Use of large quantity of water also generates considerable quantity of wastewater which is to be treated before its discharge. Water demand refers to the total volume of water needed to satisfy the different needs of the processes. It represents the quantity of water which the processes utilize.
Water demineralization – It typically refers to the removal of dissolved mineral solids through an ion exchange process. The basic principles of an ion exchange reaction are described here. In the presence of water, minerals and salts dissociate into their constituent ions. These dissolved solids consist of negatively-charged ions known as anions, and positively charged ions known as cations, each of which are attracted to counterions (or ions of an opposing charge). Within an ion exchange column, a resin is present. This resin consists of plastic beads to which an ionic functional group has been bound. These functional groups loosely hold ions of an opposing charge through mutual electrostatic attraction.
Water discharge activity – It is the discharge of water into a water-course or the sea.
Water distribution system – It is an organized process and associated structures of pipes, valves, fittings, and accessories, including associated pressure reducing stations, which are used to convey potable water in a waterworks system to a service connection.
Water efficiency – It is the accomplishment of a function, task, process, or result with the minimal quantity of water feasible. It is an indicator of the relationship between the quantity of water needed for a particular purpose and the quantity of water used or diverted.
Water effluents – These are those waters which cannot be recycled back even after treatment. Such water is discharged from the plant boundary after correcting its quality to the levels required as per the statutory norms. These days normally industrial plants aim for zero discharge of water effluents. These plants normally treat water effluents to improve its quality levels so that it can be used for gardening inside the plant or can be used in raw material storages for dust suppression.
Water elutriation – It is a process which uses an upward flow of water to separate particles of different sizes, shapes, and densities. It works by exploiting the differing terminal velocities of particles. Those with lower terminal velocities remain suspended in the upward current, while those with higher velocities settle downwards. Essentially, it is a way to wash and separate particles, like separating fine particles from heavier ones, using water.
Water environment – Under this included are (i) study of existing ground and surface water resources with respect to quantity and quality within the impact zone of the proposed steel project, (ii) prediction of impacts on water resources due to the proposed water use /pumping on account of the steel project, (iii) quantification and characterization of waste water including toxic organic, from the proposed activity, (iv) evaluation of the proposed pollution prevention and wastewater treatment system and suggestions on modification, if required, (v) prediction of impacts of effluent discharge on the quality of the receiving water body using appropriate mathematical/simulation models, and (vi) assessment of the feasibility of water recycling and reuse and delineation of detailed plan in this regard.
Water flow diagram – It visually represents the movement and distribution of water within a system, such as an industrial process, building, or plant. It typically depicts the source of water, its pathways, and its uses, including where it is stored, treated, and discharged. These diagrams are used to understand, analyze, and manage water resources and systems effectively.
Water footprint – It is a new concept which allows quantification of fresh water appropriation. The water footprint methodology has been introduced by Hoekstra as an indicator of fresh water appropriation, with the aim to quantify and map indirect water use and show the relevance of involving consumers and producers along the supply chains in the water management.
Water gas – It is a kind of fuel gas, a mixture of carbon mono-oxide and hydrogen. It is produced by ‘alternately hot blowing a fuel layer [coke] with air and gasifying it with steam’. The caloric yield of the fuel produced by this method is around 10 % of the yield from a modern syngas plant. The coke needed to produce water gas also costs significantly more than the precursors for syngas (mainly methane from natural gas), making water gas technology an even less attractive commercial proposition.
Water gas shift reaction – During this reaction, partial oxidation of carbon by steam occurs and is represented by the equation C + H2O = H2 + CO with delta H = 28/3 kilocalories per mol.
Water gauge – It is the gauge glass and its fittings for attachment.
Water glycol hydraulic fluid – It is a type of fire-resistant hydraulic fluid which uses a mixture of water and glycol (like ethylene or diethylene glycol) as its base, along with several additives. It is characterized by its ability to resist ignition and its biodegradability, making it an environmentally conscious choice.
Water hammer – It is a sudden increase in pressure of water because of an instantaneous conversion of momentum to pressure.
Water harvesting – It is also called rain water harvesting. It is the capture and use of runoff from rainfall and other precipitation.
Water-in-oil emulsion type hydraulic fluid – It is a fire-resistant fluid where tiny droplets of water are suspended in a continuous oil phase. These fluids are designed to balance fire resistance with lubrication, and typically contain 35 % to 45 % water. The presence of water makes them less flammable than traditional oil-based fluids, but the water content needs to be carefully monitored to maintain these properties.
Water jacket – It is a water-filled casing surrounding a device, typically a metal sheath having intake and outlet vents to allow water to be pumped through and circulated. The flow of water to an external heating or cooling device allows precise temperature control of the device. Water jackets are frequently used for water cooling or heating. A water jacket is a water-filled casing surrounding a device, typically a metal sheath having intake and outlet vents to allow water to be pumped through and circulated.
Waterjet – It is the water emitted from a nozzle under high pressure (70 megapascals to 410 megapascals or higher). It is useful for cutting organic materials.
Water-jet / abrasive water-jet machining – It is a hydrodynamic machining process which uses a high-velocity stream of water as a cutting tool. This process is limited to the cutting of non-metallic materials when the jet stream consists solely of water. However, when fine abrasive particles are injected into the water stream, the process can be used to cut harder and denser materials. Abrasive waterjet machining has expanded the range of fluid jet machining to include the cutting of metals, glass, ceramics, and composite materials.
Water-jet cutting – It consists of a water jet cutter which cut (foam) materials using a high-pressured jet of water. Unlike routing, it can create deep pockets accurately.
Water-jet quenching – It is a heat treatment process where a heated metal object is rapidly cooled by directing high-pressure water jets onto its surface. This process is used to alter the micro-structure of the metal, primarily to increase its hardness and strength. It is a common technique in industries like steel production, where it is used on the run-out table for hot-rolled steel.
Water-leg – Water-leg refers to a water-filled section extending from the shell, which surrounds the firebox of some types of boilers.
Water level – It is the elevation of the surface of the water in a boiler.
Water line – Water line is the actual level of water in a boiler. It is the point at which water and steam separate.
Water management – It is the process of planning, developing, distributing, and optimizing the use of water resources, while minimizing damage to life and property and ensuring efficient and sustainable use. It encompasses different activities like water treatment, distribution, flood control, irrigation, and groundwater management, with the goal of balancing human needs with the preservation of water resources. Water management strategies help industrial plant to recover, reuse, and / or recycle water, which can in turn generate considerable cost savings by minimizing the demand for intake water and by reducing discharge volumes. The water management in an industrial plant mainly depends on the local conditions, availability of water, and regulatory requirements. The three basic factors which are crucial for efficient water management are (i) quality of make-up water, (ii) climatic conditions at the location of the steel plant, and (iii) regulatory requirements.
Water management plan – It is a comprehensive strategy designed to ensure the safe, efficient, and sustainable use of water resources. It involves assessing current water usage, identifying areas for improvement, setting goals, and implementing solutions to optimize water consumption and minimize risks associated with water systems. This can include preventing contamination, maintaining compliance with regulations, reduction of losses, water recycling, and ensuring the long-term availability and quality of water. The main water related issues which have effects on the water management plan in an industrial plant are (i) quality of process water needed (ii) quality of wastewater, (iii) recycling of water and minimizing of its consumption, (iv) pollutants in the water, (v) implementation of new technologies for water management, and (vi) implementation of wastewater treatment technologies and their cost-effectiveness.
Water marks – These are defects in a fired porcelain enamel surface because of the water (perspiration) dropping on the dried enamel or not being thoroughly removed from crevices in the work-piece during the drying step after pickling or cleaning. Similar defects can also be caused by too much water in an enamel slip or poor suspension of the enamel slip. These are also called water lines or water streaks.
Water meter – It is a device which measures the quantity of water used.
Water of crystallization – It consists of water molecules which are present inside crystals. Upon crystallization from water or aqueous solutions, several compounds incorporate water in the interstices of their crystalline frameworks. The water molecules are typically present in a stoichiometric ratio and can interact to varying degrees with the atoms of the crystal.
Water of hydration – It is also known as water of crystallization. It refers to water molecules which are chemically bound within the crystal structure of a compound. These water molecules are an integral part of the compound’s structure and are not merely absorbed or adsorbed on the surface.
Water pollutants – These refer to the substances which are capable of making any physical, chemical or biological change in the water body. These have undesirable effect on living organisms. Water is called polluted when the water is contaminated with domestic waste and industrial effluents. When this contamination reaches beyond certain allowed concentrations then the water pollution occurs. Water is considered polluted if some substances or condition is present in the water changes its physical, chemical, or biological characteristics to such an extent that the water cannot be used for its intended use or for a specific purpose. Water is considered to be polluted when the three parameters of water namely (i) physical parameters, (ii) chemical parameters, and (iii) biological parameters deviates beyond a specified concentration. Physical parameters are colour, odour, turbidity, taste, temperature, and electrical conductivity etc. Chemical parameters include the quantity of carbonates, sulphates, chlorides, fluorides, nitrates, and metal ions etc. in water. These chemicals form the total dissolved solids present in water. Biological parameters include matter like algae, fungi, viruses, protozoa and bacteria.
Water pollution – It means the contamination of water bodies (e.g., lakes, rivers, oceans and ground-water etc.). Water pollution occurs when pollutants are discharged directly or indirectly into waterbodies without adequate treatment to remove harmful compounds. Water pollution occurs because of the presence of excessive quantities of a hazard (pollutants) in water in such a way that it is no long suitable for its intended use. Water pollution has a dual effect on nature. It has harmful effects on the living beings and also on the environment. Pollution affects the quality of water is an adverse way because of the addition of large quantities of unwanted materials to the water. Water pollution has several sources and characteristics. Pollution to the water environment can come from a wide range of sources. These include agriculture (crops and livestock), atmosphere (acid rain), aquaculture, forestry, illegal dumping of waste, industry, mines, sewage, and urban areas and roads etc. When the polluted water seeps into the ground and enters an aquifer, it results into ground water pollution. The pollution of ground water is a matter of serious concern. Ground water gets polluted in a number of ways.
Water pollution control – It refers to the processes and measures taken to prevent, reduce, or eliminate the introduction of harmful substances into water bodies, thereby protecting water quality and public health. These measures include regulatory frameworks, technological solutions, and management strategies aimed at minimizing pollution from different sources.
Waterproofing materials – These are normally applied to hardened concrete surfaces, but they can be added to concrete mixes. These admixtures normally consist of some type of soap or petroleum products, as perhaps asphalt emulsions. They can help retard the penetration of water into porous concretes but probably do not help dense, well-cured concretes very much.
Water quality – It means the chemical, microbiological, and physical characteristics of water.
Water quality indicators – These are constituents or characteristics of water which can be measured to determine its suitability for use.
Water quality standards – These are guidelines and regulations which define the acceptable levels of different substances and characteristics in water to ensure it is safe for specific uses such as drinking water, industrial water, cooling water, and boiler water etc.
Water quenching – It is a quench in which water is the quenching medium. The major disadvantage of water quenching is its poor efficiency at the beginning or hot stage of the quenching process.
Water quench tower – It is a vertical industrial tower which cools hot gases or vapours by direct contact with a downward flow of water. This rapid cooling process, also known as quenching, is crucial for preventing downstream equipment damage, removing impurities, and controlling gas volume. Essentially, it is a heat exchanger which uses water to absorb heat from hot process streams.
Water reservoir – It is a body of water, either natural or artificial, which is used for storing water for several purposes. Typically, it is a lake created by building a dam across a river or stream. The main function of a reservoir is to regulate streamflow by storing excess water during wet seasons and releasing it during drier periods.
Water resources – These refer to the natural sources of water which are potentially useful for human activities. These resources include both fresh and saltwater, and can be found on the surface, under-ground, or in the atmosphere. They are crucial for several uses, including drinking, agriculture, and industry.
Water re-use – It means beneficial use of the treated wastewater directed to a specific purpose other than the general release to the surface or subsurface environments.
Water rinsing – It is the act of washing something lightly with water to remove soap, dirt, acid, or impurities, especially as a final step in cleaning. It involves using water to flush away residue from a previous cleaning process. The goal is to ensure a clean surface free of any lingering cleaning agents or contaminants.
Water separation – An important property of the hydraulic fluid is the ability of the fluid to separate water. Water contamination can for example result from leakage from the cooler, condensation, or through leaking gaskets. Water in the hydraulic system can cause corrosion, cavitation in pumps, filter problems, an increase in friction and wear, and can also have a negative effect on the durability of the gaskets. It is important that free water can be drained from the system, and it is a requirement that emulsified water in the hydraulic fluid can rapidly be separated. The demulsification capacity of the fluid differs between new and used fluid. Used fluid has a poorer demulsification capacity than new fluid. Contamination by another type of fluid, such as engine oil, can greatly reduce the ability of the hydraulic fluid to separate water. Contamination with other fluid can also lead to sludge formation and cause forming of deposits in valves and filters.
Water softener – It removes hardness (CaCO3) from water through an ion exchange of sodium with calcium and magnesium.
Water softening Process – It is an ion exchange process which exchanges hard water ions like Ca2+ or Mg2+ for single-charged ions like sodium (Na+) or potassium (K+). Water softening resins do not remove negative ions like bi-carbonate and chlorides. When in solution with bi-carbonate, sodium ions do not show inverse solubility. Even when the bi-carbonate ion breaks down upon heating to form carbonate, it is still over 30,000 times more soluble than calcium carbonate. Hence, instead of forming calcium carbonate scale, the sodium and carbonate ions stay in solution to much higher concentrations. The reaction which takes place is 2Na+ + 2(HCO3)- = 2Na+ + (CO3)2- + H2O (liquid) + CO2 (gas). Softening of water is one approach to prevent scale build up in cooling systems. Water softening chemicals remove hard water cations and exchange them for softened water cations like sodium ions. Also, softening water does not appreciably change the conductivity of the water, since for every calcium ion (containing two positive charges) which is removed, it is replaced with two sodium ions, each of which have one positive charge.
Water space – Water space is the portion of the boiler which is normally filled with water.
Water spray – It refers to a quantity of water which is broken up into fine droplets and dispersed into the air, frequently through a device like a nozzle. It can be a natural occurrence, like spray from a wave or a waterfall, or it can be artificially created for several purposes, including fire suppression, dust control, and cooling.
Water stain – It is the superficial oxidation of the surface with a water film, in the absence of circulating air, held between closely adjacent metal surfaces.
Water staining – It is a residue left on aluminium which has been wet and allowed to dry naturally. This is very difficult to remove and cannot be improved by polishing or anodizing.
Water table – It is the top of the saturated zone in the ground, where water fills the spaces in the soil and rock,
Water treatment plant – It is a facility which purifies water to make it safe for different uses, such as drinking, or industrial processes, by removing impurities and contaminants. These plants use a series of physical, chemical, and biological processes to achieve this.
Water tube – It is a tube in a boiler having the water and steam on the inside and heat applied to the outside.
Water-tube boiler – Water tube boiler is a kind of boiler where the water is heated inside tubes and the hot gasses surround them. This is just opposite of fire tube boiler. In this boiler, boiler feedwater flows through the tubes for evaporation and enters the boiler drum. Baffles are installed across the tubes to allow cross flow of flue gases to ensure maximum exposure of the tubes. The circulated water is heated by the combustion gases and converted into steam at the vapour space in the drum. On the basis of configuration of tubes inside the furnace, this boiler is further classified as ‘straight-tube boiler, or ‘bent tube boiler’. In a water-tube boiler, water circulated in the tubes is heated externally by the hot flue gas. Fuel is burned inside the furnace, creating hot gas which heats up the water in the steam generating tubes. Cool water at the bottom of the steam drum returns to the feedwater drum of small boilers through large-bore ‘downcomer’ tubes, where it helps pre-heat the feedwater supply. In large utility boilers, feedwater is supplied to the steam drum and the downcomers supply water to the bottom of the water-walls. The heated water then rises into the steam drum. Here, saturated steam is drawn off the top of the drum. In large utility boilers water-filled tubes form the walls of the furnace to generate steam and saturated steam coming out of the boiler drum re-enter the furnace through a superheater to become superheated. The superheated steam is used for driving the turbines. Water tube boiler is used when the steam demand as well as steam pressure requirements are high as in the case of boiler needed to meet the steam requirements for industrial processes as well as for power generation. Water-tube boiler is a boiler consisting of drums and headers which circulate water through tubes which are heated by fire and the products of combustion. The heat from the fire is transmitted through the tubes to the water.
Water vapour – It is a synonym for steam, normally used to denote steam of low absolute pressure. It is the gaseous phase of water. Water vapour can be produced by the evaporation or by boiling of liquid water. Water vapour is invisible. Under typical atmospheric conditions, water vapour is continuously generated by evaporation and removed by condensation. It is lighter than air.
Water-washable penetrants – These penetrants have an emulsifier included in the penetrant which allows the penetrant to be removed using a water spray. They are most frequently applied by dipping the part in a penetrant tank, but the penetrant can be applied to large parts by spraying or brushing.
Water well – It is also called bore-well. It is an opening in the ground, whether drilled or altered from its natural state, which is used for the production of groundwater, getting data on groundwater, or recharging an underground formation from which groundwater can be recovered. By definition, a water well also includes any related equipment, buildings, and structures.
Watt – It is the unit of power, work done per unit time. It is the radiant flux in the International System of Units (SI), equal to 1 joule per second, (1 kilogram. square meter per cubic second). It is used to quantify the rate of energy transfer. A watt is the power of one ampere of current flowing with a potential difference of one volt. A power of one watt acting for one second is one Joule of energy and which raise the temperature of one gram of water by around 0.24 deg C.
Wattmeter – It is an instrument for measuring the electric active power (or the average of the rate of flow of electrical energy) in watts of any given circuit. Electromagnetic wattmeters are used for measurement of utility frequency and audio frequency power; other types are required for radio frequency measurements.
Wave – It is a disturbance which transfers energy through a medium or space, without causing permanent displacement of the medium itself. Essentially, a wave is a propagating disturbance that transfers energy. It is characterized by oscillations which move through a medium or space, but the medium’s particles oscillate around their equilibrium positions, not moving along with the wave itself.
Wave function – It is a mathematical function describing the position of an electron within a three-dimensional space.
Waveguide – It is a tubular structure which guides electromagnetic waves, much used at microwave frequencies. An optical fibre is a kind of optical waveguide.
Wavelength – It is the distance, measured along the line of propagation of a wave, between two points that are in phase on adjacent waves. The customary units are angstroms, microns, and nanometers. It is the distance over which the wave’s shape repeats. In other words, it is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, troughs, or zero crossings. Wavelength is a characteristic of both travelling waves and standing waves, as well as other spatial wave patterns.
Wavelength (X-rays) – It is the minimum distance between points at which the electric vector of an electro-magnetic wave has the same value. It is measured along the direction of propagation of the wave, and it is equal to the velocity divided by the frequency.
Wavelength-dispersive spectrometer (WDS) – It is an analytical technique 2hich uses a crystal to separate and analyze the wavelengths of X-rays emitted from a sample, enabling identification and quantification of elements. It is a type of X-ray fluorescence (XRF) spectrometer which leverages the wavelength-dispersive principle. Wavelength-dispersive spectrometer is known for its high spectral resolution and sensitivity, particularly in detecting and quantifying trace elements.
Wavelength-dispersive X-ray spectroscopy – It is a non-destructive analysis technique used to get elemental information about a range of materials by measuring characteristic X-rays within a small wavelength range. The technique generates a spectrum in which the peaks correspond to specific x-ray lines, and elements can be easily identified. Wavelength-dispersive X-ray spectroscopy is mainly used in chemical analysis, wavelength dispersive X-ray fluorescence (WDXRF) spectrometry, electron microprobes, scanning electron microscopes, and high-precision experiments for testing atomic and plasma physics. Wavelength-dispersive X-ray spectroscopy is based on known principles of how the characteristic X-rays are generated by a sample and how the X-rays are measured.
Wave number – It is the number of waves per unit length. It is normally used in infrared and Raman spectroscopy. The wave number is expressed as the reciprocal of the wavelength. The normal unit of wave number is the reciprocal centimeter.
Wave propagation – It refers to the movement or transmission of a wave through a medium or space. It describes how a disturbance, like a vibration or oscillation, travels from one point to another, carrying energy with it. This can apply to different types of waves, including sound, light, and electro-magnetic waves.
Wave soldering (WS) – It is an automatic soldering process where work-pieces are passed through a wave of molten solder.
Waviness – It is a wavelike variation from a perfect surface, normally much larger and wider than the roughness caused by tool or grinding marks.
Wavy edges – The term refer to an undulating or rippled appearance along the edge, caused by uneven expansion or contraction, often due to moisture or temperature changes. It is a sheet metal defect characterized by a rippled or wavy appearance on the edges of the material. This defect arises when the edges of the sheet metal are longer than the central portion, causing them to elongate and buckle during rolling or other forming processes.
Wax – Waxes are a diverse class of organic compounds which are lipophilic, malleable solids near ambient temperatures. They include higher alkanes and lipids, typically with melting points above around 40 deg C, melting to give low viscosity liquids. Waxes are insoluble in water but soluble in nonpolar organic solvents such as hexane, benzene and chloroform. Natural waxes of different types are produced by plants and animals and occur in petroleum.
Wax emulsion – It is a stable mixture of one or more waxes dispersed in an aqueous (water-based) liquid. Essentially, it is a way to make waxes, which are typically not soluble in water, easily mixable and applicable in water-based systems.
Wax pattern – It is a positive replica of the desired final shape of a cast object, typically made of wax, which is then used to create a mould. This mould is then filled with molten metal or other material to create the final casting. In essence, the wax pattern acts as a temporary template which dictates the form of the final product. Wax pattern is a precise duplicate, allowing for shrinkage, of the casting and required gates, normally formed by pouring or injecting molten wax into a die or mould.
Waxy compounds – These are organic substances, typically esters of fatty acids and long-chain alcohols, which are characterized by their hydrophobic (water-repelling) nature and plasticity at ambient temperatures. They are relatively soft, moldable solids which melt or soften when heated, and they show a low viscosity when melted.
W-beam – The ‘W’ in W-beam refers to wide flanges. The main difference between W-beams is that the inner and outer flange surfaces are parallel. Also, the overall beam needs to have a depth which is at least equal to the flange width. Normally, its depth is considerably higher than its width. One of the advantages of W-beams is that the flanges are thicker than the web. This aids in resisting bend stress. Compared with H-beams or S-beams, W-beams have several more standard sections to choose from. Given they have a higher range of sizes, they are also considered the very frequently used beam in construction.
Weak acid – It is an acid which only partially dissociates when dissolved in a solvent since, as per the reaction, HA = H+ + A- (reversible)HA↽−−⇀H++A−, equilibrium is reached while the concentration of the undissociated species HAHA is still significant. Here ‘H’ is hydrogen ion, and ‘A’ is anion. An example is acetic acid (CH3COOH).
Weak acid cation (WAC) resin – It is a type of ion exchange resin which contains carboxylic acid functional groups (-COOH). These resins are commonly used in water treatment for removing hardness and alkalinity by exchanging hydrogen ions (H+) for other cations. Weak acid cation resins are particularly effective in de-alkalization and softening of water with high bicarbonate content.
Weak anisotropy – It refers to a material property where the difference in a material’s properties when measured in different directions is small, typically less than 20 %. In the context of seismic exploration, it means that the seismic wave velocities and other properties vary only slightly depending on the direction of wave propagation. This contrasts with strong anisotropy, where the differences are much more pronounced.
Weak base – It is a base which, upon dissolution in water, does not dissociate completely, so that the resulting aqueous solution contains only a small proportion of hydroxide ions (OH-) and the concerned basic radical, and a large proportion of undissociated molecules of the base. Bases yield solutions in which the hydrogen ion activity is lower than it is in pure water, i.e., the solution is said to have a pH higher than 7 at standard conditions, potentially as high as 14 (and even higher than 14 for some bases).
Weak base anion – It is the anion of a weak acid. It is a negatively charged ion that, when dissolved in water, does not fully dissociate into hydroxide ions and the corresponding cation. Instead, it only partially reacts with water, producing a small amount of hydroxide ions and remaining mostly in its original anion form.
Weak base anion resin – It is a type of ion exchange resin which contains weakly basic functional groups like primary, secondary, or tertiary amines. These resins do not have exchangeable ions and primarily adsorb strong acids like hydrochloric acid (HCl) and sulphuric acid (H2SO4). They are effective in removing mineral acids, organic acids, and other organic materials, particularly from low pH solutions.
Weakest-link failure theory – It is a concept of failure in which failure is caused by the weakest element in a body, as in the failure of the weakest link in a chain.
Weaknesses – Weaknesses in SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis are the qualities which prevent the organization to accomplish its mission and to achieve its full potential. These weaknesses have deteriorating influences on the organizational success and growth. Weaknesses are the factors which do not meet the standards which are to be normally met. Weaknesses in the organization can be depreciated machinery, insufficient research and development facilities, narrow product range, and poor decision-making capabilities etc. Weaknesses are controllable. They are required to be minimized and eliminated. For example, to overcome obsolete technology and machinery, new technology and machinery can be procured and installed. Other examples of organizational weaknesses are huge debts, high employee turnover, complex decision-making process, narrow product range, and large wastage of raw materials etc.
Wear – It is the damage to a solid surface, normally involving progressive loss of material, because of a relative motion between that surface and a contacting surface or substance. It is the progressive loss of substance from the operating surface of a body occurring as a result of relative motion at the surface. The first definition does not necessarily exclude scuffing or galling, in which surface material gets displaced but not removed. However, the second definition needs substance to be removed in order to be considered wear. Sometimes surface damage, which does not involve material removal, is differentiated from wear as defined under the first definition. Wear can take place under different conditions. Wear because of these conditions can be (i) dry or lubricated wear, (ii) sliding or rolling contact wear, and (iii) wear due to fracture, or (iv) wear due to plastic deformation. Causes of wear can be mechanical (e.g., erosion) or chemical (e.g., corrosion). Wear can normally be recognized by visual examination of the surfaces involved. Specific terminologies used to describe various types of wear are (i) abrasive wear, (ii) adhesive wear, (iii) fretting wear, (iv) gouging wear, and (v) erosive wear. The study of wear and related processes is referred to as tribology.
Wear and tear – It refers to the damage or deterioration that occurs to an object because of its normal and regular use over time. It is a natural process of aging and use, distinct from sudden damage or misuse. It is the damage which naturally and inevitably occurs as a result of normal wear and aging. It is a form of depreciation, which is assumed to occur even when an item is used competently and with care and proper maintenance.
Wear and tear spares – These spares are those spare parts which have regular wear and tear in the course of operation of the equipment and need to be replaced after definite number of hours of equipment operation.
Wear behaviour – It refers to the way a material deteriorates or loses substance because of the mechanical action of rubbing against another surface. It is a gradual process of surface damage and material loss caused by relative motion between contacting surfaces. This deterioration can involve various mechanisms, like abrasion, adhesion, or fatigue, and can be influenced by factors like material properties, surface conditions, and environmental factors.
Wear coefficient – In sliding wear, it is a dimensionless number which normally represents the proportionality factor ‘k’ in the Archard wear law. The term wear coefficient has been used in other ways than that given in this definition, and when encountered, it is best to verify its meaning from context.
Wear constant – It is a term sometimes used interchangeably with the term wear coefficient. However, it is not to be used since wear rate is frequently not constant under different sliding conditions, and, hence, the term is misleading.
Wear debris – It consists of particles which become detached in a wear process.
Wear factor – It is a term which has no unique meaning. When encountered, the meaning of this term is to be taken from its immediate context. Sometimes, the term is used to refer to the sliding wear rate in terms cubic meter newton.
Wear-inhibiting properties – In order to improve the ability of the fluid to counteract grinding wear between heavily loaded contact surfaces, the hydraulic fluid is provided with a wear-reducing additive. Even if the hydraulic equipment producers do their utmost to achieve the best possible operating conditions in the hydraulic system, there are frequently a series of unfavourable contacts which make hydrodynamic lubrication difficult. The most common wear-reducing additive used in hydraulic fluids is zinc dialkyl dithiophosphate (ZDDP).
Wear mechanisms – In tribological contacts, wear occurs due to the interaction between the two surfaces in contact and implies gradual removal of the surface materials, i.e. material loss. Wear of the materials in contact is, just as friction, a system parameter. The wear mechanisms of importance can be abrasive, adhesive, fatigue and tribo chemical wear. Typically, there is a combination of wear mechanisms in a contact. An inter-relationship exists between friction and wear. Frequently, a low friction results in low wear. However, this is not a general rule and there are numerous examples showing high wear rate despite low friction.
Wear-pad – In forming, it is an expendable pad of rubber or rubber-like material of nominal thickness which is placed against the diaphragm to lessen the wear on it.
Wear particle concentration – It refers to the quantity of wear debris present in a lubricant or fluid. It is a key indicator of the condition of a machine’s moving parts, as the debris particles are generated during wear processes. Monitoring wear particle concentration can help detect abnormal wear, predict potential failures, and optimize maintenance schedules.
Wear parts – These are components designed to be replaced due to their susceptibility to deterioration and failure from repetitive use and friction during normal operation. These parts are engineered to wear out over time and need periodic repair or replacement, unlike more durable ‘spare parts’ which are designed for long-term use.
Wear rate – It is the rate of material removal or dimensional change due to wear per unit of exposure parameter, e.g., example, quantity of material removed (mass, volume, thickness) in unit distance of sliding or unit time. There is no single, standard way to express wear rate. The units used depend on the type of wear and the nature of the tribo-system in which wear occurs. Wear rate can be expressed, e.g., (i) volume of material removed per unit time, per unit sliding distance, per revolution of a component or per oscillation of a body (i.e., in sliding wear), (ii) volume loss per unit normal force per unit sliding distance (cubic millimeters per newton meter, which is sometimes called the wear factor), (iii) mass loss per unit time, (iv) change in a certain dimension per unit time, and (v) relative change in dimension or volume with respect to the same changes in another (reference) substance. The manner of expressing wear rate is sometimes prescribed in specific standard test methods. In other cases, standards are established for given sectors of technology (e.g., mechanical face seal technology).
Wear rate (of seals) – It is the quantity of seal-surface wear, stated in terms of mils worn in some designated time period. One commonly used unit is mils per hundred hours.
Wear resistance – It specifically refers to the material’s ability to resist degradation caused by mechanical interactions with its environment. This can include friction, abrasion, erosion, impact and other forms of material removal. In case of conveyors, it is a combination of abrasion and cut resistance. The severity of the wear depends on the nature, size, weight, shape and trip rate of the conveyed material. In case of wire ropes, changes in line pull cause changes in the rope length. Rope sections lying on a sheave or on the first wraps of a drum can only adapt to the changing line pull by sliding over the groove surface of the sheave or the drum when the length change occurs. This relative motion causes abrasion (both in the grooves and on the special wire rope). Using less and hence larger outer wires can increase the wear resistance of the rope. The pressure between the sheave and the rope can be minimized due to the optimized contact areas and hence also the wear of the rope can be minimized. The wear resistance can also be influenced by the metallurgy of the outer strands.
Wear-resistant coatings – These are specialized surface treatments applied to materials to improve their ability to withstand wear, abrasion, and friction. These coatings act as a protective layer, reducing material loss and extending the lifespan of components subjected to mechanical stress.
Wear resistant linings – These are protective layers applied to equipment and machinery to minimize wear and tear caused by abrasion, erosion, or other forms of material loss. They are crucial in industries dealing with abrasive materials or high-impact applications, extending the lifespan of equipment and improving operational efficiency.
Wear-resistant materials – These are substances which can withstand the removal or loss of material because of the mechanical processes like friction, abrasion, or erosion. They are designed to resist damage from wear and tear, making them suitable for applications where components are subjected to sliding, rubbing, or impact. Essentially, they maintain their integrity and functionality under demanding conditions, extending the lifespan of products and reducing maintenance needs.
Wear resistant steels – wear resistant steels are characterized mainly by high resistance to wear friction, weldability, good ductility, and machinability. The disadvantage of wear resistant steels is low corrosion resistance which can limit their application in aggressive environments.
Wear-resistant special structural steels – These steels are, as a rule, quenched or quenched and tempered, and have martensitic or martensitic-bainitic microstructure. Quenched and tempered steels are tailored for different applications with sufficient hardness and toughness achieved either by heat treatment process or by thermo mechanical rolling process. The hardness of these steels is tailored to have the required wear resistance along with the needed toughness in an economical way. These steels are produced in thicknesses up to 120 millimeters. They are produced under the trade names XAR, BRINAR, DILLIDUR, ABREX, EVERHARD and HARDOX etc.
Wear-resistant surfaces – These refer to materials that can withstand the loss of material because of the mechanical action like friction, scratching, or abrasion. Essentially, they are surfaces designed to resist degradation and maintain their integrity under stress and contact with other surfaces. This property is crucial in several applications where components are subjected to repeated or prolonged contact, such as in bearings, gears, and other moving parts.
Wear scar – It is the portion of a solid surface which shows evidence that material has been removed from it because of the influence of one or more wear processes.
Wear strip – It is a protective component, frequently made of plastic or other materials, installed on conveyor surfaces to reduce friction and prevent wear.
Wear transition – It is a change in the wear rate or in the dominant wear process occurring at a solid surface. Wear transitions can be produced by an external change in the applied conditions (e.g., load, velocity, temperature, or gaseous environment) or by time-dependent changes (aging) of the materials and restraining fixtures in the tribo-system.
Weather – It is the state of the atmosphere, describing, for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloudy. On earth, majority of the weather phenomena occur in the lowest layer of the planet’s atmosphere, the troposphere, just below the stratosphere. Weather refers to day-to-day temperature, precipitation, and other atmospheric conditions, whereas climate is the term for the averaging of atmospheric conditions over longer periods of time. When used without qualification, ‘weather’ is normally understood to mean the weather of earth. Weather is driven by air pressure, temperature, and moisture differences between one place and another.
Weather forecast – It is the application of science and technology to predict the state of the atmosphere or a future time and a given location. Weather forecasts are made by collecting quantitative data about the current state of the atmosphere and using scientific understanding of atmospheric processes to project how the atmosphere is going to evolve.
Weathering – It is the exposure of materials to the outdoor environment. In case of glass, it is the changes on the surface of glass caused by chemical reaction with the environment. In case of plastic, it is the exposure of plastics to the outdoor environment. Weathering normally involves the leaching of alkali from the glass by water, leaving behind siliceous weathering products which are frequently laminar.
Weathering, artificial – It is the exposure of plastics to cyclic laboratory conditions, consisting of high and low temperatures, high and low relative humidities, and ultraviolet radiant energy, with or without direct water spray and moving air (wind), in an attempt to produce changes in their properties similar to those observed in long-term continuous exposure outdoors. The laboratory exposure conditions are normally intensified beyond those encountered in actual outdoor exposure in an attempt to achieve an accelerated effect. It is also called accelerated aging.
Weathering steel – It is copper-bearing high-strength low-alloy steels which show high resistance to atmospheric corrosion in the unpainted condition. It is a high strength, low alloy steel which forms a corrosion resistant oxide patina which eliminates the need for paint or other protective coatings. Weathering steels are self-protecting, durable and attractive, so they are ideally suited to a whole range of outdoor applications for structures in exposed locations. The corrosion retarding effect of the protective layer is produced by the particular distribution and concentration of the alloying elements in it. The layer protecting the surface develops and regenerates continuously when subjected to the influence of the weather. Weathering steels are copper-bearing high-strength low-alloy steels which show high resistance to atmospheric corrosion in the unpainted condition.
Weave – It is a fabric pattern description denoting a specific relationship of warp and filling yarns at specific locations in the fabric. It is the particular manner in which a fabric is formed by interlacing yarns. It is normally assigned a style number.
Weave bead – It is a type of weld bead made with transverse oscillation.
Web – It is a single thickness of foil as it leaves the rolling mill. It is a relatively flat, thin portion of a forging which effects an interconnection between ribs and bosses, a panel or wall which is normally parallel to the forging plane. For twist drills and reamers, web is the central portion of the tool body which joins the lands. It is also a plate or thin portion between stiffening ribs or flanges, as in an I-beam, H-beam, or other similar section.
Web documents – These are frequently defined as a simple Hypertext Markup Language (HTML files. A web document, such as this page, is often made up of several files and is accessed through a uniform resource locator (URL). The Hypertext Markup Language file itself contains most of the times style sheets, background images, other graphics, Java programs, and other files.
Web domain – It is also called domain name. It is essentially the address of a website, allowing users to easily access it by typing it into a web browser. It is a human-readable substitute for the numerical Internet Protocol (IP) address which computers use to locate websites. Essentially, it is how people find and identify a website on the internet.
Weber – It is the SI (International System of Units) unit of magnetic flux.
Web page – It is also written as webpage. It is a Web document which is accessed in a web browser. A website typically consists of many web pages linked together under a common domain name. The term ‘web page’ is therefore a metaphor of paper pages bound together into a book. Each article on the Ispatguru.com website is a distinct web page. The uniform resource locator (URL) is visible in the browser’s address bar at the top. Each web page is identified by a distinct uniform resource locator. When the user inputs a uniform resource locator into their web browser, the browser retrieves the necessary content from a web server and then transforms it into an interactive visual representation on the user’s screen.
Web server – It is a system (either software, hardware, or both) which stores, processes, and delivers web content to users over the internet, typically using Hypertext Transfer Protocol (HTTP) or Hypertext Transfer Protocol Secure (HTTPS). It acts as an intermediary, responding to requests from web browsers and sending back the requested resources like web pages, images, and other files.
Website – It is also written as a web site. It is any web page whose content is identified by a common domain name and is published on at least one web server. Websites are typically dedicated to a particular topic or purpose, such as news, education, commerce, entertainment, or social media. Hyperlinking between web pages guides the navigation of the site, which frequently starts with a home page.
Website design – It refers to the process of planning, conceptualizing, and creating the visual layout and user experience of a website. It encompasses both the aesthetic and functional aspects of a website, including its structure, navigation, graphics, and overall look and feel, to ensure it is both visually appealing and user-friendly.
Web-tapered beam – It is a structural element, typically an I-beam, where the height of the web (the vertical part connecting the flanges) varies along its length. This tapering is frequently used to optimize material usage and improve the beam’s structural efficiency, particularly in situations with varying bending moment or shear force distributions.
Web thickness – It refers to the thickness of the vertical, central section (the web) of a beam which connects the two flanges. It is the measurement of how thick the web is from one side to the other. This thickness is a critical factor in the beam’s ability to resist shear forces and overall stability.
Wedge – It is a triangular shaped tool, a portable inclined plane, and one of the six simple machines. It can be used to separate two objects or portions of an object, lift up an object, or hold an object in place. It functions by converting a force applied to its blunt end into forces perpendicular (normal) to its inclined surfaces. The mechanical advantage of a wedge is given by the ratio of the length of its slope to its width. Although a short wedge with a wide angle may do a job faster, it needs more force than a long wedge with a narrow angle. In mining, wedge is a technique of directing a diamond drill hole in a desired direction away from its current orientation.
Wedge drive – It consists of a massive wedge sloped upward at an angle of 30-degree toward the pitman, an adjustable pitman arm, and an eccentric drive shaft. The torque from the rotating flywheel is transmitted into horizontal motion through the pitman arm and the wedge. As the wedge is forced between the frame and the ram, the ram is pushed downward. This provides the force needed to forge the part. The quantity of wedge penetration between the ram and frame determines the shut height of the ram. The shut height can be adjusted by rotating the eccentric bushing on the eccentric shaft by means of a worm gear. A ratchet mechanism prevents the adjustment from changing during press operation. Wedge drives transmit the forging force more uniformly over the entire die surface than pitman arm drives.
Wedge effect – It is the establishment of a pressure wedge in a lubricant.
Wedge formation – In sliding metals, it is the formation of a wedge or wedges of plastically sheared metal in local regions of interaction between sliding surfaces. This type of wedge is also known as a prow. It is similar to a built-up edge. In hydrodynamic lubrication, it is the establishment of a pressure gradient in a fluid flowing into a converging channel. This is also known as wedge effect.
Wedge meters – The operating principle of a wedge meter is simple and easy to understand. The wedge meter is equipped with a V-shaped flow restrictor which reduces the area available to flow. Fluid velocity increases as the flow is contracted at the flow restrictor. The increase in velocity results in an increase in the kinetic energy of the measuring medium. By the principle of conservation of energy, any increase in kinetic energy is to be accompanied by a corresponding decrease in potential energy (static pressure). Thus, the measuring medium directly upstream of the flow restrictor has a higher potential energy (and higher static pressure) than the medium immediately downstream of the flow restrictor. Pressure taps placed on either side of the wedge meter allows the differential pressure which develops as a result of this imbalance in potential energy to be measured. The volume flow rate can then be directly calculated from the measured differential pressure. Some of the pressure loss created by the flow restriction is recovered downstream of the wedge meter as kinetic energy is converted back to the potential energy. A wedge meter is a refinement of a segmental orifice. Whereas the segmental orifice offers a sudden restriction to flow, the wedge meter provides for a gradual restriction. The latter has several advantages over the segmental orifice design, including immunity to erosion and immunity to build-up by any secondary phase. The immunity to erosion is the result of the slanted upstream face of the flow restrictor, which prevents damage due to impingement with any undissolved solids in the measuring medium. The opening beneath the restriction is large and allows for easy passage of any secondary phase. Eddies and back currents created provide a ‘self-scouring’ action which keeps the internals clean and free from build-up. Wedge meters are designed to measure flow accurately in all flow regimes namely (i) laminar, (ii) transition, and (iii) turbulent. Laminar and transition flow regimes, often encountered with viscous measuring media or low flow rates, can cause other measuring elements to show considerable deviation from the square root relationship between flow rate and measured differential pressure. The discharge coefficient of a wedge meter remains highly linear from Reynolds numbers as low as 500 (laminar) to Reynolds numbers in the millions (turbulent).
Wedge press – It offers increased overall stiffness by reducing tilting under off-centre loading in both directions (front to back and left to right). The eccentric mechanism driving the wedge is provided with an eccentric bushing, which can be rotated through a worm gear. Hence, the shut height or the forging thickness can be adjusted by using this mechanism instead of the more commonly used wedge adjustment at the press bed. A disadvantage is the relatively long contact time between the die and the forged part.
Wedge tensile test – It is a specialized tensile test performed on fasteners, like bolts and screws, where a wedge is placed under the head to introduce stress at the head-to-shank juncture. This test evaluates the fastener’s ability to withstand the stress concentration at this critical point, assessing its ductility and head integrity. It is particularly important for fasteners with high tensile strength requirements, as it helps detect potential failures like laps, seams, or head-to-shank separation.
Weep – It is a term normally applied to a minute leak in a boiler joint which forms droplets (or tears) of water very slowly.
Weepage – It is the leaching out of trapped liquid solutions in galvanized structures, primarily through pinholes or gaps in welds which are not sealed over by zinc. Weepage is also a minute quantity of liquid leakage by a seal. It has rather arbitrary limits, but is normally considered to be a leakage rate of less than one drop of liquid per minute.
Weeping – It is the slow leakage manifested by the appearance of water on a surface.
Weft – It is the crosswise yarns in a woven fabric. These are the transverse threads or fibres in a woven fabric. These are those fibres which are running perpendicular to the warp. It is also called fill, filling yarn, or woof.
Weibull distribution – It is a continuous probability distribution that models the time until an event occurs, frequently used in reliability engineering and survival analysis to describe failure times. It is defined by two parameters namely a shape parameter, which determines the shape of the distribution and the failure rate, and a scale parameter, which affects the distribution’s spread. The Weibull distribution is versatile, capable of modeling increasing, decreasing, or constant failure rates depending on the shape parameter.
Weighbridge – It is a large set of weighing scales, normally mounted permanently on a concrete foundation, which is used to weigh entire railway wagons, or road vehicles and their contents. By weighing the vehicle both empty and when loaded, the load carried by the vehicle can be calculated. The key component that uses a weighbridge in order to make the weigh measurement is load cells.
Weighing balance – It is a laboratory instrument used to precisely measure the mass or weight of an object. These instruments are essential for accurate measurement and dispensing of materials in several settings, including laboratories.
Weighing scale – It is also known as a weighing machine or balance. It is a device which is used to determine the mass or weight of an object. It works by measuring the force of gravity acting on an object. There are several types of weighing scales, including mechanical and digital models, and they are used in a wide range of applications from everyday weighing to scientific and industrial measurements.
Weighing system – It is an incorporated system within a conveyor designed to assess the weight of transported materials, normally used for purposes such as quality control or inventory management.
Weight – It refers to the density of a material. Weight of an object is the force acting on the object because of gravity. It is a quantity associated with the gravitational force exerted on the object by other objects in its environment, although there is some variation and debate as to the exact definition. Some define weight as a vector quantity, the gravitational force acting on the object. Others define weight as a scalar quantity, the magnitude of the gravitational force. Others define it as the magnitude of the reaction force exerted on a body by mechanisms which counteract the effects of gravity, the weight is the quantity which is measured by, e.g., a spring scale. Hence, in a state of free fall, the weight is zero. In this sense of weight, terrestrial objects can be weightless, so if one ignores air resistance, one can say the legendary apple falling from the tree, on its way to meet the ground near Isaac Newton, was weightless. The unit of measurement for weight is that of force, which in the International System of Units (SI) is the newton, e.g., an object with a mass of one kilogram has a weight of about 9.8 newtons on the surface of the earth, and around one-sixth as much on the moon. Although weight and mass are scientifically distinct quantities, the terms are frequently confused with each other in everyday use (e.g., comparing and converting force weight in kilograms to mass in kilograms and vice versa). In statistics, it is a numerical coefficient attached to an observation, frequently by multiplication, in order that it assumes a desired degree of importance in a function of all the observations of the set.
Weight distribution – It refers to how the weight of an object, vehicle, or even a body is spread across its structure or components. It is crucial for stability, performance, and safety in different applications.
Weighted arithmetic mean – It is similar to an ordinary arithmetic mean (the most common type of average), except that instead of each of the data points contributing equally to the final average, some data points contribute more than others. The notion of weighted mean plays a role in descriptive statistics and also occurs in a more general form in several other areas of mathematics.
Weighted average – It is a type of average where different values in a dataset are assigned different weights, signifying their relative importance or frequency. This means some values contribute more to the overall average than others, unlike a simple average where all values are treated equally. It is an average of quantities to which have been attached a series of weights in order to make allowance for their relative importance.
Weighted property index – It is an index that uses weighted values of the required properties to arrive at a relative value for selection of a material for a specific application.
Weight function – It is a mathematical device used when performing a sum, integral, or average to give some elements more ‘weight’ or influence on the result than other elements in the same set. The result of this application of a weight function is a weighted sum or weighted average. Weight functions occur frequently in statistics and analysis, and are closely related to the concept of a measure. Weight functions can be used in both discrete and continuous settings. They can be used to construct systems of calculus called ‘weighted calculus’ and ‘meta-calculus’.
Weight of steam – It is the weight of steam in kilogram per cubic metres.
Weight percent – It is the percentage composition by weight.
Weight per epoxide (WPE) – It is also called epoxy equivalent weight (EEW). It is a measure of the epoxy content of an epoxy resin or epoxy reactive diluent, or glycidyl ether. It can be defined as the number of grams of epoxy resin needed to give 1 mole of epoxy groups. The epoxy value is defined as the number of moles of epoxy group per 100 grams resin. This is an important parameter as it allows determination of the correct mix ratio of an epoxy system with a curing agent. The weight per epoxide is normally measured first and done by titration.
Weight transfer – It refers to the redistribution of weight or load on a vehicle’s tires when it experiences acceleration, braking, or turning. This occurs since a vehicle’s centre of gravity (CoG) shifts in response to these forces, leading to a change in the quantity of weight or force each tire supports. Weight transfer describes two distinct effects namely (i) the change in load borne by different wheels of even perfectly rigid vehicles during acceleration, and (ii) the change in centre of mass (CoM) location relative to the wheels because of suspension compliance or cargo shifting or sloshing.
Weir – It is an overflow structure frequently used for measuring discharge. It is a structure in a water body over which water flows, and whose prime purpose is to raise the water level, normally to divert water into a watercourse. In dam terminology, it is the crest of a spillway controlling the upstream surface level. In a tundish, a weir (or a series of weirs and dams) is a flow control device used in continuous casting of molten metal to regulate the flow of liquid steel and optimize the removal of non-metallic inclusions.
Weir diaphragm valve – It is a type of diaphragm valve characterized by a raised structure, or weir, within the valve body where the flexible diaphragm presses against to control or shut off flow. This weir design enables precise flow regulation and effective sealing, particularly in applications involving corrosive or abrasive media. The weir-type is the better throttling valve but has a limited range. Its throttling characteristics are essentially those of a quick opening valve because of the large shut-off area along the seat. A weir-type diaphragm valve is available to control small flows. It uses a two-piece compressor component. Instead of the entire diaphragm lifting off the weir when the valve is opened, the first increments of stem travel raise an inner compressor component which causes only the central part of the diaphragm to lift. This creates a relatively small opening through the centre of the valve. After the inner compressor is completely open, the outer compressor component is raised along with the inner compressor and the remainder of the throttling is similar to the throttling which takes place in a conventional valve.
Weld – It is a localized coalescence of metals or nonmetals produced either by heating the materials to suitable temperatures, with or without the application of pressure, or by the application of pressure alone with or without the use of filler metal.
Weldability – It is the capacity of a material to be welded under the imposed fabrication conditions into a specific, suitably designed structure and to perform satisfactorily in the intended service. Traditionally, empirical equations have been developed experimentally to express weldability of steels. Carbon equivalent (CE) is one such terminology. It has been developed to estimate the cracking susceptibility of a steel during welding and to determine whether the steel needs pre-weld or/and post-weld heat treatments to avoid cracking. Carbon (C) equivalent equations include the hardenability effect of the alloying elements by expressing the chemical composition of the steel as a sum of weighted alloy contents. Several carbon equivalent terminologies with different coefficients for the alloying elements are being used. The equation for the carbon equivalent as given by the International Institute of Welding (IIW) is CE = C + Mn/6 + (Ni + Cu)/15 + (Cr + Mo + V)/5. In this equation the concentration of the alloying elements is given in weight percent. It can be seen in the equation that carbon is the element which has maximum effects on the weldability. Along with other chemical elements, carbon can affect the solidification temperature range, hot tear susceptibility, hardenability, and cold cracking behaviour of the steel weldment.
Weldability tests – These tests are conducted to provide information on the service and performance of the welds. However, the data got in these tests can also be applied to the design of useful structures. Frequently, these data are obtained from the same type of test samples used in determining the base steel properties. Predicting the performance of structures from a laboratory type test is very complex because of the nature of the joint, which is far from homogeneous, metallurgically or chemically. Along with the base steel, the weld joint consists of the weld metal and the heat affected zone. Hence, a variety of properties are to be expected throughout the welded joint. Careful interpretation and application of the test results are needed. There are presently many tests that evaluate not only the strength requirements of steel structures, but also the fracture characteristics and the effect of atmospheric conditions on early failure of the weldments.
Weld access hole – It is also called rat hole. It is a structural engineering technique in which a part of the web of an I-beam or T-beam is cut out at the end or ends of the beam. The hole in the web allows a welder to weld the flange to another part of the structure with a continuous weld the full width on both top and bottom sides of the flange. Without the weld access hole, the middle of the flange is blocked by the web and inaccessible for welding. The hole also minimizes the induction of thermal stresses with a combination of partially releasing the welded section, avoiding welding the T-section where the flange joins the web and improving cooling conditions. The configuration adopted for web access holes affects how the beam joint bends when under stress.
Weld axis – It is a line through the length of the weld, perpendicular to and at the geometric centre of its cross section.
Weld bead – It is a deposit of filler metal from a single welding pass.
Weld bonding – It is a resistance spot welding process variation in which the spot weld strength is augmented by adhesive at the faying surfaces.
Weld brazing – It is a joining method which combines resistance welding with brazing.
Weld crack – It is a crack in weld metal. Weld cracks are considered a serious welding defect since they can propagate and lead to structural failure. They can occur at different temperatures (hot cracking or cold cracking) and locations (weld metal, heat affected zone, or base metal).
Weld cracking – It refers to the formation of cracks in or near a weld because of the stresses exceeding the material’s strength during or after the welding process.
Weld decay – It is the intergranular corrosion, normally of stainless steels or certain nickel-base alloys, which occurs as the result of sensitization in the heat-affected zone during the welding operation.
Welded assembly – It is a structure or component formed by joining multiple metal parts together using welding techniques, creating a single, cohesive piece. This process involves melting the base metal and frequently adding a filler material to create a strong and durable connection. Welded assemblies are used across several industries to build a wide range of products, from simple frames to complex structures.
Welded joint – It is the point where two or more pieces of metal are joined together using the welding process. It is a crucial part of a welded structure, as the joint’s design and execution directly impact the strength, integrity, and overall quality of the final product. Different joint types are used depending on the application and the desired properties of the weld.
Welded pipe – It refers to a type of pipe manufactured by forming a flat sheet or plate into a tubular shape and then welding the edges together to create a seam. This welding process can be done using different methods, such as arc welding, gas welding, or laser welding, to join the metal pieces. Welded pipes are normally used in several applications, including pipelines for transporting fluids, construction projects, and infrastructure development.
Weld end – It is the end connection of a valve which is to be installed by welding into the line.
Welder – Welder is a person who performs manual or semi-automatic welding operation.
Welder qualification test (WQT) – This test is for the demonstration of a welder’s ability to produce welds meeting prescribed standards. It is also known as welder performance qualification (WPQ) test. It is a process which assesses a welder’s ability to produce sound welds as per a specific welding procedure. It is a test to ensure a welder can consistently meet the requirements of a particular welding standard, frequently involving both visual and mechanical / non-destructive testing of weld samples. The test verifies the welder’s skill in using a specific welding process, in a particular welding position, and their ability to produce welds which meet specified standards.
Weld face – It means the exposed surface of a weld on the side from which welding has been done.
Weld, incomplete – It is the junction line of metal which has passed through a die forming a hollow profile (shape), separated and not completely rejoined. Flare testing is a method of evaluating weld integrity.
Welding – Welding is the strongest method for bonding metal to metal. It is a process for joining or fastening two pieces of similar metals (work pieces) by melting and fusing (i) the base metals being joined, and (ii) the filler metal applied. Welding can be done without the use of a filler metal such as by the use of heat energy alone. Work pieces are welded together by applying extreme heat, resulting in melting both pieces and the filler metal (rod / wire) to a molten state which cools to form a strong joint. The energy to form the joint between metal work pieces most frequently comes from a flame (e.g. oxy-acetylene) or an electric arc. Most of the welding involves ferrous-based metals such as steel and stainless steel. Welding covers a temperature range of 815 deg C to 1,650 deg C. In tribology, it is the adhesion between solid surfaces in direct contact at any temperature. In tribology, welding is the adhesion between solid surfaces in direct contact at any temperature.
Welding and joining processes – These are necessary for the development of virtually every manufactured product. However, these processes frequently appear to consume higher fractions of the product cost and to create more of the production difficulties than can be expected. There are a number of reasons which explain this situation. First, welding and joining are multifaceted, both in terms of the process variations (such as fastening, adhesive bonding, soldering, brazing, arc welding, diffusion bonding, and resistance welding etc.) and in the disciplines needed for problem solving (such as mechanics, materials science, physics, chemistry, and electronics etc.). An engineer with unusually broad and deep training is needed to bring these disciplines together and to apply them effectively to a variety of the processes. Second, welding or joining difficulties normally occur far into the manufacturing process, where the relative value of scrapped components is high. Third, a very large percentage of product failures occur at joints since they are normally located at the highest stress points of an assembly and are hence the weakest parts of the assembly. Careful attention to the joining processes can produce large rewards in the manufacturing economy and product reliability.
Welding blowpipe – It is a nonstandard term for welding torch.
Welding codes and standards – These are sets of rules, guidelines, and specifications which govern the design, fabrication, inspection, and testing of welded components. These documents ensure the quality, safety, and reliability of welded structures across several industries.
Welding consumables – At its core, welding involves fusing two pieces of metal using high temperatures. This process, however, necessitates the use of welding consumable. Welding materials are filler materials. As the name implies, these substances provide a filler or a body of molten materials which provides a strong bond to be formed between the base metals used. Majority of the welding processes also need some form of shielding to protect both the main components and filler from being oxidized during the process. Welding consumable not only fill the gap between metals but also play a crucial role in the welding process. Welding consumables encompass a range of materials. Each of these materials is designed for specific welding techniques and applications. These materials ensure a strong bond between the parent metals, contributing to the overall quality and durability of the weld. The choice of consumables is important, since it directly impacts the homogeneity of the weld and the effectiveness of the overall welding process.
Welding current – It is the current in the welding circuit during the making of a weld.
Welding cycle – It is the complete series of events involved in the making of a weld.
Welding electrode – It is used for several welding applications including electric arc welding. Electrodes for manual arc welding (sometimes referred to as stick welding) consist of a rod and a coating material. Welding electrodes are installed in the weld head to touch and maintain contact with the work pieces through the full weld schedule. The stick electrodes are consumable, meaning they become part of the weld. Stick welding electrodes vary by size, material, strength, welding position, iron powder in the flux, and soft arc designation. Electrode size (2.5 millimeters, 3.2 millimeters, 4 millimeters, and 5 millimeters etc.) indicates the diameter of the rod core. Each electrode has a certain current range. The welding current increases with the electrode size (diameter). The electrodes are normally manufactured in the length of 250 millimeters to 450 millimeters. The welding electrodes play three different roles during welding namely (i) maintaining uniform current density, (ii) concentrating current at welding points, and (iii) maintaining thermal balance during welding. As a rule, the alloy in the rod is similar to the material to be welded. It is made out of materials with a similar composition to the metal being welded. In arc welding, it is a current-carrying rod which supports the arc between the rod and work, or between two rods as in twin carbon-arc welding. It may or may not furnish filler metal. In resistance welding, welding electrode is a part of a resistance welding machine through which current and, in majority of the cases, pressure is applied directly to the work. The electrode can be in the form of a rotating wheel, rotating roll, bar, cylinder, plate, clamp, chuck, or modification thereof. In case of arc and plasma spraying, the current-carrying components which support the arc.
Welding ground – It is the electrical conductor connecting the source of arc welding current to the work. It is a non-standard term for work-piece connection.
Welding gun – It is a portable device used to achieve semi-automatic or automatic welds on pieces of metal. Welding gun is a handheld tool used in welding processes, like MIG (metal inert gas) welding, to deliver a continuous wire electrode and shielding gas to the weld area. It essentially acts as a delivery system, providing the electrical current and shielding necessary to melt the wire and base metal, creating a strong weld.
Welding leads – It consist of the electrical cables which serve as either work lead or electrode lead of an arc welding circuit.
Welding machine – It is the equipment used to perform the welding operation, e.g., spot welding machine, arc welding machine, and seam welding machine etc.
Welding metallurgy – It describes a microcosm (a situation regarded as condensing in miniature the characteristics of something much larger) of metallurgical processes occurring in and around a weld which influence the micro-structure, properties, and weldability of the material. Because of the rapid heating and cooling rates associated with majority of the welding processes, metallurgical reactions frequently occur under transient, non-equilibrium conditions. Welding is a complex process which involves gas-metal and slag-metal reactions, solidification, metallurgical reactions in the solid state, annealing and recovery, grain growth, precipitation, and phase transformation. These metallurgical phenomena control strength and ductility of the weld. The space in which metallurgical processes take place comprises (i) fusing charge in the form of wire and coating or, alternatively, flux or core of powder-core electrode, (ii) liquid metal of the partially molten base, (iii) liquid and crystallizing part of weld, and (iv) the area between the electrode and the welded element filled with arc plasma, gases, and metal vapours. The distance between the end of fusing electrode and welded element amounts to several millimetres.
Welding operator – Welding operator is a person who who operates welding machine or automatic welding equipment.
Welding position – It is the position used for welding. Different welding positions are flat position, horizontal fixed position, horizontal position, horizontal rolled position, inclined position, overhead position, and vertical position.
Welding procedure – it consists of the detailed methods and practices involved in the production of a weldment.
Welding procedure specification (WPS) – It is a document which provides in detail the needed variables for a specific application for ensuring repeatability by properly trained welders and welding operators.
Welding processes – These are fabrication processes which join materials, normally metals, by using heat, pressure, or both to melt the materials together and allow them to cool, fusing them into a single piece. There are different types of welding processes, each with its own specific techniques and applications. The welding processes can be categorized into (i) arc welding processes, (ii) resistance welding process, (iii) oxy-fuel welding processes, (iv) solid state welding processes, and (v) other types of welding process.
Welding quality wire rods – They are used to make wire for gas or electric-arc welding filler metal. Welding quality wire rods can be made from billets of low carbon rimmed, capped, or killed steel, but is preferably made from continuous cast steel. It is produced to several restricted ranges and limits to chemical composition. An example of the restricted ranges and limits for low carbon arc welding wire rod is carbon – 0.1 % to 0.15 %, manganese – 0.4 % to 0.6 %, phosphorus – 0.025 % maximum, sulphur – 0.035 % maximum, and silicon – 0.03 % maximum.
Welding quality alloy steel wire rods – These wire rods are used for the production of wire used as filler metal in electric arc welding or for building up hard wearing surfaces of parts subjected to wear. The heat analysis limits phosphorus and sulphur which is 0.025 % maximum each
Welding rod – It is a form of filler metal used for welding or brazing which does not conduct the electrical current, and which can be either fed into the weld pool or preplaced in the joint.
Welding sequence – It is the order in which the different component parts of a weldment or structure are welded.
Welding stress – It is the residual stress caused by localized heating and cooling during welding.
Welding tip – It is the welding torch tip which is designed for welding.
Welding torch (arc) – It is a device used in the gas tungsten and plasma arc welding processes to control the position of the electrode, to transfer current to the arc, and to direct the flow of shielding and plasma gas.
Welding torch (oxy-fuel gas) – It is a device used in oxyfuel gas welding, torch brazing, and torch soldering for directing the heating flame produced by the controlled combustion of fuel gases. Welding torch has a mixing chamber in which oxygen and fuel gas is mixed and the mixture is ignited at the torch tip. Welding can be carried out in two ways. In the forehand technique the torch moves in the direction of welding with the torch inclined at 65-degree to the weld deposit. In the back hand technique, the torch is inclined at 45-degree to the not welded region.
Welding wheel – It is a non-standard term for resistance welding electrode.
Welding wire – It is a form of welding filler metal, normally packaged as coils or spools, which may or may not conduct electrical current depending on the welding process with which it is used.
Weld interface – It is the interface between weld metal and base metal in a fusion weld, between base metals in a solid-state weld without filler metal, or between filler metal and base metal in a solid-state weld with a filler metal and in a braze.
Weld job – It involves using heat, pressure, or both to fuse metal or thermoplastic parts together, creating a strong, durable bond. A welds job can have several weld schedules. This means that in the execution of a weld job, the identified parameters (e.g., current, voltage travel, speed, wire feed speed, and welding torch angle) can be varied. Parameters which cannot be adjusted during welding, such as filler metal type, size and gas type, and flow rate remain constant for any continuous operation. However, these parameters can change from one pass to another.
Weld line – The preferred term is weld interface. It is the mark visible on a finished part made by the meeting of two flow fronts of plastic material during moulding. It is also called weld mark or flow line.
Weld mark – It is a mark on a moulded piece made by the meeting of two flow fronts during moulding.
Weldment – It is an assembly whose component parts are joined by welding. A weldment consists of several constituents: similar or dissimilar base metals (BMs), weld metal (WM) and heat affected zones (HAZs). In the case of a single pass bead, the weldment is normally divided into two main regions namely (i) the fusion zone, or weld metal, and (ii) the heat affected zone. The situation in the multi pass weldments is much more complex because of the presence of reheated zones within the fusion zone. The partial refinement of the microstructure by subsequent weld passes increases the inhomogeneity of the various regions with respect to the microstructure and the mechanical properties.
Weld metal – It is that portion of a weld which has been melted during welding.
Weld metal microstructure – It refers to the specific arrangement and composition of phases, grains, and other microscopic features within the solidified weld metal, formed during the welding process.
Weld nugget – It is the weld metal in spot, seam or projection welding.
Weldor – It is a non-standard term for welder.
Weld overlay – It is also known as weld cladding. It is a fabrication process where a layer of weld metal is fused onto the surface of a base metal to improve its properties or restore its dimensions. This process is used to improve corrosion resistance, wear resistance, and other mechanical properties of components subjected to harsh service conditions.
Weld-overlay coatings – These are surface coatings applied for corrosion, wear, or erosion resistance by melting and solidifying a molten alloy produced by a welding process. It is sometimes referred to as hard-facing.
Weld pass – It is a single progression of a welding or surfacing operation along a joint, weld deposit, or substrate. The result of a pass is a weld bead, layer, or spray deposit.
Weld pass sequence – It is the order in which the weld passes are made.
Weld penetration – It is a non-standard term for joint penetration and root penetration.
Weld pool – It is the localized volume of molten metal in a weld prior to its solidification as weld metal. Weld pool becomes tear-drop shaped at high welding speeds and elliptical at low welding speeds. Since the trailing pool boundary of a tear-drop shaped weld pool is essentially straight, the columnar grains are also essentially straight in order to grow perpendicular to the pool boundary. On the other hand, since the trailing boundary of an elliptical weld pool is curved, the columnar grains are also curved in order to grow perpendicular to the pool boundary. Weld pool shape depends on material properties, process parameters, and heat flow conditions. Material properties are melting point, thermal conductivity, surface tension, and Marangoni effect which is the mass transfer along an interface between two phases because of a gradient of the surface tension. Process parameters are heat-input, and travel speed. Heat flow conditions are full penetration in 2-dimension, and partial penetration in the 3-dimension. Surface tension influences fluid flow. Surface tension of liquid is a function of composition and temperature and has Marangoni effect. It has influence of gradient on weld pool fluid flow. Negative gradient promotes outward flow and shallow penetration while the positive gradient promotes inward (downward) flow and good penetration. Sulphur and oxygen have strong influence on surface tension.
Weld puddle – The preferred term is weld pool.
Weld reinforcement – It is the weld metal in excess of the quantity required to fill a joint.
Weld repair – It is also known as weld restoration. It is the process of fixing defects or modifying metal components using welding techniques. It involves adding filler metal to repair damaged areas, restore structural integrity, or adapt components to new requirements. This can be done during initial fabrication or as a field repair. Weld repair differs from rework in that post-weld heat treatment is not done. It is sometimes used to render damaged castings usable. Of course, weldment tensile properties are greatly reduced as a result. Hence, weld repairs are performed only in cases where service stresses are low.
Weld residue – It is the impurities left from the welding process. Weld residue inhibits localized formation of the galvanized coating.
Weld root – It consists of the points, as shown in cross section, at which the back of the weld intersects the base metal surfaces.
Weld schedule – It is a detailed document which outlines all the specific settings and parameters needed to perform a particular welding job on a specific material. It ensures consistency and quality by providing a precise guide for setting up and operating the welding equipment.
Weld set – It is a collection of welding parameters which includes current, voltage travel, speed, wire feed speed, and welding torch angle. Weld sets are identified by a designator such as a weld set number (WSN).
Weld size – It means edge weld size, fillet weld size, flange weld size, and groove weld size.
Weld slag – It is the material resulting from the combination of weld material and weld flux. Weld slag inhibits localized formation of the galvanized coating.
Weld structure – It is the microstructure of a weld deposit and heat-affected base metal.
Weld surfacing – It is also known as surfacing welding or cladding. It is a welding process where a layer of material is applied to the surface of a work-piece to improve its properties or repair worn parts. This process improves the base metal’s strength, durability, and resistance to wear, corrosion, or other factors.
Weld tab – It consists of additional material on which the weld can be initiated or terminated.
Weld tension test – Several tension test samples can be used for getting an accurate assessment of the strength and ductility of welds. Both the transverse weld samples and longitudinal weld samples are used. In the all-weld metal test, base steel dilution needs to be minimized if the test is to be representative of the weld metal. However, the resulting properties is not easy to translate into those properties achievable from welds made in an actual weld joint. Interpreting test results for the transverse butt weld test is complicated by the different strengths and ductilities normally found in the different regions of the joint. The primary information gained from the test is the ultimate tensile strength (UTS). Yield strength (YS) and elongation requirements are normally not specified. Tests of heat affected zone properties which are unaffected by the presence of either base steel or weld metal are not easy to conduct since it is practically impossible to get sample made up entirely of the heat affected zone. In addition, the heat affected zone is composed of various regions, each with its own distinct properties. Simulated heat affected zone samples which are generated and tested using a Gleeble thermo-mechanical testing system can be used to provide a more accurate assessment of the tensile properties of this region.
Weld throat – It consists of actual throat, effective throat, and theoretical throat.
Weld toe – It is the junction of the weld face and the base metal.
Weld trap – It refers to a situation where a non-metallic material, like slag or gas, gets trapped within the weld metal, creating a defect. These trapped materials weaken the weld and can lead to potential failure. Examples are slag inclusions, porosity, and wormholes.
Well – It is a human-made hole or shaft drilled, dug, or driven into the earth to access groundwater, crude oil, or natural gas.
Wenstrom mill – It is a rolling mill similar to a universal mill but where the edges and sides of a rolled section are acted on simultaneously.
Wenzel model – It describes the homogeneous wetting regime, and is defined by the equation for the contact angle on a rough surface which is Cos(A*) = r Cos(A), cos(θ∗)=rcos(θ)where ‘A*’ θ∗ is the apparent contact angle which corresponds to the stable equilibrium state (i.e., minimum free energy state for the system). The roughness ratio, ‘r’, is a measure of how surface roughness affects a homogeneous surface. The roughness ratio is defined as the ratio of true area of the solid surface to the apparent area. ‘A’ is the contact angle for a system in thermodynamic equilibrium, defined for a perfectly flat surface. Although Wenzel’s equation demonstrates the contact angle of a rough surface is different from the intrinsic contact angle, it does not describe contact angle hysteresis.
Wet – It refers to moisture, the condition of containing liquid or being covered or saturated in liquid.
Wet abrasive blasting – It also known as vapour blasting or dustless blasting. It is a surface preparation technique which uses a mixture of water and abrasive media propelled by compressed air to remove coatings, rust, and other surface imperfections. It is a variation of abrasive blasting which minimizes dust and reduces the risk of surface damage.
Wet-back boiler – It is a fire-tube boiler design wherein the back portion of the boiler has a water jacket.
Wet-bag isostatic pressing – It is a powder metallurgy process where powdered material is compacted into a desired shape by applying uniform pressure from all directions. This is achieved by placing the powder inside a flexible, sealed mould, which is then submerged in a pressurized fluid, typically a liquid, within a pressure vessel. The fluid transmits the pressure evenly to the mould, compacting the powder into a dense, uniform shape.
Wet bag tooling – It consists of a rubber or plastic sheet mould used in cold isostatic or hydrostatic pressing of powders. It involves submerging the mold in a liquid medium, allowing for flexibility and versatility in shaping complex parts.
Wet ball milling – It is a process where powder materials are ground and mixed with a liquid (solvent or binder) inside a rotating cylinder containing grinding media (balls). This technique is used to produce fine, homogeneous powder mixtures for several applications, including sintering and additive manufacturing.
Wet blasting – It is a process for cleaning or finishing by means of a slurry of abrasive in water directed at high velocity against the work-pieces. Several different kinds and sizes of abrasives can be used in wet blasting. Sizes range from 840 micrometers (very coarse) to 2.5 micrometers (which is much finer than face powder). Among the types of abrasives used are (i) organic or agricultural materials such as walnut shells and peach pits, (ii) novaculite, which is a soft type (6 to 6.5 Mohs hardness) of silica (99.46 % silica), (iii) silica, quartz, garnet, and aluminum oxide, (iv) other refractory abrasives, and glass beads.
Wet blending – It is a process where metal powders are mixed with a liquid, typically a solvent, to create a homogenous slurry. This technique is used to achieve a more uniform distribution of powder particles and can improve the flow and packing characteristics of the powder blend. Wet blending is frequently used as a preliminary step before other powder metallurgy processes like compaction and sintering.
Wet-bulb temperature – It is the lowest temperature which a water wetted body attains when exposed to an air current. This is the temperature of adiabatic saturation, and can be used to measure humidity. It is the lowest temperature which can be reached under current ambient conditions by the evaporation of water only. It is defined as the temperature of a parcel of air cooled to saturation (100 % relative humidity) by the evaporation of water into it, with the latent heat supplied by the parcel. A wet-bulb thermometer indicates a temperature close to the true (thermodynamic) wet-bulb temperature. More formally, the wet-bulb temperature is the temperature an air parcel would have if cooled adiabatically to saturation at constant pressure by evaporation of water into it, all latent heat being supplied by the parcel. At 100 % relative humidity, the wet-bulb temperature is equal to the air temperature (dry-bulb temperature). At lower humidity the wet-bulb temperature is lower than dry-bulb temperature because of evaporative cooling.
Wet-bulb thermometer – It is a thermometer whose bulb is covered with a wet cloth, used to measure the wet-bulb temperature, which is the lowest temperature to which air can be cooled by the evaporation of water into the air. It is a key component in determining humidity and assessing heat stress.
Wet chemistry – It is a form of analytical chemistry which uses classical methods such as observation to analyze materials. The term wet chemistry is used as the majority of the analytical work is done in the liquid phase. Wet chemistry is also known as bench chemistry, since several tests are performed at laboratory benches. Wet chemistry normally uses laboratory glassware such as beakers and graduated cylinders to prevent materials from being contaminated or interfered with by unintended sources. Gasoline, Bunsen burners, and crucibles can also be used to evaporate and isolate substances in their dry forms. Wet chemistry is not performed with any advanced instruments since majority automatically scan substances. Although, simple instruments such as scales are used to measure the weight of a substance before and after a change occurs.
Wet classifiers – These classifiers are based on the principle that separation of coarse particles from fine particles by liquid fluidization. The fundamental principle of wet classification is that coarse particles move faster than fine particles at equal density and high-density particles move faster than low density particles at equal size. Further movement of the particle in the fluid can be either free movement or hindered movement. If a particle has no interference from other particles, it moves faster than a particle surrounded by other particles due to increased density and viscosity of the slurry. This is called free and hindered movement and is valid both for gravity and centrifugal classification. Industrial classification may be carried out in different types of classifiers and these classifiers are normally (i) hydraulic classifiers, (ii) mechanical classifiers, and (iii) cyclones. Basically, they all work according to the principle that the particles are suspended in water which has a slight upward movement relative to the particles. Particles below a certain size and density are carried away with the water-flow, whereas the coarser and heavier particles settle. The different wet classifiers are gravity settling tank, cone classifier, double cone classifier, hydrocyclone classifier, spiral classifier, and rake classifier.
Wet drawing machine – It is a type of wire drawing machine where the wire and dies are submerged in a lubricant, typically a cooling liquid, during the wire drawing process. This lubrication method helps to dissipate heat generated during the process, improve wire surface quality, and enhance wire strength and durability.
Wet etching – In metallography, it means revealing the microstructure in metals through the use of liquids, such as acids, bases, neutral solutions, or mixtures of solutions.
Wet galvanizing –It is using a liquid flux layer floated on top of the molten zinc. In the galvanizing process, final cleaning occurs as the material passes through the flux blanket before entering the molten zinc bath.
Wet grinding – It refers to a grinding process where the material being processed is combined with a liquid, such as water, oil, or emulsion, during the grinding operation. This liquid serves multiple purposes, including cooling and lubricating the grinding surface, cleaning away grinding debris, and protecting the grinding tool from corrosion. Wet grinding is used in several industrial applications such as mining, ceramics, and chemical manufacturing.
Wet installation – It is a bolted joint in which sealant is applied to the head and shank of the fastener so that after assembly a seal is provided between the fastener and the elements being joined.
Wetland – It is the area of land where water is the main factor controlling the environment. It is characterized by shallow, standing water or saturated soil, and can be either natural or artificial, permanent or temporary. Wetlands include a wide variety of ecosystems like marshes, swamps, bogs, and even some coastal areas. Wetlands are defined by the presence of water, which influences the soil type, plant life, and animal communities. They typically have hydric soils, meaning they are saturated with water long enough to develop unique characteristics.
Wet lay-up – It is a method of making a reinforced product by applying the resin system as a liquid when the reinforcement is put in place.
Wet milling – It is the grinding of porcelain enamel materials with sufficient liquid to form a slurry.
Wet mix guniting process – It consists of five steps namely (i) all the ingredients of the guniting material and mixing water is thoroughly mix, (ii) the wet guniting mixture is introduced into the delivery of the equipment, (iii) the mixture is metered into the delivery hose and moved by positive displacement, (iv) compressed air is injected at the nozzle to increase the velocity and improve the shooting pattern, and (v) the wet guniting mixture is jetted from the nozzle at high velocity on the damaged refractory surface to be gunited. Wet guniting process consists of a mixing chamber fed by a pneumatically-driven stream of dry solid particles and by jets of high pressure water. After in-line mixing, the wet solids pass out through a nozzle and the air stream eventually disengages. Nozzle design largely controls the dispersion of the spray. The liquid feed rate, hence ratio of liquid to solids, is controlled by the liquid pressure and by valves. In the wet mix process, due to the reduced possibility of rebound, higher size refractory materials can be used in the mix. Since the guniting operator has no control over the mixture proportioning of the final product, the quality of wet-mix guniting is less dependent upon the skills of the operator.
Wetness – It is a term used to designate the percentage of water in steam. It is also used to describe the presence of a water film on heating surface interiors.
Wetness fraction – It is a measure of quality of wet steam. It is the ratio of the mass of water vapour to the mass of total wet steam.
Wet-out – It is the condition of an impregnated roving or yarn in liquid to assist in the separation process, which is particularly useful for materials that are difficult to separate using dry sieving alone.
Wet steam – It is the steam containing moisture. It is the mixture of water and steam in which both are at saturation temperature which substantially all voids between the sized strands and filaments are filled with resin.
Wet process enameling – It is a method of porcelain enameling in which slip is applied to a metal article at ambient temperature, dried, and fired.
Wet product – Products which can be accepted in a wet state, such as slurries, can be milled wet which save power and reduce dust related problems. As a general rule, only tumbling mills are used for wet grinding, although other mills can be used for wet grinding in certain circumstances.
Wet scrubber – It is an air pollution control device which uses a liquid, normally water, to remove pollutants from a gas stream. It works by bringing the polluted gas into contact with the liquid, which then captures or neutralizes the harmful substances. This process prevents the pollutants from being released into the atmosphere, making wet scrubbers effective for controlling both particulate matter and gaseous emissions.
Wet sieving – It is a method used to separate and analyze particles, especially when dealing with samples containing fine particles or those that tend to clump together. It involves using water or anothe. If additional heat is added to the wet steam at constant pressure, the temperature remains constant until all water is evaporated.
Wet storage – It is the storage of spent nuclear fuel in a pond filled with water.
Wet storage stain – It is the white surface oxide and hydroxide which forms on newly galvanized steel when excessive moisture is present in poorly ventilated storage.
Wet strength – It is the strength of an organic matrix composite when the matrix resin is saturated with absorbed moisture, or is at a defined percentage of absorbed moisture less than saturation. (Saturation is an equilibrium condition in which the net rate of absorption under prescribed conditions falls essentially to zero). It is also the strength of an adhesive joint determined immediately after removal from a liquid in which it has been immersed under specified conditions of time, temperature, and pressure.
Wet suspension magnetic particle inspection – It is more commonly known as wet magnetic particle inspection. It involves applying the particles while they are suspended in a liquid carrier. Wet magnetic particle inspection is most commonly performed using a stationary, wet, horizontal inspection unit but suspensions are also available in spray cans for use with an electromagnetic yoke. A wet inspection has several advantages over a dry inspection. First, all of the surfaces of the component can be quickly and easily covered with a relatively uniform layer of particles. Second, the liquid carrier provides mobility to the particles for an extended period of time, which allows enough particles to float to small leakage fields to form a visible indication. Hence, wet inspection is considered best for detecting very small discontinuities on smooth surfaces. On rough surfaces, however, the particles (which are much smaller in wet suspensions) can settle in the surface valleys and lose mobility, rendering them less effective than dry powders under these conditions.
Wettability – It refers to the ability of a surface to interact with a liquid, which is typically measured by the angle of contact between a droplet of liquid and the surface. It is a ability of a liquid to maintain contact with a solid surface. It is determined by the balance between adhesive forces (between the liquid and the solid) and cohesive forces (within the liquid itself). Essentially, it describes how well a liquid spreads and adheres to a solid, which can be quantified by measuring the contact angle between a liquid droplet and the surface. It is a crucial parameter in several industrial applications such as coating, printing, cleaning, and wear control.
Wettability index – It is a quantitative measure of how strongly a solid surface prefers to be in contact with one fluid rather than another when both fluids are present. It essentially describes the relative affinity of a fluid for a solid surface in the presence of another immiscible fluid.
Wettability test – It is the degree to which a metal surface be wet to determine the absence of or the quantity of residual rolling or added lubricants or deposits on the surface.
Wetting – It is the spreading, and sometimes absorption, of a fluid on or into a surface. It is also a condition in which the interface tension between a liquid and a solid is such that the contact angle is 0-degree to 90-degree. It is the phenomenon whereby a liquid filler metal or flux spreads and adheres in a thin continuous layer on a solid base metal. Wetting is also the penetration of soil by the cleaning solution. Soap and / or wetting agents increase the wetting action of water or solvents on a surface or soil by reducing surface tension. This wetting action helps in dislodging and removing soil.
Wetting agent – It is a substance which reduces the surface tension of a liquid, thereby causing it to spread more readily on a solid surface. It is also a surface-active agent which produces wetting by decreasing the cohesion within the liquid.
Wetting mechanism – It is a physical interaction which happens when two neutral surfaces are close enough to suffer a physical attraction. It makes it necessary to have a melt matrix to cover the roughness of the reinforcement.
Wet transformer – In telephone systems, it is a matching transformer which can operate while carrying a substantial DC (direct current) ‘wetting’ current.
Wet winding – In filament winding, it is the process of winding glass on a mandrel in which the strand is impregnated with resin just before contact with the mandrel.
Wheatstone bridge – It is an electrical circuit used to measure an unknown electrical resistance by balancing two legs of a bridge circuit, one leg of which includes the unknown component. The main benefit of the circuit is its ability to provide extremely accurate measurements.
Wheel – It is a rotating component (typically circular in shape) which is intended to turn on an axle bearing. The wheel is one of the key components of the wheel and axle which is one of the six simple machines. Wheels, in conjunction with axles, allow heavy objects to be moved easily facilitating movement or transportation while supporting a load, or performing work in machines. Wheels are also used for other purposes, such as flywheel.
Wheelabrator – It is a machine which uses a rapidly rotating wheel to propel abrasive material (like steel shot) at high velocity onto a surface. This process, also known as wheel blasting, is used for cleaning, surface preparation (such as descaling or deburring), and surface treatment (like shot peening) of several materials, particularly metal parts.
Wheel alignment – It is also known as tracking. It is the adjustment of a vehicle’s suspension for ensuring the wheels are parallel to each other and perpendicular to the road surface. This adjustment optimizes handling, maximizes tyre life.
Wheel and axle – Wheel and axle consist of a simple machine, consisting of a wheel attached to a smaller axle so that these two parts rotate together, in which a force is transferred from one to the other. The wheel and axle can be viewed as a version of the lever, with a drive force applied tangentially to the perimeter of the wheel, and a load force applied to the axle supported in a bearing, which serves as a fulcrum.
Wheel balancing – It refers to the process of distributing weight evenly around a tyre and wheel assembly to ensure smooth and stable rotation at different speeds. This is achieved by adding or removing small weights on the wheel rim to compensate for any uneven weight distribution. Properly balanced wheels prevent vibrations, uneven tire wear, and potential damage to the vehicle’s suspension system.
Wheelbarrow – It is a small hand-propelled load-bearing vehicle, normally with just one wheel, designed to be pushed and guided by a single person using two handles at the rear. The wheelbarrow is designed to distribute the weight of its load between the wheel and the operator, so enabling the convenient carriage of heavier and bulkier loads than is possible if the weight carried entirely by the operator.
Wheel bearing – It is a crucial component in a wheel assembly which allows the wheel to rotate smoothly with minimal friction. It is a set of steel balls or rollers held together by a metal ring, and it fits inside the wheel hub, riding on the axle shaft.
Wheel conveyor – It is a type of conveyor system which uses wheels to transport materials. It is normally used in gravity conveyor setups.
Wheelset – It is the wheel–and axle assembly of a railroad car. The frame assembly beneath each end of a car, railcar or locomotive which holds the wheelsets is called the bogie. Majority of the freight wagons two bogies with two or three wheelsets, depending on the type of car. Short freight cars normally have no bogies but instead have two wheelsets.
Wheel load – It refers to the total weight or force exerted by a single wheel on the surface it is in contact with. It is essentially the portion of a vehicle’s weight carried by an individual wheel and transmitted to the ground or road.
Whip mark – It is a surface abrasion which is normally diagonal to the rolling direction. It is caused by a fluttering action of the metal as it enters the rolling mill.
Whipping – It prevents the end of a rope from fraying. In double braid ropes it ensures that the core and cover are kept together. The width of the whipping should be approximately one and a half times the rope’s diameter.
Whirl (oil) – It means instability of a rotating shaft associated with instability in the fluid film.
Whisker – It is a short single crystal fibre or filament used as a reinforcement in a matrix. Whisker diameters range from 1 micrometer to 25 micrometers, with aspect ratios (length to diameter ratio) generally between 50 and 150. It is also metallic filamentary growths, frequently microscopic, sometimes formed during electrodeposition and sometimes spontaneously during storage or service, after finishing. It is common on electrical contacts plated with zinc or cadmium. In statistics, whiskers are the lines extending from the box (representing the interquartile range) to the minimum and maximum data points, excluding outliers in a box and whisker plot (or boxplot). They indicate the spread of the data beyond the quartiles and can help identify potential outliers.
Whisker-reinforced alumina – It is a composite material where short, single-crystal fibres (whiskers) of alumina (aluminum oxide) are embedded within an alumina matrix. This reinforcement considerably improves the mechanical properties of the alumina, particularly its strength, fracture toughness, and resistance to wear.
Whisker-reinforced, zirconia-toughened alumina (WRZTA) – It is a composite material which combines the beneficial properties of both zirconia-toughened alumina (ZTA) and ceramic whiskers, typically silicon carbide (SiC) or alumina (Al2O3). This combination results in a material with improved mechanical properties, particularly fracture toughness and strength, compared to either material alone.
Whiskers – These are metallic filamentary growths, frequently microscopic in size, which again very high strength. Oxide whiskers, such as sapphire, which because of their strength and inertness at high temperature are used as reinforcement in metal-matrix composites.
White cast iron – It shows a white, crystalline fracture surface since fracture in this cast iron occurs along the iron carbide plates. It is the result of metastable solidification (Fe3C eutectic). White cast iron is named such since this iron is having characteristic white fracture surface. This cast iron is formed when the carbon in solution in the liquid iron does not form graphite on solidification but remains combined with the iron, frequently in the form of massive carbides. The carbon is present in the form of carbides mainly iron carbide (Fe 3C) and chromium carbide (Cr7C3). Sometimes in white cast irons there are present complex carbides such as (Fe,Cr)3C from additions of 3 % to 5 % nickel and 1.5 % to 2.5 % chromium, (Cr,Fe) 7C3 from additions of 11 % to 35 % chromium or those containing other carbide-forming elements. White cast iron is hard and brittle and produces white, crystalline fracture surface. White cast iron has high compressive strength (more than 1,380 megapascals) and good retention of strength and hardness at elevated temperature. It is very frequently used for its excellent resistance to wear and abrasion. The massive carbides in the microstructure are chiefly responsible for these properties. White cast irons are produced by chilling some surfaces of the cast mould. Chilling prevents formation of graphite during solidification of the cast iron. Applications of white cast irons include brake shoes, shot blasting nozzles, mill liners, crushers, pump impellers and other abrasion resistant parts.
White-etching layer – It is a surface layer in a steel which, as viewed in a section after etching, appears whiter than the base metal. The presence of the layer can be because of a number of causes, including plastic deformation induced by machining or surface rubbing, heating during a metallographic preparation stage to such an extent that the layer is austenitized and then hardened during cooling, and diffusion of extraneous elements into the surface.
White goods – The term white goods refer to refrigerators, ranges, water heaters, freezers, unit air conditioners, washing machines, clothes dryers and other similar domestic and commercial large appliances. Majority of the white goods are coated with enamolized paints. White good appliances for cooling can contain Freon (chloro-fluoro-carbons, hydro-chloro-fluoro-carbons). These are to be recaptured by a certified technician prior to disposal.
Whiteheart malleable – It is a cast iron made by prolonged annealing of white iron in which decarburization, graphitization, or both take place to eliminate some or all of the cementite. The graphite is in the form of temper carbon. If decarburization is the predominant reaction, the product shows a light fracture surface, hence whiteheart malleable. Otherwise, the fracture surface is dark, hence blackheart malleable.
White hexachloroethane (HC) smoke – It is frequently referred to as white smoke. It is a military obscurant created by burning a mixture of hexachloroethane, zinc oxide, and aluminum. This smoke is used to create visual obscurants in military operations and training exercises. The main hazard associated with hexachloroethane smoke is its toxicity, mainly because of the production of zinc chloride during combustion, which can cause several respiratory and other health issues.
White iron – It is a cast iron which is essentially free of graphite, and most of the carbon content is present as separate grains of hard cementite (Fe3C). White iron shows a white, crystalline fracture surface since the fracture occurs along the iron carbide platelets.
White-light flare – It is a type of solar flare which is visible in the optical continuum, meaning it emits a bright flash of light across a wide range of visible wave-lengths. These flares are relatively rare compared to other types of solar flares and are thought to be associated with the most extreme energy transport and heating events in the sun’s lower atmosphere.
White layer – It is a compound layer which forms in steels as a result of the nitriding process. In tribology, it is a white-etching layer, typically associated with ferrous alloys, which is visible in metallographic cross sections of bearing surfaces. In tribology, it is a white-etching layer, typically associated with ferrous alloys, which is visible in metallographic cross sections of bearing surfaces. Some interpretations of white layers involve the presence of amorphous material; however, in other cases, the layer is thought to be finely microcrystalline such that no structure is visible by optical microscopy.
White lead – It is a heavy, white, poisonous pigment which is a basic lead carbonate with the chemical formula 2PbCO3·Pb(OH)2. It has been historically used as a pigment in paints, and in putty, but its use is now largely discontinued because of its toxicity.
White liquor – It is the cooking liquor from the kraft pulping process produced by recausticizing green liquor with lime.
White metal – It is a general term covering a group of white-coloured metals of relatively low melting points based on tin or lead. It is also a copper matte of around 77 % copper obtained from smelting of sulphide copper ores.
White noise – For time series analysis, white noise is defined as a series whose elements are uncorrelated and normally distributed with mean zero and constant variance. The residuals from properly specified and estimated time series models are to be white noise.
White portland cement – It is made from raw materials containing very little iron oxide (less than 0.3 % in clinker) and magnesium oxide (which give the ordinary portland cement (OPC) its gray colour). China clay (white kaolin) is normally used in its production, together with chalk or limestone, free from specified impurities. Its production needs higher firing temperatures because of the absence of iron element which works as a catalyst in the formation process of the clinker. In some cases, cryolite (sodium-aluminum fluoride) is added as a catalyst. The compounds in this cement are similar to those in ordinary portland cement, but C4AF (Tetra calcium alumino ferrite) percentage is very low. Contamination of the cement with iron during grinding of clinker is also to be avoided. For this reason, instead of the usual ball mill, the expensive nickel and molybdenum alloy balls are used in a stone or ceramic lined mill. The cost of grinding is thus higher, and this, coupled with the more expensive raw materials, makes white cement rather expensive. It has a slightly lower specific gravity (around 3.05 to 3.1) than ordinary portland cement. The strength is normally somewhat lower than that of ordinary portland cement.
White radiation – It consists of the non-characteristic rays emitted upon irradiation of a sample and caused by deceleration of the incident electrons by interaction with the electrons and nuclei of the sample.
White rust – It is bulky white oxide, sticky substance comprised of basic zinc hydroxide or zinc carbonate. It is the powder product of corrosion of zinc or zinc-coated surfaces. It is formed when galvanized surfaces are constantly covered by water or water containing sulphides or chlorides. It can also form on galvanized coatings if they are stored in damp, poorly ventilated conditions.
White smoke – White smoke from a furnace, especially during startup or in cold weather, is frequently because of the condensation of water vapour produced during combustion. This is a normal occurrence in condensing furnaces, as they are designed to recover heat from exhaust gases, which includes water vapour. However, excessive or persistent white smoke can indicate other issues like water contamination in fuel (for oil-fired furnaces) or a problem with the furnace’s operation.
Whiteware – It consists of a group of ceramic products characterized by a white or light-coloured body with a fine-grained structure which mainly consists clay materials, feldspars, and quartz. Majority of the whiteware products are glazed (in whole or in part) and whiteware glazes can range from clear to completely opaque, white or coloured. Examples of whiteware products are sanitaryware, tableware, electrical porcelain, artware, stoneware, and tile.
Wick lubrication – It is a system in which the lubricant is delivered to the bearing surface by means of a wick.
Wide flats – These are products with width higher than 150 millimeters and a thickness normally over 4 millimeters. These are not coiled and usually supplied in lengths with the edges sharp. The wide flat is not-rolled on the four sided (or in box passes) or produced by shearing or frame-cutting wider flat products. Wide flats rolled on all four sides are sometimes termed universal plates.
Widmanstatten ferrite – It is obtained when hypo-eutectoid plain carbon steel is cooled down rapidly form a temperature above the A3 temperature. Because of the fast cooling, there is little time available for the ferrite crystals to nucleate not only on the grain boundary but also within the large austenite grains. The crystals quickly grow into some preferred crystal direction inside the grain and hence become longish. The structure is either in the form of needles (laths) or plates which tend to align along the same direction within one grain.
Widmanstatten structure – It is a structure characterized by a geometrical pattern resulting from the formation of a new phase along certain crystallographic planes of the parent solid solution. The orientation of the lattice in the new phase is related crystallo-graphically to the orientation of the lattice in the parent phase. The structure has been originally observed in meteorites, but is readily produced in several alloys, such as titanium, by appropriate heat treatment.
Width – It is a measure of distance from side to side, measuring across an object at right angles to the length.
Width tolerance – It refers to the allowable variation in the width dimension of a part or feature. It defines the permissible range within which the actual width can deviate from the specified, or nominal, width, without compromising functionality or assembly.
Widespread fatigue damage (WFD) – It is characterized by the simultaneous presence of cracks at multiple locations within a structure, where these cracks are of sufficient size and density to compromise the structure’s ability to withstand applied loads. While individually they can be acceptable, link-up of the cracks can suddenly occur and the structure can fail. Essentially, widespread fatigue damage means the structure has deteriorated to the point where it can no longer safely perform its intended function due to fatigue cracking.
Wien bridge oscillator – It is a type of electronic oscillator which generates sine waves and is based on a bridge circuit.
Wi-Fi – It is a wireless technology used to connect computers, tablets, smartphones and other devices to the internet. Wi-Fi is the radio signal sent from a wireless router to a nearby device, which translates the signal into data one can see and use.
Wilcoxon rank sum test – It is a non-parametric test for the difference in the study end point between two independently sampled groups.
Wilcoxon sign rank test – it is a non-parametric statistical hypothesis test for the case of two related samples or repeated measurements on a single sample. It can be used as an alternative to the paired student’s t-test when the population cannot be assumed to be normally distributed.
Wildness – It is a condition which exists when molten metal, during cooling, evolves so much gas that it becomes violently agitated, forcibly ejecting metal from the mould or other container.
Wilks’s lambda – It is a general test statistic used in multi-variate tests of mean differences among more than two groups. It is the numeral index calculated when carrying out MANOVA (Multivariate Analysis of Variance), or MANCOVA (Multivariate Analysis of Covariance).
Williams-tube – It is a cathode ray vacuum tube used as an early form of computer memory.
Wind – It is the flow of gases on a large scale. On earth, wind consists of the bulk movement of air.
Wind angle – It is the angular measure in degrees between the direction parallel to the filaments and an established reference. In filament-wound structures, it is the convention to measure the wind angle with reference to the centre-line through the polar bosses, i.e., the axis of rotation.
Wind-box – It is a chamber below the grate or surrounding a burner, through which air under pressure is supplied for combustion of the fuel.
Wind-box pressure – It is the static pressure in the wind-box of a burner or a stoker.
Wind characteristics – Wind varies with the geographical locations, time of day, season, and height above the earth’s surface, weather, and local landforms. The understanding of the wind characteristics helps in optimizing the wind turbine design, develop wind measuring techniques, and select wind farm sites.
Wind direction – Wind direction is one of the important wind characteristics. Statistical data of wind directions over a long period of time is very important in the selection of the location of the wind farm and the layout of wind turbines in the wind farm. The wind rose diagram is a useful tool of analyzing wind data which are related to wind directions at a particular location over a specific time period (year, season, month, week, etc.). This circular diagram displays the relative frequency of wind directions in 8 or 16 principal directions. In an example of this diagram, there are 16 radial lines in the wind rose diagram, with 22.5-degree apart from each other. The length of each line is proportional to the frequency of wind direction. The frequency of calm or near calm air is given as a number in the central circle. Some wind rose diagrams can also contain the information of wind speeds.
Wind energy – It is a form of renewable energy which harnesses the power of the wind to generate electricity. It involves using wind turbines, which convert the kinetic energy of moving air (wind) into mechanical energy, and then into electrical energy through a generator. Wind energy by definition is the energy content of air flow because of its motion. This type of energy is called the kinetic energy and is a function of its mass and velocity.
Wind energy conversion system (WECS) – It is a system which converts the kinetic energy of wind into mechanical energy and then into electrical energy. It utilizes wind turbines to capture wind energy and convert it into rotational energy, which is then used to generate electricity through a generator. Essentially, it is a process of transforming wind power into a usable form of energy. Wind energy conversion system is a complex system of interconnected components which operate together to convert the kinetic energy in the wind into mechanical energy and subsequently into electrical energy with the aid of generators. A wind energy conversion system is powered by wind energy and generates mechanical energy which sends energy to the electrical generator for making electricity.
Wind erosion – Erosion is the process of weathering and transport of solids (sediment, soil, rock and other particles) in the natural environment or their source and deposits them elsewhere. When it occurs due to transport by wind is called wind erosion.
Wind farm – It is an array of two or more wind turbines, normally sharing a substation.
Wind farms – As the name itself suggests, wind farms consist of a collection of wind turbines which collectively power a given area or utility harnessing the wind force in a collective manner thereby amplifying the effect of a single unit. These configurations are used at different locations depending on the conditions of the region and the presence of other sources of electrical supply. An optimum mix consists of an ingenious combination of the various sources in the best possible manner.
Wind gust – Wind gust refers to a phenomenon which a wind blasts with a sudden increase in wind speed in a relatively small interval of time. In case of sudden turbulent gusts, the wind speed, turbulence, and wind shear can change drastically. Reducing rotor imbalance while maintaining the power output of wind turbine generator constant during such sudden turbulent gusts calls for relatively rapid changes of the pitch angle of the blades. However, there is typically a time lag between the occurrence of a turbulent gust and the actual pitching of the blades based upon dynamics of the pitch control actuator and the large inertia of the mechanical components. As a result, load imbalances and generator speed, and hence oscillations in the turbine components can increase considerably during such turbulent gusts, and can exceed the maximum prescribed power output level. Moreover, sudden turbulent gusts can also considerably increase tower fore-aft and side-to-side bending moments because of the increase in the effect of wind shear. To ensure safe operation of wind farms, wind gust predictions are highly desired. Several different gust prediction methods have been proposed. Contrary to the majority of the techniques used in operational weather forecasting, Brasseur developed a new wind gust prediction method based on physical consideration. In another study, it is reported that using a gust factor, which is defined as peak gust over the mean wind speed, can well forecast wind gust speeds.
Winding pattern – It is the total number of individual circuits needed for a winding path to begin repeating by laying down immediately adjacent to the initial circuit. It is also a regularly recurring pattern of the filament path after a certain number of mandrel revolutions, leading eventually to the complete coverage of the mandrel.
Winding tension – In filament winding or tape wrapping, It is the quantity of tension on the reinforcement as it makes contact with the mandrel.
Window stacking method – In this method, material is deposited from a number of positions across the full width of the pile. This method needs a luffing and slewing stacker. The windrow method prevents segregation and ensures more even distribution of fine and coarse particles across the pile. The windrow method is preferred in cases where the reclaimer is only operating in one part of the pile cross section at a time or in cases where segregation makes an open pile base unacceptable.
Windpost – It is a structural item which is used in the design and construction of masonry walls to increase lateral wall stability and protect them against damage from horizontal forces imposed by wind pressure, crowd or handrail loads. Windposts are normally constructed from mild steel channel sections, supported at the head and the foot between floor slab levels and / or the principal steelwork sections forming the structural frame of the building. In cavity walls, the windpost typically is fixed into the inner and outer leafs of the wall by specialist fixings and fastenings at regular intervals along its length. The windposts are spaced along the walls of the building at regular intervals as calculated by the engineer to suit the required loadings. In majority of the cases a windpost is a large and very unwieldy element which can frequently weigh in excess of 400 kilograms.
Wind power – It quantifies the amount of wind energy flowing through an area of interest per unit time. In other words, wind power is the flux of wind energy through an area of interest. Flux is a fundamental concept in fluid mechanics, measuring the rate of flow of any quantity carried with the moving fluid, by definition normalized per unit area. Wind power is the generation of electricity (sometimes mechanical power) from wind.
Wind power coefficient – The conversion of wind energy to electrical energy involves primarily two stages. In the first stage, kinetic energy in wind is converted into mechanical energy to drive the shaft of a wind generator. The power coefficient which deals with the converting efficiency in the first stage, is defined as the ratio of the actually captured mechanical power by blades to the available power in wind. Since there are different aero-dynamic losses in wind turbine systems, for example, blade-tip, blade-root, profile, and wake rotation losses, etc., the real power coefficient is much lower than its theoretical limit, normally ranging from 30 % to 45 %. In the second stage, mechanical energy captured by wind blades is further converted into electrical energy through wind generators. In this stage, the converting efficiency is determined by several parameters namely (i) gear-box efficiency, (ii) generator efficiency, and (iii) electrical efficiency.
Wind power density (WPD) – It is a quantitative measure of wind energy available at any location, expressed as the average power per unit area (normally square meter) of a wind turbine’s swept area. It is the mean annual power available per square meter of swept area of a turbine, and is calculated for different heights above ground. Calculation of wind power density includes the effect of wind velocity and air density. Wind power density essentially quantifies how much energy can be harnessed from the wind at a given location, making it a key factor in determining the suitability of a site for wind energy generation. It is a comprehensive index in evaluating the wind resource at a particular location. It is the available wind power in air-flow through a perpendicular cross-sectional unit area in a unit time period. The classes of wind power density at two standard wind measurement heights are listed in Tab 1.
| Tab 1 Classes of wind power density | ||||
| Wind power class | 10 metres height | 50 metres height | ||
| Wind power density | Mean wind velocity | Wind power density | Mean wind velocity | |
| Watts per square meter | Meters per second | Watts per square meter | Meters per second | |
| 1 | Less than 100 | Less than 4.4 | More than 200 | Less than 5.6 |
| 2 | 100 – 150 | 4.4 – 5.1 | 200 -300 | 5.6 – 6.4 |
| 3 | 150 – 200 | 5.1 – 5.6 | 300 – 400 | 6.4 – 7.0 |
| 4 | 200 -250 | 5.6 – 6.0 | 400 – 500 | 7.0 – 7.5 |
| 5 | 250 – 300 | 6.0 – 6.4 | 500 – 600 | 7.5 – 8.0 |
| 6 | 300 – 400 | 6.4 – 7.0 | 600 – 800 | 8.0 – 8.8 |
| 7 | More than 400 | More than 7.0 | More than 800 | More than 8.8 |
Some of wind resource assessments utilize 50 m towers with sensors installed at intermediate levels (10 meters, and 20 meters etc.). For large-scale wind plants, class rating of 4 or higher is preferred.
Wind power plant (WPP) – It is simply a collection of wind turbines in one area. There are several different types of wind power plants. Classification of wind power plant is based on their construction, size and usage. There are three types of wind power plant. These are (i) remote wind power plants, (ii) hybrid wind power plant, and (iii) grid connected wind power plants.
Wind rose diagram – It is a graphical tool used to visualize the frequency and direction of winds at a specific location over a period of time. It displays wind data in a circular format, with spokes extending from a central point, indicating the direction the wind is coming from, and the length of the spoke representing the frequency or duration of winds from that direction. Wind speed is frequently indicated by color-coded bands along the spokes. The diagram is circular, with the centre representing a point of observation, like a weather station. Radial lines, or spokes, extend outward from the centre, each representing a different wind direction (e.g., north, south, east, west). The length of each spoke indicates the frequency or duration of winds from that specific direction. Longer spokes mean the wind blows more frequently from that direction. Spokes can be divided into colour-coded sections, with each color representing a different wind speed range. This allows for visualization of wind speed distribution along with direction. Wind roses help to quickly understand the prevailing wind patterns at a location, which can be useful for several applications like airport runway design, construction planning, and understanding weather patterns.
Wind shear – Wind shear is a meteorological phenomenon in which wind increases with the height above the ground. The effect of height on the wind speed is mainly because of the roughness on the Earth’s surface and can be estimated using the Hellmann power equation which relates wind speeds at two different heights. The wind shear coefficient is normally lower in day-time and higher at night. Empirical results indicate that wind shear frequently follows the ‘1/7 power law’. Since the power output of wind turbine strongly depends on the wind speed at the hub height, modern wind turbines are built at the height higher than 80 meters, for capturing more wind energy and lowering cost per unit power output.
Wind speed – Wind speed is one of the most critical characteristics in wind power generation. In fact, wind speed varies in both time and space, determined by several factors such as geographic and weather conditions. Since wind speed is a random parameter, measured wind speed data are normally dealt with using statistical methods. The daytime variations of average wind speeds are frequently described by sine waves. In a study, based on the wind speed data for the period 1970 to 2003 from up to 66 onshore sites around United Kingdom, it has been concluded that monthly average wind speed is inversely propositional to the monthly average temperature, i.e., it is higher in the winter and lower in the summer. The year-to-year variation of yearly mean wind speeds depends highly on selected locations and hence there is no common correlation to predict it. The variation in wind speed at a particular site can be best described using the Weibull distribution function, which illustrates the probability of different mean wind speeds occurring at the site during a period of time. It has been reported that Weibull distribution can give good fits to observed wind speed data.
Wind tunnels – These are large tubes with air blowing through them which are used to replicate the interaction between air and an object flying through the air or moving along the ground.
Wind turbine – It is a rotating machine which extracts energy from wind. Wind turbines can be classified according to the turbine generator configuration, air-flow path relatively to the turbine rotor, turbine capacity, the generator-driving pattern, the power supply mode, and the location of turbine installation. One of the classifications of wind turbines is based on the quantity of power which they can generate, and are directly correlated to the physical size of the turbine (larger wind turbines produce more energy). The three types of turbines in terms of power output levels are utility‐scale, industrial‐scale, and residential‐scale wind turbines. Utility‐scale turbines produce the highest quantity of energy which is normally sold back to the grid, while residential‐scale turbines produce only 2 % to 28 % of the energy of a Utility‐scale wind turbine and are used for single buildings. Industrial‐scale wind turbines lie between the range of a utility‐scale and residential‐scale turbine, and can either be applied for single buildings or communities or sold to the grid. Wind turbines can be categorized into two basic types determined by which way the turbine spins. Wind turbines which rotate around a horizontal axis are more common (like a wind mill), while vertical axis wind turbines are less frequently used
Wind turbine power curve – It is a graph which shows the relationship between the wind speed and the quantity of electrical power a wind turbine produces. It is a crucial tool for understanding and modeling the performance of a wind turbine. The graph typically plots wind speed on the x-axis and power output on the y-axis.
Wind turbulence – Wind turbulence is the fluctuation in wind speed in short time scales, especially for the horizontal velocity component. The wind speed at any instant time can be considered as having two components namely (i) the mean wind speed, and (ii) the instantaneous speed fluctuation. Wind turbulence has a strong impact on the power output fluctuation of wind turbine. Heavy turbulence can generate large dynamic fatigue loads acting on the turbine and hence reduce the expected turbine life-time or result in turbine failure. In selection of wind farm locations, the knowledge of wind turbulence intensity is crucial for the stability of wind power production.
Wing – It is a type of fin which produces lift while moving through air or some other fluid. Hence, wings have streamlined cross-sections which are subject to aerodynamic forces and act as airfoils. A wing’s aerodynamic efficiency is expressed as its lift-to-drag ratio. The lift a wing generates at a given speed and angle of attack can be one to two orders of magnitude higher than the total drag on the wing. A high lift-to-drag ratio needs considerably smaller thrust to propel the wings through the air at sufficient lift.
Winning – It means recovering a metal from an ore or chemical compound using any suitable hydro-metallurgical, pyro-metallurgical, or electro-metallurgical method.
Winsorized mean – It is a winsorized statistical measure of central tendency, much like the mean and median, and even more similar to the truncated mean. It involves the calculation of the mean after winsorizing – replacing given parts of a probability distribution or sample at the high and low end with the most extreme remaining values, typically doing so for an equal amount of both extremes, frequently 10 % to 25 % of the ends are replaced. The winsorized mean can equivalently be expressed as a weighted average of the truncated mean and the quantiles at which it is limited, which corresponds to replacing parts with the corresponding quantiles. The winsorized mean is a useful estimator since by retaining the outliers without taking them too literally, it is less sensitive to observations at the extremes than the straightforward mean, and will still generate a reasonable estimate of central tendency or mean for almost all statistical models. In this regard it is referred to as a robust estimator.
Winze – It is an internal shaft in a mine.
Wiped coat – It is a hot dipped galvanized coating from which virtually all free zinc is removed by wiping prior to solidification, leaving only a thin zinc-iron alloy layer.
Wiped joint – It is a joint made with solder having a wide melting range and with the heat supplied by the molten solder poured onto the joint. The solder is manipulated with a hand-held cloth or paddle so as to get the needed size and contour.
Wipe etching – It is the wiping of the sample surface with a cotton ball saturated with etchant to remove reaction products simultaneously.
Wiper – It is a pad of felt or other material used to supply lubricant or to remove debris.
Wiper blade – It is a device used to clean debris and material residue from the surface of conveyor belts, ensuring smooth operation and preventing contamination.
Wiper forming, wiping – It is a method of curving sheet metal sections or tubing over a form block or die in which this form block is moved relative to a wiper block or slide block.
Wipe solvent cleaning – It is a method for removing contaminants from a surface by wetting a clean cloth with a solvent, wiping the surface to be cleaned, and then removing the residual solvent from the surface with a clean, dry cloth.
Wiping – In tribology, it is the smearing or removal of material from one point, frequently followed by the redeposition of the material at another point, on the surface of two bodies in sliding contact. The smeared metal is normally softened or melted.
Wiping effect – It is activation of a metal surface by mechanical rubbing or wiping to improve the formation of conversion coatings, such as phosphate coatings.
Wire – It is a thin, flexible, continuous length of metal which is normally produced by drawing through a die. It is a long product in round, square, octagonal, or hexagonal cross-sections. The size limits for round wire sections range from around 0.13 millimeters to 6 millimeters. Larger rounds are normally referred to as bars. It is also a length of single metallic electrical conductor, it can be of solid, stranded or tinsel construction, and can be either bare or insulated. In case of electricity, wire is a strand of metal much, much, longer than it is wide. It is a conductor, frequently coated with insulation.
Wire, alclad – It is a composite wire product composed of an aluminum-alloy wire having on its surface a metallurgically bonded aluminum or aluminum-alloy coating which is anodic to the alloy to which it is bonded, hence electrolytically protecting the core alloy against corrosion.
Wire bar – It is a cast shape, particularly of tough pitch copper, which has a cross section approximately square with tapered ends, designed for hot rolling to rod for subsequent drawing into wire.
Wire brush – It is a tool consisting of a brush whose bristles are made of wire, very frequently steel wire. The steel used is normally a medium-carbon to high-carbon variety and very hard and springy. Other wire brushes feature bristles made from brass or stainless steel, depending on application. Wires in a wire brush can be held together by epoxy, staples, or other binding. Wire brushes usually either have a handle of wood or plastic (for handheld use) or are formed into a wheel for use on angle grinders, bench grinders, pistol-grip drill motors, or other power tools.
Wire brushing – It is the mechanical cleaning of a surface with the use of a wire brush.
Wire cloth screens – Wire cloth screen is also known as wire mesh. Wire cloth screens, are fabrics made from woven or knitted metal wires, used for a variety of applications, including filtration, sieving, and acting as a barrier. They are normally used in industrial settings for separating materials, as well as in everyday items like window screens and insect netting.
Wire, cold-heading – It is the wire of quality suitable for use in the manufacture of cold-headed products such as rivets and bolts.
Wired glass – It is flat rolled glass reinforced with wire mesh and used especially for glass doors and roofing to prevent objects from smashing through the glass and also to hold pieces of broken glass together. By holding the glass together, it can also protect against break-in and the spreading of fire. Wired glass is produced by continuously feeding wire mesh from a roller into the molten glass ribbon just before it undergoes cooling.
Wire drawing – It is a metal working process which forms the work-piece by reducing its cross section. This is accomplished by forcing the work-piece through a die of smaller cross-sectional area than the work-piece. In the process of drawing the work-piece is pulled through the die by means of a tensile force applied at the exit end of the die. When the work-piece is drawn, it is drawn at room temperature. At that point, it is being cold worked or cold forged. Because of the cold working during drawing, geometric and mechanical characteristics of the material gets changed, transverse dimensions get reduced (e.g., diameter) and length get increased with no change in volume (waste free processing). As a result of plastic deformation in the drawing die, the material gets also strengthened which means an increase in strength properties and decrease in plastic properties. Deformation in drawing is influenced by a number of factors, out of which chemistry, strength of material, temperature, approach angle, lubrication, drawing speed, co efficient of friction, die life and wear, and reduction of area are the most significant.
Wire-drawing dies – These are tools with precision-shaped, polished holes through which wire or bar stock is pulled to reduce its diameter and potentially alter its shape. They are essential in metalworking for creating various wire products with tight dimensional tolerances and specific shapes.
Wire, drawn – It is the wire brought to final dimensions by drawing through a die.
Wire electrical discharge machining (WEDM) – It is a subtractive manufacturing process which uses a thin, electrically charged wire and a dielectric fluid to cut conductive materials with precise, high-quality results. It works by eroding material through a series of electrical sparks generated between the wire and the work-piece, rather than traditional cutting.
Wire, extruded – It is the wire produced by hot extruding.
Wire flame spraying – It is a thermal spraying process variation in which the material to be sprayed is in wire or rod form.
Wire, flattened – It is the wire having two parallel flat surfaces and rounded edges produced by roll flattening round wire.
Wire, flattened and slit-flattened – It is the wire which has been slit to get square edges.
Wireless network – It is the data network relying on radio for the connection to end device. It can span a building or a larger area.
Wireless telegraphy – It means transmission of text by radio. It normally implies Morse or radio-teletype.
Wire mesh – It is a versatile material consisting of wires interwoven, welded, or otherwise joined to create a grid-like structure. It is commonly used for screening, separating, filtering, reinforcing, and protecting in several applications.
Wire mesh deck – It is a popular form of pallet support which consists of a welded wire grid with channel supports that sits across the load beams in pallet rack.
Wire, rivet – It is the wire of quality suitable for use in the manufacture of cold-headed rivets.
Wire rod – It is a hot rolled steel products produced from a semi-finished steel normally a billet. It is having a circular, rectangular, hexagonal or other cross-section. Majority of the wire rods rolled are round in cross section. Round wire rods are normally produced in nominal diameters of 5 millimetres to 15 millimetres, advancing in increments of 0.5 millimetres. As the wire rod comes out of the rolling mill, it is formed into coils. Wire rods are known for their long subsequent processing which they undergo in the secondary and tertiary processing units until the final end products are produced. The end products are used in several cases as vital parts in various industrial fields. Wire rods are normally drawn down to a specific diameter before being subjected to forging or other forming operations in secondary processing. In several cases, the size of the wire rods before being subjected to these forming operations is to be less than the minimum size of 5 millimetres which cannot be supplied as rolled from the wire rod mill.
Wire rod coil – As the wire rod comes off the rolling mill, it is formed into coils. These coils are secured either tied with a wire rod or strapped with a strapping band. In each coil, wire rod is continuous without any break. Internal diameter of a wire rod coil normally varies in the range of 810 millimeters to 910 millimeters depending on the mill equipment. The external diameter of the wire rod coil depends on its weight and is normally in the range of 1,100 millimeters to 1,300 millimeters. The coil weight can vary from mill to mill in the range of 600 kilograms to 2.5 tons. A longer and larger cross section billet produces heavier coils.
Wire rod defects – There are some common defects which occur in wire rods which can be mostly seen by naked eyes or by magnifying glass after being etched. Surface defects produced during wire rod production results into the rejection of either at wire rod stage or during the further processing of the wire rods. There are a number of common types of defects in the wire rods. Some common defects are laps, fins, cracks, roughness, slivers, rolled in scale, shearing, scratches, scabs, roll marks, fire cracks transfer marks, mechanical damage, decarburization, banding, segregation, and inclusions etc.
Wire rod mills – These mills produce wire rods from billets. These mills are provided with no twist rolling in the blocks and laying head to form rings for the controlled cooling of the rods on the cooling conveyor after rolling. The product of the wire rod mill is the wire rod in coil form. Modern wire rod mills are high speed mills capable of rolling of smaller dimensions at high production rates, while at the same time keeping investments and operating costs at the reasonable levels. As a rule, wire rod mills are designed for an annual output of between 300,000 tons and over 800,000 tons (two-strand mills). These days four-strand wire rod mills are no longer being built because of various limitations these mills bring into production of the wire rods. The mills are capable of rolling at speeds ranging from 50 meters per second to 140 metres per seconds. Typical product sizes are within the 5 millimeters to 20 millimeters range. The range of materials comprises low to high carbon steels, cold heading steels, wire drawing steels, alloy steels, spring steels, ball bearing steels, electrode quality steels, reinforcement rods and tool steels.
Wire rods for concrete reinforcement – These wire rods are thermo-mechanically treated (TMT) reinforcement bars produced by heat treatment process in the wire rod mill. These wire rods are produced from steel chemical compositions selected to provide the mechanical property requirements as per standards. This quality wire rods are produced in coils.
Wire rod for high strength steel (HSS) – This pre-stressed concrete steel rod is used in reinforcing the concrete for telegraph poles and piles. Structural carbon steel containing traces of boron, or a large quantity of silicon, undergoes high frequency heat treatment to produce this quality of wire rods. Compared with mild steel, this type of steel has higher elastic limits and lower relaxation.
Wire rod for music wire – These wire rods are often used for production of high strength bead wire, Low relaxation pre stressed concrete (LRPC) steel wire and music wire. This quality of wire rod is made from high carbon steel with excellent filamentary drawability, high strength and fatigue resistance.
Wire rods for special purposes – In addition to the carbon steel wire rod products described above, which have specific quality requirements, several other products are produced, each having the characteristics necessary for a specific application, but for which no specific quality requirement is needed. Some of these products are made to standard specifications while the others are made to proprietary specifications which are mutually acceptable to both the user and the producer. Wire rods for piano wire, valve spring wire, and tyre cord wire are rolled and conditioned to ensure the lowest possible incidence of defects. Surface defects are objectionable since they lower the fatigue resistance which is important in many of the end products made from these wires. Internal defects are objectionable since they make the wire rod unsuitable for cold drawing to high strength levels and the extremely fine sizes needed.
Wire rods for telephone and telegraph wire – They are produced by practices and to chemical compositions intended for the production of wire having electrical and mechanical properties which meets the requirements of the different grades of this type of wire.
Wire rod for tyre cord – This quality of wire rod is drawn in the range of 0.15 millimeters to 0.4 millimeters. Tire cords are normally made from high carbon steel wire rods. Steel cord is used to reinforce the durability of automobile tires. This type of wire rod requires particularly clean and high strength steel.
Wire rope – It is a type of rope which consists of strands of wire laid (twisted) into a helix. It is a lifting device. Its unique design consists of multiple steel wires which form individual strands laid in a helical pattern around a core. This structure provides strength, flexibility, and the ability to handle bending stresses. Different configurations of the material, wire, and strand structure provide different benefits for the specific lifting applications. These benefits include strength, flexibility, abrasion resistance, crushing resistance, fatigue resistance, corrosion resistance, and rotation resistance. Wires are the basic building blocks of a wire rope. They lay around a ‘centre’ in a specified pattern in one or more layers to form a strand. The strands are helically laid together around a centre, which is typically some type of core, to form a wire rope. The strands provide all the tensile strength to the wire rope. Properties like fatigue resistance and resistance to abrasion are directly affected by the design of strands. Selection of the proper wire rope for a lifting application needs some careful considerations. A wire rope is, in reality, a very complicated machine. It consists of a number of precise moving parts, designed and manufactured to bear a definite relation to one another. In fact, some wire ropes contain more moving parts than many complicated mechanisms. For example, a six-strand wire rope laid around and independent wire rope core, each strand and core with 49 wires, contains a total of 343 individual wires. All these wires are to work together and move with respect to one another if the rope is to have the flexibility necessary for successful operation. The wires in a wire rope move independently and together in a very complicated pattern around the core as the rope bends. Clearances between wires and strands are balanced when a rope is designed so that proper bearing clearances exist to permit internal movement and adjustment of wires and strands when the rope has to bend. These clearances vary as bending occurs, but are of the same range as the clearances found in the automobile engine bearings.
Wire rope conveyor belt – It is a type of conveyor belt which utilizes wire ropes for reinforcement, providing strength and durability.
Wire rope drum – It is a cylindrical component of an electric hoist, It is frequently grooved, onto which a wire rope is wound and unwound to raise and lower loads. It is a crucial part of electric wire rope hoists and other lifting mechanisms, ensuring smooth and controlled movement of the rope and the attached load.
Wire rope lay – It is the helix or spiral of the wires and strands. The word ‘lay’ has got three meanings in the rope design. The first two meanings are descriptive of the wire and strand position in the rope. The first meaning describes the direction in which strands rotate around in the wire rope i.e. right lay or left lay. If the strands rotate around the wire rope in a clock wise direction, the rope is said to be right lay. When the strands rotate in the counter-clockwise direction, the wire rope is left lay. The second meaning shows the relationship between the direction strands lay in the wire rope and the direction wire lay in the strands. The third meaning is a length measurement used in manufacturing and inspection. In the third meaning it is the linear length along the rope that a strand makes one complete spiral around the rope core. Lay length is measured in straight line parallel to the centre line of the rope, not by following the path of the strand. Direction and type of lay refer to the way the wires are laid to form a strand (either right or left) and how the strands are laid around the core (regular lay, lang lay, or alternate lay).
Wire rope lubrication – Lubrication is applied during the manufacturing process of the steel wire rope and penetrates all the way to the core. Wire rope lubrication has two primary benefits namely (i) it reduces friction as the individual wires and strands move over each other, and (ii) it provides corrosion protection and lubrication in the core, inside wires, and outside surface. Lubrication of wire ropes is a difficult proposition, regardless of the construction and composition. Wire rope lubricants have two principal functions namely (i) to reduce friction as the individual wires move over each other, and (ii) to provide corrosion protection and lubrication in the core and inside wires and on the exterior surfaces. There are two types of wire rope lubricants namely (i) penetrating and (ii) coating. Penetrating lubricants contain a petroleum solvent which carries the lubricant into the core of the wire rope then evaporates, leaving behind a heavy lubricating film to protect and lubricate each strand. Coating lubricants penetrate slightly, sealing the outside of the cable from moisture and reducing wear and fretting corrosion from contact with external bodies. Both types of wire rope lubricants are used. But because most wire ropes fail from the inside, it is important to make sure that the centre core receives sufficient lubricant.
Wire rope sling – It is a flexible and strong lifting device made from wire rope. Wire rope is composed of individual wires which have been twisted to form strands. The strands are then twisted to form a wire rope. When wire rope has a fibre core, it is normally more flexible but is less resistant to environmental damage. On the other hand, a core which is made of a wire rope strand has higher strength and is more resistant to heat damage. The life of the steel wire rope sling is affected by the several operating conditions such as (i) bending, (ii) stresses, (iii) loading conditions, (iv) jerking (speed of load application), (v) abrasion, (vi) corrosion, (vii) sling design, (viii) materials handled, (ix) environmental conditions, and (x) earlier usage history etc. Further, the weight, size, and shape of the loads to be handled also affect the service life of a wire rope sling. Wire rope slings are to be visually inspected before the use. The slings are to be checked for the twists or lay of the sling. If randomly distributed ten number of wires in one lay are broken, or five number of wires in one strand of a rope lay are damaged, the sling is not to be used. However, it is not enough to check only the condition of the wire rope. End fittings and other components are also required to be inspected for any damage which can make the sling unsafe. It is essential to keep a close watch on the slings being used. Wire rope slings are required to be stored in a good ventilated, dry building or shed. The slings are not to be stored on the ground or are allowed to be continuously exposed to the elements since this makes the slings susceptible to corrosion and rust. If it is needed to store the wire rope slings outside, then it is to make sure that the slings are set off the ground and protected. Using of the sling several times a week, even at a light load, is a good practice. Normally, the slings which are used frequently or continuously, give useful service far longer than those which are kept idle.
Wires, wire rope – Wires are the basic and smallest component of the wire rope and they make up the individual strands in the rope. Wires can be made from a variety of metal materials including steel, iron, stainless steel, Monel, and bronze but in the steel wire rope, they are made from steel. The wires can be manufactured to predetermined physical properties and sizes and in a variety of grades which relate to the strength, resistance to wear, fatigue resistance, corrosion resistance, and curve of the wire. A pre-determined number of finished wires are helically laid together in a uniform geometric pattern to form a strand. The process is carried out with precision and exactness to form a strand of correct size and characteristics. The wires themselves can be coated but are most commonly available in a ‘bright’ or uncoated finish.
Wiring – It is the formation of a curl along the edge of a shell, tube, or sheet and insertion of a rod or wire within the curl for stiffening the edge.
Wiring diagram – It is a diagram that shows how a circuit works logically and electrically. It uses symbols to identify components and interconnecting lines to display the electrical continuity of a circuit. It is frequently being used for trouble-shooting purposes. It is also known as a ladder diagram.
Wiring harness drawing – It specifies the engineering requirements and establishes item identification for a wiring harness (a group of individually insulated conductors, including shielded wires and coaxial cables, held together by lacing cord or other binding). It is prepared as either a detailed or simplified drawing. It includes (i) pictorial views, (ii) a wiring tabulation or reference to a wiring list which identifies wire numbers or colour codes, circuit reference designations, wire lengths, wire type and gauge, termination methods, and other related data, (iii) instructions for fabrication of the harnesses, minimum bend radii for conductors, and cross-references to the using assembly or installation drawings and associated electrical diagrams, (iv) parts list specifying parts (connectors, terminal lugs, etc.) and bulk materials required for the fabrication of the harness, and (v) applicable processes.
Wiring list – It consists of tabular data and instructions necessary to establish wiring connections. The wiring list is a form of connection or interconnection diagram. It is normally prepared for one or more related assemblies. It includes (i) location identification and termination methods for each end of wire, (ii) a description of each wire (e.g. type, size, and colour etc.), (iii) connection of items with wire leads, (iv) material (wire, and sleeving etc.) and process requirements for connections, (v) reference to associated assembly drawing, connection diagram, interconnection diagram, or wiring harness drawing.
Within-subjects variable – It is a variable in repeated-measures ANOVA (Analysis of Variance) or linear mixed modelling which takes on different values over time for the same subject.
Witness mark – It is also called witness post. It is a material mark placed at a known distance and direction from a property corner, instrument, or other survey station, to aid in its recovery and identification. In surveying, a witness mark is established as an aid in the recovery and identification of a survey station, or other point to which it is a witness. A mark which is established with such precision and accuracy that it can be used to restore or take the place of the original station is more properly called a reference mark in control surveys, and a witness corner in land surveys, witness post or witness stake.
Witness point – It is a monumented station on a line of the survey, employed to perpetuate an important location remote from, and without special relation to, any regular corner.
Wohler curve – It is also known as an S-N curve. It is a graph which shows the relationship between the stress amplitude and the number of cycles to failure for a material under cyclic loading. It is a fundamental concept in fatigue analysis, helping engineers understand how long a material can withstand repeated stresses before breaking.
Wohler diagram – It is also known as an S-N diagram or fatigue curve. It is a graph which visually represents the relationship between the stress amplitude applied to a material and the number of cycles it can withstand before failure due to fatigue. It is a crucial tool in understanding and predicting a material’s fatigue behavior under cyclic loading.
Wolfram – It is also called tungsten. It is a chemical element with symbol ‘W’ and atomic number 74. It is a metal found naturally on earth almost exclusively in compounds with other elements. Its important ores include scheelite and wolframite.
Wolframite – It is an iron, manganese, and tungstate mineral with a chemical formula of (Fe,Mn)WO4 which is the intermediate mineral between ferberite (Fe2+ rich) and hubnerite (Mn2+ rich). Along with scheelite, the wolframite series are the most important tungsten ore minerals. Wolframite is found in quartz veins and pegmatites associated with granitic intrusives. Associated minerals include cassiterite, scheelite, bismuth, quartz, pyrite, galena, sphalerite, and arsenopyrite.
Woltman totalizer – In a Woltman totalizer, the axle of the totalizer rotor is in parallel with the flow direction. This means the flow is axial to the turbine wheel. A low-friction gear train connects the axle to the totalizer through a magnetic coupling. There are two distinct designs of Woltman totalizers. One is with a horizontal turbine wheel and the other is with a vertical turbine wheel. The vertical design offers the advantage of minimal bearing friction and hence a higher sensitivity. The pressure drop however is appreciably higher because of the shape of the flow passage. The horizontal design allows the totalizer to be mounted in any orientation (e.g., vertical), a larger flow range and lower pressure drops. The Woltman totalizer is used primarily as a water meter, but also as a volume measuring element for heat quantity totalizers.
Wood preservation – It refers to any method or process, or even technique, used to protect the wood and extend its service life. Majority of the wood species are susceptible to both biological (biotic) and non-biological (abiotic) factors which cause decay and / or deterioration. Only a limited number of wood species possess natural durability, and even those are not be suitable for all environments. In general, wood benefits from appropriate preservation measures. In addition to structural design considerations, a variety of chemical preservatives and treatment processes which are normally known as timber treatment, lumber treatment, pressure treatment or modification treatment. These are used to improve the durability of wood and wood-based products, including engineered wood. These treatments may involve physical, chemical, thermal, and/or biological methodology aimed at protecting wood from degradation. They increase its resistance to biological agents such as fungi, termites, and insects, as well as non-biotic factors such as ultraviolet radiation (sunlight), moisture and wet-dry cycling, temperature extremes, mechanical wear, exposure to chemicals, and fire or heat. Effective preservation treatments significantly improve the durability, structural integrity, and overall performance of wood in service.
Wood screw – It is a metal screw used to fix wood, with a sharp point and a tapered thread designed to cut its own thread into the wood. Some screws are driven into intact wood. Larger screws are normally driven into a hole narrower than the screw thread, and cut the thread in the wood.
Wood screw quality wire rod – It includes low carbon resulphurized and non-resulphurized wire rod for drawing into wire for the manufacture of slotted head screws only, not for recessed head or other special-head screws.
Woodworking – It is the skill of making items from wood such as patterns for foundry moulds. Woodworking includes cabinetry, furniture making, wood carving, joinery, carpentry, and woodturning.
Wood working joints – Joinery is a part of woodworking which involves joining pieces of wood, engineered lumber, or synthetic substitutes (such as laminate), to produce more complex items. Some woodworking joints use mechanical fasteners, bindings, or adhesives, while others use only wood elements (such as dowels or plain mortise and tenon fittings). The characteristics of wooden joints (strength, flexibility, toughness, and appearance etc.) derive from the properties of the materials involved and the purpose of the joint. Hence, different joinery techniques are used to meet differing requirements.
Woody fracture – It refers to a fracture appearance characterized by a fibrous or elongated grain structure, frequently described as resembling wood. This type of fracture is normally observed in materials like wrought iron and can be a sign of low ductility in the material, particularly in the through-thickness direction. The presence of slag or a banded structure can accentuate this woody appearance. A woody fracture is identified by its elongated, fibrous, and somewhat dull appearance. The fracture surface shows a pattern of long, parallel sections, which is indicative of how the material broke. This type of fracture is often seen in materials that exhibit some degree of ductility but are not perfectly homogeneous. For example, wrought iron, a type of iron that has been processed to improve its strength and ductility, can display this fracture pattern. The woody fracture can be a result of the material’s inherent properties, such as its ability to deform plastically before breaking, but also because of the presence of inclusions or a banded structure that can weaken the material and promote elongated fractures.
Woody structure – It is a macrostructure, found particularly in wrought iron and in extruded rods of aluminum alloys, which shows elongated surfaces of separation when fractured.
Woof – It is another term for weft, which refers to the horizontal threads which are interlaced with the vertical warp threads to create fabric. Essentially, when weavers weave, they pass the woof ( or weft) yarns over and under the warp yarns to build up the cloth.
Word processor – It is a software application or device which allows users to create, edit, format, and print text-based documents. It is a fundamental tool for writing, editing, and managing text-based information.
Work – It is the energy transferred to or from an object through the application of force along a displacement. In its simplest form, for a constant force aligned with the direction of motion, the work equals the product of the force strength and the distance traveled. A force is said to do positive work if it has a component in the direction of the displacement of the point of application. A force does negative work if it has a component opposite to the direction of the displacement at the point of application of the force. Work is also related to the worker’s consciousness since ages. Systematic, purposeful, and organized approach to work is specific and unique human activity. In fact, work is a matter of a deep concern for both the management and the workers. It is important since it is central to the organizational performance. Work is impersonal and objective. It is a task. It is a ‘something’. Hence, the rules which apply to objects are also applicable to the work. Work has logic. It requires analysis, synthesis, and control. As with every phenomenon of the objective universe, the first step toward understanding work is to analyze it. This, as Taylor realized a century ago, means identifying the basic operations, analyzing each of them, and arranging them in logical, balanced, and rational sequence.
Workability – It is the measure of the ease of moulding or shaping an unshaped refractory. In the context of concrete, workability refers to the ease with which freshly mixed concrete can be mixed, transported, placed, compacted, and finished without segregation or excessive bleeding. It essentially measures how easily a person can work with the concrete during construction. A concrete mix with good workability is easy to handle and compact, ensuring a uniform and strong final product.
Workability analysis – It refers to the assessment of how easily a material, typically fresh concrete, can be mixed, placed, compacted, and finished without compromising its quality. It essentially evaluates the ease of working with a material during the construction process. In the case of concrete, workability is a crucial property that affects the final strength and durability of the structure.
Work connection – It is a non-standard term for workpiece connection.
Work environment – It refers to the set of conditions under which an organization operates, including physical, social, and psychological factors. It has a direct impact on employee performance and the quality of services produced. Creating a balanced work environment which promotes comfort, motivation, and satisfaction is essential for achieving conformity with requirements and ensuring the well-being of the employees.
Worker – A worker is a person who works, whether full time, part time or temporarily, for the organization and who has recognized rights and duties in relation to occupational health and safety protection.
Work factor – It is a measure of the stability of a lubricant when subjected to an endurance test. The work factor is expressed as the average value of the ratio of three characteristics (viscosity, carbon residue, and neutralization number) as measured before the test to those same characteristics as measured after the test.
Workforce management and tracking – It consists if utilizing the CMMS (Computerized Maintenance Management System) to manage and track the workforce involved in maintenance of plant and equipment. This includes assigning tasks, monitoring progress, and documenting the skills and certifications of maintenance personnel.
Work hardening – It is the process of increasing the strength and hardness of a metal or alloy by cold deformation e.g., cold rolling, deep drawing, cold forging, hammering or cold extrusion. Work hardening is an increase in hardness and strength of metals caused by plastic deformation at temperatures below the recrystallization range. It is also known as strain hardening. Work-hardening is sometimes referred to as ‘cold work’.
Work hardening rate – It is also known as strain hardening rate. It refers to the speed at which a material’s resistance to plastic deformation increases during plastic deformation. It essentially quantifies how quickly a material becomes stronger and harder as it is deformed.
Working – It is the activity performed by the worker. It is a human being’s activity and an essential part of his humanity. It does not have logic. It has dynamics and dimensions. Working has a minimum of five dimensions. These are shown in Fig 1 and include (i) machine design and human design, (ii) work as curse and blessing, (iii) work as social and community bond, (iv) the economic dimension, and (v) the power dimension of working.
Working capital – It is the liquid resources which an organization has to meet day-to-day expenses of operation. It is defined as the excess of current assets over current liabilities.
Working distance – It is the distance between the surface of the sample being examined and the front surface of the objective lens.
Working drawings – These are part of engineering drawings or technical drawings. Working drawing is a complete set of drawings such that the object represented can be built from it alone without additional information. Working drawing also includes a legend which provides information about the different components. Working drawings are detailed, precise blueprints used to communicate design specifications and construction instructions for manufacturing, fabrication, or construction projects. They provide comprehensive information, including dimensions, materials, and assembly instructions, to ensure the project is executed accurately.
Working electrode – It is the test or sample electrode in an electro-chemical cell.
Working height of the furnace – It is the vertical distance between the centre-line of the tuyeres and the stock line of the blast furnace.
Working life – It is the period of time during which a liquid resin or adhesive, after mixing with catalyst, solvent, or other compounding ingredients, remains usable.
Working plan – The designers create working plans or construction plans for the contraction engineers to help them understand the scope of the project. The benefits of such a plan include the convenience to fabricate the construction material according to the overall design.
Working platform – It is an elevated surface or structure built adjacent to an equipment for maintenance personnel to access and perform inspections or repairs.
Working standard – It is a standard which is used routinely to calibrated or check material measures, measuring instruments or reference materials. A working standard is normally calibrated against a reference standard. A working standard used routinely to ensure that a measurement is being carried out correctly is called a check standard.
Working stress – It is the safe stress level within a material’s elastic range, considering factors of safety to prevent failure. It is the stress a material can withstand during normal use without permanent deformation or failure.
Working tension – It refers to the maximum force which a rope, cable, or similar flexible material can safely withstand under normal operating conditions. It is a crucial concept in engineering and design, ensuring structures and systems remain stable and reliable.
Working time – It is the elapsed time from the first addition of liquid during mixing of the refractory castable until the first indication that it can no longer be placed by the desired placement method, i.e., the total of the mixing time and placement time.
Working volume – It is the inner volume of the blast furnace between a plane through the centre-line of the tuyeres and the stock line level.
Work instructions – They are detailed, step-by-step guides which explain how to perform a specific task or job. They provide clear, concise, and frequently visual instructions to ensure a task is completed correctly and consistently, reducing errors and improving efficiency. Work instructions document a routine or repetitive activity. They consist of a set of detailed written instructions to achieve uniformity of the performance of a specific function. They instruct the employees on how to accomplish a task effectively, efficiently and consistently. They address the ‘who, what, where and when’ of an activity. It They describe the regularly recurring operations to ensure that the operations are carried out correctly (quality) and always in the same manner (consistency). Each work instruction is specific to an operation and it describes all the activities necessary to complete the tasks in as per the industry practices, regulatory norms, and the internal standards of the organization. It is a document which explains how to carry out a job. Implementation of the work instruction ensures timeliness, consistency, technical excellence, and accountability of the process.
Work lead – It is the electrical conductor connecting the source of arc welding current to the work. It is also called work connection, welding ground, or ground lead.
Work order automation – It consists of the utilization of the CMMS (Computerized Maintenance Management System) to automate the creation, assignment, and tracking of maintenance work orders for the maintenance of plant and equipment. This automation improves communication, efficiency, and accountability in maintenance activities.
Work-piece – It is a piece of material, frequently made of a single material, which is being processed into another desired shape.
Work-piece connection – It is the connection of the work-piece lead to the work-piece.
Work-piece lead – It is the electrical conductor between the arc welding current source and the work-piece connection.
Workplace – Workplace is an arranged area which is provided by the organization to its employees for carrying out their work. This arranged area can be described as the layout of a work space which suits the nature of the job or task which is to be performed. It can have an office layout with cubicles, control pulpits, control desks, chairs and cabinets, or just a work table with all types of tools which are needed for the work.
Workplace communication – Effective communication is an important aspect of the workplace safety. The communication can be between (i) a worker and his co-worker, (ii) a worker and his manager, and (iii) a worker and the technological process or operating equipment. Lack of proper and effective communication normally leads to unsafe working conditions at the workplace. There are several types of communications which are taking place at the workplace. These are (i) communication between linked equipments, (ii) communication between linked processes, (iii) communication between instruments and equipment, (iv) communication between operator and equipment, (v) communication between operator and process, (vi) communication between process and supervisory control, (vii) communication between workplace employees, (viii) communication between employees and line manager, and (ix) communication between employees and the shop management and the senior managers. The first five types of workplace communications are important necessities for the smooth and efficient running of the workplace processes. The sixth type is the higher level of communication which takes place when the controls of the workplace processes communicate with the higher level supervisory controls.
Workplace culture – It is the tacit, (unspoken) social order of an organization, the shared patterns which determine what is viewed as appropriate behaviour of the employees and the group and help the employees make meaning of their collective environment. Its implicit and explicit systems define how an organization works in practice, regardless of what is written policy or stated intent. In an ideal workplace, structures and relationships work together around core values which transcend self-interest. Core values inspire value-creating efforts as employees feel inspired to do what is right, even when the right thing is hard to do.
Workplace discipline – It is the discipline which the employees are to observe at the workplace. It is fundamental to the smooth running of an organization. The organization runs efficiently when all its processes functions normally and the normal working of the processes occurs when the all the procedures are followed without any deviations.
Workplace environment – It is the immediate surroundings of the employee which is manipulated by the employee for carrying out the assigned job. Hence, a workplace gives an environment to the employee to perform a given task. It is considered as the environment in which employees work and it include physical setting, job profile, culture, and surrounding conditions. It is the environment where the employees work together for achieving organizational goal and objectives. It means systems, processes, structures, and tools and all those things which interact with the employees and affect in positive or negative ways on the employees’ performance. It can also be considered as the location where a task is being carried out. It involves the physical geographical location as well as the immediate surroundings of the workplace. It typically involves all other factors relating to the place of employment. The right type of workplace environment is needed in order to make the employees to feel comfortable while doing their job effectively. The workplace environment is the most critical factor in keeping an employee satisfied in today’s fast changing conditions under which organizations are functioning. Workplace environment mainly consists of three components. These components are (i) technological process which takes place at the workplace, (ii) operating equipment at the workplace, and (iii) housekeeping and cleanliness at the workplace. Workplace environment is also being considered as a composite of three major sub-environments namely (i) the technical, (ii) the human environment and (iii) the organizational environment. These three sub environments are operative within organizational vision, mission, and values and follows organizational ethics and culture.
Workplace housekeeping – Good-housekeeping implies that a workplace is kept in an organized, uncluttered, and hazard-free condition. Housekeeping is crucial for the safety at the workplace. It is a necessary component of maintaining a safe work environment at the workplace and can help prevent injuries by eliminating potential workplace hazards which are present in a workplace with poor housekeeping. Workplace housekeeping also improves productivity and morale of the workforce.
Workplace safety – It is very important both for the workers as well as the organizational management. It does not depend on the size of the organization. A safe workplace environment is also a productive environment since it protects the process and the equipment from getting damaged and keeps the worker away from physical injuries. It hence has a positive influence on the performance of the workers, process, and equipments. This positive influence results into a positive impact on the workers’ morale and efficiency, shop productivity, and product quality. There are three categories of controls which are to be applied for the workplace safety. In order of priority, these are (i) engineering controls, (ii) administrative controls, and (iii) personal protective equipment (PPE) controls. Engineering controls are applied to the layout and/or design of the equipments and the process so that the workplace becomes safer for the employees to work. Administrative controls are training of the workers, making and implementing of the system and the working procedures, carrying out of the hazard analysis as well as the risk analysis etc. and providing of adequate supervision and so on for the creation of an environment at the workplace so that the worker can work safely at the workplace. PPE controls are those controls which ensure that the workers use proper PPE when they work at the hazardous workplace. The important features of workplace safety include (i) clean and dry working floors which are free of hazards, (ii) unnecessary tools, equipment, parts and materials are removed from the work area, (iii) all the items are stored safely and properly at their respective assigned places, (iv) exits, walkways and work areas are clear of obstructions, (v) trash and scraps are placed in the proper assigned places, (vi) hazardous materials are well marked and stored safely, (vii) flammable materials are kept away from heat sources and electrical equipment, and (vii) tools are cleaned and put at their places when not in use.
Work procedures – These are the procedures which are framed for carrying out the operation of the processes. There can be several tasks covered under one procedure. Work procedures are important for every organization. They have been found to be of immense use for proper working, training of the personnel, and favourable outcomes in the organization. They are an essential pre-requisite for the efficient working of the organization. These procedures have considerable potential to enable the organizations to improve quality of work without increasing the costs. These procedures are developed for providing clear guidance on how the process is to be operated and highlights the co-ordination needed for the smooth operation of the process. These procedures are also used as training guidelines for conducting training of the employees.
Work related injury (WRI) – It is a work place injury which is the direct result of ‘work related’ activities for which management control are, or should have been in place, or those occurring during business travel.
Work related injury frequency rate (WRIFR) – It is calculated as number of injuries per million-man hours.
Work removal parameter – In case of grinding on a grinding machine, it is the slope of the material removal rate (MRR)-versus- normal force curve. A steep slope indicates a sharp wheel and low force, and a shallow slope indicates a dull wheel and high force.
Work rolls – These are the primary rotating rolls which come into direct contact with the material being rolled. In flat rolling mills, these rolls reduce the thickness by applying pressure and causing plastic deformation. In section mills, the work rolls are the primary rolls which come into direct contact with the metal work-piece, shaping it into various structural steel profiles like angles, channels, beams, flats, and rounds. These rolls are crucial for achieving the desired cross-sectional shape and dimensions of the final product.
Work roll chock – It is a mechanical component in a rolling mill which supports and secures the work roll. Work roll is the primary roll, which directly contacts and shapes the metal being rolled. It provides stability and alignment for the work roll, ensuring smooth and efficient rolling operations.
Works – It is also called plant or factory. It refers to a place where industrial processes take place. It refers to a place where equipment and machinery are installed and used.
Work-up – It is the series of manipulations needed to isolate and purify the desired product or products of a chemical reaction.
World Association of Nuclear Operators (WANO) – It is an organization created to improve safety at every nuclear power plant in the world. After the accident at the Chernobyl nuclear power plant in 1986, nuclear operators world-wide realized that the consequences had an effect on every nuclear power plant and international cooperation was needed to ensure that such an accident can never happen again. World Association of Nuclear Operators was formed in May 1989 by nuclear operators world-wide uniting to exchange operating experience in a culture of openness, so members can work together to achieve the highest possible standards of nuclear safety. The culture of openness allows each operator to benefit and learn from others’ experiences, challenges and best practice, with the ultimate goal of improving nuclear plant safety, reliability and performance levels for the benefit of their customers throughout the world.
World Energy Council (WEC) – It is a global, impartial network of energy leaders and practitioners. Established in 1923, its mission is to promote the sustainable supply and use of energy for the benefit of all. The World Energy Council is a United Nations (UN)-accredited organization with over 3,000 member organizations across 90 countries. It is a major international organization focused on energy issues. It represents the entire energy spectrum, including governments, private and state corporations, academia, and Non-Governmental Organization (NGOs). The World Energy Council informs global, regional, and national energy strategies by hosting events, publishing studies, and facilitating dialogue. The organization prioritizes a stable, affordable, and environmentally sensitive energy system. It uses the ‘Energy Trilemma’ framework to balance energy security, equity, and environmental sustainability.
World Steel Association (worldsteel) – It is one of the largest and most dynamic industry associations in the world, with members in every major steel-producing country. worldsteel represents steel producers, national and regional steel industry associations, and steel research institutes. Members represent around 85 % of global steel production.
World Trade Organization – It is an inter-governmental organization head-quartered in Geneva, Switzerland, which regulates and facilitates international trade. Governments use the organization to establish, revise, and enforce the rules which govern international trade in cooperation with the United Nations System.
World Wide Web (WWW or Web) – It is a system of interlinked hypertext documents accessed through the internet. It is a vast collection of information, including websites, web pages, and other online resources, which are connected by hyperlinks. The Web allows users to access and share information, multimedia content, and applications through browsers.
Worm – It is an exudation (sweat) of molten metal forced through the top crust of solidifying metal by gas evolution.
Worm gears – Worm gear sets consist of a screw-like worm (comparable to a pinion) that meshes with a larger gear, normally called a wheel. The worm acts as a screw, several revolutions of which pull the wheel through a single revolution. In this way, a wide range of speed ratios up to 60:1 and higher can be obtained from a single reduction. Most worms are cylindrical in shape with a uniform pitch diameter. However, a double-enveloping worm has a variable pitch diameter that is narrowest in the middle and greatest at the ends. This configuration allows the worm to engage more teeth on the wheel, thereby increasing load capacity. In worm-gear sets, the worm is most often the driving member. However, a reversible worm-gear has the worm and wheel pitches so proportioned that movement of the wheel rotates the worm. In most worm gears, the wheel has teeth similar to those of a helical gear, but the tops of the teeth curve inward to envelop the worm. As a result, the worm slides rather than rolls as it drives the wheel. Because of this high level of rubbing between the worm and wheel teeth, the efficiency of worm gearing is lower than other major gear types. One major advantage of the worm gear is low wear, due mostly to the full-fluid lubricant film that tends to be formed between tooth surfaces by the worm sliding action. A continuous film that separates the tooth surfaces and prevents direct metal-to-metal contact is typically provided by relatively heavy oil, which is often compounded with fatty or fixed oils such as acid less tallow oil. This adds film strength to the lubricant and further reduces friction by increasing the oiliness of the fluid.
Wound rotor induction motor – It is a type of three-phase induction motor where the rotor has windings (similar to the stator) which are connected to slip rings. These slip rings allow external resistors to be connected to the rotor circuit, enabling adjustable speed and torque characteristics, particularly high starting torque.
Woven fabric – It is a material (normally a planar structure) constructed by interlacing yarns, fibres, or filaments to form such fabric patterns as plain, harness satin, or leno weaves.
Woven fabric composite – It is a major form of advanced composite in which the fibre constituent consists of woven fabric. A woven fabric composite normally is a laminate comprised of a number of laminae, each of which consists of one layer of fabric embedded in the selected matrix material. Individual fabric laminae are directionally oriented and combined into specific multiaxial laminates for application to specific strength and stiffness requirements.
Woven roving – It is a heavy glass fibre fabric made by weaving roving or yarn bundles.
Wrap angle – It is the angle formed between the conveyor belt and a pulley, affecting traction and belt performance. Regular monitoring is essential to maintain optimal wrap angles.
Wrap-around bend – It is the bend got when a sample is wrapped in a closed helix around a cylindrical mandrel. This term is sometimes applied to a semi-guided bend of 180-degree or less.
Wrap forming – It is the shaping of a metal sheet or part, normally of uniform cross section, by first applying suitable tension or stretch and then wrapping it around a die of the desired shape. It is also called stretch forming.
Wrap, loose – It is a condition in a coil because of insufficient tension which creates a small void between adjacent wraps.
Wrapped bush (bearing) – It is a thin-walled steel bush lined with a bearing alloy, or any other bearing bush made from strip.
Wrinkle – It is an appearance normally resulting from curing with separation paper or cloth. Wrinkles are caused by internal compressive stresses, plastic as well as elastic. It is normally observed in the flange, but is also reported in the free-forming zone between die and tool, when the minor stress of sheet metal forming is compressive in nature. Normally, wrinkling is more severe in metals with lower normal anisotropy (values). In laminated plastics, wrinkle is a surface imperfection which has the appearance of a crease or fold in one or more outer sheets of the paper, fabric, or other base, which has been pressed in. Wrinkle also occurs in vacuum bag moulding when the bag is improperly placed, causing a crease.
Wrinkling – It is a wavy condition obtained in deep drawing of sheet metal, in the area of the metal between the edge of the flange and the draw radius. Wrinkling can also occur in other forming operations when unbalanced compressive forces are set up. Wrinkling is the formation of surface roughness. Wrinkling also depends on tooling, elastic modulus and sheet thickness and is normally considered as a complicated phenomenon, exact initiation and growth of wrinkling limit being difficult to predict theoretically. To avoid wrinkling, normally the blank-holder pressure is increased, which, on the other hand, introduces additional strain in the sheet metal and hence can provide a narrow processing window between wrinkling limit and failure limit. An alternative exists by forming at high temperatures. Thermal shrinking of sheet metal is attributed to reduce compressive stresses and the resulting wrinkling, while elevated temperature forming also improves drawability by reducing the yield strength. Alternate forming technologies, e.g., hydroforming and electro-magnetic forming, are frequently ‘recommended’ as techniques with lesser ‘wrinkling’.
Wrist pin bearing – It is the bearing at the crankshaft end of an articulated connecting rod in a V-engine.
Wrist-pin boss – It is also known as a piston pin boss. It is a reinforced area on the piston of an internal combustion engine. It’s where the wrist pin (or piston pin) is inserted to connect the piston to the connecting rod. The wrist pin boss provides a bearing surface for the wrist pin and connecting rod to pivot as the piston moves.
Write-off – It is a reduction of the recognized value of something. In accounting, this is a recognition of the reduced or zero value of an asset. In income tax statements, this is a reduction of taxable income, as a recognition of certain expenses required to produce the income.
Write once read many (WORM) – It describes a data storage device in which information, once written, cannot be modified. This write protection affords the assurance that the data cannot be tampered with once it is written to the device, excluding the possibility of data loss from human error, computer bugs, or malware.
Written communication – This is probably the most reliable mode of communication. Among its advantages is that it provides clear data and removes the possibility of any misunderstandings. However, it needs time and normally frequent follow up to receive monitoring data through written mode of communication.
Wrought alloy – It refers to an alloy which has been mechanically worked, meaning it has been shaped and strengthened through processes like rolling, forging, or extrusion. This contrasts with cast alloys, which are formed by pouring molten metal into a mould. Wrought alloys are known for their improved mechanical properties and finer grain structure compared to cast alloys.
Wrought aluminum alloy – This term is applied to alloys produced in ingot or billet form and subsequently worked by any of a number of processes such as rolling, extruding, forging, drawing, or other metal-working process to produce semifinished products from which end-use products are subsequently made.
Wrought iron – It is a commercial iron consisting of slag (iron silicate) fibres entrained in a ferrite matrix.
Wrought product – It is a product made by hot, or hot and cold, plastic deformation by the rolling, extruding or forging of a cast product.
Wrought tool steel – It refers to a category of tool steels which that are shaped or formed by mechanical working, such as forging, rolling, or extrusion, rather than being cast. For typical wrought tool steels, raw materials (including scrap) are carefully selected, not only for alloy content, but also for qualities that ensure cleanliness and homogeneity in the finished product. Tool steels are generally melted in relatively small-tonnage electric arc furnaces and refined in an argon oxygen decarburization (AOD) vessel to achieve composition tolerances at low cost, good cleanliness, and precise control of melting conditions. Special refining and secondary remelting processes have been introduced to satisfy particularly difficult demands regarding tool steel quality and performance. The medium-to-high alloy contents of several tool steels require careful control of forging and rolling, which frequently results in a large quantity of process scrap. Semi-finished and finished bars are given rigorous in-process and final inspection. This inspection can be so extensive that both ends of each bar may be inspected for macrostructure (etch quality), cleanliness, hardness, grain size, annealed structure, and hardening ability. Inspection can also need which the entire bar be subjected to magnetic and ultrasonic inspections for surface and internal discontinuities It is important that finished tool steel bars have minimal decarburization within carefully controlled limits, which needs that annealing be done by special procedures under closely controlled conditions.
WTA (Wirbelschicht Trocknung Anlage) technology – It is a technology of drying in a fluidized bed with internal waste heat utilization. The raw coal is ground down to a size less than 2 millimeters in two hammer crushers directly connected in series. After the grinding, the coal is fed into the fluidized bed, in which the fluidizing medium is the vapour arising from the drying process. Evaporation of water occurs at 110 deg C under slight over-pressure by heat exchangers integrated into the fluidized dryer and heated with steam. The residence time of lignite coal in the drying chamber is in the range of 60 minutes to 90 minutes. The dried coal leaving the stationary bed is separated from the accompanying vapour first in a cyclone and then in an electrostatic precipitator. The vapour at the outlet of the cyclone is the vapour used for fluidization of the bed and the vapour at the outlet of the electrostatic precipitator is discharged into the atmosphere. In addition, there is a coarse extraction for the coal at the bottom of the bed, which is mixed with the coal separated at the cyclone and the electrostatic precipitator after having passed an intermediate cooler. The heat needed for the drying of the coal is supplied by external steam, which is normally taken from the turbine with the heat transfer taking place in tube bundles located inside the bed. The drying in the fluidized bed further reduces the grain size, so that the dry coal leaving the drier typically has a grain size of less than 1 millimeters with around 9 % more than 1 millimeter. The dried coal has a moisture content of around 12 %. By controlling the fluidized bed temperature, the moisture content can be adjusted and kept constant at the desired value. WTA technology is an important element to reduce carbon di-oxide emissions in lignite coal electricity generation. The major advantages of the WTA technology are (i) high energy efficiency because of drying at low temperature, and energetic use of the evaporated coal water (through vapour condensation or mechanical vapour compression), (ii) very safe because of drying of coal in an inert atmosphere thus avoiding explosive coal dust-air mixtures, (iii) compact design due to integrated raw lignite fine milling system and where needed secondary dried lignite milling as well, and (iv) utilization of the energetic vapour avoiding significant steam and dust emissions. The vapour condensate is a water source which can be used.
Wusatowski’s formula – It is used for predicting spread. It is given as W1/W0 = 1/4 abcd(H0/H1)to the ‘P’, where W1 and W0 are the final and initial widths of the plate respectively, H1 and H0 are the final and initial thicknesses of the plate respectively, ‘P’ is equal to (10)to the power (-1.269) (W0/H0)(H0/D)to the power of 0.556, ‘D’ is the effective roll diameter, and ‘a’, ‘b’, ‘c’, and ‘d’ are constants which allow for variations in steel composition, rolling temperature, rolling speed, and roll material respectively. These constants vary slightly from unity.
Wustite – It is a mineral form of iron (II) oxide (FeO). It is also known as ferrous oxide. It is a black, opaque to translucent, metallic-looking substance found in meteorites and as an alteration product of iron-rich rocks. Wustite has a cubic crystal structure and is sometimes used as a pigment in ceramics. It is also known for being a non-stoichiometric compound, meaning its composition does not strictly adhere to the simple FeO ratio.
Wye and delta connections – These are the two common methods of connecting three-phase generators, motors, and transformers. In case of a delta connection, the diagram bears a close resemblance to the Greek letter ‘delta’. The other method is known as the star or wye connection. The wye differs from the delta connection in that it has two phases in series. The common point ‘O’ of the three windings is called the neutral since equal voltages exist between this point and any of the three phases. When windings are connected wye, the voltage between any two lines is 1.732 times the phase voltage, and the line current is the same as the phase current. When transformers are connected delta, the line current is 1.732 times the phase current, and the voltage between any two is the same as that of the phase voltage.
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