A Coatings - Coatings on hot-dipped galvanized steels processed to convert the coating completely to zinc-iron alloys; dull gray in appearance, have no spangle, and after proper preparation, are well suited for painting.
A Elevation - The top level of the boiler firebox where four oil guns are located. The oil guns are used to produce steam and maintain pressure while the boiler is on oil fire.
A.G.C. Systems - (Automatic Gauge Control) Hydraulic or electric system that supplies the force to the A.G.C. roll force cylinders.
A Sheet Metal Screw - Sheet metal screws with (a) sharp-pointed ends; and (b) fewer threads per inch than type AB screws; and (c) deeper threads with bettere gripping power than type AB. The industrial Fasteners Institue incorrectly labes type A an obsolete thread though it is universally preferred in 18-8 stainless over type AB, especially by the marine industry.
AB Srews - Sheet metal screws with pointed ends similar to type-A screws and thread dimensions similar to type-B. Type AB screws are seldom used in stainless.
Abrasion - The displacement and/or detachment of metallic particles from a surface as a consequence of being exposed to flowing solids, fluids or gases. The process of rubbing, grinding, or wearing away by friction.
Abrasion Resistance - Degree of resistance of a material to abrasion or wear
Abrasion-Resistant Steels - A family of steel products developed for those applications involved in sliding and/or impact abrasion.
Abrasive - Material for grinding, polishing, blasting, either in loose form or bonded to form wheels, bricks, or files, or applied to paper and cloth by glue or resin. Natural abrasives include emery, corundum, garnet, sand, flint, etc. Metallic shot and grit are also used as abrasives in cleaning castings.
Abrasive - Natural sandstone,emery,corundum,diamonds, or Artificial silicon carbide,aluminum oxide material used for making grinding wheels,andpaper,abrasive and lapping compunds.
Abrasive Wheels - Wheels of a hard abrasive, such as Carborundum used for grinding.
Abrasive Wear - The displacement and / or detachment of metallic particles from a surface as a consequence of being exposed to flowing fluids or gases.
Ac1 - The temperature at which austenite begins to form on heating.
Ac3 - In hypoeutectoid steel, the temperature at which transformation of ferrite into austenite is completed upon heating.
Accelerator - A substance that hastens a reaction usually acting as a catalyst; as used in sand additive resins.
Accm - In hypereutectoid steel, the temperature at which cementite goes into complete solution with austenite.
Accordion Reed Steel - Hardened, tempered, polished and blued or yellow flat steel with dressed edges. Carbon content about 1.00. Material has to possess good flatness, uniform hardness and high elasticity.
Accumulator - A device used to dampen pressure pulsations in the hydraulic and morgoil systems.
Accurate - Conforms to a standard or tolerance.
Acetyl Tributyl Citrate - One of the lubricating oils generally applied on tin Mill Products (tin plate, TFS-chrome/chrome oxide coated steel, and blackplate).
Acid - 1) A solution or liquid with a pH less than 7, 2) term applied to slags, refractors, and minerals containing a high percentage of silica.
Acid Brittleness (Pickling Brittleness) - Brittleness resulting from pickling steel in acid; hydrogen, formed by the interaction between iron and acid, is partially absorbed by the metal, causing acid brittleness.
Acid Embrittlement - Embrittlement during pickling due to absorption of hydrogen.
Acid Process - A process of making steel, either Bessemer, open-hearth or electric, in which the furnace is lined with a siliceous refractory and for which low phosphorus pig iron is required as this element is not removed.
Acid Process - A steel making method using an acid refractory-lined (usually silica) furnace. Neither sulfur or phosphorus is removed.
Acme Thread - A screw thread having a 29 degree included angel. Used largely for feed and adjusting screws on machine tools.
Activation - The changing of the passive surface of a metal to a chemically active state. Contrast with passivation.
Actual Weight - The customer buys by the actual (scale) weight of the steel. The theoretical weight is used in estimating, however, it is not to be used for billing.
Acute Angle - An angle that is less than 90 degrees.
Adapters - Steel segments that are bolted to the reel mandrel to increase their diameter so that large (24" ID) coils can be run.
Adapti Investment Casting Process - A lost wax process employing one of three methods; centrifugal, vacuum or gravity-pouring casting.
Addition Agent - 1) Any material added to a charge of molten metal in bath or ladle to bring alloy to specifications, 2) reagent added to plating bath.
Addendum - That portion of a gear tooth that extends from the pitch circle to the outside diameter.
Adeline Steelmaking Process - Method of producing a precision casting of steel or steel alloys using aluminolthermic process and lost wax, followed by centrifugal action.
Aecm, Ae1, and Ae3 - Equilibrium transformation temperatures in steel.
Aeration - Making contact between air and a liquid by spraying liquid into the air or by agitating the liquid to promote absorption of air. Also act of fluffing molding sand.
AFS Tests - A number of standard tests determined by American Foundrymen's Society to evaluate molding and core sands.
Age Hardening - Hardening by aging, usually after rapid cooling or cold working. The term as applied to soft, or low carbon steels, relates to a wide variety of commercially important, slow, gradual changes that take place in properties of steels after the final treatment. These changes, which bring about a condition of increased hardness, elastic limit, and tensile strength with a consequent loss in ductility, occur during the period in which the steel is at normal temperatures.
Agglomerating Processes - "Fine particles of limestone (flux) and iron ore are difficult to handle and transport because of dusting and decomposition, so the powdery material usually is processed into larger pieces. The raw material's properties determine the technique that is used by mills. 1) SINTER Baked particles that stick together in roughly one-inch chunks. Normally used for iron ore dust collected from the blast furnaces. 2) PELLETS Iron ore or limestone particles are rolled into little balls in a balling drum and hardened by heat. 3) BRIQUETTES Small lumps are formed by pressing material together. Hot Iron Briquetting (HBI) is a concentrated iron ore substitute for scrap for use in electric furnaces.
Aging - A change in the properties of certain metal and alloys (such as steel) that occurs at ambient or moderately elevated temperatures after a hot working heat treatment or cold working operation. Typical properties impacted are hardness, yield strength, tensile strength, ductility, impact value, formability, magnetic properties, etc. See also Non-aging.
Air Furnace - Reverbatory-type furnace in which metal is melted by heat from fuel burning at one end of the hearth, passing over the bath toward the stack at the other end. Heat also is reflected from the roof and side walls.
Air Hardening Steel - A steel containing sufficient carbon and other alloying elements to harden fully during cooling in air or other gaseous mediums from a temperature above its transformation range. Such steels attain their martensitic structure without going through the quenching process. Additions of chromium, nickel, molybdenum and manganese are effective toward this end. The term should be restricted to steels that are capable of being hardened by cooling in air in fairly large sections, about 2 in. (51 mm) or more in diameter.
Air Heaters - Bank of boiler tubes located in the exhaust gas ductwork which preheats the incoming combustion air by transferring heat from the exhaust gases passing through them to the incoming air passing around them. Preheating the air reduces boiler fuel requirements.
Aircraft Quality - Denotes stock of sufficient quality to be forged into highly stressed parts for aircraft or other critical applications. Such materials are of extremely high quality, requiring closely controlled, restrictive practices in their manufacture in order that they may pass rigid requirements, such as magnetic particle inspection (Ref: Aerospace Material Specification 2301).
Air-Lift Hammer - A type of gravity drop hammer where the ram is raised for each stroke by an air cylinder. Because length of stroke can be controlled, ram velocity and thus energy delivered to the workpiece can be varied.
Air Quenching - Accelerated cooling of alloy in an air stream from temperatures above the Ac3 temperature.
Air Scale - Scale left on ferrous metal in processing, usually from heating in presence of air.
Airblasting - A cleaning operation, as cleaning sand from molds.
AISI Steels - Steels of the American Iron and Steel Institute. Common and alloy steels have been numbered in a system essentially the same as the SAE. The AISI system is more elaborate than the SAE in that all numbers are preceded by letters: A represents basic open-hearth alloy steel, B acid Bessemer carbon steel, C basic open-hearth carbon steel, CB either acid Bessemer ar basic open-hearth carbon steel, E electric furnace alloy steel.
Alclad - Composite sheet produced by bonding either corrosion-resistant aluminum alloy or aluminum of high purity to base metal of structurally stronger aluminum alloy. The coatings are anodic to the core so they protect exposed areas of the core electrolytically during exposure to corrosive environment.
Align - To adjust or set to a line or center.
Alkaline Derusting - An electrical process for derusting steel, cast iron and other ferrous alloys without using heat.
Alkyd - A type of resin made from a polyhydroxy alcohol combined chemically with the acids of various oils. They are particularly adapted for use where hardness and high gloss are required. Used largely for outside decoration.
Allotropy - The property whereby certain elements may exist in more than one crystal structure.
Allowance (Tolerance) - In a foundry, the clearance specified; difference in limiting sizes, as minimum clearance or maximum interference between mating parts, as computed arithmetically.
Alloy - A substance having metallic properties and composed of two or more chemical elements of which at least one is metal. Usually possesses qualities different from those of the components.
Alloy Steel - Steel with modified properties that is made by combining iron with one or more elements in addition to carbon. Alloys change the properties of the steel making it, for example, harder, more formable, etc., depending on the combination and amounts of alloys used. An iron-based mixture is considered to be an alloy steel when manganese is greater than 1.65%, silicon over 0.5%, copper above 0.6%, or other minimum quantities of alloying elements such as chromium, nickel, molybdenum, or tungsten are present. An enormous variety of distinct properties can be created for the steel by substituting these elements in the recipe.
Alloy Surcharge - The addition to the producer's selling price included in order to offset raw material cost increases caused by higher alloy prices.
Alloying Element - Any metallic element added during the making of steel for the purpose of increasing corrosion resistance, hardness, or strength. The metals used most commonly as alloying elements in stainless steel include chromium, nickel, and molybdenum.
Alpha Bronze - A copper-tin alloy consisting of the alpha solid solution of tin in copper. Commercial forms contain 4 or 5% of tin. This alloy is used in coinage,springs,turbine,blades,etc,
Alpha - ferrite - Body-centered cubic type of pure iron stable below 1670F (910C).
Alpha Iron - The polymorphic form of iron, stable below 1670 (degrees) F. has a body centered cubic lattice, and is magnetic up to 1410 (degrees) F.
Alpha Martensite - A form or stage of martensite of somewhat arbitrary distinction, probably representing the least developed and most distorted stage in the transformation of austenite to martensite at ordinary temperatures.
Alpha Process - A shell molding and core-making method in which a thin resin-bonded shell is baked with a less expensive, highly permeable material.
Alternating Stress - Stress produced in a material by forces acting alternating in opposite directions.
Alumina - Aluminum oxide produced fron bauxite by a complicated chemical process. It is a material that looks like granulated sugar. Alumina is an intermediate step in the production of aluminum from bauxite, and is also a valuable chemical on its own.
Aluminum - A silver-white soft metal, noted for its lightness, high reflectivity, high thermal conductivity, non-toxicity, and corrosion resistance. It is the most abundant metallic element, comprising about 1/12th of the earths crust. It is never found in nature as an elemental metal, but only in combination with oxygen and other elements. In ordinary commercial and industrial use, the word aluminum is often understood to mean aluminum alloy, rather than the pure metal.
Aluminum oxide - A chemical compound of aluminum with oxygen, which forms immediately on an unprotected surface exposed to air. Unlike iron oxide (the rust that forms on steel) aluminum oxide does not flake off, but forms a protective layer that blocks further oxidation and so protects the integrity of the metal. It is transparent and does not alter the appearance of the aluminum surface.
Aluminum Killed Steel - (Special Killed) Steel deoxidized with aluminum in order to reduce the oxygen content to a minimum so that no reaction occurs between carbon and oxygen during solidification.
Ambient Temperature - Temperature of the surrounding air.
American Iron and Steel Institute (AISI) - A non-profit association of North American producers, suppliers to and users of steel. Its mission is to promote steel as the material of choice and to enchance the competetiveness of its members and the North American Steel Industry.
American Standard Beam - Common name for a S-shape steel beam.
Ames Portable Hardness Tester - The Rockwell penetration method of testing hardness of metals can be made with this tester by applying pressure to the penetrator by screw action.
Amorphous - Non-crystalline.
Angle - Structural steel resembling L. May be Equal Leg Angle or Unequal Leg Angle. Used in trusses and built-up girders.
Angle Iron - An iron or steel structural member that has been cast,rolled or bent (folded) so that its cross section is l-shaped.
Angle Plate - A precision holding fisture made of cast iron,steel or granite. The two principal faces are at right angles and may be slotted for holding the work or clamping to a table.
Anneal - To heat a metal to a temperature slightly below its melting point, then cool it gradually so as to soften it thoroughly. Fully annealed aluminum is said to be in the O temper.
Anneal Cycle Code - Steel heat specification unique to the annealing base being charged.
Annealing - "WHAT A heat or thermal treatment process by which a previously cold-rolled steel coil is made more suitable for forming and bending. The steel sheet is heated to a designated temperature for a sufficient amount of time and then cooled. WHY The bonds between the grains of the metal are stretched when a coil is cold rolled, leaving the steel brittle and breakable. Annealing ""recrystallizes"" the grain structure of steel by allowing for new bonds to be formed at the high temperature. HOW There are two ways to anneal cold-rolled steel coils D1batch and continuous. (1) BATCH (BOX). Three to four coils are stacked on top of each other, and a cover is placed on top. For up to three days, the steel is heated in a non-oxygen atmosphere (so it will not rust) and slowly cooled. (2) CONTINUOUS. Normally part of a coating line, the steel is uncoiled and run through a series of vertical loops within a heater: The temperature and cooling rates are controlled to obtain the desired mechanical properties for the steel."
Arbor Press -
Annulus - A ring-like part or, the orifice of a hollow die, through which extruded metal flows from the press.
Anodes - Tin bars that are put in the plater cells and are important to the
Anodized (And Painted) Aluminum - Aluminum coated with a thin film of oxide (applied by anodic treatment) resulting in a surface with extreme hardness. A wide variety of dye-colored coatings are made possible by impregnation in the anodizing process.
Anodizing - Forming or thickening an oxide coating on aluminum by immersing it in an eletrolyte bath and passing a current through the bath, using the aluminum as the anode. The process may be used to increase the protective effect of aluminums transparent natural oxide surface; it may also be given a decorative coloration. plating process in the Tin Mill.
ANSI - Stands for American National Standards Institute
Antimony - Chemical symbol Sb. Silvery white and lusteous, it exhibits poor heat and electrical conductivity. It is used primarily in compunds such as anitmony trioxide for flame-retardents. Otheer applications include storage battery components.
Anticarburizing Compounds - Compounds applied to metallic surfaces to prevent surface carbonization.
Anvil - A heavy iron or steel block upon which metal is forged or hammered. Also the fixed jaw on a micrometer against which parts are measured.
AOD - Argon Oxygen Decarburization
API - American petroleum institute-issues stamdards for oil industry
Aperture - In an extrusion die, the shaped opening through which the heat-softened metal is forced and which gives the extruded product its cross-sectional shape. Also called the orifice.
Apparent Contraction - The net contraction of a casting dimension due to true metal contraction, mold wall movement and restraint during solidification and cooling.
Apron - Device that the molten slag flows across on its way from the spout to the doughnut. It is cooled by water spray.
Arbor - A shaft or spindle for holding cutting tools; most usually on a milling machine.
Arbor Press -
Arc Cutting - Using an electric arc to cut metal.
Arc Furnace - A steel melting furnace in which heat is generated by an arc between graphite electrodes and the metal. Both carbon and alloy steels are produced in electric arc furnaces and scrap,rather than molten metal,is used as the base material. Furnaces with capacities up to 200 tonnes are now in use.
Arcair Torch - An electric arc torch with air ducts running parallel to the electrode, used to remove metal and surface defects from ferrous castings.
Architectural finish - An architectural finish is a standard finish characterized by a uniformly good appearance. This finish is most often specified for exposed surfaces.
Argon-Oxygen Decarburization (AOD) - "WHAT A process for further refinement of stainless steel through reduction of carbon content. WHY The amount of carbon in stainless steel must be lower than that in carbon steel or lower alloy steel (i.e., steel with alloying element content below 5%). While electric arc furnaces (EAF) are the conventional means of melting and refining stainless steel, AOD is an economical supplement, as operating time is shorter and temperatures are lower than in EAF steelmaking. Additionally, using AOD for refining stainless steel increases the availability of the EAF for melting purposes. HOW Molten, unrefined steel is transferred from the EAF into a separate vessel. A mixture of argon and oxygen is blown from the bottom of the vessel through the melted steel. Cleaning agents are added to the vessel along with these gases to eliminate impurities, while the oxygen combines with carbon in the unrefined steel to reduce the carbon level. The presence of argon enhances the affinity of carbon for oxygen and thus facilitates the removal of carbon. "
Arnold's Fatigue Test - A test for fractures using 850 cyclic stress reverses per min., recording the number of cycles required to produce fracture. Named after John Arnold, British Metallurgist)
As Cast (as-cast, u.m.) - Referring to metal which has not received finishing (beyond gate removal or sandblasting) or treatment of any kind including heat treatment after casting. Similarly, as drawn, as forged and as rolled. (See Finishing)
ASD - Aluminum Standards and Data published by the Aluminum Association.
Ash Box - Brick lined collection point for slag and ash.
Ash Tank - Holding tank for ashes. The tank is located outside the boiler house. The ashes are dumped once or twice a week, depending on the ash accumulation.
Askania - 1.) A strip-centering device consisting of two electric eyes to ensure that the strip will stay centered during re-coiling. 2) Device with an electronic eye which is associated with tracking of strip going through the side trimmers.
Assembly - A unit of fitted parts that naje yo a mechanism or machine, such as the headstock assemble of a lathe.
Assembly fit - Refers to two parts designed for mating assembly and requiring exact dimensions and contours to assure a proper fit.
ASTM - American Standard of Testing and Materials. A non-profit organization that parovides a forum for producers,users,ultinmate consumers, and those having a general interest (representatives of government and academia) to meet on common ground and write standards for materials,products,systems and services.
ASTM Standards - A series of documents, approved and published by ASTM, that include specifications or requirements, practices, guides, test methods, etc., covering various materials, products, systems or services. In the steel industry, the steel related ASTM standards are used by both the producers and users to ensure that a steel product or service meets all intended requirements. See American Society for Testing and Materials.
A53A, A53B, A53F, A106 - ASTM grades of carbon steel pipe.
ATBC - Acetyl Tributyl Citrate.
Atmosphere, Furnace - Gases with which metal is in contact during melting or heat treating.
Atmosphere, Neutral - Furnace atmosphere which is neither oxidizing nor reducing can be made up of an inert gas e.g. argon, or the products of combustion.
Atmosphere, Oxidizing - Furnace atmosphere which gives off oxygen under certain conditions or where there is an excess of oxygen in the product of combustion, or the products of combustion are oxidizing to the metal being heated.
Atmosphere, Reducing - Furnace atmosphere which absorbs oxygen under suitable conditions or in which there is insufficient air to completely burn the fuel, or the product of combustion is reducing to the metal being heated.
Atmosphere Valve - A valve that is located in the exhaust line of a turbine and is designed to open and get a positive pressure in the exhaust line.
Atomic-Hydrogen Weld - Arc welding with heat from an arc between two tungsten or other suitable electrodes in a hydrogen atmosphere. The use of pressure and filler metal is optional.
Atomizing Steam - Low pressure steam which is introduced to the oil gun to help atomize the oil, to assist the burning process, and to keep the oil gun from plugging.
Attemperator - Header connecting the primary and finishing superheaters into which feed water is sprayed to control the final temperature of the steam leaving the boiler.
Attrition - A natural redcution in work force as a result of resignations, retirements or death. Most unionized companies cannot unilaterally reduce their employment levels to cut costs, so management must rely on attrition to provide openings that they, in turn, do not fill. Because the median ages of work forces at the integrated mills may be more than 50, an increasing number of retirments may provide these companies with added flexibility to improve their competitiveness.
Austenite - Phase in certain steels, characterized as a solid solution, usually of carbon or iron carbide, in the hamma form of iron. Such steels are known as austenitic. Austenite is stable only above 1333 (degrees) F. in a plain carbon steel, but the presence of certain alloying elements, such as nickel and manganese, stabilizes the austenitec form, even at normal temperatures.
Austenite Steel - Any steel containing sufficient alloy to produce a stable austenitic (gamma iron) crystalline structure at ambient temperatures.
Austenitic - Steel which, because of the presence of alloying elements, such as manganese,nickel,chromium,etc., shows stability of Austenite at normal temperatures
Auto Stamping Plant - A facility that presses a steel blank into the desired form of a car door or hood, for example, with a powerful die (pattern). The steel used must be ductile (malleable) enough to bend into shape without breaking.
Automatic - Describes the status of the operation when the O2 pulpit has control and the boiler logic has control.
Automatic Gauge Control - Using hydraulic roll force systems, steelmakers have the ability to control precisely their steel sheet's gauge (thickness) while it is traveling at more than 50 miles per hour through the cold mill. Using feedback or feed-forward systems, a computer's gap sensor adjusts the distance between the reduction rolls of the mill 50-60 times per second. These adjustments prevent the processing of any off-gauge steel sheet.
Automatic Stop - A device which may be attached to any of several parts of a machine tool to stop the operation of the machine at any predetermined point.
Autoradiograph - A radiograph recorded photgraphically by radiation spontaneously emitted by radioisotopes that are produced in or added to the material. This technique identifies the location of the radioisotopes.
Auxiliary Air - A controller for auxiliary air dampers on boilers. For proper combustion on oil fire.
Auxiliary Hydraulic System - Hydraulic system that supplies the force to run the various hydraulic cylinders associated with the finishing mill which are not taken care of by the A.G.C. or C.V.C hydraulic system.
Auxiliary Oil Pump - A steam or electric pump that maintains oil pressure on the controls and the bearings of a turbo blower when it is not up to maximum speed.
Auxilliary Operations - Additional processing steps performed on forgings to obtain properties, such as surface conditions or shapes, not obtained in the regular processing operation.
Auxiliary Pump - Pump on the auxiliary system which supplies the pressure for the system.
AW-100 - The hydraulic oil used in all the hydraulic systems located in the finishing mill oil cellar and the furnace hydraulic system.
AWG (American Wire Gauge) - A system of conventional designations of standard wire diameters. For example, 10 gauge denotes wire of 0.135-inch diameter. In the AWG system, higher numbers designate smaller diameters and lower numbers designate larger diameters.
Axil Rolls - In ring rolling, vertically displaceable frame opposite from but on the same centerline as the main roll and rolling mandrel. The axial rolls control the ring height during the rolling process.
Axis - The line,real or imaginery,passing through the center of an object about which it could rotate; a point of reference.
Abrasion - The process of rubbing, grinding, or wearing away by friction.
Abrasive - A substance capable of grinding away another material.
Acid Steel - Steel melted in a furnace with an acid bottom and lining and under a slag containing an excess of an acid substance such as silica.
Acid-Brittleness - Brittleness resulting from pickling steel in acid; hydrogen, formed by the interaction between iron and acid, is partially absorbed by the metal, causing acid brittleness.
Acid-Process - A process of making steel, either Bessemer, open-hearth or electric, in which the furnace is lined with a siliceous refractory and for which low phosphorus pig iron is required as this element is not removed.
Aging - A change in properties that occurs at ambient or moderately elevated temperatures after hot working or a heat treating operation (quench aging in ferrous alloys), or after a cold working operation (strain aging). The change in properties is often, but not always, due to a phase change (precipitation), but does not involve a change in chemical composition. In a metal or alloy, a change in properties that generally occurs slowly at room temperature and more rapidly at higher temperatures.
Air Cooling - Cooling of the heated metal, intermediate in rapidity between slow furnace cooling and quenching, in which the metal is permitted to stand in the open air.
Air-Hardening Steel - A steel containing sufficient carbon and other alloying elements to harden fully during cooling in air or other gaseous mediums from a temperature above its transformation range. Such steels attain their martensitic structure without going through the quenching process. Additions of chromium, nickel, molybdenum and manganese are effective toward this end. The term should be restricted to steels that are capable of being hardened by cooling in air in fairly large sections, about 2 in. or more in diameter.
Allotriomorph - A particle of a phase that has no regular external shape.
Alloy - A substance having metallic properties and composed of two or more chemical elements of which at least one is a metal.
Alloy Steel - Steel containing substantial quantities of elements other than carbon and the commonly-accepted limited amounts of manganese, sulfur, silicon, and phosphorus. Addition of such alloying elements is usually for the purpose of increased hardness, strength or chemical resistance. The metals most commonly used for forming alloy steels are: nickel, chromium, silicon, manganese tungsten, molybdenum and vanadium, Low Alloy steels are usually considered to be those containing a total of less than 5% of such added constituents.
Alloying Element - An element added to a metal, and remaining in the metal, that effects changes in structure and properties.
Alpha Brass - A copper-zinc alloy containing up to 38% of zinc. Used mainly for cold working.
Alpha Bronze - A copper-tin alloy consisting of the alpha solid solution of tin in copper. Commercial forms contain 4 or 5% of tin. This alloy is used in coinage, springs, turbine, blades, etc.
Aluminizing - Forming an aluminum or aluminum alloy coating on a metal by hot dipping, hot spraying, or diffusion.
Aluminum (Chemical symbol Al) - Element No. 13 of the periodic system; Atomic weight 26.97; silvery white metal of valence 3; melting point 1220 (degrees) F; boiling point approximately 4118 (degrees) F.; ductile and malleable; stable against normal atmospheric corrosion, but attacked by both acids and alkalis. Aluminum is used extensively in articles requiring lightness, corrosion resistance, electrical conductivity, etc. Its principal functions as an alloy in steel making; (1) Deoxidizes efficiently. (2) Restricts grain growth (by forming dispersed oxides or nitrides) (3) Alloying element in nitriding steel.
Aluminum Killed Steel - A steel where aluminum has been used as a deoxidizing agent.
Angstrom Unit - (A) A unit of linear measure equal to 10(-10)m, or 0.1 nm; not an accepted Si unit, but still sometimes used for small distances such as interatomic distances and some wavelengths.
Anisotropy - The characteristics of exhibiting different values of a property in different directions with respect to a fixed reference system in the material.
Annealing - Heating to and holding at a suitable temperature and then cooling at a suitable rate, for such purposes as reducing hardness, improving machinability, facilitating cold working, producing a desired microstructure, or obtaining desired mechanical, physical, or other properties. When applicable, the following more specific terms should be used: black annealing, blue annealing, box annealing, bright annealing, flame annealing, graphitizing, intermediate annealing, isothermal annealing, malleablizing, process annealing, quench annealing, recrystallization annealing, and spheroidizing. When applied to ferrous alloys, the term annealing, without qualification, implies full annealing. When applied to nonferrous alloys, the term annealing implies a heat treatment designed to soften an age-hardened alloy by causing a nearly complete precipitation of the second phase in relatively coarse form. Any process of annealing will usually reduce stresses, but if the treatment is applied for the sole purpose of such relief, it should be designated stress relieving.
Annealing Twin - A twin formed in a metal during an annealing heat treatment.
Anodizing (Aluminum A dic Oxide Coating) - A process of coating aluminum by anodic treatment resulting in a thin film of aluminum oxide of extreme hardness. A wide variety of dye colored coatings are possible by impregnation in process.
Arc Welding - A group of welding processes wherein the metal or metals being joined are coalesced by heating with an arc, with or without the application of pressure and with or without the use of filler metal.
Artifact - In microscopy, a false structure introduced during preparation of a specimen.
Artificial Aging - An aging treatment above room temperature.
ASTM - Abbreviation for American Society For Testing Material. An organization for issuing standard specifications on materials, including metals and alloys.
Atomic-Hydrogen Weld - Arc welding with heat from an arc between two tungsten or other suitable electrodes in a hydrogen atmosphere. The use of pressure and filler metal is optional.
Attenuation - The fractional decrease of the intensity of an energy flux, including the reduction of intensity resulting from geometrical spreading, absorption, and scattering.
Ausenitic Grain Size - The size of the grains in steel heated into the austenitic region.
Austempering - Quenching a ferrous alloy from a temperature above the transformation range, in a medium having a rate of heat abstraction high enough to prevent the formation of high-temperature transformation products, and then holding the alloy, until transformation is complete, at a temperature below that of pearlite formation and above that of martensite formation.
Austenitic Steel - Steel which, because of the presence of alloying elements, such as manganese, nickel, chromium, etc., shows stability of Austenite at normal temperatures.
Austenitizing - Forming austenite by heating a ferrous alloy into the transformation range (partial austenitizing) or above the transformation range (complete austenitizing).
Austentite - A solid solution of one or more elements in face-centered cubic iron.
Autofrettage - Pre-stressing a hollow metal cylinder by the use of momentary internal pressure exceeding the yield strength.
Autoradiograph - A radiograph recorded photographically by radiation spontaneously emitted by radioisotopes that are produced in, or added to, the material. This technique identifies the locations of the radioisotopes.