Chemical element (Fe), volume 7,85g/cm©è (heavy metal). As a metal softer and higher ductility than steel. Per Euro-Norms pig iron and cast iron are iron alloys with a carbon content of more than 2%.

Any without re-treatment forgeable materials of iron with a carbon content of less then 2% are called steel. Depending on the content of additional alloys there is a differentiation between alloyed steel and unalloyed steel.

Cooling a plate with water immediately following the final rolling operation. Generally the plate is water cooled from about 1400­F to approximately 1100­F.

Steel is considered to be an alloy steel when either (1) the maximum of the range given for the content of alloying elements exceeds one or more of the following percentages: manganese 1.65, silicon 0.60, copper 0.60; or (2) a definite range or definite minimum quantity of those elements considered alloys is specified. For example, chromium, molybdenum and nickel.

A thermal cycle involving 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 or other properties.

alternatively:

This term is often used to define a heat treatment process that produces some softening of the structure.  True annealing involves heating the steel to austenite and holding for some time to create a stable structure.  The steel is then cooled very slowly to room temperature.  This produces a very soft structure, but also creates very large grains, which are seldom desirable because of poor toughness.

The process of forming the austenite phase by heating a ferrous alloy into the transformation range (partial austenitizing above the lower critical temperature) or above this range (complete austenitizing above the upper critical temperature).

A decomposition product of austenite consisting of an aggregate of ferrite and carbide. In general, it forms at temperatures lower than those where very fine pearlite forms, and higher than those where martensite begins to form on cooling.

A measure of hardness determined by the Brinell hardness test, in which a hard steel ball under a specific load is forced into the surface of the test material. The number is derived by dividing the applied load by the surface area of the resulting impression.

As it relates to plates, camber is the horizontal edge curvature in the length, measured over the entire length of the plate.

The most popular technique for solidifying steel. Involves pouring steel into an intermediate tundish before entering a water-cooled copper mold. A solidifying steel strand is drawn through a machine where it continues to cool before exiting the machine.

The gradual degradation of steel caused by atmosphere, moisture or other agents. Can also lead to cracking of various forms, e.g., stress corrosion cracking, hydrogen induced cracking and sulfide stress cracking.

Synonymous with "transformation range," which is the preferred term. See Austenitizing.

The loss of carbon from the surface of steel as a result of heating in a medium that reacts with the carbon.

A process used during melting and refining of steel to remove and/or chemically combine oxygen from the molten steel to prevent porosity in the steel when it is solidified.

The ability of a material to deform plastically without fracturing, usually measured by elongation or reduction of area in a tension test, or, for flat products such as sheet, by height of cupping in an Erichsen test.

The greatest stress a steel can see without permanent deformation.

A measure of ductility, determined by the amount of permanent extension achieved by a tension test specimen, and expressed as a percentage of that specimen's original gauge length (as: 25 percent in 2 inches).

A method for determining the hardenability of steel by water-quenching one end of an austenitized cylindrical test specimen and measuring the resulting hardness at specified distances from the quench end.

The room temperature form of alpha iron, one of the two major constituents of steel (cementite) in which it acts as the solvent to form solid solutions with such elements as manganese, nickel, silicon and, to a small degree, carbon.

A hardening process in which the surface is heated by direct flame impingement and then quenched.

The property of steel that determines the depth and distribution of hardness induced on cooling after austenitizing.

The resistance of a material to plastic deformation. Usually measured in steels by the Brinell, Rockwell or Vickers indentation-hardness test methods.

Portion of the base plate that was heated during a thermal cutting or welding operation.

A technique for solidifying molten steel by pouring it into cast iron ingot molds.

A microconstituent or structure in hardened steel, characterized by an acicular or needle-like pattern, and having the maximum hardness of any of the decomposition products of an austenite.

The metallurgical structure for a steel determined by polishing and etching samples and examining them at high magnifications using light or electron optical methods. Examples include ferrite, pearlite, bainite and martensite.

A thermal treatment consisting of heating to a suitable temperature above the transformation range and then cooling in still air. Usually employed to improve toughness or machinability, or as a preparation for further heat treatment.

A microconstituent of iron and steel consisting of a lamellar aggregate of ferrite and cementite (a compound of iron and carbonÜFe3C).

A process to heat plate prior to thermal cutting or welding to prevent hard areas or cracking.

Occurs in medium carbon and alloy steels during quenching & tempering heat treatment. Proper part design, heat treating and quenching practices will prevent this problem.

A thermal process used to increase the hardness and strength of steel. It consists of austenitizing, then cooling at a rate sufficient to achieve partial or complete transformation to martensite. Tempering involves reheating to a temperature below the transformation range and then cooling at any rate desired. Tempering improves ductility and toughness, but reduces the quenched hardness by an amount determined by the tempering temperature and time.

also see Tempering

A measure of hardness determined by the Rockwell hardness tester, by which a diamond spheroconical penetrator (Rockwell C scale) or a hard steel ball (Rockwell B scale) is forced into the surface of the test material under sequential minor and major loads. The difference between the depths of impressions from the two loads is read directly on the arbitrarily calibrated dial as the Rockwell hardness value.

A prolonged heating of the steel in a controlled-atmosphere furnace at or near the lower critical point, followed by retarded cooling in the furnaces, to produce a lower hardness than can be obtained by regular annealing. 

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A thermal cycle involving heating to a suitable temperature, usually 1000-1200­F, holding long enough to reduce residual stresses from either cold deformation or thermal treatment, and then cooling slowly enough to minimize the development of new residual stresses.

The carbon trapped in the martensite transformation can be released by heating the steel below the A1 transformation temperature.  This release of carbon from nucleated areas allows the structure to deform plastically and relive some of its internal stresses. This reduces hardness and increases toughness, but it also tends to reduce tensile strength.  The degree of tempering is dependant on temperature and time; temperature having the greatest influence. 

also see Quenching & Tempering

The maximum tensile stress in pounds per square inch that a material is capable of sustaining, as developed by a tension test.

A test in which a machined or full-section specimen is subjected to a measured axial load sufficient to cause fracture. The usual information derived includes the elastic properties, ultimate tensile strength, and elongation and reduction of area.

A process for cutting plate steel to size using an oxy-fuel, plasma or laser heat source. Oxidation or burning of steel is initiated by melting with the heat source and then a stream of high parity oxygen continues the reaction.

Any operation involving the heating and cooling of a metal or alloy in the solid state to obtain the desired microstructure or mechanical properties.

Steel with a higher carbon and alloy content. Used to make tools for cutting, forming or otherwise shaping a material into a part or component for a definite use.

An indication of a steel's capacity to absorb energy, particularly in the presence of a notch or a crack.

Those ranges of temperatures within which austenite forms during heating and transforms during cooling.

The temperature at which a change in phase occurs. The term is sometimes used to denote the limiting temperature of a transformation range.

The minimum stress at which a marked increase in strain occurs without an increase in stress, as indicated by a sharp knee in the stress-strain curve.

The stress at which a material exhibits a specified deviation from the proportionality of stress to strain. The deviation is expressed in terms of strain, and in the offset method, usually a strain of 0.2 percent is specified.