Industry Terminology

Age Hardening:
Hardening by aging, usually after rapid cooling.
A change in metallurgical properties that generally occurs slowly at room temperature (natural aging) and more rapidly at higher temperature (artificial aging).
Alloy Steel:
Steel containing significant quantities of alloying elements (other than carbon and the commonly accepted amounts of manganese, silicon, sulfur, and phosphorus) added to effect changes in the mechanical or physical properties.
Heating to and holding at a temperature appropriate for the specific material and then cooling at a suitable rate, for such purpose as reducing hardness, improving machinability, or obtaining desired properties.
The face-centered crystalline phase of iron-base alloys.
Austenitic Steel:
A steel whose microstructure at room temperature consists predominately of austenite.
Forming austenite by heating a ferrous metal to a temperature in the transformation range (partial austenitizing) or above the transformation range (complete austenitizing).
A technique whereby residual compressive stresses are created at the interior of a thick-walled component by application and release of internal pressure that causes yielding to the metal near the ID or bore of the component.
Joining metals by flowing a thin layer (of capillary thickness) of a lower-melting point nonferrous filler metal in the space between them.
Brinell Hardness:
A hardness value obtained by use of a 10mm-diameter hardened steel (or carbide) ball and normally a load of 3,000 kg, in accordance with ASTM E 10.
Smoothing surfaces with frictional contact between the material and some other hard pieces of material, such as hardened steel balls.
Carbon Steel:
An alloy of carbon and iron containing up to 2% carbon and up to 1.65% manganese and residual quantities of other elements, except those intentionally added in specific quantities for deoxidation (usually silicon and/or aluminum). Carbon steels used in the petroleum industry usually contain less that 0.8% carbon.
Case Hardening:
Hardening a ferrous alloy so that the outer portion, or case, is made substantially harder than the inner portion, or core. Typically processes are carburizing, cyaniding, carbonitriding, nitriding, induction hardening, and flame hardening.
Cast Component:
Metal that is obtained at or near its finished shaped by (Casting) solidification of molten metals in a mold.
Charpy Impact Test:
A pendulum-type single-blow impact test in which the specimen (usually notched) is supported at both ends as a simple beam and broken by a falling pendulum. The energy absorbed, as determined by the subsequent rise of the pendulum, is a measure of impact strength or notch toughness.
Check Analysis:
An analysis of the metal after it has been rolled or forged into semi-finished or finished forms. It is not a check on the ladle analysis, but is a check against the chemistry ordered, i.e. Product Analysis.
The Coordinate Measurement Machine used in inspection to determine product conformance.
Cold Working:
Deforming metal plastically under conditions of temperature and strain rate that induce strain hardening, usually, but not necessarily, conducted at room temperature.
Double Tempering:
A treatment in which normalized or quench-hardened steel is given two complete tempering cycles (cooling to a suitable temperature after each cycle) with the second tempering cycle performed at a temperature at or below the first tempering temperature. The object is to temper any martensite that may have formed during the first tempering cycle.
Duplex (Austenitic/Ferritic) Stainless Steel:
A stainless steel whose microstructure at room temperature consists primarily of a mixture of austenite and ferrite.
EDM (Wire and Plunge):
Electric Discharge Machine that uses electrical current to remove or shape steel material.
Elastic Limit:
The maximum stress to which a material may be subjected without any permanent strain remaining upon complete release of stress.
The amount of permanent stretch, usually referring to a measurement of a specimen after fracture is a tensile test. It is expressed as a percentage of the original gauge length.
A body-centered cubic crystalline phase of iron-based alloys.
Ferritic Steel:
A steel whose microstructure at room temperature consists predominantly of ferrite.
Ferrous Metals:
A metal in which the major constituent is iron.
Plastically deforming metal (usually hot) into desired shapes with compressive force, with or without dies.
A measure of the degree of a materialís resistance to indentation. It is usually determined by measuring resistance to penetration, by such tests as Brinell (A, B, & C), Rockwell Hardness Test, Rockwell Superficial Hardness Test, Brinell Hardness Test, Vickers Hardness Test, Microhardness Test, and Mohs Hardness Test.
A Generic term denoting a specific lot of steel, based upon a steel making and casting consideration.
Heat Analysis:
The Chemical Analysis determined by the steel producer as being representative of a specific heat of steel.
Heat Number:
The alpha, numeric, or alphanumeric designator used to identify a specific heat of steel.
Heat Treatment:
Heating and cooling a solid metal or alloy in such a way as to obtain desired conditions or properties.
Heat-Affected Zone:
That portion of the base metal which was not melted during brazing, cutting, or welding, but those microstructure and physical properties were altered by the heat.
The Process of measuring, examining, testing, gauging, or otherwise comparing the unit of product with the applicable requirements.
Ladle Analysis:
Chemical analysis obtained from a sample taken during the pouring of steel, i.e. heat analysis.
A surface defect, appearing as a seam, caused by folding over hot metal, fins, or sharp corners and then rolling or forging them into the surface, but not welding them.
Liquid Dye Penetrant (LP):
Non-destructive test employing a dye or fluorescent chemical and sometimes black light to reveal surface breaking flaws by bleedout of a colored or fluorescent dye from the flaw.
Low-Alloy Steel:
Steel with a total alloying element content of less than about 5%, but more than specified for carbon steel.
Magnetic-Particle Inspection:
A nondestructive method of inspection for determining the existence and extent of possible defects in ferromagnetic materials. Finely, divided magnetic particles, applied to the magnetized part, are attracted to and outline the pattern of any magnetic-leakage fields created by discontinuities.
The organization responsible for the conversion of materials into products meeting the requirements of a product specification.
The structure of a metal as revealed by microscopic examination of a suitably prepared specimen.
Material Test Report
Non Conformance Report
Nonferrous Metals:
A metal in which the major constituent is one other than iron.
Heating a ferrous metal to a suitable temperature above the transformation range (austenitizing), holding at temperature for a suitable time, and then cooling in still air or protective atmosphere to a temperature substantially below the transformation range.
Plastic Deformation:
Permanent deformation caused by stressing beyond the elastic limit.
Positive Material Identification.
Precipitation Hardening:
Hardening a ferrous metal by austenitizing and then cooling rapidly enough so that some or all of the austenite transforms to martensite.
The rapid cooling of a material after a heating operation such as forging or heat treatment.
Rapid Prototyping:
Is the automatic construction of physical objects using solid freeform fabrication. Rapid prototyping takes virtual designs from computer aided design (CAD) or animation modeling software, transforms them into thin, virtual, horizontal cross-sections and then creates each cross-section in physical space, one after the next until the model is finished. It is a WYSIWYG process where the virtual model and the physical model correspond almost identically.
Reduction of Area:
(1) Commonly, the difference, expressed as a percentage of original area, between the original cross-sectional area of a tensile test specimen and the minimum cross-sectional area measured after complete separation. (2) The difference expressed as a percentage of original area, between original cross-sectional area and that after straining the specimen.
Shot Peening:
Inducing compressive stresses in a material's surface layer by bombarding it with a selected medium (usually round steel shot) under controlled conditions.
Solution Anneal:
Heating steel into a temperature range wherein certain elements or compounds dissolve, followed by cooling at a rate sufficient to maintain these elements in solution at room temperature. The expression is normally applied to stainless and other special steels.
Stabilizing Treatment:
Any treatment intended to stabilize the structure of an alloy of the dimensions of a part. Heating austenitic stainless steels that contain titanium, columbium, or tantalum to a suitable temperature below that of a full anneal in order to inactivate the maximum amount of carbon by precipitation as a carbide of titanium, columbium, or tantalum.
Stainless Steel:
A Steel that conforms to a specification that requires, by mass percent, a minimum chromium content of 10.5 or more, and a maximum carbon content of less than 1.20.
A material that conforms to a specification that requires, by mass percent more iron than any other element and a maximum carbon content of generally less than 2.
Stress Corrosion Cracking:
Cracking of metal produced by the combined action of corrosion and tensile stress (residual or applied).
Stress Relieving (Thermal):
Heating a metal to a suitable temperature, holding at that temperature long enough to reduce residual stresses, and then cooling slowly enough to minimize the development of new residual stresses.
Sulfide Stress Cracking:
Brittle failure by cracking under the combined action of tensile stress and corrosion in the presence of water and H2S.
Tensile Strength:
In tensile strength, the ratio of maximum load to original cross-sectional area. Also called ultimate strength.
Tensile Stress:
The net tensile component of all combined stresses-axial or longitudinal, circumferential or "hoop", and residual.
Ultrasonic Testing:
The method of detecting defects or welds by passing high-frequency sound waves into a material, then monitoring and evaluating the reflected signals.
Water Jet:
A tool capable of slicing into metal or other materials using a jet of water at high velocity and pressure, or a mixture of water and an abrasive substance. It is often used during fabrication or manufacture of parts, machinery, and other devices
Metal in the solid condition that is formed to a desired shape by working (Rolling, Extruding, Forging, etc.) usually at an elevated temperature.
Yield Strength:
The stress at which a material exhibits a specified deviation from proportionality of stress to strain. The deviation is expressed in terms of strain by either the offset method (usually at a strain of 0.2%) or total-extension-under-load method (usually at a strain of 0.5%) (See ASTM A370).

Copyright © 2008-2009 Engineering 2 Production, Inc.