ASTM A941-00a
(Terminology)Standard Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
Standard Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
SCOPE
1.1 This standard is a compilation of definitions of terms related to steel, stainless steel, related alloys, and ferroalloys.
1.2 When a term is used in an ASTM document for which Committee A01 is responsible, it is included herein only when judged, after review by Subcommittee A01.92, to be a generally usable term.
1.3 Some definitions include a discussion section, which is a mandatory part of the definition and contains additional information that is relevant to the meaning of the defined term.
1.4 Definitions of terms specific to a particular standard will appear in that standard and will supersede any definitions of identical terms in this standard.
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NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
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Designation: A 941 – 00a An American National Standard
Terminology Relating to
Steel, Stainless Steel, Related Alloys, and Ferroalloys
This standard is issued under the fixed designation A 941; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
DISCUSSION—Except as required above, it is permissible for carbon
1. Scope
steel specifications to prescribe limits (minimum or maximum, or both)
1.1 This standard is a compilation of definitions of terms
for each specified alloying element, subject to the following restrictions
related to steel, stainless steel, related alloys, and ferroalloys.
for the heat analysis limits in mass percent:
1.2 When a term is used in an ASTM document for which
(a) for wrought carbon steel products, the specified maximum limit is
Committee A-1 is responsible, it is included herein only when not to exceed: 0.10 for aluminum, 0.60 for silicon, and 0.050 for
titanium;
judged, after review by Subcommittee A 01.92, to be a
(b) for carbon steel castings, the specified maximum limit is not to
generally usable term.
exceed: 0.10 for aluminum, 1.00 for silicon, and 0.050 for titanium.
1.3 Definitions of terms specific to a particular standard will
(c) for carbon steels that are required to be rephosphorized, the
appear in that standard and will supersede any definitions of
specified minimum limit for phosphorus is not to be less than 0.040;
identical terms in this standard.
(d) for carbon steels that are required to be resulfurized, the specified
minimum limit for sulfur is not to be less than 0.060;
2. Referenced Documents
(e) for carbon steels that are not required to be rephosphorized or
resulfurized, the specified maximum limit is not to exceed: 0.60 for
2.1 ASTM Standards:
copper, 0.050 for phosphorus, and 0.060 for sulfur; and
E 112 Test Methods for Determining Average Grain Size
(f) for carbon steels that are required to contain boron, copper, or lead,
the specified minimum limit is not to exceed: 0.0005 for boron, 0.35 for
3. Terminology
copper, and 0.25 for lead.
3.1 Definitions of General Terms:
cast analysis—Deprecated term. Use the preferred term heat
alloy steel, n—a steel, other than a stainless steel, that
analysis.
conforms to a specification that requires one or more of the
certificate of compliance, n—in manufactured products,a
following elements, by mass percent, to have a minimum
document that states that the product was manufactured,
content equal to or greater than: 0.30 for aluminum; 0.0008
sampled, tested, and inspected in accordance with the
for boron; 0.30 for chromium; 0.30 for cobalt; 0.06 for
requirements of the specification (including year of issue)
columbium (niobium); 0.40 for copper; 0.40 for lead; 1.65
and any other requirements specified in the purchase order or
for manganese; 0.08 for molybdenum; 0.30 for nickel; 0.60
contract, and has been found to meet such requirements.
for silicon; 0.05 for titanium; 0.30 for tungsten (wolfram);
DISCUSSION—A single document, containing test report information
0.10 for vanadium; 0.05 for zirconium; or 0.10 for any other
and certificate of compliance information, may be used.
alloying element, except sulphur, phosphorus, carbon, and
nitrogen.
cold working, n—mechanical deformation of a metal at
capped steel, n—a rimmed steel in which, during ingot
temperatures below its recrystallization temperature.
solidification, the rimming action was limited by mechanical
defect, n—an imperfection of sufficient magnitude to warrant
or chemical means.
rejection based on the specified requirements.
carbon steel, n—a steel that conforms to a specification that
direct quenching, n—in thermomechanical processing,
prescribes a maximum limit, by heat analysis in mass
quenching immediately following the final hot deformation.
percent, of not more than: 2.00 for carbon and 1.65 for
electronic data interchange, n—the computer to computer
manganese, but does not prescribe a minimum limit for
exchange of business information in a standardized format.
chromium, cobalt, columbium (niobium), molybdenum,
grain size, n—the dimensions of the grains or crystals in a
nickel, tungsten (wolfram), vanadium, or zirconium.
polycrystalline metal, exclusive of twinned regions and
subgrains when present.
DISCUSSION—Grain size is usually estimated or measured on the
This terminology is under the jurisdiction of ASTM Committee A01 on Steel,
cross section of an aggregate of grains, and designated by an ASTM
Stainless Steel, and Related Alloys and is the direct responsibility of Subcommittee
grain size number. (See Test Methods E 112.)
A01.92 on Terminology.
Current edition approved May 10, 2000. Published July 2000. Originally
heat, n—a generic term denoting a specific lot of steel, based
published as A 941 – 95. Last previous edition A 941 – 00.
upon steelmaking and casting considerations.
Annual Book of ASTM Standards, Vol 03.01.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
A 941
DISCUSSION—Where it is necessary to be more definitive, the follow- weighted average analysis of the individual primary heats contained in
ing more specific terms are used: primary heat, multiple heat, and the multiple heat. Two or more molten primary heats sequentially
remelted heat. In product specifications, the term heat generally is strand cast (poured into an oscillating mold) constitute a series of
used, without qualification, to mean the primary, multiple,or re- individual heats, not a multiple heat.
melted heat, whichever is applicable.
plate-as-rolled, n—the quantity of plate product rolled at one
heat analysis, n—the chemical analysis determined by the
time, either from an individual slab or directly from an ingot.
steel producer as being representative of a specific heat of
DISCUSSION—This term does not refer to the surface condition or the
steel.
heat-treatment state of the material; a plate-as-rolled may be in the
heat number, n—the alpha, numeric, or alphanumeric desig-
as-rolled condition, or may have received one or more surface
nator used to identify a specific heat of steel.
treatments or heat treatments, or both.
high-strength low-alloy steel, n—a steel, other than a carbon
primary heat, n—the product of a single cycle of a batch
steel or an interstitial-free steel, that conforms to a speci-
melting process.
fication that requires the minimum content for each specified
alloying element to be lower than the applicable limit in the
DISCUSSION—In the investment casting industry, the term master heat
is used.
definition for alloy steel, and the yield point or yield strength
of the product to be at least 36 ksi or 250 MPa.
remelted heat, n—the product of the remelting of a primary
hot-cold working, n—the mechanical deformation of austen-
heat, in whole or in part.
itic and precipitation hardening steels at a temperature just
DISCUSSION—In the investment casting industry, the term sub-heat is
below the recrystallization temperature to increase the
used.
yield strength and hardness by plastic deformation or pre-
cipitation hardening effects induced by plastic deformation,
residual element, n—in steel, a specified or unspecified
or both.
element, not intentionally added, originating in the raw
hot working, n—mechanical deformation of a metal at tem-
materials, refractories, or surrounding atmospheres used in
peratures above its recrystallization temperature.
steel making.
imperfection, n—a material discontinuity or irregularity that is
rimmed steel, n—a steel that contained sufficient oxygen to
detectable by inspection.
generate carbon monoxide at the boundary between the solid
inspection, n—the process of measuring, examining, testing,
metal and the remaining molten metal during solidification,
gaging, or otherwise comparing the unit of product with the
resulting in an outer layer low in carbon.
applicable requirements.
semikilled steel, n—an incompletely deoxidized steel that
interstitial-free steel, n—a steel that has essentially all of its
contained sufficient oxygen to form enough entrapped car-
carbon and nitrogen chemically combined with stabilization
bon monoxide during solidification to offset solidification
elements rather than being present interstitially.
shrinkage.
specified element, n—in steel, an element controlled to a
DISCUSSION—The heat analysis limits (minimum or maximum, or
specified minimum, maximum, or range, in accordance with
both) that are permitted to be prescribed in interstitial-free steel
specifications are as given in the definition for carbon steel, except that
the requirements of the applicable product specification.
the 0.050 % maximum limit for titanium does not apply.
stainless steel, n—a steel that conforms to a specification that
requires, by mass percent, a minimum chromium content of
killed steel, n—a steel deoxidized to such a level that
10.5 or more, and a maximum carbon content of less than
essentially no reaction occurred between carbon and oxygen
1.20.
during solidification.
steel, n—a material that conforms to a specification that
laser beam welding, n—a welding process that uses a laser
requires, by mass percent, more iron than any other element
beam as the heat source.
and a maximum carbon content of generally less than 2.
lot, n—a definite quantity of product manufactured under
conditions that are considered uniform.
DISCUSSION—The iron content requirement is not normally stated in
low-alloy steel, n—a steel, other than a carbon steel or an the specification and is not normally determined by chemical analysis,
but is taken to be 100 % minus the sum of the mean values permitted
interstitial-free steel, that conforms to a specification that
by the specification for all other elements having a specified range or a
requires the minimum content for each specified alloying
specified maximum. For conformance purposes, this calculated value
element to be lower than the applicable limit in the definition
for iron is compared on an individual basis to the mean values
for alloy steel.
permitted by the specification for each of the other elements having a
manufacturer, n—the organization responsible for the conver-
specified range or a specified maximum. Some chromium-containing
sion of materials into products meeting the requirements of
steels may contain more than 2 % carbon; however, 2 % carbon is
generally considered to be the demarcation between steel and cast iron.
a product specification.
multiple heat, n—two or more molten primary heats,in
strain hardening, n—an increase in hardness and strength of
whole or in part, combined in a common ladle or in a
a metal caused by plastic deformation at temperatures below
common non-oscillating mold.
its recrystallization temperature. (Syn. work hardening)
DISCUSSION—A multiple heat is identified by a single heat number test record, n—a document or electronic record that contains
representative of the multiple heat, or by the individual heat numbers
the observations and derived data obtained by applying a
of the primary heats contained in the multiple heat. The heat
given test method.
analysis of a multiple heat identified by a single heat number is the
A 941
DISCUSSION—This is usually accomplished by using an inert material
test report, n—a document that presents the applicable quali-
in place of the nitriding agent, or by applying a suitable protective
tative or quantitative results obtained by applying one or
coating on the object being heat treated.
more given test methods.
bluing, n—subjecting the scale-free surface of a steel object to
DISCUSSION—A single document, containing test report information
the action of air, steam, or other agents at a suitable
and certificate of compliance information, may be used.
temperature, thereby forming a thin blue film of oxide and
unspecified element, n—in steel, an element not controlled to
improving the object’s appearance and corrosion resistance.
a specified minimum, maximum, or range, in accordance
DISCUSSION—This term is ordinarily applied to sheet, strip, or
with the requirements of the applicable product specifica-
finished parts. It is used also to denote the heating of springs after
tion.
fabrication in order to improve their properties.
3.2 Definitions of Terms Relating to Heat Treatment of
box annealing, n—annealing in a sealed container under
Steels:
conditions that minimize oxidation.
Ac , Ac , Ac , Ac —See transformation temperature.
cm 1 3 4
Ae , Ae , Ae , Ae —See transformation temperature.
cm 1 3 4
DISCUSSION—The charge is usually heated slowly to a temperature
age hardening, n—hardening by aging, usually after rapid
below the transformation range, but sometimes above or within it,
cooling or cold working.
and is then cooled slowly.
aging, n—a change in the properties of certain steels that
bright annealing, n—annealing in a protective medium to
occurs at ambient or moderately elevated temperatures after
prevent discoloration of the bright surface.
hot working or a heat treatment (quench aging, natural
carbon potential, n—the carbon content at the surface of a
aging, or artificial aging) or after a cold-working operation
specimen of pure iron in equilibrium with the carburizing
(strain aging).
medium considered, and under the conditions specified.
DISCUSSION—The change in properties is often, but not always, due to carbon restoration, n—replacing the carbon lost from the
precipitation hardening, but never involves a change in the chemical
surface layer in previous processing by carburizing this layer
composition of the steel.
to substantially the original carbon level.
carbonitriding, n—case hardening in which a suitable steel
annealing, n—a generic term covering any of several heat
object is heated above Ac in a gaseous atmosphere of such
treatments. 1
composition as to cause simultaneous absorption of carbon
DISCUSSION—This treatment is used for purposes such as reducing
and nitrogen by the surface and, by diffusion, to create a
hardness, improving machinability, facilitating cold working, produc-
concentration gradient.
ing a desired microstructure, or obtaining desired mechanical, physical,
carburizing, n—a process in which an austenitized steel object
or other properties. Where applicable, it is preferred that the following
is brought into contact with a carbonaceous environment of
more specific terms be used: black annealing, box annealing, bright
sufficient carbon potential to cause absorption of carbon at
annealing, flame annealing, full annealing, graphitization anneal-
ing, intermediate annealing, isothermal annealing
...
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