ASTM A941-2018 Standard Terminology Relating to Steel Stainless Steel Related Alloys and Ferroalloys.pdf

1、Designation: A941 18Standard Terminology Relating toSteel, Stainless Steel, Related Alloys, and Ferroalloys1This standard is issued under the fixed designation A941; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last

2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This standard is a compilation of definitions of termsrelated to steel, stainless steel, related alloys, and ferroalloys.1.

3、2 When a term is used in an ASTM document for whichCommittee A01 is responsible, it is included herein only whenjudged, after review by Subcommittee A01.92, to be a gener-ally usable term.1.3 Some definitions include a discussion section, which isa mandatory part of the definition and contains addit

4、ionalinformation that is relevant to the meaning of the defined term.1.4 Definitions of terms specific to a particular standard willappear in that standard and will supersede any definitions ofidentical terms in this standard.1.5 This international standard was developed in accor-dance with internat

5、ionally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E112 Tes

6、t Methods for Determining Average Grain Size3. Terminology3.1 Definitions of Terms Specific to This Standard:Accm, Ac1, Ac3, Ac4See transformation temperature.Aecm, Ae1, Ae3, Ae4See transformation temperature.age hardening, nhardening by aging, usually after rapidcooling or cold working.age hardenin

7、g, nsee precipitation hardening.aging, na change in the properties of certain steels thatoccurs at ambient or moderately elevated temperatures afterhot working or a heat treatment (quench aging, naturalaging, or artificial aging) or after a cold-working operation(strain aging).DISCUSSIONThe change i

8、n properties is often, but not always, due toprecipitation hardening, but never involves a change in the chemicalcomposition of the steel.alloy steel, na steel, other than a stainless steel, thatconforms to a specification that requires one or more of thefollowing elements, by mass percent, to have

9、a minimumcontent equal to or greater than: 0.30 for aluminum; 0.0008for boron; 0.30 for chromium; 0.30 for cobalt; 0.40 forcopper; 0.40 for lead; 1.65 for manganese; 0.08 for molyb-denum; 0.30 for nickel; 0.06 for niobium (columbium); 0.60for silicon; 0.05 for titanium; 0.30 for tungsten (wolfram);0

10、.10 for vanadium; 0.05 for zirconium; or 0.10 for any otheralloying element, except sulphur, phosphorus, carbon, andnitrogen.annealing, na generic term covering any of several heattreatments.DISCUSSIONThis treatment is used for purposes such as reducinghardness, improving machinability, facilitating

11、 cold working, produc-ing a desired microstructure, or obtaining desired mechanical, physical,or other properties. Where applicable, it is preferred that the followingmore specific terms be used: box annealing, bright annealing, fullannealing, intermediate annealing, isothermal annealing, processann

12、ealing, spheroidizing, and subcritical annealing. The term“annealing,” without qualification, implies full annealing. Any pro-cess of annealing will usually reduce stresses; however, if thetreatment is applied for the sole purpose of stress reduction, it should bedesignated stress relieving.Arcm, Ar

13、1, Ar3, Ar4See transformation temperature.artificial aging, naging above room temperature.atmospheric corrosion resistance, nthe ability to resistdegradation or alteration of material through chemical reac-tion with the surrounding atmosphere.DISCUSSIONThis term generally pertains to carbon steel, l

14、ow alloysteel, or micro-alloyed steel.austempering, nheat treatment involving quenching asteel object from a temperature above the transformationrange in a medium maintained at a temperature above themartensite range sufficiently fast to avoid the formation of1This terminology is under the jurisdict

15、ion of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.92 on Terminology.Current edition approved June 1, 2018. Published July 2018. Originally approvedin 1995. Last previous edition approved in 2017 as A941 17. DOI: 10.1520/A0941-18

16、.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box

17、C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the

18、 World Trade Organization Technical Barriers to Trade (TBT) Committee.1high temperature transformation products, and then holdingit at that temperature until transformation is complete.austenitizing, nforming austenite by heating a steel objectabove the transformation range.baking, nheating to a low

19、 temperature in order to removegases.batch furnace, na heating device within which steel objectsare held stationary or oscillated during the thermal process-ing cycle.blank carburizing, nsimulating the carburizing operationwithout introducing carbon.DISCUSSIONThis is usually accomplished by using an

20、 inert materialin place of the carburizing agent, or by applying a suitable protectivecoating on the object being heat treated.blank nitriding, nsimulating the nitriding operation withoutintroducing nitrogen.DISCUSSIONThis is usually accomplished by using an inert materialin place of the nitriding a

21、gent, or by applying a suitable protectivecoating on the object being heat treated.bluing, nsubjecting the scale-free surface of a steel object tothe action of air, steam, or other agents at a suitabletemperature, thereby forming a thin blue film of oxide andimproving the objects appearance and corr

22、osion resistance.DISCUSSIONThis term is ordinarily applied to sheet, strip, orfinished parts. It is used also to denote the heating of springs afterfabrication in order to improve their properties.box annealing, nannealing in a sealed container underconditions that minimize oxidation.DISCUSSIONThe c

23、harge is usually heated slowly to a temperaturebelow the transformation range, but sometimes above or within it,and is then cooled slowly.bright annealing, nannealing in a protective medium toprevent discoloration of the bright surface.capped steel, na rimmed steel in which, during ingotsolidificati

24、on, the rimming action was limited by mechanicalor chemical means.carbon potential, nthe carbon content at the surface of aspecimen of pure iron in equilibrium with the carburizingmedium considered, and under the conditions specified.carbon restoration, nreplacing the carbon lost from thesurface lay

25、er in previous processing by carburizing this layerto substantially the original carbon level.carbon steel, na steel that conforms to a specification thatprescribes a maximum limit, by heat analysis in masspercent, of not more than: 2.00 for carbon and 1.65 formanganese, but does not prescribe a min

26、imum limit forchromium, cobalt, molybdenum, nickel, niobium(columbium), tungsten (wolfram), vanadium, or zirconium.DISCUSSIONExcept as required above, it is permissible for carbonsteel specifications to prescribe limits (minimum or maximum, or both)for each specified alloying element, subject to the

27、 following restrictionsfor the heat analysis limits in mass percent:(a) for wrought carbon steel products, the specified maximum limit isnot to exceed: 0.10 for aluminum, 0.60 for silicon, and 0.050 fortitanium;(b) for carbon steel castings, the specified maximum limit is not toexceed: 0.10 for alum

28、inum, 1.00 for silicon, and 0.050 for titanium.(c) for carbon steels that are required to be rephosphorized, thespecified minimum limit for phosphorus is not to be less than 0.040;(d) for carbon steels that are required to be resulfurized, the specifiedminimum limit for sulfur is not to be less than

29、 0.060;(e) for carbon steels that are not required to be rephosphorized orresulfurized, the specified maximum limit is not to exceed: 0.60 forcopper, 0.050 for phosphorus, and 0.060 for sulfur; and(f) for carbon steels that are required to contain boron, copper, or lead,the specified minimum limit i

30、s not to exceed: 0.0005 for boron, 0.35 forcopper, and 0.25 for lead.carbonitriding, ncase hardening in which a suitable steelobject is heated above Ac1in a gaseous atmosphere of suchcomposition as to cause simultaneous absorption of carbonand nitrogen by the surface and, by diffusion, to create aco

31、ncentration gradient.carburizing, na process in which an austenitized steel objectis brought into contact with a carbonaceous environment ofsufficient carbon potential to cause absorption of carbon atthe surface and, by diffusion, to create a concentrationgradient.case, nin case hardening, the outer

32、 portion that has beenmade harder than the core as a result of altered compositionor microstructure, or both, from treatments such ascarburizing, nitriding, and induction hardening.case hardening, na generic term covering any of severalprocesses applicable to steel that change the chemicalcompositio

33、n or microstructure, or both, of the surface layer.DISCUSSIONThe processes commonly used are: carburizing andquench hardening; nitriding; and carbonitriding. It is preferred thatthe applicable specific process name be used.cast analysisDeprecated term. Use the preferred term heatanalysis.cementation

34、, nthe introduction of one or more elements intothe outer portion of a steel object by means of diffusion athigh temperature.certificate of compliance, nin manufactured products,adocument that states that the product was manufactured,sampled, tested, and inspected in accordance with therequirements

35、of the specification (including year of issue)and any other requirements specified in the purchase order orcontract, and has been found to meet such requirements.DISCUSSIONA single document, containing test report informationand certificate of compliance information, may be used.certifying organizat

36、ion, nin product specifications, theentity responsible for the conformance and certification ofthe product to the specification requirements.check analysisDeprecated term. Use the preferred termproduct analysis.coarse grain practice, na steelmaking practice for otherthan stainless steel that is inte

37、nded to produce a killed steelin which aluminum, niobium (columbium), titanium, andvanadium are residual elements.A941 182cold working, nmechanical deformation of a metal attemperatures below its recrystallization temperature.cold treatment, nexposing a steel object to temperaturesbelow room tempera

38、ture for the purpose of obtaining desiredconditions or properties, such as dimensional or structuralstability.conditioning heat treatment, na preliminary heat treat-ment used to prepare a steel object for a desired reaction toa subsequent heat treatment.continuous-conveyance furnace, na heating devi

39、ce throughwhich steel objects are intentionally moved at a constant rateduring the thermal processing cycle.controlled cooling, ncooling a steel object from an elevatedtemperature in a predetermined manner to avoid hardening,cracking, or internal damage, or to produce a desiredmicrostructure or mech

40、anical properties.controlling cross section thickness (Tc), ndiameter of thelargest theoretical sphere that can be inscribed within thevolume of the component.DISCUSSIONThe controlling cross section thickness (Tc) is used todetermine the size of prolongations, test blocks, or representative testpiec

41、es. It is calculated based on the dimensions of the component at thetime of heat treatment. Where components are heat treated with internaldiameters the calculation is made based on the wall thickness.core, nin case hardening, the interior portion of unalteredcomposition or microstructure, or both,

42、of a case hardenedsteel object.core, nin clad products, the central portion of a multilayercomposite metallic material.critical cooling rate, nthe slowest rate of continuous coolingat which austenite can be cooled from above the transfor-mation range to prevent its transformation above Ms.cycle anne

43、aling, nannealing employing a predeterminedand closely controlled time-temperature cycle to producespecific properties or a specific microstructure.decarburization, nthe loss of carbon from the surface of asteel object as a result of its being heated in a medium thatreacts with the carbon.defect, na

44、n imperfection of sufficient magnitude to warrantrejection based on the specified requirements.differential heating, nheating that intentionally produces atemperature gradient within a steel object such that, aftercooling, a desired stress distribution or variation in proper-ties is present within t

45、he object.diffusion coating, nany process whereby a base metal iseither coated with another metal and heated to a sufficienttemperature in a suitable environment, or exposed to agaseous or liquid medium containing the other metal,thereby causing diffusion of the coating or other metal intothe base m

46、etal, with a resultant change in the compositionand properties of its surface.direct quenching, nin thermochemical processing, quench-ing immediately following the thermochemical treatment.direct quenching, nin thermomechanical processing,quenching immediately following the final hot deformation.doc

47、ument, na written, printed, or electronic record thatprovides information, evidence, or official statements.double aging, nemployment of two different agingtreatments, in sequence, to control the type of precipitateformed from a supersaturated alloy matrix in order to obtainthe desired properties.DI

48、SCUSSIONThe first aging treatment, sometimes referred to asintermediate or stabilizing, is usually carried out at a higher tempera-ture than the second.double tempering, na treatment in which a quench-hardened steel object is given two complete temperingcycles at substantially the same temperature f

49、or the purposeof ensuring completion of the tempering reaction and pro-moting stability of the resultant microstructure.electronic data interchange, nthe computer to computerexchange of business information in a standardized format.ellipsis, nin a tabular entry, three periods (.) that indicatethat there is no requirement.ferritizing anneal, na heat treatment that produces apredominantly ferritic matrix in a steel object.ferroalloy, nan alloy of iron and one or more other metals,for use as an addition to the molten