SAE-J415-1995-Definitions-Of-Heat-Treating-Terms

SAETechnicalStandardsBoardRulesprovidethat:“ThisreportispublishedbySAEtoadvancethestateoftechnicalandengineeringsciences.Theuseofthisreportisentirelyvoluntary,anditsapplicabilityandsuitabilityforanyparticularuse,includinganypatentinfringementarisingtherefrom,isthesoleresponsibilityoftheuser.”SAEreviewseachtechnicalreportatleasteveryfiveyearsatwhichtimeitmaybereaffirmed,revised,orcancelled.SAEinvitesyourwrittencommentsandsuggestions.QUESTIONSREGARDINGTHISDOCUMENT:[phone]FAX:[phone]TOPLACEADOCUMENTORDER;[phone]FAX:[phone]SAEWEBADDRESS(R)DEFINITIONSOFHEATTREATINGTERMSForeword—ThisDocumenthasnotchangedotherthantoputitintothenewSAETechnicalStandardsBoardFormat.1.Scope—(ThesedefinitionswerepreparedbytheJointCommitteeonDefinitionsofTermsRelatingtoHeatTreatmentappointedbytheAmericanSocietyforTestingandMaterials,TheAmericanSocietyforMetals,theAmericanFoundrymen'sAssociation,andtheSAE.)ThisSAErevisionemphasizesthetermsusedinheattreatingferrousalloys,butalsoincludesforreferencesomenon-ferrousdefinitionsattheendofthedocument.Thisglossaryisnotintendedtobeaspecification,anditshouldnotbeinterpretedassuch.Sincethisisintendedtobestrictlyasetofdefinitions,temperatureshavebeenomittedpurposely.2.References2.1ApplicablePublications—Thefollowingpublicationsformapartofthisspecificationtotheextentspecifiedherein.ThelatestissueofSAEpublicationsshallapply.2.1.1SAEPUBLICATIONS—AvailablefromSAE,400CommonwealthDrive,Warrendale,PA15096-0001.SAEJ418—GrainSizeDeterminationSAEJ763—AgingofCarbonSteelSheetandStripSAEJ940—GlossaryofCarbonSteelSheetandStripTerms3.Definitions3.1Accm,Ac1,Ac3,Ac4——DefinedunderTransformationTemperature.3.2Aecm,Ae1,Ae3,Ae4——DefinedunderTransformationTemperature.3.3AgeHardening—Hardeningbyaging,usuallyafterrapidcoolingorcoldworking.SeeAging.SAEJ415RevisedJUL95-2-3.4Aging—Agenerictermdenotingatime-temperature-dependentchangeinthepropertiesofcertainalloys.Exceptforstrainagingandagesoftening,itistheresultofprecipitationfromasolidsolutionofoneormorecompoundswhosesolubilitydecreaseswithdecreasingtemperature.Foreachalloysystemsusceptibletoaging,thereisauniquerangeoftime-temperaturecombinationstowhichthesystemwillrespond.SeealsoAgeHardening,ArtificialAging,AgeSoftening,NaturalAging,Overaging,PeakAging,PrecipitationHardening,PrecipitationHeatTreatment,QuenchAging,StrainAging,andUnderaging.3.5Annealing—Agenerictermdenotingatreatment,consistingofheatingatanappropriateratetoasuitabletemperature,holdingforanappropriatetime,andcoolingatasuitablerate.Usedprimarilytosoftenmetallicmaterials,butalsotosimultaneouslyproducedesiredchangesinotherpropertiesorinmicrostructure.Thepurposeofsuchchangesmaybe,butisnotconfinedto,oneormoreof:(a)improvementofmachinability;(b)facilitationofcoldwork;(c)improvementofmechanicalorelectricalpropertiesorincreaseinstabilityofdimensions.Thetime-temperaturecyclesusedvarywidelyinheatingrate,maximumtemperatureattained,andincoolingrateemployed,dependingonthecompositionofthematerial,itscondition,andtheresultsdesired.Whenapplicable,thefollowingmorespecificcommercialprocessnamesshouldbeused:BlackAnnealing,BlueAnnealing,BoxAnnealing,BrightAnnealing,CycleAnnealing,FlameAnnealing,FullAnnealing,Graphitizing,In-ProcessAnnealing,IsothermalAnnealing,Malleabilizing,OrientationAnnealing,ProcessAnnealing,QuenchAnnealing,andSpheroidizing.Whenthetermisusedwithoutqualificationfullannealingisimplied.Anyprocessofannealingwillusuallyreducestresses,butwhenappliedonlyforthereliefofstress,theprocessisproperlycalledstressreliefannealing.3.6ArtificialAging—Agingaboveroomtemperature.SeeAgingandPrecipitationHeatTreatment.ComparewithNaturalAging.3.7Ausforming—MechanicallyworkinganappropriatehighhardenabilitysteelafterquenchingfromabovetheuppercriticaltemperaturetoatemperaturebetweenthelowercriticalandtheMstemperature,andisothermallytransformingorquenchingtoproducethedesiredproperties.3.8Austempering—Quenchingaferrousalloyfromatemperatureabovethetransformationrange,inamediumhavingarateofheatextractionsufficienttopreventtheformationofferriteorpearlite,andthenholdingthealloyjustaboveMsuntiltransformationtobainiteiscomplete.3.9Austenitizing—Formingaustenitebyheatingaferrousalloyintothetransformationrange(partialaustenitizing)orabovethetransformationrange(completeaustenitizing).Whenusedwithoutqualification,thetermimpliescompleteaustenitizing.3.10AustenticNitrocarburizing—Alower-temperaturevariantofcarbonitriding,austeniticnitrocarburizingisappliedtoferrousmaterialsattypicalprocessingtemperaturesof676°cto774°C(1250°Fto1425°F).Theprocessinvolvesthediffusionofnitrogenandcarbonintothesurfaceoftheworkpieceandtheformationofathinwhitelayerofepsiloncarbonitrides.Subsurfacemicrostructureincludesmartensiteandbainitewhichimprovetheloadcarryingcapabil