ASTM E975-2003 近随机结晶定向钢中残留奥氏体的X射线测定标准实施规程

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【英文标准名称】:StandardPracticeforX-RayDeterminationofRetainedAusteniteinSteelwithNearRandomCrystallographicOrientation
【原文标准名称】:近随机结晶定向钢中残留奥氏体的X射线测定标准实施规程
【标准号】:ASTME975-2003
【标准状态】:现行
【国别】:
【发布日期】:2003
【实施或试行日期】:
【发布单位】:美国材料与试验协会(ASTM)
【起草单位】:E04.11
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:奥氏体;试验;X射线;金相学;工艺;金属;钢;结晶的
【英文主题词】:austenite;crystallographicorientation;ferrite;martensite;retainedaustenite;X-raydiffraction;
【摘要】:Significance8212;Retainedaustenitewithanearrandomcrystallographicorientationisfoundinthemicrostructureofheat-treatedlow-alloy,high-strengthsteelsthathavemedium(0.40weight%)orhighercarboncontents.Althoughthepresenceofretainedaustenitemaynotbeevidentinthemicrostructure,andmaynotaffectthebulkmechanicalpropertiessuchashardnessofthesteel,thetransformationofretainedaustenitetomartensiteduringservicecanaffecttheperformanceofthesteel.Use8212;Themeasurementofretainedaustenitecanbeincludedinlow-alloysteeldevelopmentprogramstodetermineitseffectonmechanicalproperties.Retainedaustenitecanbemeasuredonacompanionsampleortestsectionthatisincludedinaheat-treatedlotofsteelaspartofaqualitycontrolpractice.Themeasurementofretainedausteniteinsteelsfromservicecanbeincludedinstudiesofmaterialperformance.1.1Thispracticecoversthedeterminationofretainedaustenitephaseinsteelusingintegratedintensities(areaunderpeakabovebackground)ofX-raydiffractionpeaksusingchromiumKormolybdenumKX-radiation.1.2Themethodappliestocarbonandalloysteelswithnearrandomcrystallographicorientationsofbothferriteandaustenitephases.1.3Thispracticeisvalidforretainedaustenitecontentsfrom1%byvolumeandabove.1.4Ifpossible,X-raydiffractionpeakinterferencefromothercrystallinephasessuchascarbidesshouldbeeliminatedfromtheferriteandaustenitepeakintensities.1.5Substantialalloycontentsinsteelcausesomechangeinpeakintensitieswhichhavenotbeenconsideredinthismethod.Applicationofthismethodtosteelswithtotalalloycontentsexceeding15weight%shouldbedonewithcare.Ifnecessary,theuserscancalculatethetheoreticalcorrectionfactorstoaccountforchangesinvolumeoftheunitcellsforausteniteandferriteresultingfromvariationsinchemicalcomposition.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:H26
【国际标准分类号】:77_080_20
【页数】:7P.;A4
【正文语种】: