ASTM E1290-2008e1 测量裂缝尖端开口位移(CTOD)断裂韧度测量的标准试验方法

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【英文标准名称】:StandardTestMethodforCrack-TipOpeningDisplacement(CTOD)FractureToughnessMeasurement
【原文标准名称】:测量裂缝尖端开口位移(CTOD)断裂韧度测量的标准试验方法
【标准号】:ASTME1290-2008e1
【标准状态】:现行
【国别】:美国
【发布日期】:2008
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:E08.07
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:Bendtesting--metallicmaterials;Brittleness;Clipgagedisplacement;Cracking--metallicmaterials;Crack-tipopeningdisplacement(CTOD);Crossheaddisplacement;CTODvalues;C(T)specimentesting;Displacement--metals/alloys;Ductility--metals/alloys;
【摘要】:Thistestmethodcharacterizesthefracturetoughnessofmaterialsthroughthedeterminationofcrack-tipopeningdisplacement(CTOD)atoneofthreeevents:(a)onsetofunstablecrackextensionwithoutsignificantpriorstablecrackextension,or(b)onsetofunstablecrackextensionwithsignificantpriorstablecrackextension,or(c)theend-of-testaftersignificantslowstablecrackextension.ThistestmethodmayalsobeusedtocharacterizethetoughnessofmaterialsforwhichthepropertiesandthicknessofinterestprecludethedeterminationofKlcfracturetoughnessinaccordancewithTestMethodE399.ThedifferentvaluesofCTODdeterminedbythistestmethodcanbeusedtocharacterizetheresistanceofamaterialtocrackinitiationandearlycrackextensionatagiventemperature.ThevaluesofCTODmaybeaffectedbyspecimendimensions.IthasbeenshownthatvaluesofCTODdeterminedonSE(B)specimensusingthesquaresectiongeometrymaynotbethesameasthoseusingtherectangularsectiongeometry,andmaydifferfromthoseobtainedwitheithertheC(T)orA(B)specimens.ThevaluesofCTODdeterminedbythistestmethodmayservethefollowingpurposes:Inresearchanddevelopment,CTODtestingcanshowtheeffectsofcertainparametersonthefracturetoughnessofmetallicmaterialssignificanttoserviceperformance.Theseparametersincludematerialcomposition,thermo-mechanicalprocessing,welding,andthermalstressrelief.CTODtestingmaybeusedinspecificationsofacceptanceandmanufacturingqualitycontrolofbasematerials,weldmetals,andweldheataffectedzones.PreviousversionsofTestMethodE1290madeeffectiveuseofthevalueofCTODatthefirstattainmentofamaximumforceplateauforsuchpurposes.Qualitativecomparisonsofthistypecanonlybemadeifaconsistentspecimengeometryisusedandthematerialscomparedhavesimilarconstitutiveproperties.ThevalueofCTODatthefirstattainmentofamaximumforceplateauwasremovedfromthistestmethodbecauseiswasnotassociatedwithameasurementofcrackextensionandthereforecannotbeconsideredameasurementoffracturetoughness.Thex03B4;eotvaluemaybeusedinplaceofthevalueofCTODatthefirstattainmentofamaximumforceplateauforqualitycontrolandspecifications.Thex03B4;candx03B4;eotvaluesfromCTODtestingcanbeusedforinspectionandflawassessmentcriteria,whenusedinconjunctionwithotherstandardssuchasTestMethodsE1921andE1820andinformedfracturemechanicsanalyses.Awarenessofdifferencesthatmayexistbetweenlaboratorytestandfieldconditionsisrequiredtomakeproperflawassessment(see4.3and4.4).1.1Thistestmethodcoversthedeterminationofcriticalcrack-tipopeningdisplacement(CTOD)valuesatoneormoreofseveralcrackextensionevents,andmaybeusedtomeasurecleavagecrackinitiationtoughnessformaterialsthatexhibitachangefromductiletobrittlebehaviorwithdecreasingtemperature,suchasferriticsteels.Thistestmethodappliesspecificallytonotchedspecimenssharpenedbyfatiguecracking.Therecommendedspecimensarethree-pointbend[SE(B)],compact[C(T)],orarc-shapedbend[A(B)]specimens.Theloadingrateisslowandinfluencesofenvironment(otherthantemperature)arenot......
【中国标准分类号】:H22
【国际标准分类号】:77_040_10
【页数】:15P.;A4
【正文语种】:英语