Designation:E2818−11StandardPracticeforDeterminationofQuasistaticFractureToughnessofWelds1ThisstandardisissuedunderthefixeddesignationE2818;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1ThispracticeprovidesmethodsforpreparingspecimensfromweldsinmetallicmaterialsandinterpretingsubsequenttestresultswhenusedinconjunctionwithstandardsTestMethodsE1290andE1820forthedeterminationoffracturetoughness.Thefatiguepre-crackingproceduresincludedinthispracticemayalsobeusedtoaidinpreparingstraightpre-cracksforweldspecimensinaccordancewithTestMethodE1681.1.2ThispracticedrawsheavilyfromISO15653:Metallicmaterials–Methodoftestforthedeterminationofquasistaticfracturetoughnessofwelds.AllreferencestoISO12135inthattestmethodshouldbereplacedwiththeapplicableASTMTestMethods(E1820,E1290orE1681).1.3Therecommendedspecimenisasingle-edgebend[SE(B)]withwidth,W,equaltotwicethespecimenthickness,B.AnalternateSE(B)specimenwithW/Bequaltooneandaspan,S,toWratioof4maybeusedbutmayproducedifferenttoughnessvalues.Acompacttension[C(T)]specimenmaybeusedifitcanbedemonstratedthattheanalysisofresultsproperlyaccountsforweld-to-basemetalstrengthmismatcheffectsonfracturetoughness.1.4Therecommendedlimitationonweld-to-basemetalyieldstrengthratiois0.5,σysweldσysbase,1.5(1)Undermatchingwithinthislimitationleadstoconservativeestimatesoffracturetoughness,whileovermatchingmayleadtoanoverestimationofthefracturetoughnessbyupto10%.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2E8/E8MTestMethodsforTensionTestingofMetallicMa-terialsE1290TestMethodforCrack-TipOpeningDisplacem...
