Designation:A844/A844M−09(Reapproved2015)StandardSpecificationforSteelPlates,9%NickelAlloy,forPressureVessels,ProducedbytheDirect-QuenchingProcess1ThisstandardisissuedunderthefixeddesignationA844/A844M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thisspecificationcovers9%nickel-alloysteelplatesproducedbythedirect-quenchingprocess.Theplatesareintendedprimarilyforuseinweldedpressurevessels.1.2Thedirect-quenchingprocessconsistsofquenchingtheplatesdirectlyafterrolling,withoutpermittingtheplatestocoolbelowthecriticaltemperaturepriortoinitiationofthequenchingoperation,andsubsequentlytemperingtheplates.(Thisdiffersfromthe“conventional”processinwhichtheplatesarepermittedtocooltoatemperaturesignificantlybelowthecriticaltemperature,usuallytoambienttemperature,priortoreheatingtoatemperatureabovetheuppercriticaltemperature,thenquenching,andsubsequentlytempering.)1.3Themaximumnominalthicknessofplatesfurnishedunderthisspecificationshallnotexceed2in.[50mm].1.4Thismaterialissusceptibletomagnetization.Useofmagnetsinhandlingafterheattreatmentshouldbeavoidedifresidualmagnetismwouldbedetrimentaltosubsequentfabri-cationorservice.1.5Thevaluesstatedineitherinch-poundorSIunitsaretoberegardedseparatelyasstandard.Withinthetext,theSIunitsareshowninbrackets.Thevaluesstatedineachsystemarenotexactequivalents;thereforeeachsystemmustbeusedinde-pendentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnonconformancewiththespecification.2.ReferencedDocuments2.1ASTMStandards:2A20/A20MSpecificationforGeneralRequirementsforSteelPlatesforPressureVesselsA435/A435MSpecificationforStraight-BeamUltrasonicExaminationofSteelPlatesA577/A577MSpecificationforUltrasonicAngle-BeamEx-aminationofSteelPlatesA578/A578MSpecificationforStraight-BeamUltrasonicExaminationofRolledSteelPlatesfor...
