Designation:A768/A768M−05(Reapproved2015)StandardSpecificationforVacuum-Treated12%ChromiumAlloySteelForgingsforTurbineRotorsandShafts1ThisstandardisissuedunderthefixeddesignationA768/A768M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope1.1Thisspecificationcoversvacuum-treated12%chro-miumsteelforgingsforturbinerotorsandshafts.1.2ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnon-conformancewiththestandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2A275/A275MPracticeforMagneticParticleExaminationofSteelForgingsA370TestMethodsandDefinitionsforMechanicalTestingofSteelProductsA418/A418MPracticeforUltrasonicExaminationofTur-bineandGeneratorSteelRotorForgingsA472/A472MSpecificationforHeatStabilityofSteamTur-bineShaftsandRotorForgingsA788/A788MSpecificationforSteelForgings,GeneralRe-quirements3.OrderingInformation3.1InadditiontotheorderinginformationrequiredbySpecificationA788/A788M,thepurchasershallincludewiththeinquiryandorderadetaileddrawing,sketch,orwrittendescriptionoftheforging,includingthemechanicaltestspecimenlocation.4.GeneralRequirements4.1MaterialsuppliedtothisspecificationshallconformtotherequirementsofSpecificationA788/A788Mwhichoutlinesadditionalorderinginformation,manufacturingrequirements,testingandretestingmethodsandprocedures,marking,certification,produ...
