Designation:B661−12StandardPracticeforHeatTreatmentofMagnesiumAlloys1ThisstandardisissuedunderthefixeddesignationB661;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheDepartmentofDefense.1.Scope*1.1Thispracticeisintendedasanaidinestablishingasuitableprocedurefortheheattreatmentofmagnesiumalloystoassureproperphysicalandmechanicalproperties.1.2Timesandtemperaturesaretypicalforvariousforms,sizes,andmanufacturingmethodsandmaynotexactlyde-scribetheoptimumheattreatmentforaspecificitem.Consequently,itisnotintendedthatthispracticebeusedasasubstituteforadetailedproductionprocessorprocedure.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2B557TestMethodsforTensionTestingWroughtandCastAluminum-andMagnesium-AlloyProductsE21TestMethodsforElevatedTemperatureTensionTestsofMetallicMaterialsE527PracticeforNumberingMetalsandAlloysintheUnifiedNumberingSystem(UNS)3.Terminology3.1DefinitionsofTermsSpecifictoThisStandard:3.1.1aging—Describesatime-temperature-dependentchangeinthepropertiesofcertainalloys.Exceptforstrainagingandagesoftening,itistheresultofprecipitationfromasolidsolutionofoneormorecompoundswhosesolubilitydecreaseswithdecreasingtemperature.Foreachalloysuscep-tibletoaging,thereisauniquerangeoftime-temperaturecombinationstowhichitwillrespond.3.1.2heattreatment—Acombinationofheatingandcoolingoperationsappliedtoametaloralloyinthesolidstatetoobtaindesiredconditionsofproperties.Heatingforthesolepurposeofhotworkingisexcludedfromthemeaningofthisdefinition.3.1.3solutionheattreatment—Atreatmentinwhi...
