Designation:A602−94(Reapproved2014)StandardSpecificationforAutomotiveMalleableIronCastings1ThisstandardisissuedunderthefixeddesignationA602;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thisspecificationcoverscastingsofferritic,pearlitic,temperedpearlitic,andtemperedmartensiticgradesofmal-leableironusedintheproductsoftheautomotiveandalliedindustries.Castingsshallbeheattreatedtomeetthisspecifi-cation.1.2Thevaluesstatedininch-poundunitsaretoberegardedasstandard.ThevaluesgiveninparenthesesaremathematicalconversionstoSIunitsthatareprovidedforinformationonlyandarenotconsideredstandard.2.ReferencedDocuments2.1ASTMStandards:2E10TestMethodforBrinellHardnessofMetallicMaterials3.Grades3.1ThespecifiedgradeswithrequiredhardnessrangeandfinalheattreatmentareshowninTable1.3.2ThefoundrymayalsoproduceGradesM4504andM5003byliquidquenchingandtemperingoralloying,orboth.4.Hardness4.1Thefoundryshallexercisethenecessarycontrolsandinspectionprocedurestoensurecompliancewiththespecifiedhardnessrange.HardnessreadingsshallbetakeninaccordancewithTestMethodE10aftersufficientmaterialhasbeenremovedfromthecastingsurfacetoensurerepresentativehardnessreadings.Theareaorareasonthecastingwherehardnessistobecheckedshallbeestablishedbyagreementbetweensupplierandpurchaserandshownonthedrawing.5.MicrostructureRequirements5.1GradeM3210FerriticMalleableIron:5.1.1ThemicrostructureofGradeM3210malleableironshallconsistoftemper-carbonnodulesdistributedinamatrixofferrite.5.1.2Becauseofreactionwiththeannealingfurnaceatmosphere,somedepletionofcarbonandsiliconoccursatthesurfaceofthecastings.Thisusuallyresultsinarimwhichcanconsistofcoarselamellarpearliteunderlyingagraphite-freeferriticsurfacelayer.Ifthepearlitelayerisexcessive,itcanresultinpoormachinability.Therim,therefore,shallnotexceedadepthgreat...
