AMS-2759-9

SAETechnicalStandardsBoardRulesprovidethat:“ThisreportispublishedbySAEtoadvancethestateoftechnicalandengineeringsciences.Theuseofthisreportisentirelyvoluntary,anditsapplicabilityandsuitabilityforanyparticularuse,includinganypatentinfringementarisingtherefrom,isthesoleresponsibilityoftheuser.”SAEreviewseachtechnicalreportatleasteveryfiveyearsatwhichtimeitmaybereaffirmed,revised,orcancelled.SAEinvitesyourwrittencommentsandsuggestions.Copyright©2003SAEInternationalAllrightsreserved.Nopartofthispublicationmaybereproduced,storedinaretrievalsystemortransmitted,inanyformorbyanymeans,electronic,mechanical,photocopying,recording,orotherwise,withoutthepriorwrittenpermissionofSAE.TOPLACEADOCUMENTORDER:Tel:[phone](insideUSAandCanada)Tel:[phone](outsideUSA)Fax:[phone]Email:[e-mail]:(Baking)ofSteelParts1.SCOPE:1.1Form:Thisspecificationcoverstherequirementsforembrittlementrelief(baking)ofheattreatedsteelpartstoremovehydrogeninfusedduringplatingandotherchemicalprocessing(e.g.,stripping,chemicalmilling,pickling,andetching).1.2Application:Thisspecificationisapplicabletopartsmadefromcarbon,low-alloy,andmartensiticstainlesssteelheattreatedtoaminimumstrengthof180ksi(1241MPa)orhigherorheattreatedtoaminimumhardnessof40HRCorequivalent,orharder.Itisalsoapplicabletothreadedfastenersmadefromcarbon,low-alloy,ormartensiticstainlesssteelsheattreatedtoaminimumstrengthof150ksi(1034MPa)or34HRCorequivalent,partsmadefromhighstrengthprecipitationhardeningstainlesssteelsotherthanA-286,andsteelpartswhichhavebeencasehardened(carburized,nitrided,nitrocarburized,orcarbonitrided).See8.2.2.APPLICABLEDOCUMENTS:Theissueofthefollowingdocumentsineffectonthedateofthepurchaseorderformsapartofthisspecificationtotheextentspecifiedherein.Thesuppliermayworktoasubsequentrevisionofadocumentunlessaspecificdocumentissueisspecified.Whenthereferenceddocumenthasbeencanceledandnosupersedingdocumenthasbeenspecified,thelastpublishedissueofthatdocumentshallapply.2.1SAEPublications:AvailablefromSAE,400CommonwealthDrive,Warrendale,PA15096-0001or=MessierDowty/5905381001NotforResale,10/11/200521:56:44MDTNoreproductionornetworkingpermittedwithoutlicensefromIHS--``,,``,`,`,,,,,`,`,,``,,,``,,-`-`,,`,,`,`,,`---AMS2759/9BSAEAMS2759/9B-2-3.TECHNICALREQUIREMENTS:3.1Pyrometry:ShallconformtoAMS2750.Temperatureuniformityshallbe±25°F(±14°C).3.2HeatTreatmentEquipment:ShallconformtoAMS2759andrequirementsspecifiedherein.Furnacesshallbecirculating-airtype.3.3Baking(See8.2):Partsshallbebakedaftercompletionofeachplatingorotherchemicalprocessexceptwhennotrequiredafteretchinspection(surfactantadditiontoetchant)andunderthefollowingmultiplestepprocessingconditions:3.3.1Bakingisnotrequiredafterpreplatestrikesandafterthenickelplatefordiffusednickel-cadmium.3.3.2Bakingisnotrequiredbetweenstepsinamultiplestep(plating/chemicalprocess)sequenceifinterruptionsdonotexceedtwohours,bakingisstartedwithinfourhoursafterthefinalstep,andtotaltimebetweenstartoffirststepandstartofbakingdoesnotexceed24hours.3.3.2.1Whentheconditionsof3.3.1or3.3.2arenotmet,bakingisrequiredbutthesoakingtimemaybereducedforpartsotherthanthosecoveredby3.3.2.2.Theminimumsoakingtimeshallbethreehoursforpartsheattreatedtoaminimumstrengthof240ksi(1655MPa)orlower,oraminimumhardnessof49HRCorless;forhigherstrengthorharderparts,theminimumsoakingtimeshallbesixhours.3.3.2.2Fornickelplatedpartsheattreatedtoaminimumstrengthof200ksi(1379MPa)orhigheroraminimumhardnessof43HRC,orequivalent,orharder,noreductionispermitted;bakingsoaktimebetweenstepsshallbeasspecifiedinTable1.3.4Procedure:3.4.1Cleaning:Partsshallbecleanpriortobaking.3.4.2RackingandSpacing:Partsshallbeplacedinracksortrays,madeofmeshorexpandedmetal,orsupportedorsuspendedsoastoallowfreecirculationoftheheatingmedium,exceptsmallpartsmayberandomlyarrangedintraysprovidingthatlayersofpartsarenotthickerthantwoinches(51mm)andthedistancebetweenthelayersisnotlessthantwoinches(51mm).3.4.2.1Thicknessoflayersofsmallpartsrandomlyarrangedintraysmaybegreaterthantwoinches(51mm)providingthattestshavebeenmadewithloadthermocouplestoconfirmthatthecenterofthecoldestloadwillreachthesettemperatureminus25°F(14°C)degreeswithinonehourofloading.CopyrightSAEInternationalProvidedbyIHSunderlicensewithSAELicensee=MessierDowty/5905381001NotforResale,10/11/200521:56:44MDTNoreproductionornetworkingpermittedwithoutlicensefromIHS--``,,``,`,`,,,,,`,`,,``,,,``,,-`-`,,`,,`,`,,`---AMS2759/9BSAEAMS2759/9B-3-TABLE1-MinimumBakingTime(Hours)atStandardTemperatureof375°F(191°C)ExceptWhereIndicatedby*SpecifiedTemper,MinimumStrengthPlatings(9)Platings(9)ChemicalTreatmentsChemicalTreatmentsSteel/PartorMinimumCd&NiPlatings(9)Platings(9)Platings(9)Platings(9)Platings(9)ChemEtchDescriptionHardness(1)Cd-Ti(2)CrAgAuSnZn-Ni(3)(4)AISI1095180ksi(1241MPa)or40HR