简介：SomenewNi-saving25Crduplexstainlesssteels(DSS)havebeendeveloped.Theresultsindicatethatthealloyhasabalancedferrite-austeniterelationafterhotforgeandsolidsolutiontreatmentat1000℃.TheelementsWandCuhaveamarkedeffectonthemicrostructureofthealloy.ThepittingpotentialofthesteeladdingWandCuelementsreachesthemaximumvalueof435mV.Thetensilestrengthandpercentageofareareductionofallsteelsinthispaperare800-900MPaand60%-70%,respectively.Thetensileelongationsofthealloysareallabove30%.Theexperimentalsteelshavegoodcorrosionandmechanicalproperty.

简介：InordertosuppressthesurfacecrackinginducedbyCuduringreheatingandhotrollingprocess,Cuenrichmentanditsmigrationatthesteel-scaleinterfacewasinvestigatedduringheatingofsteelcastattemperaturesbetween1000℃and1200℃inN2-O2andN7-H2Oatmospheres.ForoxidationofCucontainingsteel,CuenrichedphasewasformedbythepreferentialoxidationofFeandtheenrichmentandmigrationbehaviorofCudependsontheoxidationtemperature,steelchemistryandatmospherecondition.NiinsteelinducedtheformationofsolidCuandNienrichedphaseatsteel/scaleinterfaceandinscalelayerandtheformationofunevensteel/scaleinterface,whichsuppressestheCuenrichmentbecauseofextrusionofCuenrichedregionbeforetheformationofliquidphase.Ontheotherhand,SnadditionpromotestheliquidCuformationatsteel/scaleinterfaceandpenetrationintograinboundaryofCuenrichedphasebydecreasingsolidustemperatureandsolubilitylimit.Inaddition,foroxidationat1200℃,thebehaviorofCuatandaroundthesteel-scaleinterfacewasfounddependenttoalargeextentonmorphologyoftheoxidescaleformedduringoxidation.Attheearlystageofoxidation,Cu-richphaseformedandaccumulatedatthesteelscaleinterfaceunderbothO2-N2andH2O-N2atmospheres.Astheoxidationproceeded,however,Cuenrichmentatanditsmigrationfromthesteel-scaleinterfacewerevastlydifferentfordifferentoxidizingatmospheres.InthecaseofO2-N2oxidation,anoxidelayerformedinitiallyatthesteelsurface,butsoonafteragapwasdevelopedatthesteel-scaleinterfaceandgrewinitssize,whichpracticallyseparatedthescalefromthesteelsubstrate.Thescalelayerformedunderthisconditionwasporous.TheCu-richphaseinitiallyformedattheinterfacewasfoundmigratingtothescalelayer,leavingnoCu-richphaseattheinterface.InthecaseofH2O-N2oxidation,however,thescalelayerformedwasdenseandtightlyattachedtothesteelsurface,andtheCurich-phasecontinuedto

简介：CuprecipitationbehaviorsintwoCu-bearingausteniticantibacterialstainlesssteels,type304andtype317L,weresystematicallystudiedbyusingrelativelysimplemethodsformaterialsanalysis,includingmicro-hardness,electricalresistivity,electrochemicalimpedancespectroscopy,X-raydiffractionanddifferentialscanningcalorimetry.Theresultsindicatedthatafteragingatelevatedtemperature,themicro-hardness,electricalresistivity,electrochemicalimpedanceandlatticeconstantofthesteelwereallvariedatdifferentdegreesduetotheprecipitationandgrowthofCu-richphases.TheresultsalsoshowedthattheheatevolutionduringtheprocessofCuprecipitationcouldbesensitivelydetectedbymeansofdifferentialscanningcalorimetry,obtainningthestartingtemperature,peaktemperature,peakareaoftheCu-richprecipitation,andeventheactivationenergybycalculation.TheresultsconfirmedthattheCu-richphasedprecipitationintheCu-bearingausteniticantibacterialstainlesssteelshouldbeathermalactivationprocesscontrolledbyCudiffusion.AllthematerialsanalysismethodsusedinthisstudycanbemoresimpleandeffectiveforapplicationinR&DoftheCu-bearingantibacterialstainlesssteels.

简介：Thereisanincreasingtrendforproducingcopper-containingsteels,withcopperbeingeitheraresidualelementfromscrapsoranintentionaladdition,i.e.,inweatheringsteel.Theissueofsurfacehotshortnessoccursduringthehotworkingofsteelscontainingcopper,andasignificantamountofworkhasbeenperformedonthistopic.Thispaperprovidesareviewofrelatedstudiesonthisphenomenon.Theformationmechanism,asanalyzed,istheliquidmetalembrittlementcausedbytheliquidcopperpenetrationintoaustenitegrainboundariesatthemetalsurface,wherethecopperoriginatesfromtheselectiveoxidationofthesteelathightemperature.Onthebasisofthemechanism,moreimportanceisplacedonanalyzingtheeffectonthephenomenonbyvaryingthecontrollingfactors,includingtheheatingprocess,alloyingadditions,anddeformationconditions.Possiblesolutionstotheproblemarefinalized,andsomefurtherworkmustbeperformedinthefuture.

简介：Withpricesformetalresourcessuchasnickelandmolybdenumsoaring,thereisaheightenedsenseofcrisisconcerningresourcescarcity.WhileType304,themostcommonstainlesssteel,offersexcellentcorrosionresistance,itspriceisaffectedsignificantlybythecostofnickelbecauseofits8%nickelcontent.ThestainlesssteelthathasthesamecorrosionresistanceasthatofType304anddoesnotcontainnickelandmolybdenumhasbeenrequired.JFESteelCorporationhasdevelopedanew21%Cr-0.4%Custainlesssteel,theworld’sfirstferriticstainlesssteel,whichoffersequivalentcorrosionresistancetoType304whilecontainingabsolutelynonickelormolybdenum,tworaremetals.Thenewlydevelopedsteelcontains21%chromiumwiththeadditionof0.4%copper.Thedevelopmentofthesteelisbasedonanewdiscoverythatthepassivefilmsofstainlesssteelscouldbestrengthenedbythesynergyeffectofhighchromiumcontentandcopperaddition.Copperadditionenrichesthechromiumcontentinpassivefilmsafterfieldexposure.Newlydeveloped21%Cr-0.4%CustainlesssteelisadoptedformanyapplicationsasasubstitutionforType304,includingcommercialkitchenware,buildingmaterialsandindustrialmachinery.ThesteelisexpectedtobeanewstandardofaferriticstainlesssteelasasubstitutionforType304.

简介：通过铁水脱硫→转炉→RH真空精炼→连铸→热轧→酸洗→冷轧→罩退→平整→重卷→消除应力退火等生产工艺,采用C≤0.003%,Si+Als≤1.80%成分体系,成功开发出无取向半工艺电工钢50W300牌号。消除应力退火后产品铁损值P15/50达到2.75w/kg,磁感应强度B5000达到1.68T,达到国标50W300牌号磁性要求。对比实验炉820℃和850℃消除应力退火后磁性能值,850℃消除应力退火后铁损值优于820℃消除应力退火后的铁损值,磁感强度变化不大。工业炉内800℃消除应力退火磁性能值优于实验炉820℃和850℃消除应力退火磁性能值。