简介:Cr2O3-formingferriticstainlesssteelshavebeenwidelyexploredasintermediatetemperaturesolidoxidefuelcells(SOFCs)interconnects.However,theevaporationofchromiascalemightmigratetoandpoisonthecathode,leadingtodegradationofthecellperformance.Inthisstudy,Ni-Co-Fe-Pcoatingsweredepositedontheferriticstainlesssteelbymeansofacost-effectivetechniqueofelectrolessmethod.Theyareexpectedtobeconvertedinto(Ni,Co,Fe)3O4spinelwithahighelectricalconductivityandCTEmatchwithstainlesssteel,whichcanblocktheevaporationofchromiaformedonsteelsubstrateexposedtothecathodeenvironmentoftheSOFC.TheeffectsofpH,massratioofFeSO4/(FeSO4+NiSO4+CoSO4)andtemperatureofsolutiononthedepositionrate,compositions,surfacemorphologiesandstructuresoftheNi-Co-Fe-Pcoatingswereinvestigated.TheresultsindicatedthatthedepositionrateincreasedwithincreasingpHwhenpHwaslowerthan9andthenreducedwhenpHwashigherthan9.Thedepositionrateincreasedwithincreasingtemperaturewhentemperaturewaslowerthan80℃andthendecreasedwhentemperaturewashigherthan80℃.ThedepositionratedecreasedwiththeincreaseinmassratioofFeSO4/(NiSO4+CoSO4+FeSO4).ThecoatingsconsistedofNi,Co,FeandP.Thephasestructureofthecoatingwasamorphous.
简介:SomenewNi-saving25Crduplexstainlesssteels(DSS)havebeendeveloped.Theresultsindicatethatthealloyhasabalancedferrite-austeniterelationafterhotforgeandsolidsolutiontreatmentat1000℃.TheelementsWandCuhaveamarkedeffectonthemicrostructureofthealloy.ThepittingpotentialofthesteeladdingWandCuelementsreachesthemaximumvalueof435mV.Thetensilestrengthandpercentageofareareductionofallsteelsinthispaperare800-900MPaand60%-70%,respectively.Thetensileelongationsofthealloysareallabove30%.Theexperimentalsteelshavegoodcorrosionandmechanicalproperty.
简介:ThehotductilityofFe-36NiinvaralloywithdifferentadditionsoftheelementceriumwasinvestigatedusingaGleeble-3800thermal-mechanicalsimulatoroverthetemperaturerange850-1050℃,andtheimprovementmechanismofthehotductilitywasanalyzedusingacombinationofSEM,EDS,andOM.TheresultsindicatedthatFe-36Niinvaralloyexhibitedpoorhotductilitybelow1050℃,whichwasmainlyattributedtoweakgrainboundariesandtheactionofgrainboundarysliding.However,thealloyswithceriumcontentsof0.016%and0.024%bothdemonstratedsubstantialimprovementinthehotductilityovertheentiretestingtemperaturerange.Theobservedimprovementofthehotductilityofthealloywith0.016%ceriumat950℃andthealloywith0.024%ceriumat900℃wasassociatedmainlywiththegrainboundarystrengtheningandtherestrictionofthegrainboundaryslidingbecausetheadditionofceriumreducedthesegregationofsulfuratgrainboundariesandrefinedthegrainstructure.Theoccurrenceandaccelerationofdynamicrecrystallizationwerefoundtoberesponsibleforthehighhotductilityofthealloywith0.016%ceriumat1000℃andthealloywith0.024%ceriumat950-1000℃asaresultoftherefinementofthegrainstructurebyadditionofcerium.
简介:TheeffectofCe,LaandmischmetalonthesolidificationstructureofFe-36Niinvaralloywasinvestigated.Theresultsshowthatgreatamountsofhigh-meltingpointcompounds(Ce2O3,La2O2Sand(Ce,La)2O2S)respectivelyformedinthealloywiththeadditionofCe,Laormischmetal.Basedonthetheoryoflatticemisfit,thelatticemisfitbetweenthe(0001)surfacesofCe2O3,Ce2O2SandLa2O2Sand(100)surfaceofFe-36Niinvaralloywere6.21%,5.77%and5.42%,respectively,whicharerelativelylow.Therefore,Ce2O3,La2O2Sand(Ce,La)2O2Scouldserveasthecoreofheterogeneousnucleation,improvetheequiaxedgrainratio,reducetheequiaxedgrainsizeandrefinethesolidificationstructureofalloy.
简介:Inrecentyears,manyNi-containingmaterialsmanufacturedfromlateritehaveplayedasignificantroleinsupportingtherapiddevelopmentofthestainlesssteelindustryinChina.Currently,pyrometallurgyisthemainprocessforlateritesmelting,whereblastfurnacesareemployedtomakeNi-containinghotmetal.Withtheaimofgivingsomereferencesformakinggooduseoflaterite,technicalandeconomicanalysiswasconductedinthispaper,basedonthediscussionofthekeytechnologiesofNi-containinghotmetalproductionwithlaterite(50.4%Fe)inblastfurnaces.
简介:Inthisstudy,metallographicanalysisandnanoindentationcharacterizationwereusedtoanalyzethepropertiesandmicrostructuresofas-castnitrogenalloyed27Cr-7Ni-4Mosuperduplexstainlesssteel(super-DSS).Theas-castmicrostructureofthesuper-DSSwascharacterizedbyitsferriteandisland-likeaustenitephases.Duringthesolutionannealingprocess,theaustenitevolumepercentageofthesteeldecreasedgraduallywithincreasedannealingtemperature.Asamainelement,thechromiumcontentintheferriticandausteniticphaseselevatedslightlyatfirstthendecreasedwithincreasedannealingtemperature.Thechromiumpartitioncoefficientinthesteelvariedbyaround1.0.Thecontentsofnickel,anothermainalloyelement,alsoincreasedintheferriticandausteniticphaseswithincreasedannealingtemperature,asdidthenickelpartitioncoefficientinthesteel,whichtendedtobecloseto1.0.Thenanoindentationcharacterizationresultsindicatethatthehardnessoftheaustenitephaseisslightlygreaterthanthatoftheferritephase.Theyweresimilartoeachotherwithinacertaintemperaturerangefrom1050℃to1100℃.Thistemperaturerangewasconsistentwiththetemperaturerangeinwhichthecontentratioofthetwophaseswascloseto1∶1.WefoundtheYoung'smodulusoftheferritephasetobegreaterthanthatoftheaustenitephase.Withincreasedannealingtemperature,theYoung'smodulusoftheferritephasedecreasedwhilethatoftheaustenitephaseremainedalmostunchanged.
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。
简介:Themechanicalandcorrosivepropertiesof00Cr13Ni4Mo(S13-4N)weretestedandcomparedwiththoseof00Cr13Ni6Mo(S13-6).Theeffectsofnitrogenonthepropertiesofthesteelswereanalyzed.Theresultsofthetensileandcorrosiontestsshowthestrength,theductility,andthepittingcorrosionresistanceofS13-4Narehigher,lowerandpoorerthanthoseofS13-6respectively,whentemperedatatemperaturebelow550℃andviceversawhenthetemperingtemperatureishigherthan550℃.TheresultsoftheX-raydiffraction(XRD)andtheelectronbackscattereddiffraction(EBSD)analysesrevealthatinversedausteniteappearsat550℃andtheamountofitpeaksat600℃withthebestductility.AndthetotalamountoftheinversedausteniteinS13-6ismorethanthatinS13-4Nindifferentforms.Nitrogenperformsbetterintermsofstabilizinginversedaustenitewhilenickelismorefavorableforforminginversedaustenite,theamountandstabilityofwhichaffecttheductilityremarkably.ThereasonfortheembrittlementofS13-4Nat450℃canbetheresultofcarbideandnitrideprecipitatingatgrainboundaries.
简介:Improvingtheunitheatefficiency,reducingcoalconsumptionandtheemissionofCO2andmeetingtherequirementsofenvironmentalprotectionandenergyconservationisthegoaloftheboilerandthepowerindustry.Developmentsoflargecapacityandhighparameterultra-supercritical(USC)unitsarethetendencyofthepowerindustry.ThereisnodoubtthatthedevelopmentofUSCunitsisbasedonthedevelopmentofmaterials,especiallythematerialsusedforsuper-heaterandreheaterinhigh-temperatureUSCboiler.Duetothelongtimeexposuretotheharshenvironment,suchasbearingthe600℃steamoxidation,andwithstandingthecorrosivefluegasandflyasherosion,thematerialsrequirenotonlygoodhigh-temperaturestrength,butalsoagoodcorrosionresistance.Inconsiderationoftherequirementscitedabove,foreigncountrieshaddevelopedTP310HCbN(07Cr25Ni21CbN)austeniticheat-resistantsteel.However,thedomesticdemandsforthismaterialstilldependonimportandthecostishigh,sotheboilerandthepowerindustryexpectseagerlythatthesesteelscanbeproducedbydomesticmetallurgicalindustry,especiallyBaosteel,toreplacetheimportedproducts.Inordertosatisfytherequirementsofdomesticmanufacturingsuper-heaterandreheaterusedinultra-supercriticalpowerboiler,afterdevelopedT23、T91、T92、S30432highpressureboilertube,BaosteelbegantodevelopTP310HCbN(07Cr25Ni21CbN)austeniticstainlesssteeltubeinJanuaryof2007.Thisstudydescribesthecompositiondesign,themanufacturingprocessofproduct,andtheassessmentofperformanceofBaosteel’sTP310HCbN(07Cr25Ni21CbN).ThedataindicatesthatpropertiesofBaosteel’sTP310HCbN(07Cr25Ni21CbN)conformtotheASMESA-213standardandGB5310standard,soitcansubstitutetheimportedproductsandissuitableformanufacturingpowerstationboilerofgreatcapacityandhighsteamparameters.