学科分类
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201 个结果
  • 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℃.Thistemperaturerangewasconsistentwiththetemperaturerangeinwhichthecontentratioofthetwophaseswascloseto11.WefoundtheYoung'smodulusoftheferritephasetobegreaterthanthatoftheaustenitephase.Withincreasedannealingtemperature,theYoung'smodulusoftheferritephasedecreasedwhilethatoftheaustenitephaseremainedalmostunchanged.

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  • 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.

  • 标签: 回火性能 氮化物 马氏体不锈钢 奥氏体形成 电子背散射衍射 合金
  • 简介:Inthelastthreedecadesnewstrongermodified9%Crsteelshavebeenintroducedinnewpowerplantswithsteamparametersupto300bar(1bar=10~5Pa)and600℃.Inordertofurtherincreasethesteamparametersofsteelbasedpowerplantsuptoatargetvalueof650℃/325baritisnecessarytodoublethecreepstrengthcomparedwithtodaysstrongest9%Crsteels,andatthesametimetheresistanceagainststeamoxidationmustbeimprovedbyadding12%Crtothesteel.However,sofarallattemptstomakestronger12%Crsteelshavebeenunsuccessfulbecausethehighchromiumcontentintroducedseveremicrostructureinstabilitiesinthetestedsteels.Recently,itwasfoundthatthemicrostructureinstabilitiesin11%-12%CrsteelscanbeexplainedbytheprecipitationofcoarseCr(V,Nb)NZ-phases,whichdissolvefine(V,Nb)Nnitrides.AnewpossibilitytousetheZ-phaseforstrengtheningof12%Crsteelshasbeenidentified,andthedevelopmentofstablestrongmartensitic12%Crsteelsbasedonthisconceptisexpectedtoallowtheconstructionof325bar/650℃steampowerplantsallbasedonsteel.

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  • 简介:4、以下2幅图片是南非德班地区的一家污水处理设施使用3Cr12不锈钢制作的楼梯踏板、扶手。该设施安装于1984年,截止2000年为止,服役时间为16年。设施距离海岸线仅为50m,常年处于海风及高度腐蚀性污水侵蚀环境中,未发生锈蚀情况。

  • 标签: 不锈钢 污水处理设施 实例 应用 设施安装 服役时间
  • 简介:Precipitationstrengtheningaswellassolutionstrengtheningiskeymechanismforheatresistantsteels.Itisveryimportanttocharacterizetheprecipitatesin9%Crferriteheatresistantsteels,especiallytoshowthenanometer-sizedparticles.Bytransmissionelectronicmicroscopeattachedwithanenergydispersivespectrometeraswellasopticalmicroscope,scanningelectronicmicroscope,themicrostructureandchemicalcompositionofprecipitatesina9%Crheatresistantsteelafterdifferentheattreatmentswereinvestigated.ItwasfoundthatthemicrostructureofnormalizedsamplewasmartensitewithfineNbCandFe3C.Themicrostructureoftemperedsampleistemperedmartensite,andtheremainlyweretwotypesofprecipitates,M23C6withthesizerangeof50-300nmandMXwiththesizeof10-100nm.SuperfineM23C6precipitatedpreferablyonpriorausteniticgrainboundariesandmartensiticlathboundaries,whilenanometer-sizedMXprecipitatesweredistributedrandomly.Aftershort-termcreep,Lavesphaseformedalonggrainboundariesofthe9%Crsteel,andM23C6andMXprecipitateswerefoundtobecomecoarser.Moreinformationaboutprecipitatesinthe9%Crsteelhadbeenexhibitedbyatomicforcemicroscopy.Thereby,distribution,sizeandshapeoftheprecipitatesaswellastheircompositionsandstructureswererevealed.

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  • 简介:介绍1^#、2^#竖炉利用加工后的海砂矿生产高钛球的生产实验方案及过程控制。并就生产过程参数的变化情况进行分析,采取相应的调整措施。在工业生产实验的基础上,总结生产实践取得的经验和技术。

  • 标签: 高钛球 海砂矿 粒度组成 成球性能 冶金性能
  • 简介:选烧厂1#2#烧结机蒸汽预热的使用,对提高混合料料温起到一定积极作用,同时对烧结机固体燃料消耗、能源消耗、烧结成本等造成一定的波动,本文主要通过对烧结技术经济指标的分析研究,摸索蒸汽预热的使用对实际烧结生产的影响。

  • 标签: 蒸汽预热 烧结 经济指标
  • 简介:通过化学成分检验、金相分析、及对连铸工序进行调查,分析了转炉冶炼40Cr热轧圆钢表面裂纹的产生原因。结果表明,连铸拉速不稳定是造成裂纹的主要原因。并跟踪分析了一个浇次连铸拉速的控制情况。

  • 标签: 表面裂纹 连铸 拉速
  • 简介:Inordertoutilizetheadvantageofoxidesinstainlesssteel,theformationoftitaniumnitride(TiN)andoxide(TixOy)inthe17CrsteelwasinvestigatedbythecalculationofthefreeenergyofreactionandthermodynamiccalculationwithThermo-calcsoftware.Theresultindicatesthatthecompetitivereactionbetweenthedissolved[O]andthedissolved[N]withthedissolved[Ti]inmoltensteelresultsindifferentprecipitationsequencesofTiNandTixOy.TheprimaryprecipitationofTiNrequiresalow[O]andtheprimaryprecipitationofTixOyrequiresalow[N].Theincreaseof[Ti]causesahigherprecipitationtemperatureofTiNandTixOyinbothTi-NandTi-Oalloysystems.Equilibriumrelationsof[Ti]vs[N]and[Ti]vs[O]showthatthesolubilityproductsfallwiththedecreaseofthetemperature,andthentheprecipitationoftheinclusionsbecomeseasier.IntheTi-Oalloysystem,ahigh[O]andalow[Ti]arefavorabletotheprecipitationofTi3O5,andahigh[Ti]contentandalow[O]favorabletotheTi2O3precipitation.

  • 标签: STAINLESS steel titanium INCLUSION PRECIPITATION t
  • 简介:针对40Cr圆钢个别炉号冲击功不合问题,通过分析钢种成分、金相组织,并对生产过程进行调查,得出A类夹杂物是造成圆钢冲击功不合的主要原因。通过采取有效措施,40Cr圆钢冲击功不合问题得到控制。

  • 标签: 冲击功 A类夹杂 精炼周期
  • 简介:为达到国家对钢铁行业能耗指标的要求,酒钢选烧厂通过改善混合料粒度组成,研究料层燃料分布状况,降低了1#、2#烧结机燃料消耗。

  • 标签: 混合料粒度 燃料分布 固体燃耗
  • 简介:Martensiticstainlesssteelcontaining12%-18%Crhavehighhardnessduetohighcarboncontent.Thesesteelsarecommonutilizedinquenchingandtemperingprocessesforknifeandcutlerysteel.Thepropertiesobtainedinthesematerialsaresignificantlyinfluencedbymatrixcompositionafterheattreatment,especiallyasCrandCcontent.Comprehensiveconsideredthehardnessandcorrosionresistance,anewtypemartensiticstainlesssteel6Cr15MoVhasbeendeveloped.Thisstudyemphaticresearchestheeffectofheattreatmentprocessesonmicrostructureandmechanicalpropertiesof6Cr15MoVmartensiticstainlesssteel.Thermo-Calcsoftwarehasbeencarriedouttothermodynamiccalculation;opticalmicroscope(OM),scanningelectronicmicroscope(SEM)andtransmissionelectronmicroscope(TEM)havebeencarriedouttomicrostructureobservation;hardnessandimpacttoughnesstesthavebeencarriedouttoevaluatethemechanicalproperties.Resultsshowthattheequilibriumcarbidein6Cr15MoVsteelisM23,C6carbide,andfinelydistributedofM23C6carbidescanbeobservedonannealedmicrostructureof6Cr15MoVstainlesssteel.6Cr15MoVmartensiticstainlesssteelhasawiderquenchingtemperaturerange,thehardnessvalueofsteel6Cr15MoVcanreachto60.8-61.6HRCwhenquenchedat1060-1100℃.Finelydistributedcarbideswillexistinquenchedmicrostructure,andeffectivelyinhabitthegrowthofaustenitegrain.Withtheincreasingofquenchingtemperature,thevolumefractionofundissolvedcarbideswilldecrease.Theexcellentcomprehensivemechanicalpropertiescanbeobtainedbyquenchedat1060-1100℃withtemperedat100-150℃,anditismainlyduetothehighcarbonmartensiteandfinegrainsize.Atthesetemperatureranges,thehardnesswillretainabout59.2-61.6HRCandtheCharpyU-notchimpacttoughnesswillretainabout17.3-20J.Themorphologyofimpactfracturesurfaceoftestedsteelissmalldimpleswithasmallamountofcleavageplanes.Theareaofcleavageplanesincreaseswiththeincreas

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  • 简介:本文主要介绍炉后型KTO—Cr定氧仪的工作原理及其应用,井简述了运用定氧技术来指导炼钢操作和提高钢水质量。

  • 标签: 定氧仪 炉后型 炼钢 工作原理
  • 简介:Thisstudyinvestigatesthecorrosionpropertiesof0Cr11Tiand0Cr11NbTiferriticstainlesssteels(FSS)forautomotiveexhaustsystems.Theresultsindicatethatthebasemetalandweldseamof0Cr11NbTisteelexhibitbetterintergranularandcondensatecorrosionresistantpropertiesbecausecarbonandnitrogenarestabilizedbyNbandTi,andtheprecipitationofCrcarbideisretardedingrainboundaries.

  • 标签: 铁素体不锈钢 汽车排气系统 防腐性能 碳化物析出 晶间腐蚀 FSS
  • 简介:Abstract:TheeffectofTiandNbontherecrystallizationandtherecrystallizedgrainsizeofthehot-rolledplatesandcold-rolledsheetsofultralowcarbonandnitrogen(ULCN)Cr18ferriticstainlesssteel(FSS)isinvestigated.Theresultsshowthattherecrystallizationofhot-rolledplatesandcold-rolledsheetswith0.29%Nbisdelayed,andtherecrystallizedgrainsaresignificantlyrefined.

  • 标签: 不锈钢冷轧薄板 再结晶 超低碳 晶粒尺寸
  • 简介:Inrecentyears,theconcernaboutenvironmentalprotectionisincreasingonaworldscale.MajormanufacturersofhomeappliancesandOAequipmenthaveintroducedso-called'greenprocurementschemes'forreducingenvironmentallyharmfulsubstancesinmanufacturingprocessandendproducts.Undersuchbackground,anewtypeofchromate-freeorganiccompositecoatedelectro-galvanizedsteelsheetwithhighconductivitywasdevelopedbyBaosteel,whichmeetstheEURoHSDirective(RestrictionoftheHazardousSubstances)andotherrelatedlawsandregulationsonenvironmentalsafety.Italsoprovidesexcellentsurfaceelectricalconductivity,corrosionresistance,fingerprintresistance,solventresistance,coatingadhesion,heatresistance,formabilityandotherspecialpropertiestomeetthedemandofmanufacture’sprocessofOAmachine.Comparedwithpreviouslydevelopedanti-fingerprintingcoatedelectro-galvanizedsteelsheet,thisnewlydevelopedproducthasagoodbalancebetweenhighcorrosionresistance(timeto5%whiterustinsaltspraytestis120hforflatpaneland72hforworkedpotion)andconductivity(surfaceelectro-resistivityinaccordancewithLOREASTislessthan0.1milliohm)duetothespecialdesignofcoating’sstructure.Besides,Italsoprovidesthepropertiesofgroundingandshieldingagainstelectromagneticwaves.Theevaluationofsurfaceperformancesofnewproductshowedthatitiscomparableorevenbetterthanthesimilarproducts.Currently,thenewlydevelopedproducthasbeencommercialized.Inthispaper,themajorpropertiesarediscussed,suchascorrosionresistance,surfaceelectricalconductivity,fingerprintresistance,solventresistance,coatingadhesion(ink/melaminealkydpaint),heatresistanceandformability.Furthermore,theapplicationisalsobrieflydescribed.

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

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  • 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.

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