简介：铁矿石经浓盐酸和少量的SnCl2溶液加热到45℃溶解后,用SnCl2-TiCl3还原滴定Fe（Ⅲ）,使Fe（Ⅲ）还原为Fe（Ⅱ）,再以K2Cr2O7滴定全铁含量。本方法对实验操作温度,试样溶解酸的选择有一定的要求,宜选用非氧化性强酸在30-60℃溶解矿样。

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.

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。

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：最近《不锈钢世界》记者有机会与英国的国际工程建设承包商——FosterWheeler能源有限公司材料咨询工程师RichardCarroll接触，请他介绍了目前他所了解的有关耐腐蚀合金（CRAs）使用方面的若干问题。

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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.

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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。

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：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

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。

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.

简介：Thisstudyinvestigatesthecorrosionpropertiesof0Cr11Tiand0Cr11NbTiferriticstainlesssteels(FSS)forautomotiveexhaustsystems.Theresultsindicatethatthebasemetalandweldseamof0Cr11NbTisteelexhibitbetterintergranularandcondensatecorrosionresistantpropertiesbecausecarbonandnitrogenarestabilizedbyNbandTi,andtheprecipitationofCrcarbideisretardedingrainboundaries.

简介：Abstract:TheeffectofTiandNbontherecrystallizationandtherecrystallizedgrainsizeofthehot-rolledplatesandcold-rolledsheetsofultralowcarbonandnitrogen(ULCN)Cr18ferriticstainlesssteel(FSS)isinvestigated.Theresultsshowthattherecrystallizationofhot-rolledplatesandcold-rolledsheetswith0.29%Nbisdelayed,andtherecrystallizedgrainsaresignificantlyrefined.

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。

简介：Thehot-deformationbehaviorofFe-Mn-Ctwinninginducedplasticity(TWIP)steelwasinvestigatedbyconductinghotcompressiontestswithinarecommendedhotrollingtemperaturerangeatvariousstrainrates.Flowresistancecurvesduringhot-deformationwereobtained,andstrainratesensitivitiesandactivationenergiesforplasticdeformationwerecalculatedusingthepowerlaw.ItisfoundthattheadditionofAlandSiclearlyincreasesthepeakstressesforthepresentalloys,especiallyat950℃.ButMnhasaminoreffectonthestress-straincurvesandactivationenergywhenitscontentvariesfrom15mass%to22mass%forthepresentalloys.

简介：在轧钢生产中,铸钢轧辊常用于承受较大轧制力的部位。图1所示的φ400轧机K6轧辊,工作条件较为恶劣,要求轧辊在轧制过程中具有较好的抗蠕变能力和抗磨损性能。要求轧辊材质具有较高的高温强度,抗折断性好。

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.