简介：Ultra-steelProjectperformedatNationalInstituteforMaterialsScience(NIMS)1997-2005proposed'Breakthroughsforinnovationbysteelscience'.Themainconceptswerecomposedofdecreasingtheenvironmentalload,noorlessspecialalloyingelementsandsaferinfrastructurewithreducedthetotallifecost.Four'doublestrengthanddoublelife'steelsweredevelopedasfollows:①800MPa-classecologicallybeneficialsteelsforweldedstructures,②1500MPasteelswithhighresistancetofracture,③advancedferriticsteelsfor650C-USCboilersand④Ultra-steelsforstructuresinmarineandoffshoreenvironments.Worldsteelsocietyisstillgrowingwiththreateninglimitsofresourcesandenergy.Applicationoftheultra-steelideaswouldbeincreasinglyhelpfulfortheglobalsustainability.ThetalkwillintroducetherecentprogressinsteelresearchatNIMS,basedontheprojectaccomplishments.

简介：Ultrafastcoolingisanewtechnologywhichusedtocontrolthehot-rollingstripcoolinginrecentyearsontheinternationaldeveloped.Ifsuitablycooperatedwithanumberofothernewcontrolledrollingtechnologies,canachievefastandaccuratetemperaturecontrolinthehot-rolledstripproductionprocesstoobtaincorrespondingtransformationmicrostructureandidealmechanicalproperties.Thisarticledescribesthetechnicalprincipleandlayoutofultrafastcoolinginhot-rolledaswellasapplicationprofilesinthemajorironandsteelenterpriseinChinaandabroad.Carriedoutthelayoutofultrafastcoolinganalysisontheadaptabilityofsteelthatinstallbetweenthefinishingmillandlaminarcooling,onthisbasis,proposedtheuseofultrafastcoolingtechnologyproposals.

简介：Thisstudyresearchescoldrolledultrahighstrengthmartensiticsteelprocessedbywaterquenching.Itisfoundthatboththequenchingandoverageingtemperaturesgreatlyinfluencethemechanicalpropertiesofmartensiticsteel.Atensilestrengthof1500MPacanbeobtainedfrom0.2%C-1.8%Mnsteelbysoakingat840℃,quenchingat700℃andoverageingat200℃forseveralminutes.Thecontinuouscoolingtransformation(CCT)diagramrevealsthatfullmartensitecanbeobtainedatacoolingrateof100℃/sorhigher;andatacoolingrateof3-10℃/s,austenitebarelydecomposesat700℃.Forsteelwith0.2%carbonandlessmanganese,austenitedecompositionoccursbeforeitiscooledto700℃atacoolingrateof3-10℃/s,whichleadstolowertensilestrength.Itispossibletoreducethemanganesecontentofthe1500MPamartensiticsteelbyincreasingthequenchingtemperature.Toincreasethequenchingtemperature,thecontrolofflatnessduringwaterquenchingbecomesamajorconcern.

简介：Ultrapureferriticstainlesssteelhasmoreadvantagesintheperformancethantheordinaryferriticstainlesssteelbecauseofultralowcarbonandnitrogencontent,suchascorrosionresistance,toughnessandweldability,etc.Suchsteelhasthereforebeenappliedinmanyfields,leadingtotheveryrapiddevelopmentoverthepast40years.Thisstudyfocusesonthesecondaryrefiningprocesswhichisthemostimportantstepofthewholesteelmakingprocessfortheultrapureferriticstainless.Firstly,somedifficultiesofthesecondaryrefiningprocessaredescribed,includingthehighpurificationintermsofbothcarbonandnitrogencontents,highefficientandstablecontrol.Secondly,thedevelopmentandprogressofthesecondaryrefiningtechnologyforultrapureferriticstainlessisintroducedintermsoftherefiningequipments,metallurgicalprocessandassistanttechnologies.Finally,theprospectwasmadeforthedevelopmentofsecondaryrefiningprocessforultrapureferriticstainlessinthefuture.

简介：Sincethe21stcentury,greatattentionhasbeenpaidtoultrafastcooling（UFC）technologyinthewholeworld.Theindustriesandtheresearchinstitutionsbegantocarryoutinvestigationsonbasictheoriesandindustrialapplications.Since2003,theRALofNortheasternUniversityhasmadesomeprogressesonmicrostructurecontroltheories,understandingofstrengtheningmechanismsandtheirindustrialapplications.Inthispaper,theseachievementssincethelastBaosteelBACin2008willbereportedontheindustrializationofUFC,strengtheningmechanism,developmentofnewsteelgrades,andsoon.

简介：Inordertomeetthedemandsofservicelifeandthesyntheticalperformance/priceratioofstainlesssteelinthesolarwaterheaterindustry,thelowmolybdenumultra-pureferriticstainlesssteel(FSS)B445J1MwasdevelopedatBaosteel.Inthisstudy,comparativestudieswerecarriedoutonthemechanicalproperties,theformabilityandthecorrosionresistanceofB445J1M,304and444,andtheadvantagesandapplicationfieldsofB445J1Mweresummarized.

简介：Abstract:Inordertounderstandtheeffectofthesolidificationstructureontheformabilityofultralowcarbonferriticstainlesssteel(FSS),thisworkstudiestheridgingphenomenonandthedeep-drawingpropertyindetailandtheresearchmethodwasX-raydiffraction(XRD)andscanningelectronmicroscope(SEM)technique.Theresultshowsthatthecolumnargrainspecimenhadahigherridgingheightthantheequiaxedgrainspecimen,whichwasmainlyattributedtotheformationofgraincoloniesinthecolumnargrainspecimen.Afterfinalrecrystallizationannealing,theequiaxedgrainspecimenobtainedahigh-intensityγ-fibertextureandanexcellentdeep-drawingproperty.

简介：ThemorphologiesevolutionofvarioustypesofinclusionsinTi-IFsteelwereobservedbyaspecialdeptherosionmethod,andtheformationandevolutionprocesswerediscussed.TheresultsshowedthatthemaininclusionswereFeO·xMnObeforeAldeoxidizationandtheratioofintegratedoxygenandfreeoxygenwasinrangedof0.3to0.4.Inpresentstudy,themaineffectfactorsonthemorphologiesofAl2O3inclusionswere[Al]/[O]Free（solublealuminumdividefreeoxygen）andinitialfreeoxygen;clusterAl2O3wasformedeasilywithhighfreeoxygen([O]Free)andlow[Al]/[O]（blew3inpresentstudy）.Otherwise,thedendriticAl2O3wasformed;coral-likeAl2O3wasthemixtureofthedendriteAl2O3andsphericalAl2O3.SomeAl2O3·TiOxinclusionsappearedbecauseahigh[Ti]concentrationregionexistedaround70TiFe（containing70percenttitanium）particlesafter70TiFeaddition.ThemaximumsizesofAl2O3reached800μmwhen3minaluminumwasadded;asthetimepast,thelargesizeAl2O3decreasedsignificantly;themaximumsizeofAl2O3wasblew100μmand50μmincalmingsampleandtundishsamplerespectively.

简介：Inthepresentwork,themicrostructure,texture,andmechanicalpropertiesofacold-rolledTi-IFsteel,afterannealingatdifferentheatingrates,havebeeninvestigated.Theresultsrevealthatthemeangrainsizeisgraduallyrefinedfrom19.2to16.3μmastheheatingrateincreasesfrom4to50℃/s,butrefinedonlyslightlyatheatingratesofover50℃/s.Therecrystallizationmicrostructurehasastrongtexture,whichisaresultofthesharpeningofthefavorable{111}//ND(normaldirection)texturecomponentsorγ-fiber.Withincreasingheatingrates,thepeakvalueoff(g)ofγ-fiberdecreasesfrom17to9.Theyieldandtensilestrengthsincreasegraduallyastheheatingrateincreasesfrom4to50℃/s,butremainalmostunchangedatheatingratesofmorethan50℃/s.Thetotalelongationanduniformelongationincreasegraduallyastheheatingrateincreasesfrom4to100℃/s,butdecreasesslowlyforheatingrateshigherthan100℃/s.Astheheatingrateincreasesfrom4to100℃/s,theplasticstrainratioofthesteeldecreasesfrom2.8to2.2;however,itincreasesto2.9forheatingratesabove100℃/s.Thestrainhardeningexponentremainsunchangedat0.27inallannealingcycles.

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

简介：Ultra-lowcarbon(ULC),cold-rolledsheetsteelsforporcelainenamelingcontainingalloysoftitaniumandboronarestudied.Themicrostructure,mechanicalproperties,inclusions,andprecipitatesofthesheetsteelsareanalyzed.Thehydrogenpermeationtimeofthesheetsteelsas-annealedandafterskin-passedorcold-rolledatdifferentreductionsaremeasured.Itisshownthatthesheetsteelspossessdifferentfeaturesofenamelingpropertiesinhydrogenpermeability,fishscaleresistance,andpinholeresistance.