简介：ShougangGrouphascarriedoutastrategicstructureadjustmentinordertorealizethepromiseofChinesepeopletotheOlympicGames.Automotivesheetsarechosenasatypeofstrategicproductandanenginetoupgradeenterprisemanagement,technologyandoperationtoreachthetopinternationallevelduringthetransitionfromlongproductstosteelsheetsinShougangGroup.Since2006,ShougangGrouphasmadeanelaboratepreparationonsteelsheetculture,productionlineconstruction,technologyimport,pilotplantandtalentreserve.Itlaysthefoundationforthedevelopmentofautomotivesheets.Thedevelopinghistoryofcoldrolledautomotivesheetsisreviewedandtheresearchanddevelopmentofcoldrolledautomotivesheets,tacklingkeyproblemofdefectonsurfaceandthelatestprogressofautomotivesheetsconstructionaredescribedinthispaper.Themaincontentsweregivenasfollows:①TheproductsofautomotivesheetsrealizezerobreakthroughinShougangGroup.Monthlyoutputwas300toninJanuary,2009anditincreasedto48000toninJune,2010.TheratioofIFsteelsheetsincreasesto70%from40%.Theproportionofoutsidepanelinautomotivesheetsoccupysmorethan15%.②Ahighemulationalpilotplantisusedasaproductdevelopingplatformtodevelopsuccessfullyautomotivesheetswith1000MPaandbelow.ItguaranteesthattheindustrialdevelopmentofDPandTRIPsheetsgetssuccessatatime.Itcoverscontinuousannealingsheetswithtensilestrength≤780MPaandgalvanizingsheetswithtensilestrength≤590MPa.③Individualdesignisusedtomeetspecialrequirementofcustomer.Shougangowns23innerbrandsofLCAKandIFsteels.Itinsuresthatthegradesofyieldstrengthcoverwholerangefrom120to270MPa.Itkeepsthestabilizationofsteelperformancebymeansofchemicalcompositioncontrolandhighaccuracyrollingtechnology.Forexample,thestrengthofsoftsteelfluctuateswithin±15MPa.④ThesteelsheetswithsurfacegradeO5areproducedsteadilybysolvingformingstr

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.

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简介：Cold-rolledmartensiticsteelsheetsproducedoncontinuousannealinglineswithwaterquenchingfacility,haveadvantagesofhighstrengthandlowalloyingelementcontents.Theseareingoodaccordancewiththetrendoflight-weightingandfuelsavingforautomotivesteel.Inthisarticle,acold-rolledmartensiticsteelisstudiedtoinvestigatetheeffectofannealingparametersonitsmechanicalproperties.Itisfoundthatthequenchingtemperatureandtheslowcoolingspeedaswellastheoverageingtempe...

简介：Thetensilebehaviorandpropertiesofcoldformedlow-carbonmicroalloyedsteelwithitsmicrostructureofallferriteandpearlite(F+P)wereinvestigated.Bendingandflatteningdeformationswerecarriedoutinthelaboratoryonhot-rolledsheetsinordertosimulatethecoldformingprocessofsteelsheetsduringpipefabricationandsamplingofhighfrequencystraightbeadweldingpipes.Acomparisonofthetensilebehaviorandpropertiesofthematerialmadebeforeandaftercoldformingindicatesthatcolddeformationaltersthetensilebehaviorandpropertiesofthematerialtoacertaindegreedependingonthemannerofthecolddeformationandthedegree.TheresearchontheBauschingereffectindicatesthatforthesteelsinvestigated,whentheplasticstrainissmall,thebackstressincreasesrapidlywiththeincreaseoftheplasticstrainandthenrapidlytendstosaturation.ThefiniteelementanalysisindicatesthatthechangeinthepropertiesofthesteelsheetsduetocoldformingisaresultoftheBauschingereffectandworkhardening.Themechanismofthechangeinthepropertiesisalsogiveninthisstudy.

简介：316Lstainlesssteelcoatingswerepreparedbycoldgasdynamicspraying(CGDS)onacarbonsteel.Anewheaterofsprayedpowderswasaddedtothetraditionalfacility.Theresultsshowthatthecoatingqualityisobviouslyimproved,duetobetterinterfacebondingandreducedporosity.

简介：Withacomplicatedcomposition,largeproductionandseriousdamagetotheenvironment,stainlesssteelcold-rollingsludgehasbeenafocalpointconcerningenvironmentalprotectionforstainlesssteelenterprises.Uptonow,neitherathomenorabroadhaveanytechnologiescomeintobeingthatarenotonlyproper,safeandeconomicalbutalsosuitableforbulkutilizationofstainlesssteelcold-rollingsludge.Basedonthecharacteristicsofthestainlesssteelcold-rollingsludge,orthogonalexperimentswerecarriedoutonpelletproportioningandhigh-temperatureroasting,andmajormetallurgicalpropertiesofsludgepelletswerealsotested.Astheresultsshow,pelletswith30%additionofcold-rollingsludgearequalifiedregardingtheircompressivestrength,chemicalcompositionandmajormetallurgicalproperties.Noadverseimpacthappenstotheblastfurnaceoperationwhensludgepelletsaccountfor10%oftheblastfurnacerawmaterials.Therefore,thetechnicalrouteappliedinthispaperisprovedsimple,feasibleandenvironmentallyfriendlyforcold-rollingsludgetreatment.

简介：Coldrolledmartensiticsheetsteelsareachievingmoreandmoreapplicationsincar-makingbecauseoftheirultra-highstrengthandpotentialforweightreduction.Therelativelylowplasticityofultra-highstrengthmartensiticsteelsmightbeadrawbackfortheapplicationsintheaspectsofformingandsafetyprotectionfunctionandshouldbesignificantlynoted.A1500MPagradecoldrolledmartensiticsheetsteelhasbeenstudiedtoinvestigatethebendabilityat90degreebendingandimpacttoughnessaswellasfracturesurfacemorphologyatvarioustemperatures.Somediscussionshavebeenmadebasingupontheexperimentdatatogetsomeunderstandingontheperformanceofthematerialsundervariousconditionsandonhowtomakeuseofthiskindofultrahighstrengthsteelproperly.

简介：ThepapershowsthemainsurfacedefectsofcoldrollingautomobilesheetinBXSteel.Themainsurfacedefectsareunusualdefects.Thetypicalfamiliardefectsaresliverandpunctuatesthatareontherollingdirection.Theinclusionsofsteel-makingandscalesofhotrollingprocessarethemaincausesofdefects.Theyarethebiggestproblemspuzzlecoldrolledautomobilesheetsurfacequality,andaretheburningissuesofBXSteel.Weclassifyandanalysisthedefects.Weobservethepanoramaofsurfacedefectsusingportablevideomicroscopyapparatus,andcleanthesampleusingultrasonicshaker,analysisthedefectspatternandchemicalcompositionusingscanningelectronmicroscope.Atpresenttheprimarydefectsthatimpactedcoldrolledautomobilesheetqualityaredarksliverdefects.Wecontrolthesteel-makingandhotrollingprocessaimingatthecauseandpositionofdefectsmaking.Wefinecontroltheoperatingofsteelladle,gating,castingsystemandcontinuouscastingmachineinsteelmakingprocess.Thescaledefectisreducedbycontrollingfurnace,highpressurewaterdescalingsystemandfinishmilldescalinginhotrollingprocess.Alonewiththereformingandrenewingofequipment,gatheringproducingexperience,thecoldrolledautomobilesheetqualitymadeinBXSteelisupgradinggradually.

简介：Basedonthecharacteristicsofpicklingwastewaterinthecold-rollingproductionofstainlesssteel,anewprocessingroute,featuringsourcesludgereduction,wastewatertwo-stagetreatment,heavymetal-containedsludgeandcalciumsaltsludgeseparatingrecovery,wasproposed.Asshownbytheresearchresults,afterthetwo-stageprocesstreatment,theeffluentwatercansteadilyreachtheemissionstandards,thesludgeyieldcanbedecreasedbymorethan8%;withintheheavymetal-containedsludge,therecoveryratesofFe,CrandNicaneitherreachorsurpass95%,andthetotalcontentofFandScandroptoaround3%.Therefore,thesludgeinthefrontpartcanbeusedasferricdust.Inthecalciumsaltsludge,therecoveryrateofFcaneitherreachorsurpass85%,andthetotalcontentsofFe,CrandNicanfallbelow0.5%.Sothesludgeintherearpartcanbeusedasfluorgypsumorfluorite.Meanwhile,theresultsoftheanalysisonheavymetalsleachingtoxicityandmorphologicdistributionindicatethatthetwokindsofsectionalizedsludgearenotclassifiedashazardouswastes,whichhaveastablebehaviorandbetterutilizationvaluescomparedwiththeformermixed-sludge.

简介：Thisstudyanalyzestheevolutionofcarbidesinthetemperingprocessofanewlydevelopedsemi-highspeedsteelcoldforgedrollwithnitrogenadditionusingatransmissionelectronmicroscope(TEM)equippedwithanenergydispersiveX-ray(EDX).TheprecipitationsequenceofthecarbideswasidentifiedintheentiretemperingprocessanditcanbeexpressedasM3C→M3C+M(C,N)Ⅱ→M(C,N)Ⅱ+M7C3Ⅱ+M23C6.ThesecondaryhardeninginthetemperingprocesswasmainlyduetothedispersedprecipitationoffineM(C,N)Ⅱparticles.ThedissolutionofM3CtemperedathightemperaturesinducedtheprecipitationandcoarseningofM7C3ⅡandM23C6.

简介：Cold-stretchedpressurevesselsfromausteniticstainlesssteels(ASS)arewidelyusedforstorageandtransportationofliquefiedgases,andhavesuchadvantagesasthinwallandlightweight.Fatigueisanimportantconcerninthesepressurevessels,whicharesubjectedtoalternativeloads.Eventhoughseveralcodesandstandardshaveguidelinesonthesepressurevessels,therearenorelevantdesignmethodsonfatiguefailure.TounderstandthefatiguepropertiesofASS1.4301(equivalentsincludeUNSS30400andAISI304)insolution-annealed(SA)andcold-stretchedconditions(9%strainlevel)andtheresponseoffatiguepropertiestocoldstretching(CS),low-cyclefatigue(LCF)testswereperformedatroomtemperature,withtotalstrainamplitudesrangingfrom-.4%to-.8%.Martensitetransformationsweremeasuredduringthetests.Comparisonsoncyclicstressresponse,cyclicstress-strainbehavior,andfatiguelifewerecarriedoutbetweenSAandCSmaterials.ResultsshowthatCSreducestheinitialhardeningstage,butprolongsthesofteningperiodinthecyclicstressresponse.Martensitetransformationhelpsformastableregimeandsubsequentsecondaryhardening.Thestressesofmonotonicandcyclicstress-straincurvesareimprovedbyCS,whichleadstoalowerplasticstrainandamuchhigherelasticstrain.ThefatigueresistanceoftheCSmaterialisbetterthanthatoftheSAmaterial,whichisapproximately1?03to2?04cycles.TheS-NcurveoftheASMEstandardforASSiscomparedwiththefatiguedataandisjustifiedtobesuitableforthefatiguedesignofcold-stretchedpressurevessels.However,consideringtheCSmaterialhasabetterfatigueresistance,theS-Ncurvewillbemoreconservative.ThepresentstudywouldbehelpfulinmakingfulluseoftheadvantagesofCStodevelopanewS-Ncurveforfatiguedesignofcold-stretchedpressurevessels.

简介：Manyadvancedtechnologieshavebeenappliedindevelopingtheautomaticmeasuringdevicefortestingtransversethicknessdifferenceofcold-rollingsteelsheet,suchasthetechnologiesofautomaticcontrol,sensormeasurement,markingidentification,photographiclocation,computerapplicationandinformationtransmission.Thismeasuringdevicecanmeasurethetransversethicknessdifferenceofthesteelplateaccuratelyandquickly,withahighdetectionlevelofautomation.Itisaneffectivedetectionequipmentfortransversethicknesscontrolofsteelplate.Horizontalwidthofsteelplatemeasuring0.8-1.4m,horizontalmeasurementpointpositioningaccuracy±0.02mm,thicknessrange0.2-2.0mm,measurementaccuracywithin±1μm.

简介："GasTransmittingFromWesttoEastProject"issignificant.Itshouldensuretheweldingqualityandsafetyofpipeline.Thetaskisveryarduoustoguaranteethequalityoftheprojectintheconditionoflongline,complexweatherandgeologyfeatures.Inthispaper,theweldingcoldcrackingsusceptibilityofdomesticX-70pipelinesteeladoptedbytheproject,whichisoneofthemostinterestingquestionsofweldingqualityaboutpetrolpipeline,wasstudiedbymeansofobliqueY-groovecrackingtest.Thecrackratioofsurfaceandsectionwastestedundertheconditionsofdifferentweldingmaterialsandpreheattemperature.TheX-70pipelinesteelhasgoodcrackresistance.Theresearchhasimportantvaluefortheconstructionoflarge-scalepipelineengineeringandtheapplicationofdomesticX-70pipelinesteel.

简介：Theeffectsofthesubstratetemperatureonthedepositionandmicrostructureofthe304stainlesssteel(SS)coldgasdynamicspraying(CGDS)coatingswereinvestigated.Itwasfoundthatthehighersubstratetemperaturecouldincreasethedepositionrateofthe304SSparticles,eventheoxidefilmsexistedattheinterface.Therewasacriticaloxidefilmwithathicknessof3-4μmwhichcouldbedestroyedbytheimpactedparticles.Themicro-hardnessandmicrostructureofthe304SScoatingsunderdifferentsubstratepreheatingtemperatureswerealmostthesame.

简介：Thecommoncoldistheworld'smostwidespreadillness,whichisaplague(疫病)thatfleshreceives.

简介：AhighalloyedVanadis4(V4)steelwasproducedbysprayformingprocessinBaosteel,andthemicrostructureoftheas-sprayedsteelanditsevolutionduringhotrollingandannealingprocesseswerecharacterized.Itwasfoundthattheas-sprayedV4steelhasahomogeneousandfinescalemicrostructurewithuniformdispersionofcarbides.Thehotrollingtemperatureisthekeyfactorincontrollingtheevolutionoftype,morphologyanddistributionofcarbides,aswellasthematrixmicrostructureoftheas-rolledsteels.Theoptimizedprocessingparametersfortheas-sprayedV4steelarerollingat1050℃andthenannealingat900℃.Themicrostructuralevolutionmechanismsduringhotrollingandannealingaredeterminedaccordingtothemicrostructuralanalyasisofthematerialatdifferentstages.

简介：使寒冷变形的CrMnN奥氏体的不锈钢的机械性质和微观结构进化在从50敬的温度退火了吗？

简介：某些动词如:catch,have,get.take等与cold连用,表示感冒、伤风、着凉之意。有时cold前带a.有时不带a.有时可带可不带.为了弄清楚这些关系,现归纳如下。一、动词have,get与cold连用,要加a.表示状态.可与表示延续性时间状语连用。例如:1)Hehashad(got)acoldfordays.2)I’vegot(had)acoldsincemyarrival.二、动词take与cold连用,不加a。例如:1)Youusedtotakecold,usedn’tyou?2)XiaoLiuisn’tstrongenough.Sheeasilytakescolds三、动词catch与cold连用,a可有可无。例如:Putonyourcoat,oryou’llcatch(a)cold.

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