简介：Thesteelindustryhascomealongwayinincreasingitsenergyefficiency.InEuropethecarbonintensityofsteelmakingoverthelast40yearswasdecreasedbyafactor2.Thepotentialforfurtherimprovementsisnowbecominglessobviousasblastfurnaceoperationsareapproachingthethermodynamicallowerlimitofhotmetalproduction.Totakeontheclimatechangechallengeandbeabletorespondtotheexpectationforstrongreductionofcarbonemissions,ArcelorMittal（AM）hasdevelopedatwostepapproach:（1）Inafirstinstancegiventhemodestremainingpotentialforincrementalimprovementsprecisebenchmarktoolsweredeveloped.Thisallowedidentifyingthetoprunnersanddeterminingtheremainingpotentialforimprovement.Plansweredevelopedtobridgethegapwiththisachievableperformance.Intotalaplanwasdevisedwithmorethan400identifiedactionsthroughoutthegroup.Thisactionplanwillallowachievingafurther8%increaseofCO2efficiencyby2020.（2）Secondly,alreadyin2002AMengagedinthedevelopmentofbreakthroughtechnologiestofurtherdrasticallyreducethecarbonintensityofsteelmaking.Afterscreeningalargenumberofcandidatesafewwereselectedforfurtherdevelopment.Afirstbreakthroughtechnologywhichisthemostadvancedstageofdevelopmentcanbeappliedtoexistingblastfurnaceandisreachingmaturityandademonstrationonindustrialscaleofthistechnologyisunderpreparation.Initselfthistechnologywilldecreasethedependencyoncarbonaswellasincreasetheproductivityoftheoriginalblastfurnaces.Realbiggainscanbemadeifthistechnologycanbecombinedwithundergroundcarbonstorage.IntheAMroadmaptheimpactofrawmaterials（DRI,scrap）wasexcluded.Inthelongerrunhowevertheattentionwillhavetoturntotheoverallfootprintofmaterialsandthelongtermconsequencesofthechoiceofmaterials.Increasingtherecoverywhilepreservingthequalityofusedsteelproductswillleveragegreatlytheeffortsdonein

简介：Strainageinginsteelwasfirstobservedduringthe19thcenturywhenthemaximumloadcarryingcapacityofatestpiecewasincreasedafterithadbeenretestedfollowingapreviousseriesoftestinginaplasticrange.Overthelastdecades,agreatdealofresearchhasbeenperformedtogaindeeperinsightsintothephenomenonofstrainageing.Thesynergisticdevelopmentoftheoreticalhypothesisandnewexperimentalevidenceshaspromotedtheunderstandingofthemechanismsunderlyingstrainageing.Thecontentofthispaperisorganizedintofourcomponents.First,wehavecomparedthemaintheoriesdevelopedinrecentyears.Second,wehavesummarizedthemetallurgicaleffectsonthestrainageingbehaviorobservedinexperiments.Moreover,wehavemadeanattempttocorrelatetheexperimentalresultsandtheabove-mentionedtheories.Third,wehaveproposedafeasiblesolutiontocontrolstrainageinginlowcarbonsteels.Finally,wehaveelaboratedthepotentialityoftheatomprobetechniqueinfacilitatingdirectcharacterizationofthedistributionofsoluteatoms.

简介：Inthisstudy,thespheroidizationprocessoflarge-deformedsteelundervariousconditionswasresearched.Steelwithahighcarboncontent(1.0%C)wasfirsttreatedthermomechanicallyusingmultipassrolling.Thenitunderwentspheroidizationtreatmentsatdifferentheatingtemperatures,usingvariousheatingtimesandcoolingrates.Spheroidizationprocesseswithalowerheatingtemperature,shorterheatingtime,orfastercoolingratethanthoseofthetraditionalprocessallshowedgoodresults,indicatingthatthespheroidizationprocesswaspromotedsignificantlybythelargedeformationprocess.Grainrefinementandfragmentationofcementite,alongwiththelargedeformationprocess,promotedthisspheroidizationprocess.

简介：Thedynamicandstaticrecrystallizationbehaviorsoftwinrollcastlowcarbonsteelstripwereinvestigatedwithanattempttoprovideguidingdeformationparametersfortheonlinehotrolling.Inordertoinvestigatedynamicrecrystallizationbehavior,ascaststripwasreheatedandsoakedwithaustenitegrainsizesimilartothewidthleveloftheascastcolumnarstructure.Tensiletestwasusedandthedeformationtemperatureisintherangeof900℃to1100℃andstrainratesare0.01s-1,0.1s-1,1s-1.Theactivationenergyandstressexponentweredeterminedas306kJ/moland4.69respectively.Theratioofcriticalstraintothepeakstrainis0.65,andthatofcriticalstresstothepeakstressis0.92.ThedependenceofthepeakstrainontheinitialgrainsizeandZener-HollomonparametersZisεp=9.1×10-4×D00.48Z0.13.Thekineticsofthedynamicrecrystallizationandrecrystallizedgrainsizewaspredictedusingmodelspublished.Theascastcoarseausteniteweredramaticallyrefinedaftercompletedynamicrecrystallization.Forstaticrecrystallization,thetensiletestwascarriedoutonGleeble-3500thermo-mechanicalsimulator.Thedeformationtemperatureisintherangeof800℃to1200℃withstrainrate0.01s-1to1s-1.Theprestrainisfixedat0.04to0.12andtheinter-hitdelaytimevariesfrom1sto3000s.TheactivationenergyandAvramiexponentofstaticrecrystallizationweredeterminedas241kJ/moland0.54respectively.Akineticsmodelwasproposedtodescribethestaticrecrystallizationkinetics.Thepredictedresultswereingoodagreementwiththeexperimentalresults.

简介：Fluorineinmoldpowderisknownasharmfultohumanhealthandtheenvironment.Beingtheadvocateofgreenproduction,Baosteeldevelopedanenvironmentallyfriendlymoldpowderwithoutfluorine.Themainproblemoffluorine-freefluxfilmissmallheatresistanceandthustheheattransferintensityofthemoldistoolarge,whichtosomeextenthinderstheincreaseofthecastingspeed.Withtheheatflowsimulationequipment,controllingprecipitationofcrystalinfluxandsolidificationtemperatureproperly,fluorine-freemoldpowderforlowcarbonsteel,whichsubstitutesFwithB2O3,wassuccessfullydevelopedandappliedinindustrialproduction.Theproductionresultsshowthat,byusingboronicfluorine-freemoldpowder,theboronincrementinmoltensteelislessthan1.3ppmforconventionalaluminiumkilledlowcarbonsteel.

简介：Thepatentingprocessofthreehot-rolledsteelswithcarbonmasscontentsof0.70%-0.90%wasstudied.Theeffectofthequenchingtemperatureonthecementitelamellardistanceinthesteelwasevaluatedonthebasisofmicrostructuralcharacterizationandmechanicalpropertytests.Thepatentingtreatmentofhigh-carbonhot-rolledstripanditsapplicationinspringswerediscussed.

简介：Fossil-fuelburninggreenhousegasinducedglobalwarminghasbeenrecognizedasglobalenvironmentalproblems,reduceandultimatelycontroltheenergyproductionintheuseofCO2emissions,globalenergyproductionwillbeamajorchallenge.Asahighlyintensivematerialsandenergy,ironandsteelenterprises,needtobeinvestedtoproduceonetonofsteelabouttwotonsofmaterialand0.7tofstandardcoalenergy,andwhileproducingtwotonsofCO2.Therefore,reducingCO2emissionsfromironandsteelindustryhasbecomethefocusoftheglobalsteelindustry.Thispaperdescribesanintegrateddomesticandinternationalmeasurestocontrolcarbondioxideemissionsresearchprogressandfuturetechnologytrends,withemphasisonthedomesticsteelindustryemissionsofcarbondioxidestatusoftechnologydevelopmentandindustrializationofimplementationoftheproposedonthisbasis,includingdryquenchingtechnology,gas,powergeneration,coalmoisturecontroltechnology,blastfurnaceinjectionplasticstechnology,theuseofcokingprocessfortreatingmunicipalwasteplasticstechnology,sinteringheatgeneration,lowpressuresaturatedsteamforpowergeneration,metallurgicalslagheatrecoverytechnology,cokeovengashydrogentechnologyandtheotherkeytechnologiesenergysavingtechnologies,includingthedevelopment,promotionandpopularizationofthesteelindustryinChinawillbetheCO2emissionreductiontechnologydirectionandfocus.Atthisstage,theChinesesteelindustrycanbeimprovedtheenergyefficiencyandrecyclingofwasteheatandenergy,reduceunitGDP,CO2emissions;butinthelongrun,shouldincreaseCO2captureandstorageontheinputoftechnologycanpossibleeffectivecontroloftheadverseeffectsofCO2emissions.

简介：

简介：A0.06%Clowcarbonsteelwasdeformedintorsionoverthetemperaturerange877-917℃ina2%H2-Argasatmosphere.Strainsof0.25-5.0wereappliedatstrainratesofε=0.04s-1andε=0.4s-1tostudytheformationofferritebydynamictransformation（DT）attemperaturesabovetheAe3.ThecriticalstrainforferriteformationbyDTwasaboutε=0.2anditsvolumefractionincreasedwithstrainanddecreasedwithtemperatureabovetheAe3.Averageferritegrainsizesof1.5μmto5μmwereproduced,whichdecreasedwithstrainrate.Atthelowerstrainrate(ε=0.04s-1)reversetransformation（RT）tookplaceduringdeformationonceanincubationtimeofabout40s,wasexceeded.Anincreaseinstrainratefromε=0.04s-1toε=0.4s-1arrestedRTduringtestingatalltemperaturesasthetotaltesttimesdidnotexceed13s.ThepresentworkshowsthatDTisfavoredathigherstrainratesbyincreasingthedrivingforce（i.e.storedenergy）andbysuppressingRT.

简介：Thisarticleistrytoexplainoranalyzethekeytechnologiesofcontrollingthesurfacequalityoflowcarbonsteelascaststripthroughinvestigationofinterfaceheattransferbetweensolidifiedshellandliquidsteel.Theoneofthekeytechnologiesofcontrollingsurfacequalityoflowcarbonsteelascaststripisthroughthecastingrollsurfacetextureinordertoachievethehomogeneoussolidificationonthecastingroll.Anotheristhroughformingathinfilmonthecastingrollsurfaceinordertoachieveabalancebetweenrapidsolidificationandhomogeneoussolidification.Thisfilmformedbetweenthetwinrollandthemoltensteelcanbecontrolledbyadjustingthechemicalcompositionandinclusioninliquidsteelthroughcontrollingtheamountofall[O]andfree[O].

简介：Alloyingelements,suchassiliconandmanganese,haveamajorimpactonthephasetransformationpointofsteel.Specifically,manganeseisanelementfortheexpansionandstabilityoftheausteniteregion,whilesiliconcanexpandandstabilizetheferriteregion.Phasetransformationoccursduringthehotrollingprocessforthesteelwithcertainsiliconcontent,whichleadstogreatchangesofthedeformationresistance,therebyaffectingtherollingstability.Consequently,abetterunderstandingofphasetransformationintherollingprocesswillcontributetotheenhancementofproductquality.Inthispaper,theon-linerollingdatawereprocessedbymeansoftheinversecalculationmethod.Inthismethod,thesteeldeformationresistancewithvarioussiliconandmanganesecontentswasobtainedandanalyzedtodeterminethedeformationbehaviorofthesteel,whichcanhelpimprovetheon-linecontrolmodelandenhancethesteelquality.

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

简介：Themicrostructuralcharacteristicsandformabilityattheedgesoflowcarbonpickledsteelsheetshavebeeninvestigatedbasedonthegenerationofearingandcrackingdefectswhiledrawing.Themicrostructureoftheedgefeaturescoarsegrainsandmixedsizedgrains.Thestrengthofthesheetedgeisslightlylowerthanthatatthecenter.Besides,theformabilityisobviouslyworsened.Theplasticstrainratiosalongthelongitudinalandtransverseorientationsare0.31and0.6,respectively,withdistinctanisotropy.Theplasticstrainratioattheedgeisobviouslylowerthanthatatthemiddleofthesteelsheet.Theobservedmicrostructuralcharacteristicsandmechanicalpropertiesattheedgeofthesteelsheetcanbeattributedtothelowerrollingtemperatureinthetwo-phaseregionofpro-eutectoidferriteandaustenite.Thesedifferencesinmicrostructureandmechanicalpropertiesattheedgeofthesteelsheetleadtothegenerationofearingandcrackingdefectswhiledrawing.Themicrostructureandmechanicalpropertiesattheedgeoflowcarbonpickledsteelsheetscanbeimprovedviatheoptimizationoftherollingprocessandtheadjustmentofchemicalcomposition.

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:Theeffectofstabilizingelements,suchasNbandTi,onthemicrostmctureandpropertiesoflowcarbonferriticstainlesssteel(FSS)hasbeeninvestigated.TheresultsoftheThermo-calcsimulationhaveshownthattheinterstitialelements,suchasCandN,maybecompletelystabilizedbytheadditionofNbandTi.WiththeincreaseofNbandTicontents,thea+γtwophasesgraduallytransfertoasingleα-phaseunderahightemperaturecondition,andthecontentofthecarbideM_(23)C_6graduallydecreases.ThemicrostructurehasindicatedthatthecombinedadditionofNbandTicanpromotetherecrystallizationofthebandstructureandformmoreuniformequiaxedgrains.Also,withtheincreaseofNbandTicontents,theelongation,ther-valueandthecorrosionresistanceofcold-rolledandannealedsheetsareimprovedprominently.IncomparisonwiththeeffectofTi,theadditionofNbismorebeneficialtotheincreaseofr-valueandthecorrosionresistance.

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

简介：Aseriesoftestsofdeformation-inducedferritetransformation(DIFT)inalowcarbonsteelwerecarriedoutbytheGleeble-3500hotsimulationmachineatatemperaturerangeofAe3-Ar3.Theoverallstress-straincurvesduringDIFTcanbedividedintothreetypicaltypes:'double-humped','single-humped'and'transitional'.Thepeaksexhibitedinthecurveareinvolvedwithdeformation-inducedtransformationwhichhappenedingrainsoratthegrainboundaries.Accordingtothestress-timecurveandstrain-timecurve,straincapacitydramaticallypostponedthestrain-inducedtransformation,whichleadstothestartofthetransformationrightaheadofthefinishofdeformationandthemajorityoftheferritetransformationprocessmainlyhappenedafterthedeformation.Deformation-inducedtransformationisametadynamictransformationprocesswithdynamicnucleation.

简介：Coarsening,embrittlementandcorrosionsensitizationinahightemperatureheat-affectedzone(HTHAZ)arethemajorproblemswhen12%chromiumlowcarbonstainlesssteelisbeingwelded,whichinducethedeteriorationoftheimpacttoughnessatalowtemperatureandintergranularcorrosionresistanceproperty.ThisstudyinvestigatesthecorrespondingmicrostructuresinHTHAZwithdifferentchemicalcompositionsandheatinputsthroughthermalsimulationtests.Theresultsshowthatthemartensitecontentincreaseswiththedescendingofferritefactor(FF)whenFFisbelow9.0andheatinputinfluencesthemicrostructureofhighFFsteelinHTHAZ.Martensiteof12%CrstainlesssteelinHTHAZwithonlyNbstabilizationreticularlydistributesatferritegrainboundaries.