简介：ThistalkwillsummarizetherecentworkrelatedtoakindofnewnanomaterialsproducedbytheSMAT(surfacemechanicalattritiontreatment).Theconceptofsurfacenanocrystallizationofmaterialswillbepresented.Intermsofthegrainrefinementmechanisminducedbyplasticdeformation,anovelsurfacemechanicalattrition(SMA)techniquewasdevelopedforsynthesizingananostructuredsurfacelayeronmetallicmaterialsinordertoupgradetheoverallpropertiesandperformance.ThegrainrefinementmechanismofthesurfacelayerduringtheSMAtreatmentwillbeanalyzedintermsofthenanostructureobservationsinseveraltypicalmaterials.Veryhighyieldstress(5timesofthebasematerial)onthesurfacelayerofthematerialobtainedbytheSMAThasbeenobserved.Theeffectofsurfacenanostructuresonthemechanicalbehaviorandonthefailuremechanismofmetallicmaterialshowsthepossibilitytodevelopanewstrengthgradientcompositeusingco-rollingandnitriding.Theroleofresidualstressinducedduringthetreatmentwillbeinvestigatedanddiscussed.Thedevelopedmaterialsarealsoporosityfreematerialswhichcanbeusedasreferencematerialforthelocalmechanicalbehaviorinvestigationtechniquesuchasthenanoindentation.Ageneralconceptforobtaininghighstrengthandhighductilitynanostructuredmaterialswillbepresented.Theexceptionalhighstrengthandhighductilitysteelshavedeveloped.Thesimulationofthemechanismsforimprovingductilityofhighstrengthnanostructuredmaterialswillbepresented.Thepotentialapplicationsforthelandtransportationvehicles(car,bus,train)andwindenergyhavebeeninvestigated.Someexamplesofconceptdesignfortheintegrationoftheadvancednanostructuredsteelswillbepresented.

简介：Inordertoresearchthetemperaturedistributionandmechanicaldeformationofslabbulgingduringhighspeedcontinuouscasting,mathematicalmodelshavebeendevelopedtoanalyzethethermalandmechanicalbehavioroftheslab.Thethermalhistoryoftheslabhasbeenpredictedbyatwo-dimensionaltransientfiniteelementheattransfermodel,whoseresultsserveastheinputtothestressmodel.Thestressmodelhasbeenformulatedforatwo-dimensionallongitudinalplane.Inthiscase,themaximumtensilestrainduringthebulgingprocessislocatedatthesolidificationfrontjustpastthetopoftheupstreamroll,whichmaycontributetocrackformation.Themaximumtensilestressesarelocatedatthecoldsurfaceinthemiddleofthetwoback-uprolls,justatthepointofthemaximumbulging.Stressesnearthesolidificationfrontaresmallbecauseofthehightemperatureswhichproducelowerelasticmodulusvalues.Finally,theeffectofthecastingspeedonthebulgingdeformationisdiscussed.

简介：IntheMetalsIndustry,interruption-freeprocessestoproducehigh-qualityendproductsareaprerequisite.Themaindrivestogetherwiththemillstandsplayakeyroleinthesuccessofrollingmills.Thecrucialdemandsplacedonthedrivesystemare:high-dynamicperformanceofdriveanditscontrolsystem,abilitytohandletheprocessrelatedoverloads,smoothrunning,highavailability,highefficiency,easyserviceabilityandabilitytointegrateseamlesslywiththeautomationsystems.WithnumerousreferenceinstallationsandmanyyearsofexperienceSiemensVAIhasthewiderexpertiseandtheportfoliotoprovidetherightdriveforeveryapplication.Thispaperexaminesthelatestinnovation,SINAMICSdrivetechnology,forbothnewdriveapplicationsaswellasformodernizingtheexistingdrivesinrollingmillapplicationslikehotstripsmills,platemills,coldrollingmills,andlongrollingmills.

简介：Withtheextensivelywideapplicationofadvancedhighstrengthsteels(AHSS)invariousfieldsfortheexcellentmechanicalproperties,theindustrialinterestonthedamageofAHSSisincreasingintherecentyears.Forthesemodernsteels,duetothecomplexmicrostructureandtherelevantdeformationmechanisms,thedamageconceptneedstobereexamined.Inthispaper,thedefinition,lengthscaleanddifferentmechanismsofdamageareintroduced.Bothexperimentalevaluationofdamageandthenumericaldamagemodelsarebrieflyviewedandcompared.Theapproachestoimprovethedamagetolerancearegivenintheframeworkofdamagetolerancedesignprinciple.

简介：High-strengthsteelshavebeenattractingmoreandmoreattentionofpeople,Unfortunately.deteriorationofductilitylimitedtheirapplications.Tosolvethisproblem,anano-structuredstainlesssteelsheetisdevelopedtocombinehighstrengthandhighductility.Processingofthesurfacemechanicalattritiontreatment(SMAT)wasintroducedtoobtainanano-grainlayeronthedoublesurfaceofthestainlesssteelsheet.Themicrostructureofthenanostructuredsteelsheetischaracterizedbyanalternatedistributionofcoarsegrainedlayerandnanocrystallinelayer.Thenthedualsurfacenano-crystallizedstainlesssteelsheetswereco-warmrolledat500℃.Theexperimentalresultsrevealthatthemechanicalpropertiesofthenanostructuredsteelexhibithighyieldstrengthintherangeof700-950MPaandtensilestrengthhigherthan930MPa.Moreover,elongationtofracturereachesto15%-48%,togetherwithauniformelongationstabilizedto13%-45%.

简介：Steelhasbeenusedasatraditionalwheelmaterialsforalongtime.Before1980’s,over90%wheelsweremadeofsteels.Then,theyieldstrengthofwheelsteelsincreasedgraduallyfrom240-350MPato600MPaorhigher.Theadvancedhighstrengthsteelsbecomethemainwheelmaterials.Since1990’s,DP600hasbeenbroadlyappliedinsteelwheelsoversea.However,therewaslittleresearchofapplicationofhighstrengthsteelwheels(especiallywheeldisc)indomesticwheelindustrial.Inpresence,DP600steelwheelisonlydevelopedinFAWSHbyusingimportedCKD.OtherdomesticsteelwheelmanufacturersdidlittleworkonhighstrengthDP600wheeldiscs.BaosteelwheelsCo.Ltd.isthefirstdomesticcompanyproducingDP600steeldiscsandhasbecometheleadingcompanyinproductionofhighstrengthwheel.BecauseofthehighstrengthofDP600,itsformability,springback,andwrinklehavebecomethekeysofthesuccessfulapplicationofDP600steel.Inthispaper,themetallurgicalandmechanicalpropertiesarefirstlyintroducedandformationproblemsofDP600aredescribedcomparedtotraditionalsteels.Secondly,FLDanalysishasbeendone.Wrinkleandmorespringbackarerecognized.Tosolvetheseproblems,anoptimizedsolutionisdesignedandthegoodresultisobtained.ThetesthasshownthatthefatiguepropertyofsteelwheeldiscsmadebyDP600havebeengreatlyimproved.

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

简介：Low-carbonbecomesahigh-frequencyandfashionablewordwhichgetsthegreatestconcernintheworld.Low-carbonreferstoaminimaloutputofgreenhousegasemissionsintothebiosphere,specificallyreferstothegreenhousegascarbondioxide.Toreduceenergyconsumptionofautomobile,moreandmorehighstrengthsteelsareusedbyvehiclecompanies.Tomeettherequestofvehiclecompanies,varioushighstrengthsteelsaredevelopedinsteelcompaniesallovertheworld.Ansteelcanprovide,ultra-lowcarbonbakehardening(BH)steels,dualphase(DP)steelsandtransformation-inducedplasticity(TRIP)steelswiththegradesofunder780MPa,uptonow.AHSSsteelshavemuchdifferentcomposition,microstructureandstrenghtthanconventionalvehiclesteels,sotherearesometroubleinproducingincoldrollingmills,forexample,difficulttojoin,poorthicknessandflatness,accuratetemperatureandvelocitycontrolandsoon.Toreducetheopportunityofstripbreakage,wehavedonemanyweldingexperimentsandspecialresearch.Now,DPandTRIPsteelscanbecontinuouslyproducedinAnsteel.Toassurethicknessandflatnessofstrips,weoptimizedthehotrollingparametertogetlowdeformationresistance,optimizedrollingoiltogetfitfrictionalcoefficientandfixonthetargatrollingcurve.Togetmoreaccurateandrepetitiveresultsovertheproductionshifts,theMathematicalModel(MM)isusedinAnsteel.TheMManalysesinformationtransmittedbyvarioussensorsandtransmitters,comparesthecollecteddatawiththechosenparametersandadjuststhesettingsofthevariouspiecesofequipmenttohoneontheparametersetpoints.Atpresent,thekeyproductiontechnologiesofAHSSweregraspedbycoldrollingmillAnsteel,andAnsteelisthefirstcompanytoapplytheTRIPwiththegradeof780MPa.

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：ZhongyuanoilfieldsaremainlylocatedinDongpudepression,wherethegeologicalconditionswereextremelycomplicatedandtheexternalstressisabnormallyhigh,thepipeusedmayfailintheradialdirectionowingtowellshrinkagecausedbythecreepofsaltrock,leadingcatastrophiceconomicloss.Thereforethisregionhasbeenwellkownasatouchstoneforhighcollapseresistancecasingsincelongbefore.Inordertosatisfytherequirementforhigh-collapsestrengthcasingowingtothecreepofsaltbedstratuminDongpuDepressionregion,BG140TT,BG150TTandBG160TThigh-strengthcollapseresistancecasingseriesweredevelopedtobettercopewiththeseveregeologicalconditions.Amongthecasingseries,aBG160TTnon-APIspecificationcasingwithcollapsestrengthnotlessthan170MPawereprepared.Uptopresent,allthesehigh-strengthcollapseresistancecasinghavebeensuccessfullyappliedintheDongpuDepressionregion.Theresearchconcept,mechanicalproperties,aswellasapplicationresultwereintroducedinthispaper.

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

简介：Thispaperstudiesthechemicalcomposition,tensileproperties,inclusions,metallogrophicstructure,andothersuchparameterstoidentifythecausesofcrackingduringthebendingofhigh-strengthsteel.Theresultsshowthatthemajorcausesofcrackingaretheoriginaltransversecracksorholesonthesurfaceoftheslabandthepresenceofscalesrolledintothecracksorholes.Coldfracturingfromsuchdefectsisrare,andcanbeeleminatedbyenhancingthecontrolofthesteelmakingprocessandbymechanicalclean-upofthesurfacecracksandholesintheslab.

简介：Thereliabilityofsteelweldsbecomesmorecriticalissuewithincreasingsteelstrength,becausebrittlephasesaremorelikelytoformintheweldmetalsandheat-affectedzone(HAZ)andtherebythetoughnessandductilityoftheweldsaredegraded.Therefore,refinementofmicrostructureandminimizationofthebrittlephasesarenecessarytoimprovethereliabilityofthehigh-strengthsteelwelds.Inthispresentation,microstructureformationthatcontrolsthetoughnessofweldmetalsandHAZinhigh-strengthlow-alloy(HSLA)steelweldsisreviewedandpossibleroutestotheimprovementoftheweldmicrostructureandweldtoughnessarediscussed.

简介：Inthisstudy,a600MPahot-rolledcorrosion-resistantsteelplateproducedbyaspecificcompanyisinvestigated.Edgejaggeddefectsandedgesurfacedefectsgeneratedonbothsidesofthestripduringproductionarecharacterizedandanalyzed.Theresultsindicatethatthedistributionofreoxidationgranulesislocatedunderneaththesurfacepeelandthatcopper-containinggranulesdiffusealongaustenitegrainboundaries.Thisphenomenoncombinedwiththechemicalcompositionandproductionparametersofastripindicatethatcopperbrittlenessleadstoedgejaggeddefects.However,thesurfacedefectsshouldbeattributedtoinherentdefectsonthesurfaceofthestrip.Measuresthatpreventsurfaceoxidationandcoppersegregationatgrainboundarieswouldlikelyeliminatethesetwotypesofedgedefects.

简介：Traditionally,austeniticstainlesssteels304and316havebeenemployedincoastalregionsasroofingmaterialsunfortunately,theyareexpensiveandnotfullyresistanttopittingcorrosionunderseverecoastalcorrosiveenvironment.AferriticstainlesssteelB445Rwasdeveloped.Comparedwithaustenitic316L,B445Ris①lesscostly;②uperiorcorrosionresistantwithminormaintenanceforlong-termservice;③insusceptibletothermaldistortionintheweldingseam.B445Rsheetshowsahigheryieldstrengthandlowertensilestrength,lowerelongationandlowerwork-hardeningthanaustenitic316L.Itcanbeeasilyfabricatedanddeformedjustlikeplaincarbonsteel.Afterbending180o,thereisnooccurrenceof'cracking'ornoticeable'orangepeel'.Theformabilityoftheweldingseamisalsosatisfactory.ThepittingpotentialofB445Ris650mV,largerthanthatof304and316L,asshowninFig.1.ThecorrosionrateofB445Rsubmergedin6%FeCl,solutionis0.3-0.56g/(m2?h-1),muchlowerthanthatof316L,asshowninFig.2.ThesuperiorpittingcorrosionresistanceofB445RcanbeascribedtosynergeticeffectofhigherCrandMo.Dull-finishedB445RsheetshavebeenemployedastheroofingmaterialsforGuangzhouAsianGamesArena,asshowninFig.3.About380tof1.0mmB445Rwithdullfinishwasusedforroofingpanels.About100tof0.8mmB445Rwithhairlineorfluororesinpaintfinishwasusedforsidewallpanels.Thecompositeroofbuild-up（fromuptobottom）includes:①shinglesofferriticstainlesssteelB445R;②Kalzip-typestandingseamofaustenitic304;③water-proofDFM;④structuralsteel;⑤75mmthickinsulation;⑥secondarypurlinof150mm×100mm×4.5mmofgalvaniziedQ235;⑦0.8mmthickprofiledeckofgalvaniziedQ235;⑧acousticinsulation.Theroofingshinglesorpanelswiththesamewidthbutdifferentlengthwereformedbybendingfoursidesandfixedtoa'L'shapereinforcingframesofstainlesssteelbyfasteners.The'L'frameswasconnectedtoribsofthestandingseambyacl

简介：High-temperatureperformancetestsofchromium-containingstuffingsandforasteelladlewithdifferentratioswereperformed.Ahigh-temperaturesimulationtestfurnacewasusedtoanalyzetheinfluenceofthecompositionratioofladlefillersandandsinteringtimeonthehigh-temperaturecompressionresistanceofchromium-containingstuffingsandinthetemperaturerangeof1500-1600℃.Theresultsshowthattherefractorinessofladlefillersandwasthelowest(only1610℃)whenthecompositionratioofchromitesandandsilicasandwas6∶4.Moreover,thehigh-temperaturecompressionresistancewashighwhenthecontentofchromitesandwasat70%;theresistanceincreasedwithincreasingsinteringtime.Whenthesinteringtimewasextendedatatemperatureof1600℃,thehigh-temperaturecompressionresistanceofladlefillersandfirstincreasedandthendecreasedafterbeingoverburnt.

简介：Steel20Mn23AlVisatypeofhighaluminumsteelwithaverylowladlefree-openingrate.Thealuminumcompositionof20Mn23AlVrangesfrom1.6%to2.45%,whichissignificantlyhigherthanothertypesofsteel.Accordingtotherealconditionof40tladleinsteel-makingplantofBaosteelSpecialSteelCompany,previousworksshowthatthekeyfactorsaffectingtheladlefree-openingrateofhighaluminumsteelincontinuouscastingare:sandmaterial,accessoriesbaking,ladlenozzlecleaning,theprocessandamountofaddingsand,andtherateofargonstirringduringrefining.Therefore,improvingtheladlefillersandquality,bakingalloftherawmaterials,controllingtheadditionofladlefillersand,cleaningtheladlenozzle,andoptimizingargonstirringduringtherefiningprocesscanresolvetheproblemofalowladlefree-openingrateofhighaluminumsteelcausedbythelongladletimeofliquidsteel.

简介：Controlledcoolingtechnologyisgettingmoreandmoreattentionwiththedevelopmentofthermal-mechanicalcontrolprocess.Inthepastdecade,achievingthegivenfinishcoolingtemperaturewasthesolegoalforthetechnology.However,withtheresearchanddevelopmentofnewsteelssuchassuperhighstrengthsteel,researchershaveinrecentyearsrealizedthedeterminateeffectsthatdifferentcoolingpathshaveonthefinishcoolingtemperatureandpaidmoreattentiontothecontrolofthecoolingrate.Thispaperfocusesonnotonlytheoptimizationofthecontrolledcoolingsystemwithhighprecisionandfastcoolingrate,butalsotheresearchanddevelopmentofthehighstrengthsteelplatewithreducedalloyingcomponent.

简介：Improvingthegalvanizabilityofhighsiliconadvancedhighstrengthsteels(AHSS)isapracticaltechnicalchallenge.Inthisstudy,spotdefectsonanindustrialhotdipgalvanized(GI)sheetofanAHSSwith1.5%Sihasbeenstudiedin-depth.ThesurfacemorphologiesofspotdefectsbeforeandafterpartialandcompleteremovaloftheZnlayer,aswellastheinterfacebetweentheoutermostcoatinglayerandthesheetsubstratewerecharacterizedusingopticalmicroscopy(OM),scanningelectronmicroscopy(SEM),a3-Dopticalprofiler,energydispersivespectroscopy(EDS)andfocusedionbeam(FIB)analysis.Themostoutstandingspotdefectonthenormallycoatedareaofthesteelsheethasadiameterofapproximately500μm,withthefollowingcharacteristics.Inthecentralregionofthespotdefect,ZnisbarelycoatedandthesheetsubstrateiscoveredbyathinsiliconoxidefilmwithdispersedZn-Feintermetallics.Attheperipheryofthespotdefect,aburststructureofZn-Feintermetallicsformsonthesheetsubstrate.OutsidethespotdefectwheretheZnlayerisnormallycoated,thereisacontinuousFe2Al5inhibitionlayerbetweentheZncoatingandthesheetsubstrate.Theseresultsindicatethatasiliconoxidefilmformsonthesubstrateduringannealingpriortohotdipping,thuspreventingtheformationoftheFe2Al5inhibitionlayerduringhotdipping.ThiscausesspotdefectsonhighSiAHSSsheets.

简介：InwallshotblastingisamethodofimprovingthesurfacehardnessandhightemperatureoxidationresistanceoftheS30432high-pressureboilertube.Thedifferencesonresidualstress,sub-grainsize,micro-hardnessandstructurebetweentheS30432inwallshot-blastingtubeproducedbyBaosteelwithsixtechnologicalprocessparametersandtheimportedsuper304Hwerestudiedsystematicallybycontrasttestresearch.IthasbeendemonstratedthattheS30432obtainsahigherresidualstress,adeeperdistributed...