简介:Thisstudysummarizessomeseriousdisharmoniousproblemsthatubiquitouslyexistinthecastingresiduerecyclingofsteelplants,suchaslargelandoccupation,lowoperationalefficiency,hiddenhazards,hugeresourceandenergyconsumption,seriousenvironmentalpollutionandsoon.Itanalyzesthenecessityoftheon-lineinnovationandrecyclingbasedonthepresentsituationofBaosteel.ItstatestheinnovationofthenewgridtechnologyandtheachievementsofitsintegratedapplicationatBaosteel.ItalsosummarizesandelaboratessomegreentechnologyfeaturesofthetreatmentandtheutilizationoftheBaosteelcastingresidueandthenewgridtechnology,suchassafety,energy-savingandenvironmentalprotection.Inaddition,itlaysouttheprospectsforthedevelopmentandapplicationofthetechnology.
简介:Fluorineinmoldpowderisknownasharmfultohumanhealthandtheenvironment.Beingtheadvocateofgreenproduction,Baosteeldevelopedanenvironmentallyfriendlymoldpowderwithoutfluorine.Themainproblemoffluorine-freefluxfilmissmallheatresistanceandthustheheattransferintensityofthemoldistoolarge,whichtosomeextenthinderstheincreaseofthecastingspeed.Withtheheatflowsimulationequipment,controllingprecipitationofcrystalinfluxandsolidificationtemperatureproperly,fluorine-freemoldpowderforlowcarbonsteel,whichsubstitutesFwithB2O3,wassuccessfullydevelopedandappliedinindustrialproduction.Theproductionresultsshowthat,byusingboronicfluorine-freemoldpowder,theboronincrementinmoltensteelislessthan1.3ppmforconventionalaluminiumkilledlowcarbonsteel.
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:The18Ni300gradecobalt-freemaragingsteelT300wassuccessfullymanufacturedonanindustrialscalebyapplicationofvacuuminductionmelting(VIM)andvacuumarcremelting(VAR)processatBaosteel.WiththecontentofOandNlessthan15ppmand10ppmrespectively(1ppm=10-6),theT300steelproducedbyBaosteelobtainedahighdegreeofpurityandagoodcombinationofultra-highstrengthandfracturetoughness.Theeffectsofsolutiontemperatureandageingtemperatureontensilepropertyofsolution-treatedandagedT300steelwereinvestigated.Theresultsshowthatthesolutiontemperatureslightlyinfluencesthestrengthofthesolution-treatedsteel,indicatingthatthesolutionstrengtheningratherthanthegrainboundarystrengtheningismoreimportanttothesolution-treatedsteel.Forthesolution-treatedT300,theelongationandreductionofareadon'tchangemuchwitharisingsolutiontemperature,andremainabove17%and70%respectivelyatthesolutiontemperaturerangingfrom800℃to1200℃.FortheagedT300steel,thestrengthandelongationarereducedwithanincreasingsolutiontemperature,andthesolutiontemperaturehasagreatereffectonthereductionofareathanthatontheelongation.Thereductionofareaoftheagedsteelreachesahighpeakwhenthesolutiontemperaturereaches920℃.Theexperimentaldataindicatesthatprecipitationstrengtheningmakesacontributionof1100MPatothetensilestrengthoftheagedsteel.Theageingtemperatureexertsagreatereffectonthestrengththanontheelongationandreductionofarea.Thesteelachievesabettercombinationofstrengthandtoughnessatthepeakageingtemperatureof500℃.
简介:Toexploretheapplicationofsevereplasticdeformationforgrainrefinementinsteelproduction,anewmethodcalledcontinuousfrictionalangularextrusion(CFAE)wasappliedtorefinethegrainofinterstitial-freesteel.Thedeformationwascarriedoutatroomtemperatureandindividualsheetspecimenswereprocessedindifferentnumberofpasses.Anoverallgrainsizeof200nmwasachievedafter8passesandtheproportionofhigh-angleboundariestothetotalboundarieswasmorethan60%.ThroughthecharacterizationofhighresolutionEBSD,X-raydiffraction(XRD)andhardnesstesting,thispaperdiscussedtheevolutionofmicrostructuresandtexturesduringdeformationandexploredthedevelopmentdirectionofthemethod.
简介:Inrecentyears,theconcernaboutenvironmentalprotectionisincreasingonaworldscale.MajormanufacturersofhomeappliancesandOAequipmenthaveintroducedso-called'greenprocurementschemes'forreducingenvironmentallyharmfulsubstancesinmanufacturingprocessandendproducts.Undersuchbackground,anewtypeofchromate-freeorganiccompositecoatedelectro-galvanizedsteelsheetwithhighconductivitywasdevelopedbyBaosteel,whichmeetstheEURoHSDirective(RestrictionoftheHazardousSubstances)andotherrelatedlawsandregulationsonenvironmentalsafety.Italsoprovidesexcellentsurfaceelectricalconductivity,corrosionresistance,fingerprintresistance,solventresistance,coatingadhesion,heatresistance,formabilityandotherspecialpropertiestomeetthedemandofmanufacture’sprocessofOAmachine.Comparedwithpreviouslydevelopedanti-fingerprintingcoatedelectro-galvanizedsteelsheet,thisnewlydevelopedproducthasagoodbalancebetweenhighcorrosionresistance(timeto5%whiterustinsaltspraytestis120hforflatpaneland72hforworkedpotion)andconductivity(surfaceelectro-resistivityinaccordancewithLOREASTislessthan0.1milliohm)duetothespecialdesignofcoating’sstructure.Besides,Italsoprovidesthepropertiesofgroundingandshieldingagainstelectromagneticwaves.Theevaluationofsurfaceperformancesofnewproductshowedthatitiscomparableorevenbetterthanthesimilarproducts.Currently,thenewlydevelopedproducthasbeencommercialized.Inthispaper,themajorpropertiesarediscussed,suchascorrosionresistance,surfaceelectricalconductivity,fingerprintresistance,solventresistance,coatingadhesion(ink/melaminealkydpaint),heatresistanceandformability.Furthermore,theapplicationisalsobrieflydescribed.
简介:Semicontinuousequal-channelangularextrusion(SC-ECAE)isanovelsevereplasticdeformationtechniquethathasbeendevelopedtoproduceultrafine-grainsteels.InsteadofexternalforcesbeingexertedonspecimensintheconventionalECAE,drivingforcesareappliedtodiesinSC-EACE.Thedeformationofinterstitial-free(IF)steelwasperformedatroomtemperature,andindividualspecimenswererepeatedlyprocessedatvariouspasses.Anoverallgrainsizeof0.55μmwasachievedafter10passes.DuringSC-ECAE,themaintexturesofIFsteelincluded{111}<110>,{110}<112>,{112}<111>,{110}<111>,and{110}<001>Atanearlystage,increasingdislocationsinducenewtexturesandincreaseintensity.Whenthedeformationcontinues,low-angleboundariesareformedbetweendislocationcellbands,whichcausesomedislocationcellbandstochangetheirorientation,andtherefore,theintensityofthetexturesbeginstodecrease.Aftermorepasses,theintensityoftexturescontinuestodecreasewithhigh-angleboundaries,andthesub-grainsindislocationcellbandscontinuouslyincrease.Thepresentstudyreportstheevolutionoftexturesduringdeformation;thesewereexaminedandcharacterizedusinghigh-resolutionelectronbackscattereddiffraction(EBSD)inafieldemissionscanningelectronmicroscope.Themechanismsoftextureevolutionarediscussed.
简介:Ba0.85Ca0.15Ti0.9Zr0.1O3(BCTZ)lead-freepiezoelectricceramicsco-dopedwithCeO2(x=0.1wt.%,0.2wt.%,0.3wt.%,0.4wt.%,0.5wt.%)andLi2CO3(0.6wt.%)werepreparedbyconventionalsolid-statereactionmethod.InfluenceofCeO2dopingamountonthepiezoelectricproperties,dielectricproperties,phasecompositionandmicrostructureofpreparedBCTZlead-freepiezoelectricceramicsdopedwithLi2CO3wereinvestigatedbyX-raydiffraction(XRD)andscanningelectronmicroscopy(SEM)andotheranalyticalmethods.TheresultsshowedthatthesinteredtemperatureofBCTZlead-freepiezoelectricceramicsdopedwithCeO2decreasedgreatlywhenLi2CO3dopingamountwas0.6wt.%;apureperovskitestructureofBCTZlead-freepiezoelectricceramicsco-dopedwithLi2CO3andCeO2andsinteredat1050°Ccouldalsobeobtained.Thepiezoelectricconstant(d33),therelativepermittivity(εr)andtheplanarelectromechanicalcouplingfactor(kp)ofBCTZceramicsdopedwithLi2CO3increasedfirstlyandthendecreased,thedielectricloss(tanδ)decreasedfirstlyandthenincreasedanddecreasedatlastwhenCeO2dopingamountincreased.TheinfluenceofCeO2dopingonthepropertiesofBCTZlead-freepiezoelectricceramicsdopedwithLi2CO3werecausedby'softeffect'and'hardeffect'piezoelectricadditiveandcausinglatticedistortion.WhenCeO2dopingamount(x)was0.2wt.%,theBCTZceramicsdopedwithLi2CO3(0.6wt.%)andsinteredat1050°Cpossessedthebestpiezoelectricpropertyanddielectricpropertywithd33of436pC/N,kpof48.3%,εrof3650,tanδof1.5%.
简介:Pt-freecounterelectrode(CE)composedofLa2MoO6(La2O3-MoO3)wassuccessfullysynthesizedbysimplepyrolysisoflanthanumacetate(C6H9O6La·xH2O)andhexaammoniumheptamolybdatetetrahydrate((NH4)6Mo7O24·4H2O).Furthermore,threeproportionscompositescatalystsofLa2MoO6@MWCNTsbasedonLa2MoO6andmultiwallcarbonnanotubes(MWCNTs)werepreparedandcharacterizedasPtfreecatalystforCEindye-sensitizedsolarcells(DSSCs).ThemorphologyandstructureofLa2MoO6@MWCNTscompositesweredeterminedbyscanningelectronmicroscopy,transmissionelectronmicroscopeandX-raydiffraction.TheelectrochemicalperformanceofLa2MoO6@MWCNTscompositecatalystsforCEswasdeterminedbyphotocurrent-voltagemeasurements,cyclicvoltammetry,electrochemicalimpedancespectroscopy,andTafelpolarization.Thepowerconversionefficienciesof4.68%,4.87%and5.06%areobtainedforLa2MoO6:MWCNTswiththemassratiosof5:1,3:1and1:1towardsthereductionofI3-toI-underthesameconditions,respectively,whicharesuperiortothoseofMWCNTs(3,94%)andLa2MoO6(1.71%)electrodes.TheexperimentalresultsrevealthatthepresenceofMWCNTsresultsinanaugmentedactivecatalyticsurfaceareaandenhancedchargetransferfromCEtotheelectrolyte.