简介:ThegrainrefiningmechanismofC-Mnsteelsheetoncompactstripproduction(CSP)linewasinvestigatedinthisstudy.Thegrainwasabout100μmafterF1passanddecreasedallthewayoftherollingprocess(F2-F6)to15μm.Repeatedphasetransformationexperimentwasconductedtothesteelforgrainrefinement.Thephasetransformationat860℃and920℃canrefinethegrainsizeto7.5μm.
简介:AtBaoshanIron&SteelCo.,Ltd.,cornercracksofboroncontainingLCAKsteelslabshadcausedremarkablequalitylossandmassflowdisorder.Withthehelpoffractographyandthermodynamicsanalysis,theembrittlementmechanismofthissteelgradewasstudiedandtheresultsareasfollows:①Thetransformationfromγtoαstartsattheaustenitegrainboundariesandalayerofthinferritefilmgraduallyformsaroundtheaustenitegrains.Strainconcentrationwillpreferentiallystartinsidetheferritephasewhenthestressaccumulatestoacertainlevel.②ThecoarseBNparticlesacceleratedlyprecipitatedattheγ/αinterfacesfurtherdeterioratetheductilityoftheferritefilm,andbrittlenessresultsinstrainconcentrationandmicrovoidcoalescenceinsidetheferritefilm.Thereforetheaustenitegrainboundariesarepronetointergranularfailure.③ThestoichiometryamongAl,NandBisaveryimportantfactorinfluencingthehotductilityofthissteelgrade.BycontrolingtheB-to-Natomicratiotoabove1,allNcanbefixedbyBinsteadofAl.Thuscoarse-grainedsteelisavailableandfewergrainboundariesandhigherductilitycanreducetheriskofcornercracks.④ByadjustingtheB-to-Natomicratio,BaoshanIron&SteelCo.,Ltd.successfullyreducedthenumberofcrackstonearlyonetenthofthatinthepastandthehottensiletestsconfirmedremarkableimprovementinthehotductilityofthissteel.
简介:Theformationofsolidsolutioncombinedwithtricalciumphosphateanddicalciumsilicatecouldpromoteaconsiderableremovalofphosphorusfromliquidslagtosolidduringhotmetaldephosphorization,andthusthedephosphorizationbyusingmultiphasefluxescouldsignificantlydecreasetheconsumptionoflime.However,thereactionmechanismofmultiphasefluxeshasnotbeenunderstoodclearly.Inthepresentstudy,thephasediagramfortheCaO-SiO2-FeO-P2O5systemhasbeenmeasuredwithcertainoxygenpartialpressureathotmetalpretreatmenttemperature.ComparingwiththeCaO-SiO2-FeOsystem,shrinkageofliquidphaseareaathigherFeOcontentswasobservedat1673Kwithoxygenpartialpressureof9.2×10-11atm.