高品质IF钢洁净度的研究

IF___________________________________________________________________________20100622G20084072__________________________IFResearchontheCleanlinessofHighQuilityIFsteel100083DoctorDegreeCandidateWeiQianlongSupervisorBaoYanpingSchoolofMetallurgicalandEcologicalEngineeringUniversityofScienceandTechnologyBeijing30XueyuanRoadHaidianDistrictBeijing100083P.R.CHINA____________________________________________________IF_________________________20100622TF762+.8-I--III-IFIFIFIFCOIFIFRH[%C]0.025~0.035a[O]=500~700ppmTiAlAlTiTiRHRHIFMnO-FeORHAl2O3Al2O3-TiOxAl2O3-TiNSiO2IFIF-V-ResearchontheCleanlinessofIFsteelwithRefiningAbstractIFsteelisanewgenerationpunchingsteelwhichdemandhighcleannessanddeep-drawproperty.Soitiswidelyusedinautomobileandhouseholdappliancesandwasconsideredtobethesymbolofproductionlevelofsteelcorporation.ThepaperanalysisthecontrolofC,O,TandthechemicalcompositionsbasedontheproductiondataofShouGangsteelcorporation.Byindustrialexperimentsandsystematicsampling,Themorphologiesandcompositionsoftheinclusionsinthedifferentprocessduringtherefiningwerestudied.Theevolutionlawoftheinclusionsintheprocesswerediscussed.TheidealconditionfornaturaldecarbonizationduringRHisthatthe[%C]anda[O]werecontrolledin0.025~0.030percentand500~700ppmrespectivelybeforetheRHrefining.Thisconditioncanmakesurenaturaldecarbonizationworksmoothlyandshortthetimeofdecarbonization.ThelossrateofTiisproportionaltothelossrateofAl.Areasonableoxygenactivity,lowoxidationofslagandextensionoftimeofTiadditionisbeneficialforthereducingoflossofTi.BecauseofthehighoxidationoftheslagafterBOF,thesulfurandphosphoruswerebacktotheliquidsteelduringtheRHrefiningprocess.BeforeRHrefining,themaininclusionisMnO-FeOcomplexinclusion;afterRHrefining,themaininclusionisAl2O3andAl2O3-TiO2;themaininclusionoftheslabisAl2O3-TiNwhichisincludedforsquareandirregular;themainlargeinclusionoftheslabissphericalinclusionsofcalciumaluminateandirregularhigh-SiO2Inclusion.Consequently,optimizingthealloyadditionandaddingtimereasonablyisveryimportant.Besides,reducingtheoxidationofthetopslag,thenon-steadyoperationandaccuratingtheprocesscontrolarethekeysoftheproducinghigh-qualityIFsteel.KeyWordsIFSteel,clealiness,compositioncontrol,inclusion-VII-............................................................................................................................I..........................................................................................................................IIIAbstract.........................................................................................................................V1............................................................................................................................12....................................................................................................................22.1IF....................................................................22.2IF..............................................................................52.2.1....................................................................................52.2.2........................................................................................52.2.3RH..................................................................................52.2.4................................................................................................62.3IF..............................................................................................62.3.1IF............................................................................................62.3.2IF........................................................................................92.3.3IF......................................................................................102.3.4IF..................................................................................122.3.5IF..............................................................................133IF........................................................................................153.1................................................................................................153.1.1......................................................................................153.1.2RH........................................................................................153.1.3..............................................................................................163.2................................................................................................163.3CO..................................................................................................163.4....................................................................................................203.4.1[Al]s..........................................................................................203.4.2..............................................................................................223.4.3[Ti].....................................................................