简介：ThepapershowsthemainsurfacedefectsofcoldrollingautomobilesheetinBXSteel.Themainsurfacedefectsareunusualdefects.Thetypicalfamiliardefectsaresliverandpunctuatesthatareontherollingdirection.Theinclusionsofsteel-makingandscalesofhotrollingprocessarethemaincausesofdefects.Theyarethebiggestproblemspuzzlecoldrolledautomobilesheetsurfacequality,andaretheburningissuesofBXSteel.Weclassifyandanalysisthedefects.Weobservethepanoramaofsurfacedefectsusingportablevideomicroscopyapparatus,andcleanthesampleusingultrasonicshaker,analysisthedefectspatternandchemicalcompositionusingscanningelectronmicroscope.Atpresenttheprimarydefectsthatimpactedcoldrolledautomobilesheetqualityaredarksliverdefects.Wecontrolthesteel-makingandhotrollingprocessaimingatthecauseandpositionofdefectsmaking.Wefinecontroltheoperatingofsteelladle,gating,castingsystemandcontinuouscastingmachineinsteelmakingprocess.Thescaledefectisreducedbycontrollingfurnace,highpressurewaterdescalingsystemandfinishmilldescalinginhotrollingprocess.Alonewiththereformingandrenewingofequipment,gatheringproducingexperience,thecoldrolledautomobilesheetqualitymadeinBXSteelisupgradinggradually.