简介:Amulti-objectiveoptimizationapproachfortherollshiftingstrategyincrossrollingcampaignsofhotstripmillsispresented.Theeffectofdifferentrollshiftingstrategiesonrollwearcontourisstudiedbynumericalsimulation,andtwoevaluationindexes,namelybodysmoothnessandedgesmoothness,areproposed.Theaveragebodysmoothnessandaveragerollingedgesmoothnessofallstripsinarollingcampaignaretakenastheobjectivefunctions,theshiftingpositionsofallwidestripsasthedecisionvariables,andthemulti-objectivemethodofNSGA-Ⅱastheoptimizer.Thusamulti-objectiveoptimizationmodelfortherollshiftingstrategyisbuilt.Thesimulationresultsshowthatworkrollshiftingcanmakewearcontoursmooth,andadish-shapedwearcontourwithoutseverelocalwearcanbeachievedbytherollshiftingstrategywithvaryingstroke.OptimizationexperimentationshowsthatbymeansofNSGA-Ⅱ,agoodPareto-optimalfrontcanbeobtained,whichsuggestsaseriesofalternativesolutionsforrollshiftingstrategyoptimization.Theexperimentationalsoshowsthatthereisaconflictbetweenthetwoobjectives.Finally,applicationcasesconfirmthefeasibilityofthemulti-objectiveapproach,whichcanimprovethestripprofile,reduceedgewavesandextendtherollingmilesofarollingcampaign.
简介:Baosteel'sNo.8airseparationunit(ASU)isthefirstdomestically-integrated60000m3/hASU.Thispaperdescribesthemechanicalequipment,thedesignandtheconfigurationcharacteristicsofthisunit.ThepotentialfailuremodesofthemechanicaldevicesarededucedviaanalysesonthefailurehistoryofsimilardevicesinotherASUs.Finally,thispaperalsobringsupsuggestionsondailymaintenance,overhaulandpurchasesofspareparts.