简介:介绍ER70S-6X焊丝钢的生产情况。通过化学成分及残余元素控制、精炼脱氧制度优化、连铸保护浇注和铸温铸速的稳定控制等工艺措施的实施,使EK70S-6X焊丝钢的产品质量和综合性能得到了稳定提升。
简介:Overthepast10years,China'ssteelindustryhasmadeasubstantialdevelopmentintermsofscale,andhasfinallybecomeasteelgiantintheworld.Intheupcoming10years,fundamentalchangeswillbemadewiththeeconomicgrowthinChina.Againstthisbackground,China'ssteelindustrywillshiftfromarapiddevelopmenttoaslowbutsounddevelopment.InordertofulfillthesecondleapofChina'ssteelindustry,basedonitscurrentdevelopingstatusandcharacteristics,andfromtheperspectiveofbothnationalandcorporatedevelopment,mergersandacquisitionarebotheffectivewaystoraisethequalityoftheexistingstockofassetinthesteelindustry,whiletechnologicalinnovationisthesolidfoundationforitssecondleap.
简介:Loadingdistributionforheavyplatemillistofindoptimalcontrolsolutionsunderthegrantedperformanceindicatorsandconstraintsincludingmillcapacityandhypothesisofrollingmodels.Thesolutionsarequitedifferentfordifferentperformanceindicators.Inthearticle,theperformanceindicatorsandsequentialquadraticprogramming(SQPforshortbelow)methodsemployedin5000mmheavyplatemillofBaoSteelarepenetratinglyanalyzed.Generally,theSQPmethodisaneffectiveandfastwaytosolvethenonlinearprogrammingproblemswithsmallormediumscaleconstraints.Earlyin1976,HanputforwardtheSQPmethodforthefirsttimeandPowellmadeitperfectandaccomplishedthealgorithmin1977.Infact,SQPmethodwastoturnanonlinearprogrammingproblemtoaseriesofsubsetofquadraticprogrammingproblems.Inthealgorithm,eachiterationstepistosolveonequadraticprogrammingproblem.Theoptimalsolutionswillbegraduallyapproachedafterquadraticprogrammingproblemsweretotallysolved.Whensolvingthequadraticprogrammingproblem,theactivesetstrategywereemployedwhichturnedtheconstrainedquadraticprogrammingproblemtounconstrainedquadraticprogrammingproblem.Theactivesetstrategymadethewholequadraticprogrammingproblembesolvedbyaleastsquareproblem.Andfinally,thematrixoftheleastsquareproblemwouldbedecomposedbyQmatrixandRmatrix.AfterQmatrixandRmatrixwereobtained,theoptimalsolutionswouldbefinallyfound.Forloadingdistribution,theperformanceindicatorswerecomposedbyplateshapeanddraftofeachpass.Plateshapeisrepresentedbyrollingforcegraduallyreducedpassbypasswithatunablefactor.Themillcapacityisanotherperformanceindicatorrepresentedbydraftofeachpass.Forheavyplatemill,themillcapacityhereisthemotormoment.Forheavydraft,themotorwouldbeoverloadedespeciallyforthefirstseveralpasses;forsmalldraft,themotorwouldbeloadedslightly.Allthesewouldnotbepermittedtohappenwhen