简介：ZhongyuanoilfieldsaremainlylocatedinDongpudepression,wherethegeologicalconditionswereextremelycomplicatedandtheexternalstressisabnormallyhigh,thepipeusedmayfailintheradialdirectionowingtowellshrinkagecausedbythecreepofsaltrock,leadingcatastrophiceconomicloss.Thereforethisregionhasbeenwellkownasatouchstoneforhighcollapseresistancecasingsincelongbefore.Inordertosatisfytherequirementforhigh-collapsestrengthcasingowingtothecreepofsaltbedstratuminDongpuDepressionregion,BG140TT,BG150TTandBG160TThigh-strengthcollapseresistancecasingseriesweredevelopedtobettercopewiththeseveregeologicalconditions.Amongthecasingseries,aBG160TTnon-APIspecificationcasingwithcollapsestrengthnotlessthan170MPawereprepared.Uptopresent,allthesehigh-strengthcollapseresistancecasinghavebeensuccessfullyappliedintheDongpuDepressionregion.Theresearchconcept,mechanicalproperties,aswellasapplicationresultwereintroducedinthispaper.

简介：Trendsintoday’ssteelproductionshowincreasingdemandsforhighly-sophisticatedsteelgrades.Therefore,thesteelindustrywilleventuallyberequiredtoinstallbestperformingtechnologiestomeetgovernmentalspecificationsdesignedtosignificantlyreduceenvironmentalemissions.Sucheffortsaresupportedbyinnovativenewsolutionsintheentiresteelmakingprocess.Oneprocessthatwillneedtobeaddressedisthecleanlinessofthesteelintheliquidsteelphase,especiallyduringtheBOF-tappingprocess.Thenewconvertergate(CG)(Fig.1)bestsupportstheslidegatetappingtechnologyforconvertersintermsofcleansteel,productivity,yieldandavailability-atreducedcosts.TheCGgateintroducesauniquefeatureforconverterslidegates:Thebottomplatecanbeexchangedwhilethegateremainsmountedontheconverter.Thisnewfeatureallowsforanincreasedutilisationoftherefractorypartsandasignificantreductionofthedowntimeoftheconverter.This'designedefficiency'isachievedwitharefractorysetconsistingofthreeidenticalplates-twobottomplatesandonesliderplate-andanozzle.AnumberofotherimprovementssuchasautomaticcylindercouplingusingtheInterstopSNAPtechnologyandatwosteptensioningsystemhavealsobeenimplemented.ThenewsystemisdesignedtomeetminimalspacerequirementsandthereforewilladapttomostBOFshops.Toperformpreparation,serviceandmaintenanceworkthemodularCGgatecanbedismountedfromtheconverterandsimultaneouslyreplacedbyaready-to-useunit.Thedegreeofautomationfordismountingandmountingaswellasforoff-linepreparationhasbeenenhancedandreducesmanualefforts.Thispaperprovidesasolutiontotheobvioustrendtowardsefficientandcontrolledproductionofcleansteel,ingeneral,andespeciallyatBOFshops.Moreover,itspecificallydescribestheoperationalresultsofthisinnovativeBOFtappingequipmentatSalzgitterFlachstahlGmbH,Germany.