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ElectrodeismeltedbymeansofaDCarcundervacuum(electrodenegative,meltpoolpositive)RemeltingcurrentsuptokAOVacuumrangePa(some applicationsupto1,Pa)ElectrodeweighingsystemArticleemberIntroduction.Itisalsousedinthetriplexproductionofsuperalloys.Fourstatevariableswere usedtodevelopasimplestate-spacemodeloftheVARprocess:electrodegap(G),electrodemass(M),electrodeposition(X)andelectrodemeltingrate(R) IntroductionBothvacuumarcremelting(VAR)andelectroslagremelting(ESR)processes(Figure1)produceingotsofsteelandNialloyswhichareregardedas ultimateachieversofcleanmetalsAParametricStudyoftheVacuumArcRemelting(VAR)Process:EffectsofArcRadius,SideArcing,andGasCoolingThe vacuumarcremelting(VAR)processisextensivelyusedtopurifynumerousalloyssuchasstainlesssteel,Nickel-based,andTitanium-basedalloysTheheatfrom thearcmeltstheelectrodeandmoltenHe,AJLoweIngotweightsuptotonsAuthors:EbrahimKarimi-SibakiTheNi-basedalloysproducedmustexhibit excellentcleanliness,homogeneity,andbedefectfreeThevacuumarcremelting(VAR)processiswidelyusedtoimprovethecleanlinessandrefinethestructureof standardairmeltedorvacuuminductionmelted(VIM)ingots.This,inturn,dependsonthefluidmotioninthepool,sincethedominantmechanismfortransporting heatisconvectionFeaturesofVARfurnacesfromALDIngotdiametersupto1,mmThisarticleillustratestheVARprocessandthecapabilitiesandvariablesof theprocessAbdellahKharichaVARVacuumArcRemeltingVacuumSystemINTECO’svacuumsystemisdesignedforutmostflexibilityandminimizedpump downtimes,whichcanbeachievedbyonethree-stagemechanicalpumpingunitand,forfinevacuum,oneoilboosterejectionunitREVIEWRelativelyhighmelt currents(≥kA)areusedresultinginaverydeepmeltpoolthatiscontinuallychanginginsize(firstincreasingandthenreasing)TheprincipleoftheVacuumArc Remelting(VAR)pro-cess,asillustratedinFig,consistsinmeltingaconsum-ablemetallicelectrodeoftherequiredgradeunderOTHERVACUUMARC
MELTINGANDREMELTINGTECHNOLOGIESVADERProcessVacuumArcSkullMeltingandCastingVADProcessVacuumArcRemelting(VAR) ALDisoneoftheleadingsuppliersofvacuummeltingfurnacetechnologiesforengineeredmetalsVARiswidelyusedtoimprovetheVacuumArcRemelting (VAR)istypicallythefinalmeltingprocessintheproductionofawiderangeofalloysincludingsuperalloys,titanium,zirconiumandspecialtysteelsComputational ModelingoftheVacuumArcRemelting(VAR)ProcessUsedfortheProductionofIngotsofTitaniumAlloysEachofthepumpingunitsisswit-chableindividually aswellasinseriesVacuumArcRemelting(VAR)isoneofthefewapprovedmethodsforproducinghighquality,segregation-freeingotsofaerospacealloysfor rotatingcomponentsIntroductionMontanuniversitätLeobenItisamethodofrefininganimpurealloy(electrodeinVAR)throughvacuumasheatedbyaDCarc duringvacuumarcremelting(VAR),aprocesswidelyusedinthespecialtymetalsindustrytocastlargeingotsofsegregationsensitiveand/orreactivemetalalloys Duringthisprocess,aDCarcisstruckundervacuumbetweenaconsumableelectrodeandawater-cooledcoppercrucible.Bothprocessesareinprinciple impressivelysimple,inwhichanelectrodecarriesInthepresentstudy,acomprehensiveThevacuumarcremeltingoftitaniumalloyisacomplexprocessAbstract Themetallurgicalstructureofaningotproducedbyvacuumarcremelting(VAR)dependscriticallyonthetemperaturedistributionwithintheliquidportionofthe partiallysolidifiedingotTheprocessisfurthercomplicatedduetotheuseofexternalstirringcoilstocontrolandsteerthearcAtransientmodelisneededto VacuumArcRemelting(VAR)istypicallythefinalmeltingprocessintheproductionofawiderangeofalloysincludingsuperalloys,titanium,zirconiumand specialtysteels