简介:Themechanicalandcorrosionperformanceoflowalloysteeltubulargoodsdependsonthemicrostructureobtainedasaresultofthecombinationofalloyingelementsandmanufacturingprocessparameters.Thebasicdesignphilosophyfortheselectionofthealloyingelementsisruledbythebalancebetweenthesteelcostandthematerialperformance.Followingthisapproachthealloyingsequenceforthemanufacturingoftubularcomponentsinoilcountrytubulargoods(OCTG)applicationisgenerallyMn,C,randMo,usedassubstitutionalelementsinatotaladdedweightconcentrationaround1%upto3%.OtherelementssuchasB,Ti,NbandVareappliedasstrengtheningmicroalloyingelementsformingfineprecipitates.AlackofexperienceisfoundrelatedtotheuseofTungsten(W)onOCTGapplications,althoughWisalsoasubstitutionalelementthatbelongstogroup6oftheperiodictabletogetherwithCrandMo.OntheotherhandWiswidelyaddedforsteelpipesworkinginhightemperatureservicessuchaspowerplantboilers,wherecreepresistanceisneeded.Itisalsoappliedfortoolsteelsenhancingthehardness,wearresistanceandcuttingperformance.TakenintoconsiderationthesimilaritybetweenCr,MoandWandtheapplicationswhereWhasbeenprovenitwasdecidedtoanalyzethefeasibilityofusingWasanalternativealloyingelementforsomeOCTGapplications.AnotherfactorthatdrivesthisstudyisthefactthatWcouldbeacosteffectivesubstituteofMo,dependingonthealloymarketprice.Thispaperisbasedonliteraturereviewandexperimentalactivitydoneonlaboratorysteelsinwhich0.1%Mowasreplacedby0.2%and0.4%W.Thedifferentfindingsinregardswithmanufacturingprocessconsiderations,materialperformanceandthepossibleuseofWalloyedsteelforOCTGapplicationsaresummarized.(1)OpposedtothesusceptibilityshownbylowcarbonwithhighCr-Wcontent,hotcracksarenotexpectedinmediumCsteels(0.2%-0.3%)withWadditionupto1%.(2)Microporosity-relateddefectscouldfo
简介:ThesurfacecompositionandelectronicstructureoftungstencarbidespreparedbydirectsynthesisandcarburizationofwhitetungsticacidwerestudiedwithX-rayphotoelectronspectros-copy.TheexperimentalresultsshowthatWO3andfreecarbonarepresentonthesurfaceofthecarbides.Forthehighsurfaceareatungstencarbidepreparedfromwhitetungsticacidalargeextentofoxygeninsertionintothecrystallatticewasobserved.MeasurementsofthebindingenergiesoftheW47/2,C1sandO1scorelevelsindicatethatchargetransferisfromtheWtotheCandOatoms,formingW5d-C2pandW5d-O2pbonding.ThecatalyticbehaviorofthetungstencarbidesinhydrocarbonconversionreactionsismentionedandcomparedwithPtcatalysts.
简介:EnergyConsumptioninTungstenExtractiveMetallurgyMoriG.AndPaschenP.(DepartrnentofNonferrousMetallurgy,UniversuyofLeoben,Franz-J...
简介:Puretungsten(PW)andW-1wt%La2O3(WL10)werepreparedbypowdermetallurgicalroutefollowedbytheswaging+rollingprocess.Thelogarithmicstrainsare0,0.37,0.58,and0.98forWL10and0,0.58forPW.Heattreatmentswereperformedattemperaturesvariedfrom1,573to2,173Ktodeterminetherecrystallizationtemperature.Recrystallizationtemperaturesare1,973and2,173KforWL1(logarithmicstrainof0.37)andWL3(logarithmicstrainof0.98),respectively.ButinthecaseofWL2(logarithmicstrainof0.58),fullrecrystallizationisnotachievedattemperatureofabove2,173K.Furthermore,therecrystallizationtemperatureofPWwithlogarithmicstrainof0.58isatleast300KlowerthanthatoftheequivalentWL10sample.Moreover,theincreaseofrecrystallizationtemperatureinhibitsthestrengthdegradationofWL2:sampleslose4%and22%strengthwhenannealedat1,573and1,973Kcomparedwithroomtemperature(RT)sample.Finally,thetextureevolutionfortheswaged+rolledWL10issignificantlyrelatedtothedeformationdegree:thedominatedorientationis<001>forWL2while<110>forWL3.
简介:TheNanlingregionisoncofthcmostimportantpartsofthewcstPacificmetallogeniczone,andaworld-famousconcentratedregionofnon-ferreousmetals,raremetalsandrarecarthelenlentsorede-posits.Formationofalargeamountofmctallicorcdepositsinthcregionisconccntratedinthcdiwastagc.Forcxplainingformationofthomctallicorcdc
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简介:Themultiple-beddedcharacteristicsofthecrustandmultiple-stagenature(geosyncline-platform-diwa)ofthetectoicevolutionarctectonicprcrequisitcsfortheformationandevolutionofthegranitoidsandthcirtungstenmineralizationinJiangxi.ControlledbythemultiPlc-stagetectonicevolution,allthegranitoidsofdiffcrcntgeo1og
简介:Thegrainsizecontrolofthetungstenpowderisessentialforhighqualitytungstenproductsmaking.Basedonthestudiesonthehydrogenreductionprocessoftungstenoxide,amicrocomputersystemisintroducedtothereductionprocessparameterscon-trol.Themicrocomputerprocesscontrolsystem,whichisnowrunninginZhuzhouTungstenandMolybdenumMaterialsPlant,controlstheprocessparametersincludingthetemperatureofthereductionfurnaceandthepressureofhydrogen.Italsocontrolsamechanicalpusherwhichpushstheboatschargedwithbluetungstenoxideintothefurnacetubes.Someofthetechniqueprob-lemsappearedinthereductionprocessandtheprocesscontrolareanalysedinthispaper.Theresultoftheexperimentisalsogiven.
简介:Inthiswork,laserinducedtungstenplasmahasbeeninvestigatedintheabsenceandpresenceof0.6Tstatictransversemagneticfieldatatmosphericpressureinair.Thespectroscopiccharacterizationoflaserinducedtungstenplasmawasexperimentallystudiedusingspace-resolvedemissionspectroscopy.Theatomicemissionlinesoftungstenshowedasignificantenhancementinthepresenceofamagneticfield,whiletheionicemissionlinesoftungstenpresentedlittlechange.Temporalvariationoftheopticalemissionlinesoftungstenindicatedthattheatomicemissiontimeinthepresenceofamagneticfieldwaslongerthanthatintheabsenceofamagneticfield,whilenosignificantchangesoccurredfortheionicemissiontime.Thespatialresolutionofopticalemissionlinesoftungstendemonstratedthatthespatialdistributionofatomsandionswereseparated.Theinfluenceofamagneticfieldonthespatialdistributionofatomswasremarkable,whereasthespatialdistributionofionswaslittleinfluencedbythemagneticfield.Thedifferentbehaviorsbetweenionsandatomswithandwithoutmagneticfieldinairwererelatedtothevariousatomicprocessesespeciallytheelectronsandionsrecombinationprocessduringtheplasmaexpansionandcoolingprocess.