摘要
Thisresearchexplorestheprospectoffabricatingaface-centeredcubic(fee)Ni-basealloycladding(Inconel690)onanfeeFe-basealloy(316Lstainless-steel)havingimprovedmechanicalpropertiesandreducedsensitivitytocorrosionthroughgrainboundaryandmicrostructureengineeringconceptsenabledbyadditivemanufacturing(AM)utilizingelectron-beampowderbedfusion(EPBF).TheuniquesolidificationandassociatedconstitutionalsupercoolingphenomenacharacteristicofEPBFpromotes[100]texturedandextendedcolumnargrainshavinglowerenergygrainboundariesasopposedtorandom,high-anglegrainboundaries,butnocoherent{111}twinboundariescharacteristicofconventionalthermo-mechanicallyprocessedfeemetalsandalloys,includingInconel690and316Lstainless-steel.Inadditionto[100]texturedgrains,columnargrainswereproducedbyEPBFfabricationofInconel690claddingson316Lstainless-steelsubstrates.Also,irregular2-3pimdiameter,lowenergysubgrainswereformedalongwithdislocationdensitiesvaryingfrom10^8to10^9cm^-2,andahomogeneousdistributionofCH3C6precipitates.Precipitateswereformedwithinthegrains(with-3μminterparticlespacing),butnotinthesubgrainorcolumnargrainboundaries.Theseinclusive,hierarchicalmicrostructuresproducedatensileyieldstrengthof0.527GPa,elongationof21%,andVickersmicroindentationhardnessof2.33GPafortheInconel690claddingincontrasttoatensileyieldstrengthof0.327GPa,elongationof53%,andVickersmicroindentationhardnessof1.78GPa,respectivelyforthewrought316Lstainlesssteelsubstrate.AgingofboththeInconel690claddingandthe316Lstainless-steelsubstrateat685℃for50hprecipitated623C6carbidesintheInconel690columnargrainboundaries,butnotinthelow-angle(andlowenergy)subgrainboundaries.Incontrast,Cr23C6carbidesprecipitatedinthe316Lstainless-steelgrainboundaries,butnotinthelowenergycoherent{111}twinboundaries.Consequently,the
出版日期
2019年02月12日（中国期刊网平台首次上网日期，不代表论文的发表时间）
