简介:Inconel718superalloycoatingwaspreparedonamartensiticsteelsubstratebycoldgasdynamicspraying(CGDS).Microstructureandmicro-hardnessofthecoatingwerecharacterizedbymeansofscanningelectronicmicroscope(SEM),energydispersivespectrometer(EDS),andmicro-hardnessandnano-indentationtests.Theresultshaveindicatedthatthecoating’sthicknesscanreachmorethan300μm,andthereexistsagoodinterfacialcohesionbetweenthecoatingandthesubstrate.Thequantityandsizeofthedefectsatthebottom,middleandtopareasincreasegradually.ThereisnosignificantchangetotheoriginalmicrostructureoftheInconel718superalloyparticleaftertheprocessofCGDS;andanobvioustorsionaldeformationontheparticle’sprofileisproducedwhilelittledeformationatthecenterpartoccurs.Themicro-hardnessofthecoatingatthebottom,middleandtopareasdecreasesinturn.Comparedwiththebottomarea,themicro-hardnessofthemiddleandtopareasdecreasesbyabout10%and21%,respectively.Thenano-hardnessofthecoatingismuchlowerthantheoriginalparticle,whichdecreasesbyabout13.5%atthebottomareaand28%atthetoparea,respectively.Thedistributionofmicro-defectsisanimportantfactortothemicro-hardnessofthecoating.
简介:摘 要:Ni基Inconel625合金最初用于二十世纪60年代的超临界蒸汽管道,直到二十世纪90年代开始,Inconel625合金已经发展成为垃圾焚烧锅炉水冷壁、过热器等部件的重要组成材料。本文主要综述了Inconel625合金在垃圾焚烧炉中的应用及合成技术的发展,并对Inconel625合金的未来研究方向做了相应的展望。
简介:摘要在石油化工行业、船舶、电站、热交换器等产品中经常会遇到焊缝腐蚀失效现象,很容易造成巨大的损失和浪费,甚至出现安全事故。镍基合金一般都有很好的耐腐蚀性能,特别是Ni-Cr、Ni-Cr-Mo合金等常用于金属表面堆焊,其中Ni-Cr组合主要用于耐氧化性腐蚀,Ni-Cr-Mo组合主要用于耐还原性腐蚀。本文针对摩洛哥努奥II期200MW光热电站中油盐换热器设备接口SA508Gr.3Cl.1钢进行INCONEL600镍基合金的堆焊技术的应用做了研究分析,并通过各项材料的焊接性分析,充分考虑影响其焊接质量的各项不利因素并合理选择焊接工艺参数及热处理控制工艺,通过采用钨极氩弧焊(GTAW)工艺模拟INCONEL600镍基合金堆焊试验以及镍基合金堆焊层与碳钢SA516Gr.70管道焊接工艺评定试验,通过各项力学性能试验来验证该焊接工艺的合理性与正确性。
简介:摘 要:随着航空航天技术的不断发展,例如导向叶片,涡轮盘等发动机热端部件的工作温度已经远远超过Inconel718镍基高温合金的承受范围,导致材料表面发生裂纹、变形、氧化失效,无法满足使用要求。因此如何提高Inconel718镍基高温合金的表面性能是目前研究的重点。本文利用ANSYS建立了Inconel718电子束熔覆热障涂层的数学模型,在保持其他工艺参数相同的情况下,侧重研究了粉末厚度工艺参数对熔覆成形过程中温度场和应力场的分布规律。
简介: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