【摘要】 引入CMT-P复合焊接方法成功制备了成形质量优异的UNS S32750超级双相不锈钢焊接接头，选用金相显微镜、X射线衍射仪、扫描电镜、能谱仪及透射电镜等设备研究了接头不同区域的微观组织.结果表明，焊缝、热影响区和母材组织呈现显著差异.与母材和焊缝相比，热影响区内奥氏体含量最低(32.3%)，但焊接接头各微区的奥氏体含量均满足不低于30%的标准要求．由于焊接热循环过程中再加热的作用，焊根及热影响区中析出了尺度和形貌均不同的晶粒内γ2和晶粒边界γ2，而焊缝填充区没有γ2析出．此外，焊根和热影响区均析出了短棍状Cr2N，主要分布在铁素体晶粒内和晶粒边界，Cr2N析出致使相邻铁素体基体形成了明显的贫Cr区．更多还原

【Abstract】 By introducing the CMT-P welding method, the welded joints of UNS S32750 super duplex stainless steel with excellent forming quality were successfully prepared. Metallographic microscope, X-ray diffractometer, scanning electron microscope, energy dispersive spectrometer and transmission electron microscope were used to study the microstructure of different regions of the joint. The results showed that the weld,heat-affected zone and base metal structure show significant differences. Compared with the base metal and the weld, the austenite content in the heat-affected zone is the lowest（32.3%）, but the austenite content in each micro-zone of the welded joint meets the standard requirement of not less than30%. Due to the effect of reheating during the welding thermal cycle, intra-grain γ2 and grain boundary γ2 with different scales and morphologies are precipitated in the weld root and heat-affected zone, but there is no γ2 precipitation in the weld filling zone. In addition, short rod-shaped Cr₂N precipitated in the weld root and heat-affected zone, which is mainly distributed in the ferrite grains and grain boundaries. The precipitation of Cr₂N caused the adjacent ferrite matrix to form an obvious Crpoor zone.更多还原