双相不锈钢CMT-P复合焊接微区组织特征  

Microstructure characteristics of duplex stainless steel CMT-P composite welding

作　　者：徐连勇[1,2] 白玉洁 韩永典[1,2] 荆洪阳 张志强[3] XU Lianyong;BAI Yujie;HAN Yongdian;JING Hongyang;ZHANG Zhiqiang(Tianjin University,Tianjin,300350,China;Tianjin Key Laboratory of Advanced Joining Technology,Tianjin,300350,China;Civil Aviation University of China,Tianjin,300300,China)

机构地区：[1]天津大学,天津300350 [2]天津市现代连接技术重点实验室,天津300350 [3]中国民航大学,天津300300

出　　处：《焊接学报》2022年第3期1-6,I0003,共7页Transactions of The China Welding Institution

基　　金：天津市技术创新引导专项基金项目(21YDTPJC00430);国家自然科学基金资助项目(51905536);中央高校基本科研业务费(3122019084);中国民航大学科研启动基金项目(2020KYQD77)。

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Cr_(2)N,主要分布在铁素体晶粒内和晶粒边界,Cr_(2)N析出致使相邻铁素体基体形成了明显的贫Cr区.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 Cr_(2)N precipitated in the weld root and heat-affected zone,which is mainly distributed in the ferrite grains and grain boundaries.The precipitation of Cr_(2)N caused the adjacent ferrite matrix to form an obvious Crpoor zone.

关 键 词：双相不锈钢 CMT-P复合焊接 微观组织 二次相 

分 类 号：TG444[金属学及工艺—焊接]