国产TIG焊导电辊接头失效机理分析  

Analysis on failure mechanism of China-made conductor roll welded by TIG welding

作　　者：孟永红[1] 芦凤桂[1] 唐新华[1] 俞海良[1] 王弘昶[1] 

机构地区：[1]上海交通大学上海市激光制造与材料改性重点实验室,200240

出　　处：《焊接》2009年第5期49-51,共3页Welding & Joining

摘　　要：通过对国产TIG焊失效导电辊哈氏合金C-22断口进行XRD、EDAX成分分析、失效区金相组织及断口形貌观察、极化曲线测定等手段分析了国产TIG焊导电辊的失效原因及其失效机理。金相观察表明哈氏合金筒体焊后未经过固溶处理,会导致焊缝金属和母材之间存在组织差异;腐蚀裂纹宏观形貌观察表明导电辊断裂失效的裂纹源主要萌生于筒体表面的焊缝区域,并逐渐向焊缝内部扩展并最终进入母材;极化曲线测试表明填丝rTIG焊焊缝的腐蚀电位要低于母材的腐蚀电位,腐蚀电位差异是导致导电辊焊缝区域发生严重腐蚀的主要原因。这项研究成果可为进一步开展哈氏合金导电辊的制造提供理论依据和技术指导。The failure mechanism of China-made Hastelloy C-22 conductor roll welded by TIG welding were analyzed,with the help of X-ray diffraction (XRD),Energy dispersive X-ray spectroscopy (EDAX),microstructure and fracture surface of failure zone observation and the polarization curves measuring.The metallographic observations showed that Hastelloy C-22 barrel without solution heat treatment after welding can lead to the differences in structure between weld metal and base metal.The macro-morphology inspection of corrosion crack indicated that the crack source initiated from the weld zone on barrel surface.And the crack gradually spread into the inner of weld,ultimately into the base metal.The measuring of polarization curves shows that the corrosion potential of weld was lower than that of the base metal,which was the prime reason of serious corrosion in weld region.Research results of the experiment provide theoretical basis and technical support for further application of Hastelloy C-22 conductor roll.

关 键 词：TIG焊导电辊 哈氏合金C-22 失效机理 腐蚀裂纹 

分 类 号：TG404[金属学及工艺—焊接]