6082-T6铝合金协同脉冲CMT焊缝表面微观组织及其腐蚀行为  

Surface microstructure and corrosion behavior of 6082-T6 Al alloy welded joints formed by CMT MIX synchro-pulse process

作　　者：朱桢 董其鹏 陈夏明 长海博文[1,2] 曹文耀 ZHU Zhen;DONG Qi-peng;CHEN Xia-ming;HIROMI Nagaumi;CAO Wen-yao(School of Iron and Steel,Soochow University,Suzhou 215137,China;High-performance Metal Structural Materials Research Institute,Soochow University,Suzhou 215137,China)

机构地区：[1]苏州大学沙钢钢铁学院,江苏苏州215137 [2]苏州大学高性能金属结构材料研究院,江苏苏州215137

出　　处：《轻合金加工技术》2022年第3期47-52,共6页Light Alloy Fabrication Technology

摘　　要：试验选取协同脉冲CMT焊接工艺进行6082-T6铝合金薄板拼焊,利用电流电压采集系统对焊接电流进行实时采集,并采用金相显微镜(0M)和扫描电子显微镜(SEM)观察焊缝表面的微观组织和腐蚀形貌,以此研究6082-T6铝合金协同脉冲CMT焊缝表面宏观偏析与焊接电流波形特征之间的本质联系,并分析其对焊缝表面耐蚀性的影响。研究结果表明:协同脉冲CMT焊接工艺高频脉冲阶段与CMT阶段平均电流的巨大差异使得两个阶段焊丝填充量不同,焊缝形成明显的鱼鱗纹,且因焊丝填充量不同,鱼鱗纹凹陷处镁含量显著增加,析出更多的Mg_(2)Si相,严重恶化了该区域的耐蚀性,导致焊缝表面耐蚀性呈现局部区域恶化的现象。CMT MIX synchro-pulse process was selected to conduct the butt welding of 6082-T6 A1 alloy sheets.The current and voltage acquisition system was used to collect the welding current in real time,and the microstructure and corrosion morphology of the weld surface were observed by optical microscope(OM)and scanning electron microscope(SEM).The essential relationship between the macro-segregation of weld surface and the characteristics of welding current waveform were studied,and its influence on the corrosion resistance of the weld surface was analyzed based on the above conduction.The research result shows that the great difference of the average current between the high frequency pulse stage and the CMT stage in the CMT MIX synchro-pulse process makes the filling amount of the two stages different,producing significant fish-scale ripples on the weld.In addition,due to the different filling amount of the welding wire,the Mg content in the fish-scale ripple cavity increases significantly,and more Mg_(2)Si phase precipitates,which seriously worsens the corrosion resistance of the area.The corrosion resistance of weld surface deteriorates in these areas.

关 键 词：6082-T6铝合金 协同脉冲CMT焊接 宏观偏析 显微组织 耐蚀性 焊接电流 

分 类 号：TG444[金属学及工艺—焊接]