高铬镍奥氏体焊丝Ar/He/CO_2保护脉冲GMAW电弧形态与熔滴过渡  

Comparative study on arc shape and droplet transfer under different shielding gas compositions of Ar/He/CO_2 in pulsed GMAW

作　　者：李大用[1] 王苹[1] 张广军[1] 

机构地区：[1]哈尔滨工业大学先进焊接与连接国家重点实验室,哈尔滨150001

出　　处：《焊接学报》2018年第7期55-59,共5页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51575133)

摘　　要：为解决高强度Cr-Ni奥氏体焊丝脉冲GMAW电弧挺度不足,熔滴过渡不稳定的问题,文中采用高速摄像手段对Ar/He/CO_2不同组合气体保护下的脉冲GMAW电弧形态与熔滴过渡进行了对比研究,以期优化混合气体成分.结果表明,氩气弧熔滴过渡容易,但电弧漂移、挺度差;氦气和CO_2气体的加入可提高电弧挺度、增大电弧能量、熔滴过渡变为1脉多滴,先一个大滴,接着几个小滴;氦气的比例越大,第一个熔滴的尺寸越大;CO_2气体可克服阴极斑点漂移,但比例不能超过5%;40%Ar+58%He+2%CO_2三元组合的电弧挺度大,熔滴过渡均匀平稳,是奥氏体焊丝脉冲GMAW厚板焊接较理想的混合气体组分.In order to solve the problems of poor arc stiffness and unstable droplet transfer in pulsed GMAW with high-strength Cr-Ni austenitic stainless welding wire,the arc shape and droplet transfer under different shielding gas compositions ofwere investigated by the highspeed camera for optimization of mixed gas composition in this paper.The results showed that in pure Ar,the metal transferred easily but with arc wandering and poor arc stiffness.The arc stiffness and arc energy density increased with the addition of He and CO2.The droplet transfer was multiple drops per pulse type that one big drop was followed by several small drops.With the increase of the He volume fraction,the size of the first big drop increased.The CO2 was good at overcoming the cathode spot drift,but the volume fraction can not exceed 5%.The ideal mixed shielding gas was 40%Ar+58%He+2%CO2 for good arc stiffness and stable droplet transfer in this pulsed GMAW by using austenitic stainless welding wire.

关 键 词：脉冲熔化极气体保护焊 保护气体 熔滴过渡 电弧形态 

分 类 号：TG444.74[金属学及工艺—焊接]