双丝共熔池熔化极气体保护焊熔池流动的数值模拟  

Numerical Analysis of Weld Pool Convection in Double GMAW Process

作　　者：吴东升[1] 华学明[1] 叶定剑[1] 张菁[1] 顾煜[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试验室,上海200240

出　　处：《上海交通大学学报》2015年第10期1435-1440,共6页Journal of Shanghai Jiaotong University

基　　金：国家自然科学基金项目(51275299)资助

摘　　要：利用FLOW3D软件建立三维数值模型,以模拟船用A36低碳钢双丝熔化极气体保护焊(GMAW)熔池的流动行为.采用双椭球热源模型,考虑电弧压力、表面张力、电磁力及浮力所驱动的熔池内液态金属的流动和热传递,以及辐射、蒸发、熔滴的动态冲击作用,并利用高速摄影技术观察熔池的流动行为.结果表明,双丝GMAW形成了单一共熔池,后丝产生的电弧压力分量抑制了液态金属向熔池尾部的流动,双丝之间形成的"推-拉"流动方式以及熔池向外流动方式有助于形成较好的焊缝;双丝GMAW熔池内不易形成毛细不稳定流动的现象,熔池前后表面张力的法向分量相对平衡,没有出现液体通道收缩及提前凝固的现象.A three-dimensional model for weld pool convection in double gas metal arc welding（GMAW）process was built by using the commercial software FLOW3 D.The double ellipsoid heat source model was used,and the liquid metal flow and heat transfer driven by gravity,arc pressure,surface tension force,electromagnetic force and buoyancy were considered.The radiation,evaporation and droplet impinging were also taken into account.The results show that a single weld pool is formed in the double GMAW process,the effective arc pressure component caused by the trailing wire prevents the liquid metal that tends to flow to the rear of the weld pool,and the ＂pull-push＂and outward flow model help to form good weld.The absence of premature solidification of the liquid channel is mainly attributed to the good capillary stability due to the large pool width in the double GMAW weld pool.This model is of great significance to explain the mechanism that the double GMAW can inhibit the formation of humpping bead.

关 键 词：A36低碳钢 双丝熔化极气体保护焊 双椭球热源 熔池流动 驼峰焊道 

分 类 号：TG456.7[金属学及工艺—焊接]