GMAW潜弧焊电弧-熔池耦合行为数值分析

Numerical Analysis of the Coupled Arc-weld Pool Behaviors in GMAW Buried-arc Welding

GMAW潜弧焊是GMAW在大电流范围内配合高速送丝实现高熔敷率、低飞溅率的一种高效焊接方法,可对中厚板进行有效焊接,显著提高焊接效率。为研究大电流细丝GMAW潜弧焊电弧-熔池耦合机理,建立了细丝GMAW潜弧焊电弧-熔池耦合数学模型,其中特别考虑了熔滴过渡和金属蒸气的影响。数值模拟结果表明:纯CO_(2)保护气下细丝GMAW潜弧焊电弧可稳定潜入熔池;GMAW潜弧焊电弧形态与普通GMAW钟罩形的电弧形态不同,电弧进入空腔后,在扩张的同时向下挖掘,使空腔深度显著增加;GMAW潜弧焊时,由热-力耦合引起的电弧-熔池动态演变是导致大熔深的根本原因,该模型的建立为GMAW潜弧焊的应用奠定了理论基础。

GMAW buried-arc welding is an efficient welding method of GMAW in large current range with high speed wire feed to achieve high deposition rate and low spatter rate.It can realize effective welding of medium and thick plates,and significantly improve the welding efficiency.A mathematical model of arc-pool coupling for fine wire GMAW buried-arc welding is established,so as to study the arc-weld pool coupling mechanism.The effects of during droplet transition and metal vapor are especially considered.Numerical simulation results show that the welding process of fine wire GMAW buried-arc welding under pure CO_(2)shielding gas,the arc can be stably buried into the weld pool.The arc shape of GMAW buried-arc welding is different from the bell shape of ordinary GMAW,after the arc enters the cavity,it digs down while expanding,and lead to the cavity depth to increase significantly.In GMAW buried-arc welding,the dynamic evolution of arc-molten pool caused by thermal-mechanical coupling is the fundamental cause of large penetration depth,the establishment of this model lays a theoretical foundation for the application of GMAW buried-arc welding.