基于GMAW动态模型的短路过渡过程稳定性分析

基于已建立的CO₂焊短路过渡模型，模拟了短路过渡的动态过程；预测了不同送丝速度下短路过渡频率、接触熔滴和残余熔滴等效半径、熔滴的速度和位移以及液桥的变化；分析了上述参数与稳定性之间的关系，并成功预测了最佳电弧点，为焊接过程的参数优化提供依据.结果表明，当熔滴过渡频率最大时，并未达到最佳焊接条件；在最优焊接参数下，残余熔滴等效半径达到最小，且熔滴振荡速度和位移变化范围较小；接触熔滴等效半径和液桥曲率半径越小，越有利于提高短路过渡的稳定性.

Stability of short-circuiting transfer process based on GMAW dynamic model

The dynamic process of short-circuiting transfer was simulated by the established model. The short-circuiting transfer frequency, the equivalent radius of contact droplet and residual droplet, the velocity and displacement of droplet and the change of liquid bridge shape were predicted. The relationship between the metal transfer parameters and its process stability was analyzed, and the optimal arc is successfully predicted, which provides the basis for the parameter optimization of the welding process. The results show that the welding parameters that corresponds to the highest transfer frequency are not the optimal parameters. Further, the equivalent radius of residual droplet is minimum, and the variation of droplet oscillation velocity and displacement is slight under the condition of optimal welding parameter. Meanwhile, the smaller the equivalent radius of contact droplet and the principal radius of liquid bridge, the better the stability of short-circuiting transfer process.