关键词: 脉冲MAG焊, 熔滴过渡, 脉冲波形, 后中值

Abstract:

For the one droplet per pulse transfer of pulsed metal active gas(MAG) welding,a novel pulsed waveform with backward median phase was presented. The effect of backward median current and backward median time on the welding process was studied. The optimum backward median current and backward median time were found by experiment when welding steel.The experimental results demonstrate that when the backward median current is in an optimum value range, the welding effect is satisfactory, and when the backward median current is small or large,the welding effect is similar to normal pulsed MAG welding process,the sense of backward median current is not obvious.On the basis of defining the backward median current as an optimum value,the welding effect is satisfactory when the backward median time is in an optimum value range.The instantaneous short circuit occurs when the backward median current is small or large. By adjusting the backward median current and backward median time, it can enhance the controllability of droplet transfer and get one droplet per pulse transfer,and the weld seam formation will be pretty good.

Key words: pulsed metal active gas welding, droplet transfer, pulsed waveform, backward median phase