后中值电流波形脉冲MIG焊调制工艺研究

Study on Pulsed MIG Welding Modulated Process of Backward Median Current Waveform

后中值电流波形带有中值电流阶段控制熔滴过渡,在碳钢上有较好的效果。铝合金薄板材料的特点决定了其焊接难度比较高。高斯函数曲线的波形平滑,能量集中,用来调制后中值电流能够产生冷热交替的强弱脉冲群,并且焊接输入电流的平均值较低,是一种新型的铝合金材料焊接方法,在2 mm厚度的铝合金薄板成功进行了焊接试验。通过分析试验采集的信号,发现焊接电流电压波形规整、分布有规律,重复性好,能量输入集中,弧长稳定,证明了焊接试验过程平稳。焊缝外观鱼鳞纹清晰工整,表面光亮,熔高和熔深合适,无焊穿和塌陷现象;电弧声柔和,焊接过程飞溅很少。

Backward median current waveform has median current phase to control droplet transfer, acting very well in welding carbon steel. It is hard to weld aluminum alloy for inherent features. Gauss function has a smooth curve and concentrated energy input, which can generate hot and cold alternating pulse groups in modulating backward median current. It is a new welding method with low average welding current input, which is applied for welding of 2mm aluminum alloy sheet successfully. By analyzing signals acquired in experiments, it shows that the current and voltage waveforms are regular with no broken arcs or short circuits. Moreover, the arc voice sound is soft with low splatter. The weld seam surface is bright with regular scaly stripe, proper weld height and penetration.