脉冲熔化极氩弧焊熔池的震荡特性分析

Analysis of weld pool vibration characteristics in pulsed metal inert welding

通过高速摄像采集,采用数字图像处理技术,对脉冲熔化极氩弧焊熔池轮廓进行了精确提取.基于该熔池轮廓提取方法,分析了一脉一滴、一脉两滴焊接条件下,离弧柱中心不同点位置的时域和频域变化特征.结果表明,两种情况由于脉冲电弧和熔滴对熔池的冲击影响,引起的波叠加造成随着离弧柱中心距离的增加,熔池轮廓上各点震荡的振幅分布呈波动递减趋势;在一脉两滴时近弧柱中心的点震荡表现复杂、密集,熔滴所引起的熔池震荡会抵消脉冲电弧引起的震荡,振幅相对较小,且脉冲电弧引起熔池的震荡要比熔滴强.

Using high speed camera acquisition and digital image processing techniques,the contour of weld pool in PMIG process is extracted accurately. Based on this extraction method,time and frequency domain characteristics in different points along the contour of weld pool are analyzed for one pulse one droplet and one pulse two droplets,respectively. The results show that,due to the wave superposition created by pulsed arc and droplet impacting in the weld pool,the vibration amplitude along weld pool fluctuates and decreases with the increase of distance from the point to the center of arc column. Vibration near the arc column shows complexity and intensity for one pulse two droplets and the amplitude is relatively small because the vibration caused by pulsed arc can be offset by droplet impacting.Meanwhile,the weld pool vibration caused by pulsed arc is stronger than that by droplet.