熔化极脉冲氩弧焊熔滴滴落过程的分析

采用数字图像处理技术,对熔化极脉冲氩弧焊熔滴滴落过程的高速摄像图片进行了处理,提取了熔滴的边缘轮廓并获得了熔滴质心的变化坐标,得到了熔滴滴落过程中速度变化曲线. 结果表明,熔滴在弧柱区的滴落过程为匀加速,而在近阴极区和近阳极区却是减速的,且近阴极区减速幅度较大;并对熔滴在弧柱区的受力过程进行了定量分析,其主要受到等离子体流拉力和重力的作用,以及对近阴极区进行了相关的定性分析,其速度的减小主要是因为金属熔池蒸气反力的阻碍作用和等离子体流拉力的减小,理论分析与试验结果较为吻合.

Droplet transfer analysis in pulsed gas metal arc welding

The high-speed video images of droplet transfer in pulsed gas metal arc welding(GMAW-P) were processed by digital image processing technology, then the droplet velocity transfer curve was obtained, and image edge contour was extracted with the corresponding coordinate of droplet centroid. The result shows that the droplet is uniformly accelerated during the arc column region, but is decelerated in near the anode and cathode region. Furthermore, the deceleration degree in near cathode region is more intense. The forces act on the droplet in the arc column region is quantitatively analyzed, it is mainly subjected to gravity and plasma drag force. Meanwhile, the force situation in near the anode and cathode region was qualitatively analyzed, the results indicated that the theoretical analysis is consistent with the practical.