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.