Droplet rebounded spatter in dry hyperbaric gas metal arc welding process

摘要

The spatter generation of dry hyperbaric gas metal arc welding (GMAW) was investigated by using a high-speed digital camera system. Two spatter types, droplet deviated spatter and droplet rebounded spatter, were observed. The generation of droplet deviated spatter is similar to the spatter generation in globular repelled transfer of GMAW at normal pressure, which is due to the high horizontal speed of the droplet detachment. This spatter type begins to appear at ambient pressure reached 0.2 MPa. Another type, droplet rebounded spatter, is a new spatter generating process. The spatter is always generated after the cathode root burning on the droplet which contacts to the workpiece. And then, the droplet rebounds to the free space and changes into the spatter instead of adhering to the workpiece. Droplet rebounded spatter is generated at the ambient pressure over 0.4 MPa. The reason that the electromagnetic force is the driving force of droplet rebounded was analyzed.