1986 Volume 4 Issue 4 Pages 684-690
The spattering in the pulsed GMA welding with a short arc length was investigated and a practical method for suppressing the spatter was presented. An arc length is usually kept short in order to raise the welding speed without a weld flaw. But, in such a case, the short circuit between the wire and the base metal frequently takes place. The spattering was observed with a highspeed framing camera and changes of the gas density around the arc were observed by the shadowgraph method. It was made clear that the spattering was resulted from the short circuit. The spatter was genearted by the rapid Jouleheating at the minimum cross-section of the molten metal.
The practical method for suppressing the spatter was to control the current waveform so that the short circuit may take place during the base duration.
With the inverter controlled power source, the amount of splashed spatter was decreased up to onetenth of that obtained with the conventional pulsed GMA welding power source.