초록
With an expansion in automation of welding processes, emphasis has been shifted from other welding processes to the GMA welding. However, there is a problem with this process that the spatter occurs very frequently. In GMA welding, there are several types in the way of metal transfer from the electrode wire to the weld pool, which have a close relatonship with the spatter genetration. This study was concerned with the spatter occurring in the short-circuiting transfer. In welding with short-circuiting, the electromagnetic force formed by the welding current facilitatics the rupture of the metal bridge between the wire and workpiece and ensures the normal process of the welding process. However, the spatter can be genetrated from the droplet because of the upward magnetic force, when the droplet contacts with the weld pool. The passage of current through the bridge results in the accumulation of the thermal energy, which causes the bridge to explode in the final stage of short-circuiting, thus forming the spatter. Based on the above phenomena in conjunction with other experimental results published, the physical phenomenon related with the occurrence of spatter was modeled and the current waveform was investigated to reduce the spatter. Finally, the fuzzy rule based method was proposed to predict the time of short-circuiting and arcing in the metal transfer.
