To prevent generation of spatters by periodically switching a straight polarity DC current having a value producing no burn pack with an AC pulsed current having a value enabling a droplet to be released and thereby changing an arc length.
Welding current is energized in which a DC current and a pulsed current are periodically switched. Welding is performed by supplying, to an inert gas, an oxidizing gas in a range capable of maintaining spray transfer or a shielding gas mixed with oxygen. Then, with a straight polarity DC current DCS set at such a value as no droplet is released, the base current value Ib of an AC pulsed current ACP, peak current value Ip, peak current energizing period D, and peak current energizing time Tp are synchronized with each peak current and set at a value for a droplet to transfer from the tip end of the wire. Then, with the wire fed at a specific speed, the straight polarity DC current allowing no droplet to be released is periodically switched with the AC pulsed current enabling a droplet to be released, thereby changing an arc length and performing spray transfer welding.
DEWA TAKAYUKI
YAMAGUCHI KOSAKU
