PURPOSE: To provide perfect penetration of the initial bead into the base material by setting the welding current for the initial weld bead to be smaller than the welding current for the general part to be welded, and setting the welding current of the final weld bead to be larger than the welding current for the general part to be welded from immediately before the lap and until the welding is completed.
CONSTITUTION: The welding current for the initial bead 11 of the peripheral welding is set to be smaller than the welding current for the general part to be welded, and the time for the initial bead part, i.e., the peripheral length of the wheel of the initial bead part is longer. For example, if the welding current for the general part 13 to be welded is assumed a1A, the welding current for the initial bead part is set a01, and the time (length) for the initial bead part is also set to about t1 second (about 21 for the peripheral welding length), taking into consideration the non-penetrated length. The welding current in the final stage is increased than the welding current for the general part 13 to be welded immediately before the lap upon the initial bead is started, and this current continues until the peripheral welding is completed. For example if the welding current for the general part to be welded is assumed a1A, the welding current from immediately before the lap is started and until the peripheral welding is completed is set a2(a2>a1)a.
MORI KATSUMI
KOBAYASHI MASARU
SUZUKI AKIRA
