To improve the welding workability and the cracking resistance, to obtain a suitable reverse side bead, to form the sound and high toughness welded part and to easily improve the working efficiency of joining of plates in a one side welding of a curbing surface-like welded structure from a short length to a long length.
At the time of executing the butting one side welding by abutting a backing material on the back surface of a bevel tack-welding the inner surface of the bevel of a Y or V shaped curving surface-like welding material having 30-65°C bevel angle, steel particles or powder are spread onto the bevel to the height of 1/4-2/3 of the plate thickness and the welding giving a welding torch 40-150 times/min of shaking time at ≥200A/mm2 of the wire cross sectional area to the welding current density, is executed. The steel wire composed, by wt.%, of ≤0.10% C, 0.50-1.00% Si, 1.50-2.50% Mn, 0.10-1.50% Mo, 0.10-0.50% Ti, 0.0030-0.0100% B and the balance substantially Fe with inevitable impurities to the total wt. of the wire, is used. Further, molten metal just below the wire is doubly shielded.
SANO HIROBUMI
YAMASHITA KOZO
YOSHIMURA TSUKASA
