To provide a filler wire for welding of hot steel plates which prevents the joint part rupture during hot rolling after joining by suppressing weld defects and preventing the degradation in the strength of the joint parts.
The filler wire for supplying the butt parts containing 0.03 to 5.0% B by mass % can suppress the S embrittlement which occurs in heat affected zones in hot bar joining of joining the tail ends of the preceding materials and the front ends of succeeding materials of the sheet bars for hot rolling and successively passing these material through finish rolling mills in a hot rolling process step. Further, the solidification cracking and embrittlement of the weld zones may be suppressed by incorporating 0.03 to 1.5% C, ≤0.01 S, ≤0.01 P and 0.2 to 8.0% Mn into the filler wire. Further, the occurrence of blowholes may be suppressed as well by incorporating 0.1 to 8.0% Si, 0.2 to 8.0% Mn, ≤8.0% Al and ≤8.0% Ti at total ≥4.0% therein.
KOBAYASHI JUNICHI
ASO YOSUKE
