| 摘要 |
PROBLEM TO BE SOLVED: To provide steel in which the heat-affected zone in the case of being subjected to small heat input welding is excellent in toughness and corrosion resistance. SOLUTION: This steel excellent in the characteristics of the welding heat- affected zone contains, by weight, 0.015 to 0.18% C,<=1% Si, 0.5 to 2.5% Mn, <=0.05% P, <=0.007% S, 0.002 to 0.02% Al, 0.003 to 0.02% Ti and 0.001 to 0.008% N and satisfies inequality I, Ti/N <=8/√(t×P cm) and inequality II, O(oxygen)/Al <=0.89 and in the inequality I, (t) is the thickness of the weld metal part (mm), and P cm=C+Si/30+Mn/20+Cu/20+Ni/60+Cr/20+Mo/-15+V/10+5B).
|
