| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a high tensile steel for welded structures excellent in high-temperature strength and low-temperature toughness as the steel for various welded structures. SOLUTION: The cast slab or steel slab containing, by mass, 0.01 to 0.10% C,≤0.60% Si, 0.2 to 2.0% Mn,≤0.20% P,≤0.010% S, 0.05 to 0.20% Mo, 0.01 to 0.10% Nb,≤0.060% Al, 0.001 to 0.006% N, and 0.06 to 0.12% C+Mo/10+Nb; and if necessary, containing one or two or more kinds of a specific amount of V, Ti, Ni, Cu, Cr, B, Mg, Ca, REM is heated to 1,000 to 1,300°C, and after finishing the hot rolling at≥850°C as≥30% accumulated rolling-reduction ratio in austenite non-recrystallization temperature zone, air-cooling is performed. COPYRIGHT: (C)2010,JPO&INPIT
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