| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a thick steel plate excellent in a weldability and a ductility in the plate thickness direction, used to a building, bridging, ship-building, offshore structure, tank, etc. SOLUTION: After reheating at 1,000-1,350°C a steel material having the steel composition composed by mass% of 0.01-0.20% C, 0.05-0.50% Si, 0.3-3.0% Mn, ≤0.03% P, ≤0.005% S, ≤0.1% Al, ≤0.02% N, and if necessary, one or more elements selected from Cu, Ni, Cr, Mo, Nb, V, Ti, B, REM and Mg, and the balance Fe with inevitable impurities, a hot-working, desirably a hot-forging is applied with 0.05-3/s strain speed at ≥1,000°C and ≥15% accumulated pressing-reduction ratio, and further, a hot-rolling and a heat-treatment are suitably applied according to the desirable plate thickness and mechanical characteristics. COPYRIGHT: (C)2010,JPO&INPIT |
