| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a high strength thick steel plate for a marine structure excellent in weldability and in the low temperature toughness of HAZ, and can be produced at a low cost without the use of a complicated production method. <P>SOLUTION: The thick steel plate has a composition comprising 0.03 to 0.12% C, 0.05 to 0.30% Si, 1.2 to 3.0% Mn,≤0.015% P, 0.001 to 0.015% S,≤0.10% Cu+Ni, 0.001 to 0.050% Al, 0.005 to 0.030% Ti, 0.005 to 0.10% Nb, 0.0025 to 0.0060% N, and the balance iron with inevitable impurities, and has a bainitic structure of≥80% as a steel structure, and in which the grain diameter of TiN precipitates is≤0.4μm, and plate thickness is≥50 mm. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
