| 摘要 |
PROBLEM TO BE SOLVED: To provide a structural high-strength thick steel plate being excellent in the property of preventing brittle crack propagation, having a thickness of not less than 50 mm, and being suited for use in ships, and to provide a production method thereof.SOLUTION: A thick steel plate excellent in the property of preventing brittle crack propagation is characterized in that it has a metallographic structure composed of mainly bainite, it has such a texture that the density in the RD//(110) plane at the plate thickness center is not less than 1.5, the Charpy fracture surface transition temperatureTat the plate surface and at the plate thickness center is -40°C or lower, and more desirably, the Charpy fracture surface transition temperature and the density in the RD//(110) plane at the plate thickness center satisfy formula (1):T-12×I≤-70, whereinTis the fracture surface transition temperature (°C) at the plate thickness center and Iis the density in the RD//(110) plane at the plate thickness center. |
