THICK STEEL PLATE WITH HIGH YOUNG'S MODULUS FOR WELDED STRUCTURE, AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a thick steel plate for welded structures which has excellent weldability and low-temperature toughness and is increased in Young's modulus in an L direction and a C direction and also to provide its manufacturing method.;SOLUTION: A steel stock, containing 0.06 to 0.2% C and having ≤0.45 carbon equivalent Ceq, is subjected to: heating to a temperature range between 500°C and a temperature below the Ac₃ transformation point and then rolling while regulating, in a temperature range from ((Ac₃ transformation point)-40°C) to 500°C, a draft per pass and a cumulative draft to ≤10% on average and ≥50%, respectively; or heating to a temperature range between the Ac₃ transformation point and 1,180°C, primary rolling while regulating a cumulative draft in a temperature range between 900°C and ((Ar₃ transformation point)-20°C) to ≥30% and then secondary rolling while regulating, in a temperature range from ((Ar₃ transformation point)-20°C) to 500°C, a draft per pass and a cumulative draft to ≤10% on average and ≥50%, respectively.;COPYRIGHT: (C)2008,JPO&INPIT