Are superior in weldability and flame cutting Characteristic the 490MPa class high tension fire-resistant steel and the production mannered null

摘要

PROBLEM TO BE SOLVED: To provide a high-tensile strength steel which has excellent high temperature strength in the temperature range of 500 to 750°C, weldability, gas cuttability and cost effectiveness, and to provide its production method.;SOLUTION: The fire resistant steel has steel components containing, by mass, 0.005 to 0.04% C, ≤0.5% Si, 0.1 to 0.9% Mn, ≤0.02% P, ≤0.01% S, 0.1 to 0.5% Mo, 0.01 to 0.15% Nb, 0.0005 to 0.003% B, ≤0.06% Al and ≤0.006% N, and in which a carbon equivalent is 0.30%, and the balance iron with inevitable impurities.;COPYRIGHT: (C)2005,JPO&NCIPI