REFRACTORY STEEL PRODUCT FOR CONSTRUCTION AND ITS MANUFACTURING PROCESS

摘要

PROBLEM TO BE SOLVED: To provide a steel requiring a low production cost which satisfies a strength specified for SN400 or SN490 defined by JIS, ensures a strength at elevated temperature satisfying: (yield strength at 650°C)/(yield strength at ordinary temperature)≥0.5 and (yield strength at 700°C)/(yield strength at ordinary temperature)≥0.4, and shows an excellent weldability (Y crack stopping temperature of ≤0°C), and its manufacturing process.;SOLUTION: The steel contains 0.01-0.13 mass% C, 0.01-0.5 mass% Si, 0.01-0.5 mass% Mn, 0.3-1.3 mass% Mo, 0.02-0.1 mass% Nb, 0.003-0.05 mass% sol.Al and ≤0.01 mass% N, wherein the remainder comprises Fe and unavoidable impurities.;COPYRIGHT: (C)2003,JPO