| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for the manufacture of a wide flange shape for building construction, reduced in material dispersion as compared with the conventional one and excellent in refractoriness and weldability. SOLUTION: A stock, having a composition consisting of, by weight, 0.001-0.030% C, <=0.60% Si, 0.20-3.00% Mn, <=0.100% Al, 0.005-0.20% Ti, 0.0003-0.0050% B, <=0.0100% N, further one or >=2 kinds among 0.05-0.6% Mo, 0.7-2.0% Cu, and 0.7-2.0% Ni, and the balance Fe with inevitable impurities, is used. This stock is reheated to 1200-1350 deg.C. Rolling is started and then finished when the temp. difference between a web part 3 and a flange part 1 becomes <=100 deg.C and the temp. of each part reaches >=700 deg.C, followed by air cooling. |
