| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a steel member which is used for a steel structure and excellent in a fatigue-crack propagation resistant characteristic when receiving repeated loads.SOLUTION: The steel containing, by mass, 0.02-0.20% C, 0.05-0.5% Si, 0.6-2.0% Mn, ≤0.05% P, ≤0.03% S, and further, one or more kinds of Cu, Ni, Cr, Mo, Nb, V, Ti and the balance Fe with inevitable impurities, is acceleratively cooled at ≥7°C/sec in the temperature zone from Arpoint temperature or higher to 600-400°C at ≥2°C/sec cooling speed after applying a hot-rolling by heating to ≥1000°C, and successively, accelerative cooling is performed at 2°C/sec cooling speed, in the temperature range of 600-400°C after heating with the temperature raising speed of ≥2°C/sec in the temperature zone of the Acpoint+20°C or higher to the Acpoint-20°C or lower. |
