| 摘要 |
PROBLEM TO BE SOLVED: To provide a welding method of structural steel and a welded steel structure, which can suppress an increase in manufacturing cost even when a welded part of large structural steel is dehydrogenated.SOLUTION: A welding method is for structural steel 5 containing 1.5-3.5% of Cr, 0.5-1.5% of Mo, 0.15-0.5% of V in mass%. The welding method includes: a preheating process 1 of preheating a junction end part 5a of the structural steel 5 and maintaining at 150-250°C; a welding process 2 of multilayer-welding the junction end part 5a; a heating process 3 of maintaining a temperature between passes at 150-350°C during construction by multilayer-welding; and an immediate post heat treatment process 4 of heat-treating a welded part 7 maintained at a temperature 150°C or higher, under such conditions that a temperature is 250-340°C and a treatment time is 5-10 hours. Thus, an increase in manufacturing cost can be suppressed while reducing a diffused hydrogen amount to a predetermined degree. |
