METHOD FOR SUPPRESSING FATIGUE DAMAGE OF WELDED STRUCTURE AND TOOL FOR FORMING IMPACT TRACE

摘要

PROBLEM TO BE SOLVED: To provide a method for suppressing fatigue damage of a welded structure which can securely suppress the generation of fatigue damage such as a fatigue crack in the weld portion of a welded structure such as a steel bridge, and a tool for forming an impact trace.;SOLUTION: As a tool for forming the impact trace forming the impact trace on the surface of a base material adjoining a weld bead by hammer peening or ultrasonic shock peening, a tool 6 for forming the impact trace is used which has an impact trace formation surface 7 in the front end thereof, which curves in circular arc shape at a curvature radius r of 1 mm or more, 5 mm or less along the direction intersecting the weld bead at a right angle, and in which among the two end faces 8a, 8b mutually in parallel along the weld bead, the center ro of the curvature radius is decentered to one end face side. By using the tool 6 for forming the impact trace, the impact trace of which the maximum depth is 0.2 mm or more is continuously formed along the weld bead to introduce compression residual stress in the vicinity of the toe of the weld bead.;COPYRIGHT: (C)2013,JPO&INPIT