ULTRASONIC IMPACT TREATMENT METHOD

摘要

PROBLEM TO BE SOLVED: To provide an ultrasonic impact treatment method for improving the fatigue characteristics of a weld toe.SOLUTION: The ultrasonic impact treatment method for improving the fatigue strength of a weld toe of a steel structure having a weld zone using ultrasonic impact is provided that comprises: a step of widening the curvature radius of the weld toe of the steel structure by subjecting the weld toe to grinding treatment; a step of measuring the curvature radius r [mm] of the weld toe subjected to the grinding treatment; and a step of applying ultrasonic impact treatment to the surface of a steel material immediately above the weld toe with a pin having the curvature radius of the tip part greater than 1 mm and less than r [mm] after the grinding treatment and forming a working band in the direction along the weld toe.SELECTED DRAWING: Figure 3