Fatigue Life Enhancement of Austenitic Stainless-Steel Welding Joints by Ultrasonic Impact Treatment

The XRD, TEM and fatigue experiments were done to investigate variations of residual stress, micro structure and fatigue life of the austenitic stainless steel (AISI 304) welding joint after ultrasonic impact treatment (UIT) in this paper. The effect of the UIT treatment on the fatigue property of 304 welding joint was also studied. The results showed that the UIT treatment induced the compressive residual stress layer of the welding joint, smoothed the welding toe and refined the grain size on the surface of the welding joint by the twin intersection. The UIT treatment could improve the fatigue life of AISI 304 welding joint significantly.