Optimization of the fatigue resistance of AISI304 stainless steel by ultrasonic impact treatment

• Results of ultrasonic impact treatment on AISI 304 are given by the FEM.
• Damage caused by stress concentration is considered using N–R model.
• Residual stress relaxation is considered in the N–R model.
• Optimization of UIT parameters for AISI 304 is obtained.

The Navarro–Rios model was used to investigate the fatigue resistance of AISI304 stainless steel treated by ultrasonic impact treatment (UIT) in this paper. The finite element model was established using Johnson–Cook materials model to get the needed residual stress and dent profiles, and the damage was also considered in the model. The results show that fatigue property is elevated with the increase of coverage, but would not be developed with the enhancement of impact velocity when it reaches a level for the increase of stress concentration. The optimized UIT parameters for AISI304 are impact velocity of 6 mm/s and coverage of 200%.