Effect Of Ultrasonic Shot Peening On The Fatigue Characteristics Of Welded Sts304 For Rolling Stock

Author:  Cheong, DS Lee, JH Lee, Handa, Watanabe
Source:  Conf Proc: ICSP-10 Tokyo, Japan 2008
Doc ID:  2008116
Year of Publication:  2008
Abstract:  
Abstract. Fatigue fracture of structures can be easily expected if the structures have heat affected zone, i.e. welded part. However, the fatigue characteristic and durability can be improved by applying shot peening process because it induces the compressive residual stress on the surface of structures. In this paper work, the effects of ultrasonic peening on the fatigue life of the step in rolling stock are investigated. STS304 welded specimens are used for this study. Conventional shot peening process is also accomplished to compare with ultrasonic peening(CSP). To obtain S-N data, the bending fatigue test was done for conventional shot peened and ultrasonic peened specimens with the same Almen intensity. Compressive residual stress is also measured to find the factors improving the fatigue life. The results show that the fatigue life for ultrasonic shot peened specimens increases tremendously by comparing with the fatigue life of unpeened specimen. Keywords: Ultra Shot Peening(USP), STS304, SEM, Compressive Residual Stress, Rolling Stock