Application of Roller-Working on Improving the Fatigue Strength of Notched Austenitic Stainless Steel
About 90% of steel structure™s failure was induced from the notched parts due to the stress concentration. Therefore it was very important to research how to improve the fatigue property of notched parts when the stainless steel was used as structural material. Rotating bending fatigue test was preformed to investigate the effect of different notch-machining process (Conventional lathe-machining, Combination of lathe-machining and roller-working) on fatigue strength of the typical austenitic stainless steel SUS304. Fatigue limit of roller-worked specimen was improved to 285% compared to that of lathe-machined specimen. It was found that, work hardening effect induced in roller-working process played an important role to improve the fatigue strength. In addition, the residual compressive stress and the fibriform structure in the specimen surface-layer induced by roller-working were also effective to improve the fatigue strength. Non-propagating fatigue crack was observed in the notch surface of the roller-worked SUS304 for the first time.
Kikuo Kishimoto, Masanori Kikuchi, Tetsuo Shoji and Masumi Saka
J. Ding et al., "Application of Roller-Working on Improving the Fatigue Strength of Notched Austenitic Stainless Steel", Key Engineering Materials, Vols. 261-263, pp. 1257-1262, 2004