Fatigue behaviour of duplex stainless steel reinforcing bars subjected to shot peening

Abstract

ABSTRACTThe influence of shot peening on the fatigue properties of duplex stainless steel reinforcing bars manufactured using both hot‐ and cold‐rolled processes was studied. The S‐N curves of the bars before and after the shot‐peening process were determined, showing that shot peening improves the fatigue behaviour of the rebars. This improvement is essentially due to the introduction of a compressive residual stress field in the surface of the reinforcing bars, but also to the smoothing of the surface flaws and cold working generated during the manufacturing process. This improvement is much greater in the case of the hot‐rolled bars, mainly as a result of their much higher ability for plastic deformation, whereas cold‐rolled bars had a much higher hardness. A more severe peening action capable of promoting greater plastic deformation on the bar surface is judged necessary to improve the fatigue resistance of cold‐rolled rebars.