Effects of shot peening residual stresses on fatigue crack propagation behavior of 316L

To study the influence of shot peening residual compressive stress on the fatigue crack propagation behavior of 316L austenitic stainless steel, a three-dimensional finite element model of the compact tensile specimen based on abaqus software and an initial stress simulation model of a shot peening residual stress imported through the re-development of the SIGINI subroutine are established. The fatigue crack propagation behavior under the combined effect of the shot peening residual stress field and external cyclic loading is investigated using the extended finite element method. The results show that the crack propagation path and fatigue life obtained by the finite element method are in good agreement with the experimental results, and the error of the fatigue life is only about 4.05%. When the crack propagates into the shot peening region, the shot peening residual compressive stresses imported on the specimen surface and subsurface enhance the crack closure effect and suppress the crack propagation behavior. The impact of shot peening in the double side peened samples is higher than that in the single side peened samples. For 19 mm crack lengths, double side shot peened specimens presented a 1.2 times increase in fatigue life, compared to single side shot peened specimens (1.1 times).