Residual Stress Relaxation of Shot Peened Deformation Surface Layer on S30432 Austenite Steel under Applied Loading

The relaxation of residual stress in shot peened surface layer on S30432 austenite steel under static and cyclic loading was investigated. The results revealed that the compressive residual stresses were relaxed under applied tensile stress. The relaxation of residual stresses in longitudinal direction was more obvious than that in transverse direction. And when applied stress was beyond the yield strength of the materials, the relaxation of the compressive residual stress was drastic. Under cyclic loading, the results showed that the relaxation behavior was determined by the applied loading and the number of cycles. And the fast relaxation of the compressive residual stress took place in the first few cycles then became stable gradually. Finally, a model was used to quantitatively predict the compressive residual stress under cyclic loading with different applied tensile stresses.