INVESTIGATION OF CYCLIC SOFTENING BEHAVIOR OF SHOT PEENED S30432 AUSTENITIC STAINLESS STEEL BY X-RAY DIFFRACTION METHOD

Microstructure evolution of shot peened S30432 austenitic stainless steel under external loading was investigated by X-ray diffraction method. The domain size, micro-strain, and dislocation density were calculated by Voigt method and Williamson method, respectively. The results show that the dislocation density decreases sharply in initial stage, then undergoes a stable stage, following by an increase in the end. It reveals that cyclic softening happened during cyclic loading, and it can ascribe to the high dislocation density after shot peening (SP). This study suggests that cyclic softening behavior may need to take into consideration when considering the strengthening effect of SP.