Effect of shot peening on residual stress and microstructure in the deformed layer of Inconel 625

Abstract

Effect of shot peening on residual stress and microstructure in the deformed layer of Inconel 625 was investigated. Residual stress and microstructure including the domain size, micro strain and dislocation density was characterized by X-Ray diffraction method (XRD). The results showed that shot peening (SP) can significantly improve the compressive residual stress and micro hardness. Moreover, microstructure evaluation revealed that smaller domains were refined and the higher micro strain was induced by shot peening process. Thus a high dislocation density in the near-surface of the deformed layers was induced. Dual shot peening process could optimize the distribution of both compressive residual stress and the microstructure, which will help with the material fatigue and corrosion resistance.