Study of residual stress in surface nanostructured AISI 316L stainless steel using two mechanical methods

Ultrasonic mechanical attrition (UMA) treatment can be used to create a nanostructured surface layer that plays a significant role in enhancing the overall strength, stiffness and fatigue life of the treated material. Residual stress can be induced by this process. The residual stress fields are relieved by two mechanical methods i.e. cutting and hole-drilling, and measured using moiré interferometry and a method combining moiré interferometry and incremental hole-drilling (MIIHD). The experimental results of the two methods correlate well. They show that UMA can cause a high compressive residual stress of up to 531 MPa on the material surface. This helps to prevent cracks from being initiated and propagated on the surface of the material and thus improves its mechanical properties.