X-RAY DIFFRACTION CHARACTERIZATION OF RESIDUAL STRESSES PRODUCED BY SHOT PEENING

Abstract

A brief overview of the theory and practice of x-ray diffraction residual stress measurement as applied to shot peened materials is presented. The unique ability of x-ray diffraction methods to determine both the macroscopic residual stress and the depth and magnitude of the cold worked layer produced by shot peening is described. The need to obtain a complete description of the subsurface residual stress distribution, in order to accurately characterize the residual stress distributions produced by shot peening, is emphasized. Non-destructive surface residual stress measurements are shown to generally be inadequate to reliably characterize the residual stresses produced by shot peening. Practical applications of x-ray diffraction methods for quality control testing are considered. Examples are presented for steel and nickel base alloys.