Abstract
The in-depth distribution of residual stresses in shot-peened steels was measured by using high energy X-rays from a synchrotron radiation source. The relation between the 2θ and sin^2ψ was obtained with the side-inclination method (ψ diffractometer). The measurement was carried out for as shot-peened and buffed specimens. The distribution of residual stresses was first evaluated by the nonlinearity of the sin^2ψ diagram by a simplex method. The influence of the roughness of the specimen surface on an analysis of the nonlinearlity was significantly large. The estimated stress agreed with the distribution determined through the sin^2ψ method by using Cr-Kα radiation combined with the conventional surface removal method. A new method was proposed to estimate the distribution of the residual stress. The new method was a combination of the side-inclination method and the iso-inclination method (ω diffractometer) to maintain the penetration depth constant. The sin^2ψ diagram could be approximated by the linear relationship in a wide range of sin^2ψ. The evaluated stress distribution agreed well with the distribution obtained by the surface removal method.
