Microbeam X-Ray Study on the Rolling Contact Specimens (At pmax=0.7HB)

For rolling contact fatigue specimens (S35C, HB=160) which were subjected to a Hertzian stress Pmax = 113 kg/mm2 at different rolling cycles, the residual stress distribution at and below the contact surface was measured by X-ray microbeam diffraction and the changes of half-value breadth of the diffraction pattern were obtained The maximum value of residual stress in each specimen, except the one at low cycles (N=102), was obtained in the layer between 0.3～0.6mm below the surface, but not just at the contact surface. The residual stress distribution corresponds almost to the hardness distribution. The half-value breadth of diffraction pattern is the largest at the contact surface and decreases with distance from the surface for each specimen