Fatigue and Brittle Fracture Analysis of Surface Engineered Materials in Rolling Contact

An analysis is presented of the failure by fatigue and by brittle fracture of M50 tool steel surfaces subject to rolling sliding contact. The analysis includes the effects of roughness on both surfaces, of slide roll ratio and of the introduction of a shallow nitrided case such as has been previously investigated experimentally. Results suggest that the failure may be strongly influenced by the distribution of the magnitude and the cycle rate of stresses in a very shallow surface layer. The analysis agrees broadly with some published results but this may be fortuitous.