A previously presented qualitative model for the rolling contact fatigue and spalling failure of back-up rolls has been quantified in terms of crack lengths and growth directions. The morphologies of surface initiated fatigue cracks have been predicted using published data on the mode I and mode II thresholds in low carbon and roll steels, respectively, and the theoretical determination of the mode I and mode II stress intensity factors at the tips of the inclined surface cracks. The predictions have been validated by using the results of the metallographic examination of rolling contact fatigue cracks produced in test discs used in experimental simulations and the examination of spalled material from a back-up roll.
Fatigue & Fracture of Engineering Materials & Structures,
Vol. 25, no. 11 (2002), pp. 1073-1086(14)