Prediction of microgeometrical influences on micropitting fatigue damage on 32CrMoV13 steel

Micropitting is a form of surface fatigue damage that occurs in the gear teeth. It is due to the effect of variation in the mechanical loading in the contact zone between the two teeth, induced especially by flank roughness. In this study, generic roughness profiles were built with geometrical parameters to simulate the contact between two rough surfaces. Using elastohydrodynamic lubrication code and Crosslandʹs fatigue criteria, the influence on fatigue lifetime was analysed for changes in each parameter. The relevant parameters were determined that influence (i) the conventional pitting, (ii) the extent to which the von Mises equivalent stress exceeds the material yield stress in the zone where micropitting occurs, and (iii) the fatigue lifetime for steel teeth. With nitriding benefits, the same trends were shown with weaker effects.