Rolling Contact Fatigue in Bearings: Phenomenology and Modelling Techniques

Current understanding of rolling contact fatigue is reviewed. The stress developed in the subsurface as a function of loading conditions, along with the resulting microstructural changes are described. Focusing on the dissolution of hardening phases and the occurrence of recovery and recrystallization, the relationship between load and microstructure evolution is analysed in terms of component life. The role played by inclusions and intermetallic particles, as well as primary precipitates, is outlined. The complexity of rolling contact fatigue is explained in terms of the many factors influencing it, which makes difficult to generalise its fundamentals. The importance of the choice and suitability of computational techniques employed to simulate it is highlighted, along with the available characterisation techniques. A variety of modelling techniques is presented. Empirical models have been an aid in predicting rolling contact fatigue, especially when combined with statistical approaches, but fail in addressing the fundamentals of the phenomenon, particularly at submicron scales. Micromechanics modelling is useful in understanding the spatial distribution of stresses and the evolution of damage, but fails in finding strategies for controlling it. The need for models able to relate rolling contact fatigue with microstructural evolution is described, available computational tools and mathematical models are reviewed, and a new irreversible thermodynamics approach linking the phenomena across the scales is proposed.