Surface Damage Evaluation of Rolling Bearings Operating under Low Lambda Conditions

Abstract

Micro-pitting and wear phenomena were studied both experimentally and through simulation, focusing on the relationship between ball roughness and the lambda, Λ, value. The degree of damage due to micro-pitting and wear was investigated under different ball roughness conditions. Cross-sections of micro-pitting and wear were evaluated using optical microscopy, scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD). Morphological observations revealed structures indicative of micro-pitting and wear fatigue, such as plastic flow and crack. In this study, plastic flow thickness, crack angle, and crack depth were used as indicators of the damage degree for micro-pitting and wear. The results from both experiments and simulations indicate that surface roughness contributes significantly to the maximum tangential stress that can initiate the plastic flow and cracks, particularly in micro-pitting. Additionally, the internal stress is expected to have a greater influence on crack propagation.