Rolling contact experiments with slip were performed on artificial asperities and indents with pile-up. Micro-pits arose at the leading edge of the asperities and classic rolling contact fatigue (RCF) cracks initiated behind the trailing edge of the indents. The elastic-plastic run-in process and the thermal elastohydrodynamic lubrication (TEHL) load cycles were studied numerically. The run-in process caused high tensile residual stresses at the leading edge of the asperities while the TEHL load cycle caused high tensile stresses at the trailing edge of both the asperities and the indents. The conclusion was thus drawn that the classic RCF cracks behind the indents were caused by the TEHL load cycle while the micro-pits at these artificial asperities were caused by the tensile residual stresses from plastic deformation.
Validerad;2020;Nivå 2;2020-08-17 (marisr)