Influence of Contact Temperature on Contact Fatigue Failure Forms: Part 2—The Test and Analysis

Abstract

The surface roughness of contacting parts have a strong influence on the failure form of contact fatigue. Pitting failure is liable to occur on the contact parts with rougher surface. The present test shows that a plastic deformation layer (PDL) will generally occur beneath the race surface of the parts which fail in pitting; and the near-surface cracks will initiate in the plastic deformation layer, these cracks grow gradually and finally result in fatigue failure where the depth of the fatigue pit are 0.1–0.2 mm. According to the author’s analysis of contact temperature and contact stresses, the present paper suggests: when the race surface of rolling specimen is rough, the contact temperature rise reduces the transient yield strength of the metal below the maximum contact shear stress at this position, thereby, resulting in a plastic deformation layer.