The Role of Surface Finish in Pitting Fatigue of Carburized Steel

An investigation of the influence of surface roughness of lubricated rolling-sliding contact surfaces on pitting fatigue has been carried out. A significant increase in pitting resistance resulted from polishing the ground mating surfaces. When the roughness of the loading rollers (positive slip element) was reduced from 10-15 to 5-9 μin rms and that of the test specimen (negative slip element) from 10 to 2-3 μin rms, there was a gain of about 150% in load-carrying capacity before pitting occurred. The surface roughness of the loading roller appears to be the dominating factor. The degree of metallic contact and surface distress decreases when the roughness of the roller approaches the thickness of the oil film.