Effect of Metallic Contact on the Pitting of Lubricated Rolling Surfaces

The degree of metallic contact, expressed as the ratio of the surface roughness to the oil film thickness, is found to play an important part in determining the pitting behaviour of lubricated rolling surfaces. In particular under a repeated contact stress of about twice the nominal pitting endurance limit, experiments have shown that the life of the surface before pitting occurs is governed by this ratio. At the same high stress there is some evidence that, in the complete absence of metallic contact, pitting does not occur at all.