It occurs when continuous sliding, rolling, or impacting motions subject a surface to repeated stress cycling. As shown in Figure 3, the stress cycles start very small cracks on or near the surface. These cracks spread and eventually link up to form a free wear particle. Surface fatigue is also involved in spalling and pitting wear. Surface fatigue wear depends strongly on the stress at the surface and the roughness of the surface.
Corrosive wear involves both chemical activity and mechanical action.
It is a modifier of adhesion, abrasion or fatigue wear. The presence or the rate of formation of an oxide film can greatly alter the wear characteristics of a material because the oxide usually has properties which are quite different from the base metal, therefore, the wear rate is affected by the oxide layer. Failure may occur at the oxide metal interface as shown in Figure 4. To keep the wear tests meaningful, the values for the above parameters were controlled as closely as possible. Photomicrographs were taken at 1000X magnification to determine the microstructure of the steels.