The composition of the solid solution,structure, and contact fatigue of the case-hardened layer

One result of contact fatigue of metals, due to the high stress in surface contact zones, is the appearance of dimples on the surface of the case-hardened layer. Contact fatigue depends on a series of factors, the most important of which are thought to be the carbon concentration in the layer, the amount of retained austenite, and the morphology of the carbide phase.^1-4] The literature data concerning the quantitative effect of retained austenite on contact fatigue are contradictory. Vinokuret al.^5] have shown that the temperature of heating before quenching was the greatest influence on contact fatigue, since it determines the solution of carbides, the degree of alloying of the solid solution, and the amount and ratio of structural components. There are almost no data on the critical points for the carburized case or their variation with the carbon content of the case.