Nitriding of Rolling Contact Races

Abstract

Abstract In the contact zone of overrolled races high stresses are acting. In order to get a sufficient rolling contact fatigue life, a high hardness in the depth of high material stresses is necessary. One possibility to achieve high hardness in a surface near zone in case of steels is nitriding. By one example of an application to polymer processing and another example of an application to aero engines is demonstrated, how races for overrolling can be realized by nitriding. By these examples the effect of tempering and nitriding parameters on the properties of the nitrided zone as hardness, residual stress and formation of the compound layer is demonstrated. Rig tests show, that overrolling properties of nitrided and case hardened layers can be similar.