Fatigue fracture of nitrided and carbonitrided layers

The phenomenon of fatigue fracture of nitrided and carbonitrided layers is described in the paper. Fatigue bechaviour is described by analysing properties of the substrate and surface layer. The effect of microhardness of the substrate on fatigue properties of nitrided layers is obtained. Smith's diagrams for carbonitrided layers are presented. A graphical pattern for prediction of the place of failure initiation is suggested. Future directions of the examination with tribology and corrosion effects taken into account are marked in the paper.