The effect of nitriding on fatigue strength of structural alloys

Abstract

This article presents a review of expe
of the effect of distrength of stru
ence on regularity of fatigue cracks initiation and propagation in nitrided structural metallic materials. The basic regularities of static strength, low cycle fatigue and high cycle fatigue strength of structural steels after treat-ment by nitriding were studied. The results of this study have shown that inde-pendently from a method of nitriding the characteristics of high cycle fatigue of the limited durability and fatigue limit of structu
ral steels are improved. In area of low cycle fa-tigue more often decrease of durability is observed and that is connected with cracking stronger nitrided layer at high repeated loadings. The increase of fatigue strength at high cycle fatigue is connected with creation of stronger surface layer, creation of compressive residual macroscopic stresses and microstresses after nitriding.