The influence of residual stress on fatigue properties in ion-nitrided steels (SCM4, SM15C) is investigated where the residual stress is considered affecting the applied mean stress. The residual stress is measured by a blind hole drilling method. The position of the maximum stress for the applied stress combined with the residual stress, is compared with that of fatigue crack initiation which is obtained by microscopic inspection. It is found that the location of crack initiation is dependent on the magnitude of the applied load and the fatigue life changes accordingly. The proposed model is found to describe fatigue properties relatively well.
