Structural fatigue strength of surface treated notch specimen made at steel under randomized bending loading

: Oppermann, H.

Abstract
Surface treatments improve the fatigue strength of metallic components under constant amplitude and under operational random loadings. The degree of improvement can be considerable. It depends on the method and its parameters and above all on the magnitude, the number and the sequence of loadings. Particularly inductive hardening and case hardening are suitable to improve the fatigue strength. The degree of their improvement under operational loadings can be larger than the improvement of the endurance limit. Cold rolling is suitable but its degree of improvement is lower. Nitriding improves the endurance limit considerable. But under operational loading its improvement is low. Not suitable is to judge the methods by their improvement of endurance limit because these degrees of improvement differs clearly from those under operational random loadings.