Fatigue of carburised CrNiMo steel: Testing and modelling concept

In this study, a testing and modelling concept is presented, aimed at estimating the local fatigue properties of carburised CrNiMo steel, covering the fatigue limit under axial and torsional loading at various mean stresses. Aimed at predicting the bulk material properties, all specimens were ultrasonic shot‐peened prior to testing. Fractographic analyses were conducted on all specimens using scanning electron microscopy to define the type, size and chemical composition of crack initiation‐related discontinuities. An iteration of the FKM guideline is presented, relying on the external notch concept to explain the effect of large internal notches on the mean stress sensitivity.