Prediction of fatigue lives at stress raising features in a high strength steel

The fatigue properties of the high strength stainless steel CSS42L have been evaluated under strain and stress controlled conditions. The results have been used to derive a predictive approach based on the Walker strain equation. Accurate predictions are obtained for VCN and DEN specimens although the lower stress concentration RCN specimen is shown to compare more readily with plain specimen stress controlled data. The difference in fatigue life between the notched specimens has been found to be related to the crack propagation phase where the crack grows through material which has previously been operating under reduced stress conditions.