APPLICATION OF THE WEAKEST-LINK MODEL TO THE FATIGUE LIMIT OF THE STEEL SAE-52100 IN A BAINITIC CONDITION

The influence of notches and loading condition on the fatigue limit of the high strength steel SAE 52100 is investigated on specimens with g round surfaces. The behaviour can be described quantitatively by a thr ee-parametric high-cycle fatigue criterion and the weakest link model. This includes the possibility of calculating local and total survival probabilities depending on the nominal stress amplitude. Crack initia tion sites and the fatigue limit can be predicted, too. The basic rela tion between the size distribution of crack initiating inclusions and the fracture probability was proved on push-pull specimens.