Application of the weakest-link concept to the endurance limit of notched and multiaxially loaded specimens of carburized steel 16MnCrS5

Based on the weakest-link concept a method is developed., from which the endurance probability of every surface and volume element of a case-hardened part, which is loaded near the endurance limit, can be calculated. A prerequisite for the calculation is knowledge of the hardness and residual stress distribution, the surface roughness and the surface oxidation depth. By multiplication of the endurance probabilities of neighboured elements the endurance probability of a limited region or of the whole part can be calculated, which includes an endurance limit determination. It is shown, that this model can be applied successfully to specimens of a carburized steel. The necessary model parameters can be gained from a set of reference specimens. Because of the possibility to formulate an endurance probability for every volume and surface element, there are no geometrical restrictions on the parts to be assessed.