Fatigue lifetime prediction with a validated micromechanical short crack model for the ferritic steel EN 1.4003

Microstructural short crack (MSC) growth profoundly influences the fatigue lifetime of steels. For finite element simulations with crystal plasticity, a MSC model for industrial application is described for the ferritic steel EN 1.4003. As transgranular cracking is dominant in the early fatigue stages for this material, intergranular crack growth is excluded. Crack data from micro fatigue specimen is used to validate simulated crack paths. With a manual prescription of the crack initiation site, a substantial agreement between the predicted and experimental crack paths is revealed. Using an appropriate calibration strategy for the parametrization of the MSC model, the feasibility for lifetime prediction is also shown.