Multi-scale model for fatigue in carbide-rich tool steel

Carbide-rich tool steel is most commonly used not in the tooling industry, but also in engine parts, e. g. springs, bearings, diesel injections, connecting rods etc. Components made from this kind of material are often subjected to cyclic mechanical stresses. Fatigue is important as it occupies the largest cause of failure in metal, approximately estimated 90% of all metallic failures, tool steels are also susceptible to this type of failure. Fatigue resistance of this material strongly depends on the microstructural features including shapes, shape ratio, volume fractions, and distributions of primary and eutectic carbides. Thus, besides loading condition microstructural features are considered as the main factor which influences lifetime of tool components. It is known that the lifetime prediction of carbide-rich tool steel in alternating applied stress is not an easy task to perform. Therefore, gaining knowledge about the effects of microstructural features on the fatigue behavior of this material is necessary. Subsequently, the main objective of this research is to develop a simple model as well as a computational framework to quantify the influence of these microstructural features on the fatigue behavior of the material in the high cycle fatigue (HCF) regime.