Font Size: 

The fatigue damage evolution of a thermo-mechanically graded material is investigated within the framework of an ongoing collaborative research center (SFB/TR TRR 30). The first results are presented which deal with the fatigue behavior of a flange shaft. The base material is a CrV-alloyed heat treatable steel in an engineering condition. The steel has a nearly fully pearlitic microstructure in the initial state, i.e. in an annealed condition. A martensite phase is formed in parts of the flange rod in the course of the thermo-mechanical treatment. The fatigue behavior of the different regions and their damage mechanisms leading to failure are identified. A procedure of determining the lifetime of the flange shaft is presented.