Due to its valuable mechanical properties, good workability and relatively low manufacturing costs, ductile cast iron is used for highly loaded automotive components, such as engine blocks or cylinder heads. Having reliable information about the lifetime calculation of cast iron and a sound knowledge of its fatigue behavior can help in designing safe and weight-optimized components made of this important material.

We examined the fatigue behavior of cast iron under constant amplitude loading and near service loading conditions of notched and smooth specimens as well as components out of EN-GJL-250, EN-GJS-600 and EN-GJV-400. We measured mechanical stress-strain hysteresis, temperature, and electrical resistance. The measurements provided the input data for the short-time procedure PhyBaL_LITdeveloped at the Institute of Materials Science and Engineering. Due to the typical lifetime scatter of ductile cast iron, we calculated Woehler-curves for defined lifetime probabilities using a modified variant of PhyBaL.

The project is supported by the German Research Foundation (DFG).