Temperature dependent cyclic deformation and fatigue life of EN-GJS-600 (ASTM 80-55-06) ductile cast iron

Abstract

The ductile cast iron EN-GJS-600 (ASTM 80-55-06) provides several beneficial properties for a wide spectrum of applications. Its near-net shaping capabilities combined with beneficial physical and mechanical properties even at elevated temperatures result in a wide use for components of internal combustion engines. Under service conditions, fatigue loading at different temperatures occurs. In this context, the present paper focuses on the isothermal high cycle fatigue behavior of ductile cast iron EN-GJS-600 in the temperature range from ambient temperature up to 400°C at a frequency of 5Hz. At elevated temperatures, the consideration of dynamic strain aging effects on cyclic deformation and lifetime behavior is of major importance. It was proved that only one temperature increase test is necessary to determine the temperature range of pronounced dynamic strain aging effects. The physically based fatigue lifetime calculation approach “PhyBaLSIT” (SIT=strain increase test) was applied and validated for total strain controlled fatigue tests. To receive maximum information with minimum effort, both test procedures were combined enabling calculation of fatigue life in the temperature range from ambient temperature up to 400°C based on only thirteen fatigue experiments.