High temperature low cycle fatigue of spheroidal graphite cast iron

Abstract

High temperature tensile and Low Cycle Fatigue test results on a spheroidal graphite cast iron, containing between 5–10% pearlite, are reported. Cyclic hardening/softening behaviour, hysteresis loops and asymmetry are presented in relation with testing temperature and strain rate; they show some particularities at 200°C, 300°C and 500°C. Fatigue lifetime plots are presented with respect to testing temperature, and high scatter was observed for the lower temperature range. Fracture surface analysis indicates multiple crack initiation on shrinkages beneath the sample surface.