Research on the hot deformation behavior and graphite morphology of spheroidal graphite cast iron at high strain rate

The hot deformation behavior of spheroidal graphite cast iron (SGCI) was investigated quantitatively from 600 °C to 950 °C at high strain rate of 10 s⁻¹ by compression tests on a Gleeble-1500 simulator. The results show that the peak strain increases gradually with increasing deformation temperatures in the range of 600–800 °C and decreases when the temperature is raised to 800 °C and above. The optimum deformation temperature range is determined at 700–900 °C. The graphite particles become spindles or flakes after deformation, even some graphite collapse in the compressed specimens with about 0.7 peak strains. The graphite area fraction decreases as the temperature increases, at the same time, the high peak strain promotes the dissolving of carbon.