Fracture Properties at Elevated Temperatures of Ferritic Ductile Cast Irons

Abstract

  Both ferritic ductile cast irons with the Mg/P compositional ratios of 0.6 and 2.2 were tensile tested at 673K. Specimens with the Mg/P ratio of 2.2 showed lower tensile elongation of 5% at 673K, which meant the embrittlement was caused by intergranular fracture. In contrast, impact tested specimens showed the lowest absorbed energy in the temperature range of 973 to 1073K, which corresponded to the embrittlement at 673K in tensile tests. It was found that temperatures showing embrittlement increased as the strain rate increased due to differences in experimental methods.