Abstract
Spheroidal graphite cast irons containing four levels of Ni 0 to 3.5wt% and ones containing five levels of Mo 0 to 0.6wt% were prepared by the use of an induction furnace and cast. The iron into which Ni has been separately added has improved tensile strength and hardness because of solution hardening in the matrix. The impact transition temperature rises with condensation of Ni, while the upper shelf absorbed energy reduces. Separate addition of Mo has little effect on tensile strength and impact properties. Mechanical properties of spheroidal graphite cast iron can be improved by combined addition of Ni and Mo. The irons containing 1% Ni-0.1%Mo and 2.5%Ni-0.4%Mo show the lower impact transition temperature and have high toughness.
