Abstract
The growth of cast irons is referred to as the irreversible increase and unusual change in dimension after cyclic heating. In order to reveal the effect of microstructural features on the growth of cast irons, the dilatometric examination was carried out using flake graphite and spheroidal graphite cast irons in critical range of 923 K and 1225K by cyclic heating with furnace-cooling and air-cooling. Little relation lies between graphite morphology and the growth behavior. The growth is comparatively small, due to carbon consumption for pearlite transformation when the air-cooling is employed in cyclic heating. The growth is remarkably enhanced by the expansion of martensitic transformation when cast irons contain hardening elements, such as Mo and Ni. The present work of the growth of flake and spheroidal graphite cast irons is theoretically explained by the growth mechanism of irreversible graphite migration.
