On the modification of graphitized cast iron

The results of experimental and theoretical study of the formation of globular graphite upon solidification of alloys, heat and chemicothermal treatments, and surface melting of deformed cast iron are presented. The mechanism of the effect of magnesium treatment on the shape of graphite has been analyzed. It has been shown that gas bubbles play a large role in the nucleation and growth of globular and vermicular graphite. The spheroidizing effect of magnesium on the shape of graphite is considered as a result of elimination of the effect of sulfur and oxygen. The mechanism of changeover from the longitudinal to transverse graphite growth under the action of magnesium has been analyzed. The methods of producing ultradispersed states of globular graphite in deformed high-strength cast iron have been developed.