Compacted graphite (CG) cast iron is an engineering material which contains graphite morphology in a short, stubby, wormlike shape with rounded edges. Since its structure is intermediate between that of gray and ductile iron, its mechanical and physical properties are also intermediate. In the present paper, CG iron was produced by the method of controlled amount of nodularizer with or without Ti/Cu addition in the casting processing of ductile iron. The effects of alloying elements (Ti, Cu) on fracture toughness of CG iron then were investigated. The results showed that when nodularizer applied to molten iron in the amount of 0.9 wt% in this experiment, CG iron of over 80% vermicularity (balance nodular graphite) was produced with or without Ti /Cu alloying addition. The mechanical property of the CG iron thus obtained conformed to ASTM A842 Grade 300 standard. Also, it was found that the vermicularity increased (about 95%) when the alloying element (Ti or Cu) added. Titanium or copper alloying seemed to refine graphite morphology, and promote the formation of pearlite. this has an effect of upper fracture toughness of CG iron than without Ti/Cu alloying addition.
Compacted graphite cast iron Vermicularity Alloying element (Ti/Cu) Fracture toughness