Compacted Graphite Iron

This article discusses the chemical composition, castability, mechanical properties at room temperature and elevated temperature, and physical properties of compacted graphite (CG) cast iron. The change in graphite morphology from the flake graphite (FG) in the base iron to the CG in the final iron is achieved by liquid treatment with different minor elements. CG irons have strength properties close to those of spheroidal graphite (SG) irons, at considerably higher elongations than those of FG iron, and with intermediate thermal conductivities. The main factors affecting the mechanical properties of CG irons both at room temperatures and at elevated temperatures are composition, structure (nodularity and matrix), and section size. The article also discusses the applications of CG irons that stem from their relative intermediate position between FG and SG irons. The tables in the article list the values for tensile properties, hardness, thermal conductivity, fatigue strengths, endurance ratios, and compressive properties of CG, FG, and SG irons.