Investigation of microstructure and material properties for 18 different graphitic cast iron model materials with focus on Compacted Graphite Iron (CGI)

摘要

The higher mechanical strength of Compacted Graphite Iron (CGI) than Flake Graphite Iron (FGI) makes it very useful material for several commercial components. The knowledge of microstructure and hence the mechanical properties and machinability is very important for the CGI to used efficiently in manufacturing. The complex geometry of cast components makes it difficult to produce adequate microstructure in the whole component. Adequate material properties can be achieved by having good knowledge about the correlations between the casted geometry, graphite morphology and pearlite content. In the presented paper, 18 different model materials have been analysed extensively, concerning the effect of chemical composition, solidification and cooling rate on the nodularity, pearlite content, interlamellar spacing in pearlite, hardness and mechanical properties. Later, the cutting force measurement tests were performed on some of the materials and it was found that the forces have a strong positive correlation with pearlite content and the tensile strength of the materials.