Developing a Graphitic White Cast Iron

Introducing interconnected flake graphite networks into a white iron can potentially reduce thermal induced adhesive abrasion during metal-to-metal contact. Five alloys with different chromium and carbon contents were designed, produced and investigated to develop the first generation of graphitic white iron. The graphite volume percent for each alloy was measured by ImageJ freeware, and correlated with carbon equivalent and cooling rate. A linear equation was constructed by correlating the graphite volume percent with carbon equivalent. A numerical model was obtained by studying the relationship between graphite volume percent and cooling rate. It was shown that graphite volume percent needs to be higher than 7% to have an obvious increase on the thermal conductivity. Vickers hardness measurements showed that M7C3 is harder than the cementite, and the hardness of carbides increase with increasing chromium content in the alloy.