The Effect of Microstructure on the Friction and Wear of Ductile Cast Irons

The wear characteristics of the ductile cast irons were investigated under a dry friction condition at room temperature. The Pin-on-Disk wear test rig was used, where a pin specimen of the ductile cast iron was pressed against a disk of carbon steel for machine structure use. Four kinds of ductile cast iron were prepared; ferritic (FDI), ferritic/pearlitic (FPDI), pearlitic (PDI) and austempered (ADI) ductile cast iron. Two kinds of wear behavior appeared in FDI and FPDI. One type was markedly worn for a short sliding distance, and the other type was mildly worn for a long sliding distance. For the long sliding distance, the wear resistance of the ductile cast iron was increased with the increase of hardness except FDI. The wear resistance of FDI stands comaprison with that of ADI. The remarkably wear registance of FDI is caused by the graphite.