Effects of heat treatment on the erosion behavior of austempered ductile irons

The normal-angle erosion behavior of austempered ductile irons has been studied under various heat treatment parameters, including time and temperature for both austenitization and austempering process. The results indicate that the erosion rate was in generally positively related to hardness and tensile strength, and inversely proportional to percentage elongation and mechanical energy density. Un-dissolved ferrite during austenization appears to be the most erosion resistant phase. For ADI with complete austenization, the microstructure obtained inside the process window was more erosion resistant than otherwise. At different austempering temperatures, higher temperature tends to be more erosion resistant, since more ductile austenite present in the microstructure.