Processing of Nanostructured Austempered Ductile Cast Iron (ADI) by a Novel Method

Abstract

Austempered ductile cast iron (ADI) has emerged as a major engineering material in recent years. It has a unique microstructure consisting of bainitic ferrite and high carbon austenite. In this investigation, nanostructured austempered ductile cast iron (ADI) consisting of bainitic ferrite and high carbon austenite was developed by applying a unique process consisting of austenitization and simultaneous high temperature plastic deformation at the same austenitizing temperature followed by austempering. It was theorized by these authors that further refinement of this of ADI in the nanoscale region could possibly further enhance the mechanical properties of ADI and nanostructured ADI can be potentially a useful structured material. The influence of plastic deformation, single step and two-step austempering process on the resultant microstructure and mechanical properties of nanostructured ADI has been examined. Test results indicate that the application of high temperature plastic defor