Austempering heat treatment is a proven way of obtaining the desired microstructure for improved mechanical properties such as increased strength, toughness, wear resistance, hardness and fatigue strength in ductile iron components. It is an isothermal heat treatment process which depending on the applied austempering conditions, attractive combination of mechanical properties of the austempered ductile iron (ADI) may be produced. This renders the austempered ductile iron useful in a relatively large number of applications as an economical substitute for high strength steels, Blackmore 1984. The important microstructural features of austempered ductile iron (ADI) are the morphology......