Low temperature austempering of ductile cast iron

Austempered ductile cast iron (ADI) has emerged as very important engineering material in recent years because of its excellent combination of mechanical properties such as high yield strength, good fatigue strength , high fracture toughness and wear resistance. This is obtained in ADI as a result of a unique microstructure consisting of bainitic ferrite and high carbon austenite with graphite nodules dispersed in the matrix.

Traditionally Austempering is carried out in the ductile cast iron in the temperature range of 260°-400° C temperature range. In this investigation , ductile cast iron was austempered in the low temperature range of 180°-240°C with an objective of producing nanoscale microstructure in the material. The influence of low temperature austempering on the microstructure and mechanical properties of ADI has been presented in this paper.