Austempered Ductile Iron (ADI): A Review

Abstract Austempered ductile iron (ADI) is a group of ductile irons offering the design engineers remarkable mechanical properties. It exhibits an excellent combination of high strength, ductility, toughness, fatigue strength, and exceptional wear resistance that is unavailable in other grades of cast iron. Austempered ductile iron is almost twice as strong as the regular ASTM grades of ductile iron, whilst still retaining high elongation and toughness characteristics. In addition to the exceptional wear resistance and fatigue strength, it enables designers to reduce a component's weight and costs for equivalent or improved performance. Therefore, ADI has become an attractive and economic substitute for forged steel and cast steel in many engineering applications. This led to marked interest in ADI in the past few years with considerable research work to understand the effect of processing parameters on its characteristics and mechanical properties. The objective of this paper was to review works that have been conducted over the past years on the effects of process variables, mechanical properties, benefits, and applications of ADI.