A comparisson of properties of austempered ductile iron and as-cast iron

The procedures of producing bainitic ductile iron by austempering heat treatment or by alloying during casting have been analysed. Suitability of application of both processes has been investigated for producing machine parts by comparing relevant mechanical properties. Properties of austempered ductile iron have been compared with those of alloyed as-cast ductile iron. Realistic cost/benefit analysis and technological comparison of the two processes has also been performed. The chemical composition and appropriate parameters of both production processes have to be specified according to the shape of a machine component, its size and the required mechanical properties.