Effect of selected alloying elements on mechanical properties of pearlitic nodular cast irons

There is a continuous demand for low-cost nodular cast irons with improved mechanical properties, this being an industrial requirement both for pearlitic as well as for ferritic grades. Developments in pearlitic nodular irons should lead to alloys with higher and higher strength while retaining some ductility in the as-cast state so as to respond to demands related to castings for high power automotive engines in competition with steel castings and ADI. According to these aims, several alloying elements have been selected and added separately or combined to standard commercial nodular cast irons. In all cases, only low-level additions were made and their effects on the microstructure and mechanical properties at room temperature have been characterized and are discussed. A statistical analysis has been performed on the data obtained that accounts for changes in alloying additions as well as for variations in process parameters.