Effects of impurities on graphite shape during solidification of spheroidal graphite cast ions

Since the discovery that magnesium and cerium (and more generally rare earths) added at low level to cast iron melts lead to spherodized graphite, it is known that some other elements are detrimental even when present as traces. In all practicality, it has soon been recognized that adding rare earths to the melt helps counteracting the effect of these detrimental elements. Accordingly, only few works have been devoted to studying the effect of trace elements in melts without any rare earths. This is the first aim of the present work to review those studies as they contain the material to understand the mechanism for spheroidal graphite degeneracy.