GRAPHITE FLOTATION IN CAST IRON.

Abstract

This study has been conducted to better understand the phenomenon of graphite flotation in cast irons. It is well-known that graphite flotation occurs in sufficiently hypereutectic compositions of ductile cast iron, accompanied by the formation of exploded graphite. It has also been observed that graphite flotation in compacted graphite cast irons occurs as exploded graphite and that compacted graphite does not participate in flotation. A series of cast irons were prepared wherein the carbon equivalent was varied and the amount and type of nodularizer (magnesium and rare earths) added was varied. These irons were cast into different section size castings, or samples were taken at temperatures during the solidification process and were rapidly quenched to retain the structure. All specimens were examined using conventional microscopy and/or scanning electron microscopy. (Edited author abstract. )