Mechanical property investigation of hardened and tempered ductile iron

Abstract

In their attempt to develop a particular type of cast iron having better mechanical properties than the malleable iron, the scientists ultimately discovered the spheroidal graphite (S.G) Iron. In this type of cast iron, graphite is present in the form of nodules so it doesn’t break the continuity of structure. Moreover due to the regular shape of graphite, it provides ample amount of plasticity unlike gray cast iron where the flake of graphite acts of sharp notches and thus destroy plasticity. Due to its excellent combination of strength, ductility and toughness the S.G Iron is now being widely used in different structural applications and now-a-days it is replacing steel in various fields. The properties of S.G Iron can be improved further by means of proper heat-treatment procedure. In the present work, efforts have been made to study the effect of tempering on S.G Iron and correlate the properties with the micro-structure.