Property Enhancement of Cast Iron to be Used for Nuclear Cask

Abstract

Ductile iron (DI) is the most preferable material which finds its application in various structural, automotive and engineering fields due to the excellent combination of strength, toughness and ductility. The current investigation enlightens the relation between morphological aspects of ductile iron with its mechanical properties to be used for safety prospectus in nuclear industry. Ductile iron specimens with varying alloying elements are subjected to annealing and austempering heat treatment processes. Faster cooling rate appeared to increase the nodule count in austempered specimens compensating the nodularity value, subsequently decrease in ductility and impact strength. The ductility and impact energy value for annealed specimens are observed to be increasing with the increase in ferrite area fraction and nodularity, whereas the increased amount of Ni & Cr results in increase of hardness via solid solution strengthening. Austempered specimens are found to have stronger than annealed specimens and failed in somewhat brittle manner characterized by river pattern, whereas ductile failure mode is characterized by presence of dimples in latter case has been observed.