Microstructure of as cast reinforced ductile iron

Local hardening of parts made of ductile iron may be achieved by having carbides appearing in appropriate locations. The present work focuses on the study of the as cast microstructure of parts reinforced by Cr containing steel inserts. The presence of such inserts in the mold cavity results in localised chemical changes during the casting process, constituents of the insert (principally chromium) being transferred to the cast iron while carbon penetrates the insert. This leads to the formation of various carbides within and in the surroundings of the insert.