Contribution of forming parameters on the properties of hot rolled ductile cast iron alloys

Abstract

Ductile cast iron slabs have been successfully hot rolled up to 70%. The shape ratio β of graphite in pearlitic matrix alloys increases as the amount of reduction increases, in case of DHTA alloys up to 50% reduction, after which β decreases again. The matrix of moderately deformed pearlitic ductile iron contains several micro-deformed bands (striations) swept around the deformed graphite forming lensoid deformation distortion. Further deformation, leads to severe localized micro-cracking along the grain boundaries. However, in a ferritic matrix, graphite deforms plastically and then begins to strangle (necking). Further deformation leads to the fragmentation of graphite and creation of secondary nodular graphite.