A ductile iron composition including, by weight: about 3.4% to about 4.0% Si; about 3.0% to about 3.5% C; about 0.5% to about 1.0% Cr; about 0.02% to about 0.05% Mo; up to about 0.01% S; up to about 0.5% Mn; and balance iron and incidental impurities. The composition has a a ferritic body center cubic microstructure and has a graphite nodule density of greater than 100 per mm2. A method for forming a ductile iron composition is also disclosed.