Cast iron with a purely ferritic metal matrix, which consequently does not contain any combined carbon.
It provides relatively low hardness. On the other hand, however, ferritic cast iron with nodular graphite is characterized by great elongation, high notch impact strength as well as great thermal stability and good machinability (s.. a. Nodular graphite cast iron with low-temperature toughness).
Figures 1 and 2 show examples of the ferritic matrix of nodular graphite cast iron.
Metal matrix of cast iron
Structure formation of cast iron