Effects of graphite nodule count on mechanical properties and thermal conductivity of ductile iron

The effects of graphite nodule count on the mechanical properties and thermal conductivity of ferritic ductile iron were investigated. Results indicated that the strength of ferritic ductile iron changed little with the increase of graphite nodules, while the plasticity increased significantly. The similar strength was attributed to the same ferrite matrix microstructure, and the increased plasticity was because stress concentration was effectively relieved with the increase of graphite nodules during tensile test. The thermal conductivity of ferritic ductile iron decreased slightly with the increase of graphite nodules, which was related to graphite/matrix interface.