Ductile iron CNC machining parts are the metal work pieces produced by CNC machining process using raw materials of ductile cast iron. Ductile cast iron is not a single grade of cast iron, but a group of cast iron, also called nodular iron or spheroidal graphite cast iron (SG cast iron). Nodular cast iron obtains nodular graphite through spheroidization and inoculation treatment, which effectively improves the mechanical properties of the cast iron, especially the plasticity and toughness, so as to obtain higher strength than carbon steel. Ductile iron have a wide range of properties through control of the microstructure. The common defining characteristic of this group of materials is the shape of the graphite. In ductile irons, the graphite is in the form of nodules rather than flakes as it is in grey iron. The sharp shape of the flakes of graphite create stress concentration points within the metal matrix, while the rounded shape of the nodules less so, thus inhibiting the creation of cracks and providing the enhanced ductility. This is why we call them ductile cast iron.
