Ductile cast iron, also called ductile iron, spheroidal graphite iron, or nodular cast iron, is a type of cast iron invented in 1943. While most varieties of cast iron are brittle, ductile cast iron is much more flexible and elastic, due to its nodular graphite inclusions.
Graphite particles exist in the form of sphericity in ductile cast iron. Sizes graphite particle are restricted to 6 -7 class and spheroidizing rate should not be less than 80%. Thus after the spheroidizing process, ductile iron will be endowed with mechanical properties of both cast iron and steel.
Much of the production of ductile iron is in the form of ductile cast iron pipe, used for water and sewer lines. Ductile cast iron pipe is stronger and easier to tap, requires less support and provides greater flow area compared with pipes made from other materials like PVC, concrete, polyethylene or steel. Ductile Iron Pipe is the most widely-used pipeline product in water supply and water drain/sewage projects.
