About Product:Ductile iron manhole cover is a kind of Ductile iron products, Ductile iron through the spheroidization and inoculation treatment to get graphite, Effectively improve the mechanical properties of cast iron, especially improve the plasticity and toughness, Ductile iron is a kind of high strength cast iron material developed in 1950s. Its comprehensive performance is close to that of steel. It is based on Its excellent performance that ductile iron has been successfully used to cast some parts with complex force, high strength, Ductile iron has been widely developed into a second only to gray cast iron, the application of a very wide range of cast iron materials.