Spherical ink manhole cover

Nodular cast iron manhole cover is a kind of nodular cast iron products, nodular cast iron through spheroidization and inoculation treatment to obtain spherical graphite, effectively improve the mechanical properties of cast iron, especially improve the plasticity and toughness, so as to get higher strength than carbon steel. Ductile iron is a kind of high strength cast iron material developed in the 1950s, its comprehensive performance is close to steel, it is based on its excellent performance, has been successfully used to cast some complex forces, strength, toughness, wear resistance requirements of high parts. Ductile iron has rapidly developed into a cast iron material second only to gray iron and widely used. The so-called "iron instead of steel" mainly refers to ductile iron.