Nodular cast iron manhole cover is a kind of ductile cast iron
products, spheroidal graphite cast iron spheroidal graphite is
obtained by spheroidizing, effectively improve the mechanical
properties of cast iron, especially improve the plasticity and
toughness, and the strength is higher than carbon steel. Ductile
iron is in the *0 s of the *0th century developed a kind of high
strength cast iron material, its comprehensive performance is close
to steel, it is based on its superior performance, has been
successfully used in casting some complex loading, requiring higher
strength, toughness and abrasion resistance parts. Ductile cast
iron has been developed rapidly for behind of gray cast iron, cast
iron material application is very extensive. The so-called "iron
and steel", mainly refers to nodular cast iron.
