Ductile iron pipes are a type of cast iron pipe. The quality requirements call for the spheroidizing grade of the cast iron pipe to be controlled at 1-3 levels (spheroidizing rate > 80%), thus ensuring the inherent mechanical properties of the material itself.

Ductile iron pipes in finished goods storage have been significantly improved, possessing the essence of iron and the properties of steel. After annealing, the microstructure of the ductile iron pipes consists of ferrite with a small amount of spheroidite, exhibiting excellent mechanical properties, corrosion resistance, elongation, and sealing performance. They are easy to install and mainly used for municipal, industrial, and mining enterprises for water supply, gas transmission, and oil transportation.

A certain number of spherical graphite are distributed on the ferrite and spheroidite matrix. The proportion of ferrite and spheroidite in the matrix structure varies depending on the nominal diameter and the required elongation. For small diameters, the spheroidite proportion is generally not more than 20%, while for large diameters, it is typically controlled around 25%.

　　GB/T13295-2008

Bore: DN80 - DN2600