In many regions of our country, gray cast iron pipe is used for medium and small diameter pipe connections, employing socket-and-spigot or flanged joint methods; ductile iron pipes must have excellent seismic resistance and sealing properties for permissible restricted angles.

Ductile iron pipes are primarily composed of carbon, silicon, manganese, sulfur, phosphorus, and magnesium. Compliance Standard [span]GB/T ISO 2531/2003

Ductile iron pipes defined as pipes cast at high speed through centrifugal casting on a centrifugal ductile iron machine using molten pig iron of 18# grade or higher, after the addition of spheroidizing agent.

Ductile Cast Iron Pipes, commonly referred to as ductile iron pipes, spheroidal iron pipes, or spheroidal graphite cast iron pipes.

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

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 and a small amount of spheroidite, featuring excellent mechanical properties, corrosion resistance, and ductility. They offer good sealing performance, are easy to install, and are mainly used for municipal, industrial, and mining enterprises in 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 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 usually controlled around 25%.

Mechanical Properties

　　GB/TISO2531-2009

Bore Size: DN80 - DN2600