Water supply ductile iron pipe and drainage ductile iron pipe are different uses of ductile iron pipe, there are different uses, so there will be some differences. Their materials are all grey cast iron, but there will be some differences in distribution. Next, I will give you a detailed introduction. Many people may not know much about cast iron, so they will share about the types of cast iron. Hope to help those who are interested.

 

Ductile iron is a kind of gray cast iron which is added nodularizer and inoculant before melting and casting to make it present as spherical graphite with gray-white fracture surface and code number QT. Ductile iron after heat treatment can obtain better mechanical properties, high strength and ductility, wear resistance, good casting performance and low price. It can replace steel parts in many places, and some important pipe valve shells. Ductile iron is also used to replace steel castings.

 

 

 

The material of water supply ductile iron pipe and drainage ductile iron pipe is grey iron. Because water supply ductile iron pipe needs to bear pressure, HPT 200, HT250 grey iron pipe is commonly used, drainage ductile iron pipe is commonly used below HT150 grey ductile iron pipe. Centrifugal casting is used for water supply ductile iron pipe. The surface of iron pipe is smooth. If it is socket ductile iron pipe, the socket intersects deeply and the pipe wall is thicker. The length of root canal is 6 meters.

 

Some of the drainage ductile iron pipes are cast by vertical die casting or small centrifugal casting machine. The surface of the pipe is rough, the length of the single pipe is 3 meters, the socket is shallow, and the pipe wall is thin. The water supply ductile iron pipes are divided into low pressure pipes with working pressure of 0.45 MPA, medium pressure pipes with 0.75 MPA and high pressure pipes with 1.0 MPA. Water pressure test must be carried out before leaving the factory. The qualified pipes can be discharged from the factory. Cast iron pipes are only inspected for appearance and sound by tapping. No air holes, cracks and damaged sound are qualified.

 

Cast iron can be divided into several categories. Pig iron is an iron-carbon alloy with a carbon content of more than 1.7%. It also contains a small amount of silicon, manganese, sulphur, phosphorus and other elements. The content of silicon, sulphur, manganese and phosphorus has a great influence on the quality of pig iron. There are different forms of carbon in pig iron, which can be divided into four categories: white iron, gray iron, malleable iron and ring graphite iron.

 

Some carbon and iron in white iron exist in the form of FEAC. The fracture surface is silver-white, with high hardness and brittleness. It can not be machined directly. It is seldom used directly in industry. It is often used as raw material for making malleable cast iron.

 

Some iron and carbon in gray cast iron exist in the open form of ferrite and graphite, the fracture is gray, code HT, the strength and plasticity of gray cast iron are low, but the castability of gray cast iron is good, wear reduction, good machinability, vibration reduction and low notch sensitivity. Gray cast iron has lubricity, low melting point and small crystallization range because of the existence of graphite, so gray cast iron has good casting performance and graphite is in iron. Cavitation is formed, which can reduce vibration and friction.

 

Malleable cast iron is made of white cast iron by heat treatment to make graphite in iron flocculent, code KT, Valley called Ma Steel, the fracture surface is gray-black, the texture is soft, has a certain degree of legality, strength is higher than gray cast iron, often used as pipe accessories and mechanical parts with complex casting shape, thin wall thickness.

 

With strong technical force and first-class processing and testing equipment, according to GB/T 2772-2008 standard, the company produces centrifugal cast iron pipes and fittings with compact structure, high compressive strength, uniform wall thickness, fine workmanship, smooth internal and external surface, complete variety, which can be widely used in chemical floor, indoor and outdoor, building water supply and drainage engineering.