Common materials for impellers of md horizontal multistage centrifugal pumps for mining pumps
The md horizontal multi-stage centrifugal pump for mining pumps is not made of ductile iron for the entire pump, and it needs to be determined according to the user’s site conditions. The choice of impeller material is based on the condition of the conveying medium and the structure of the pump. Commonly used materials for impellers include cast iron, cast steel, stainless steel, alloy steel, carbon structural steel, and non-metallic materials.
impeller
Mine pump md horizontal multistage centrifugal pump impeller commonly used material:
1, cast iron
1) Gray cast iron
The common material of water pump impeller is generally cast iron, which is used for transporting non-corrosive media. The grades of this material are HT150, HT200, HT250, and the non-main parts of the base and backing plate are used for HT150, pump body, pump cover, suspension HT200 is used for the impeller, the mouth ring, and the shaft sleeve are HT250.
Different countries have different ways of expressing gray iron. For example, the code name for Japan is FC, the code name for Germany is GG, and the United States is Class.
2) Ductile cast iron
Nodular cast iron has a good comprehensive function. The national standard code is QT. Because the mechanics is close to steel, the forging and processing functions are better than steel. Generally, this material is used as a replacement for cast steel. Commonly used grades are QT450-10 and QT500- 7. QT600-3.
The DIN standard represents nodular cast iron as GGG, and the US represents Ductile iron.
There are also corrosion-resistant cast iron-high silicon cast iron, wear-resistant cast iron-white cast iron, high toughness cast iron-malleable cast iron, etc.
2, cast steel
Cast steel has high strength. When the pressure is greater than 1.6Mpa, the pressure-bearing parts are mostly cast steel. The national standard code is ZG, and the commonly used grade is ZG230-450. Japan and the United States usually use CS to represent cast steel.
3, stainless steel
The most widely used stainless steel impeller is austenitic stainless steel, such as 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr18Ni12Mo2Ti, etc. Except for a few media such as hydrochloric acid and dilute sulfuric acid, austenitic stainless steel is an excellent corrosion-resistant material and the most commonly used corrosion-resistant material for chemical pumps. Japan and the United States usually use SS304, SS316, and SS316L to represent austenitic stainless steel.
Martensitic stainless steels such as 2Cr13 and 3Cr13 have better mechanical properties than austenitic stainless steels. They are usually used as materials for pump shafts and sleeves. The corresponding codes in Japan and the United States are SS420.
In addition, high-alloy stainless steel (alloy 20) and double stainless steel are also ideal corrosion-resistant materials.
4, alloy steel
The most representative alloy steel is 40Cr, which is usually used as a material for high-strength pump shafts.
5. Carbon structural steel
is usually divided into ordinary carbon structural steel and high-quality carbon structural steel.
The most representative ordinary carbon structural steel is Q235, which is mostly used in various steel plates and section steels; the most representative high-quality carbon steel is No. 45 steel, which is widely used as a pump shaft material when no corrosion is required.
6, non-metallic materials
Non-metallic materials for pumps are mainly used for sealing, such as polytetrafluoroethylene, fluorine rubber, nitrile rubber, etc. Among them, polytetrafluoroethylene has excellent corrosion resistance and high temperature resistance and is used for chemical pump gaskets and static seals of mechanical seals. It is suitable for almost all chemical media within 250°C. Its disadvantages are high hardness and difficulty in assembly. Big.
Fluorine rubber is also a kind of better temperature resistance and corrosion resistance material. The upper limit of temperature resistance is 160℃. When the user has no special requirements, the company adopts the sealing ring of this material; while the nitrile rubber is mainly used for oil resistance or cleaning Static sealing in water medium.
