What are the common coal mill composite lining materials? How to choose?
1. Alloy material
After the alloy liner is quenched, the comprehensive performance has both hardness and toughness, the hardness can reach HRA65 or more, and the impact toughness can reach 10J/cm2 (U-notch value). The characteristics are that the price is not high, the performance is stable, it can be cut and welded, and it is easy to install and use; the main disadvantage is that the wear resistance is average, and if the hardness is to be improved, the price will rise sharply.
2. Medium chrome steel material
Due to the high chromium content of medium chromium steel and the addition of molybdenum, nickel and other elements, the wear resistance is higher than that of low alloy materials, and the service life is longer; the disadvantage is that the weldability is poor, the welding difficulty is high, and it is not easy to install .
3. High chromium cast iron series
The high-chromium liner material has high wear resistance, but the cost is also high, and the weldability and cutability are poor, the brittleness is high, and the processing is very difficult. It is not recommended to be used as a coal mill liner.
4. High manganese steel
High manganese steel has the properties of impact hardening. It is generally used in high impact conditions. It has excellent wear resistance in the case of large impact force. However, in coal mills and other low impact conditions, most manufacturers have eliminated it. no need.
5. Wear-resistant ceramics
As a coal mill lining material that has risen in recent years, wear-resistant ceramics have been quickly recognized by many manufacturers after appearing on the market. Its hardness can reach HRA90, and its wear resistance far exceeds that of metal. Although the impact resistance of wear-resistant ceramics is not as good as that of metals, after adding special materials such as zirconia, the impact resistance can be greatly improved, and although the coal mill has impact wear, the impact force is not large. Wear-resistant ceramics are enough to deal with. The most important thing is that the price of wear-resistant ceramic liner is moderate, but the service life is more than 10 times that of metal liner, which is an economical choice after comprehensive consideration.
