- Overview of metal wear-resistant materials
The wear resistance of the material is not only determined by the hardness Hm of the material, but more importantly by the ratio of the hardness Hm of the material to the hardness Ha of the abrasive. When the ratio of Hm/Ha exceeds a certain value, the amount of wear will decrease rapidly.
When Hm/Ha≤0.5-0.8, it is hard abrasive wear. At this time, increasing the hardness of the material does not increase the wear resistance of the material much.
When Hm/Ha>0.5-0.8, it is soft abrasive wear. At this time, increasing the hardness of the material will rapidly improve the wear resistance of the material.
Metal wear-resistant materials generally refer to wear-resistant steel, steel that can resist abrasive wear. This type of steel has not yet become a completely independent steel type, and the recognized wear-resistant steel is high manganese steel.
The titanium carbide cermet material produced by broadcarbide can effectively improve the service life of high manganese steel wear parts, reduce equipment downtime, and maximize production efficiency.
- Wear-resistant steel mainly used by cement enterprises
In the cement industry, abrasive wear is mostly used as the main wear mode. Wear-resistant materials are mainly used for mill liners, compartment plates, grate plates, balls, segments, crusher hammers, blow bars, impact plates, jaw plates, vertical mill rollers, discs, etc. From the material can be divided into the following three categories:
- High manganese steel series
This material has always occupied the dominant position of wear-resistant materials for more than a hundred years before the 1980s. Advantages: excellent toughness, work hardening under strong impact conditions; disadvantages: easy plastic deformation, not wear-resistant. It has been withdrawn from wearing parts (mill liners) applied under non-strong impact conditions, but it still maintains an irreplaceable advantage in wearing parts applied under strong impact loads.
Ordinary high manganese steel and alloy high manganese steel with various alloy elements added in order to improve the yield strength are easy to be used in large crusher hammers, blow bars, impact plates, grate plates, jaw crusher jaw plates, and cone crusher inner and outer cones. Among the damaged parts, it dominates. Ultra-high manganese steel is limited to hammer heads and blow bars of large crushers. Medium manganese steel is also partially used.
- Alloy steel series
Various alloy steels such as low-carbon medium alloy, medium-carbon low-alloy, medium-carbon medium-alloy, low-carbon high-alloy, etc., due to their chemical composition and heat treatment process can change in a wide range, the mechanical properties of the final product vary greatly. Hardness HRC40-60, impact toughness ak10-100J/cm2, so the main wear mechanism can be analyzed according to the application conditions of vulnerable parts, and the chemical composition and comprehensive mechanical properties of alloy steel can be optimized and selected to achieve the most economical and reasonable selection .
The advantages of medium-carbon low-alloy steel are: small amount of alloy, low production cost, relying on water quenching or oil quenching to increase hardness, and meeting the wear-resistant life of wearing parts.
The advantages of medium-carbon medium-alloy steel are: the medium alloy content makes the matrix structure solid-solution strengthened and has dispersed carbides, the heat treatment process is simple and stable, and the comprehensive mechanical properties are better. Compared with medium-carbon low-alloy steel, even though the hardness is the same, the wear resistance is significantly higher, but the production cost is higher.
The advantages of low-carbon high-alloy steel are: the chemical composition of low-carbon and high-alloy combined with appropriate heat treatment process can obtain very high toughness and high hardness, and it has absolute advantages for wearing parts with large impact load and complex structure. The advantage, the disadvantage is the high production cost.
- Anti-wear white cast iron series
This series includes high chromium cast iron, medium chromium cast iron, low chromium cast iron, nickel hard cast iron and high chromium cast steel. Overall advantages: high hardness, good wear resistance. Disadvantages: lack of toughness.
High chromium cast iron (Cr14-30%) has the best wear resistance and the widest application range, such as small and medium-sized mill liners, balls and segments, small crusher hammers and blow bars, vertical mill rollers and discs, etc. After the roller press is installed in front of the large mill, the high chromium cast iron can make full use of its strengths and avoid its weaknesses, giving full play to its excellent wear resistance, and the service life of the liner can reach more than 8 years.
The hardness and toughness of low-chromium cast iron (Cr1.5-3%) are much lower than those of high-chromium cast iron. And anti-wear indicators in general.
Medium chromium cast iron (Cr8-14%) is only used for casting balls. Reducing the chromium content can not only reduce the production cost, but also meet the broken rate index of the ball. It is still called high chromium ball in the market.