How to choose the appropriate material for the cutting body of mining cutters

source：http://www.xrocktools.com/ Release Time：2015-01-11 10:03:36

Mining cutters are one of the vulnerable parts in coal mining and tunnel excavation machinery. They are the main tools for coal dropping and crushing, and their performance directly affects the production capacity and power consumption of the coal mining machine. The stability of work and the service life of other related components. There are many types of cutting teeth, and the general structure is to embed a hard alloy blade head on a low alloy structural steel blade body that has been quenched and tempered. Hijacking is subjected to high cyclic compressive stress, shear stress, and impact loads during work. The main failure modes are tool head detachment, tool breakage, and wear of the tool head and body. Under certain working conditions, the mechanical performance of the tool body often directly affects the service life of the cutting teeth. Therefore, selecting the material of the tool body and effective heat treatment methods reasonably can reduce the wear and breakage of the cutting teeth, reduce the consumption of coal mining, improve the mechanical operation rate of the coal mining machine, and increase the comprehensive economic benefits of coal mining production, all of which have positive significance.

The cutting teeth bear high cyclic compressive stress, shear stress, and impact load when cutting coal and rock. Although the hardness of coal is not very high, it often encounters hard minerals such as coal gangue. Friction and impact during the cutting process of coal and rock can also cause the temperature of the cutting teeth to rise. Cutting teeth that work under such complex working conditions require their blade body to be both wear-resistant and have good impact resistance. The cutting teeth blade body is generally made of low-alloy structural steel.

From the actual use of imported and domestic cutting teeth in some domestic coal mines, it can be seen that the material of the cutting body is mostly 42CrMo, 35CrMnSi and other steel grades. Some coal mines are also using the newly developed Si Mn Mo quasi bainitic steel in China.

42CrMo steel has high strength, high hardenability, good toughness, small quenching deformation, and high creep and endurance strength at high temperatures. After heat treatment, 42CrMo steel has good low-temperature impact toughness.

35CrMnSi steel is also a material with good hardenability. After appropriate heat treatment, it can obtain comprehensive mechanical properties with good strength, hardness, toughness, and fatigue strength, which can adapt to the complex working conditions of coal mining production.

Si Mn Mo quasi bainitic steel is a new type of cutting tool developed by domestic research institutions. Under air cooling conditions, the steel obtains a multiphase structure of bainite, martensite, and residual austenite. After air cooling and tempering at 250-300 degrees Celsius, the experimental steel can achieve high strength, hardness, and good ductility. Tempering above 300 degrees Celsius is mild, with a significant decrease in hardness and the appearance of tempering brittleness.

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