How to choose the material grade of cemented carbide for mining tools?

How to choose the material grade of cemented carbide for mining tools?

Cemented carbide is an alloy material made of hard compounds of refractory metals and bonding metals through powder metallurgy.

Cemented carbide has a series of excellent properties such as high hardness, wear resistance, good strength and toughness, heat resistance and corrosion resistance, especially its high hardness and wear resistance, which remain basically unchanged even at a temperature of 500°C , it still in high hardness at 1000℃.

Cemented carbide is widely used as tool materials, such as turning tools, milling cutters, planers, drills, boring cutters, etc., for cutting cast iron, non-ferrous metals, plastics, chemical fibers, graphite, glass, stone and ordinary steel, and can also be used for cutting hard-to-process materials such as heat-resistant steel, stainless steel, high manganese steel, tool steel, etc.

In 1923, Schroeter of Germany added 10% to 20% of cobalt to tungsten carbide powder as a binder, and invented a new alloy of tungsten carbide and cobalt. The hardness is second only to diamond, which is artificially made in the world. The first cemented carbide. When a tool made of this alloy is used to cut steel, the blade will wear out quickly and even crack. In 1929, Schwarzkov of the United States added a certain amount of compound carbide of tungsten carbide and titanium carbide to the original composition to improve the performance of the tool in cutting steel. This is another achievement in the development history of cemented carbide.

Cemented carbide can also be used to make rock drilling tools, mining tools, drilling tools, measuring tools, wear-resistant parts, metal abrasive tools, cylinder linings, precision bearings, nozzles, metal molds (such as wire drawing molds, bolt molds, nut molds, and Various fastener molds, the excellent performance of cemented carbide gradually replaced the previous steel molds).

The correct selection of cemented carbide mining tool grades is one of the extremely important factors to ensure the effective use of cemented carbide.

When choosing cemented carbide grades, the toughness of the alloy should be emphasized for extremely hard rocks and heavy-duty rock drills with high impact energy, and alloy grades with higher cobalt content should be selected; for hard, brittle, and corrosive rocks, emphasis should be placed For the wear resistance of the alloy, select alloy grades with a slightly lower cobalt content; for medium-hard and below-medium-hard rocks, use alloy grades with lower cobalt content and higher hardness; for coal mining under heavy load use Cemented carbide for machine pick mining mainly adopts reduced cobalt content and increased grain size, thereby greatly improving the bending strength and impact toughness of the alloy; for cylindrical teeth, cross, and three-blade drill bits, use hard alloys with lower cobalt content. Quality alloy. At the same time, the following points should be noted:

1. The physical and mechanical properties of the rock formation, such as hardness, friction, etc. and its shape characteristics. The generally adopted principle is: the harder the rock to be cut, the better the toughness of the selected alloy sheet, but not too soft. Note that the wear resistance should not be too low, because too soft will increase the consumption of alloys and reduce the drilling efficiency. For rock formations with many cracks, regardless of the hardness and the type of rock drill used, cross-shaped bits should be used. .

2. Model of rock drill, such as light, heavy, etc.;

3. Rock crushing methods (cutting, shearing, crushing, crushing, etc.);

4. Equipment capacity (wind pressure level)