Pick having bimetal structure and preparation method thereof

Abstract

The invention relates to a pick having a bimetal structure and a preparation method thereof, in particular to a pick and a preparation method applicable to coal mining machines and tunneling machines capable of cutting coal seams and rock strata, belonging to the technical field of the research on mining machinery metallic materials and geotechnical engineering. The pick is characterized in thatthe pick body consists of two metals, wherein the most wear-prone top end of a pick head of the pick is made of tailor-made alloy steel; the wear-resistant lower ends of the pick handle and pick headare made of medium carbon alloy steel; a plurality of ring-shaped grooves are formed below the top end of the pick head; an interlayer is arranged between every two adjacent ring-shaped grooves; the ring-shaped grooves are subjected to full-surfacing process by using the tailor-made alloy steel welding rods; and since the interlayer is thin, the integral wear-resistant tailor-made alloy steel canbe formed at the top end of the pick head. The pick of the invention has the advantages of simple structure, novel design, high practicability, convenient fabrication, high hardness and wear resistance and good impact-resisting and corrosion-resisting performance; and according to industrial tests, compared with the homemade pick, the service life of the pick is prolonged by 20 to 30 times, thus saving a great deal of alloy steel materials for our country and reducing the mining cost.

Description

technical field [0001] The invention discloses a pick with a bimetallic structure and a preparation method thereof, which belong to the technical field of metal materials for mining machinery and geotechnical engineering research, and specifically relate to a pick and a pick capable of cutting coal seams and rock formations applied to coal shearers and roadheaders. its preparation method. Background technique [0002] Coal industry production at home and abroad, are widely used coal mining machine, roadheader mining. Picks of different specifications and numbers installed on coal shearers and roadheaders are indispensable and easy-to-wear parts. The cylindrical part of the pick is the tooth shank, and the conical part is the tooth head. The tooth shank and the tooth head are collectively called the tooth body. The top of the tooth head is welded with a hard alloy head. The tooth body and the hard alloy head form a complete pick. . The pick has high requirements on the har...

AI Technical Summary

Problems solved by technology

The pick bears a lot of impact during work, and it is difficult to ensure sufficient bending strength between the weld seam and the spigot, which will cause the separation of the top of the tooth head from the rest of the tooth body; although low temperature tempering can eliminate the welding at the joint stress, but does not increase the flexural strength of welds and spigot connections

The second method is: the top of the tooth head is welded with a cemented carbide head, and the surface of the tooth head is baked with a cemented carbide layer by powder metallurgy process. If the axial force is large, a large bending stress will be generated, and the strength difference between the tooth head and the hard alloy layer is large, which will cause it to fall off, and the hard alloy head will lose its protection.

Although this layer has high hardness and can resist wear, but due to the large difference in mechanical properties between the tooth head and the wear-resistant layer, the inside is soft and the outside is hard, and the wear-resistant layer peels off due to insufficient impact resistance; in addition, because there is no hard Alloy head, the thin wear-resistant layer at the top of the tooth head alone is not enough to directly cut the coal seam and rock formation to maintain a long service life

[0004] It can be seen that the purpose of the above structures is to improve the hardness and wear resistance of the tooth head part of the pick to protect the carbide head, but the key problem is that there is an obvious interface between this reinforced part and the metal material of the original tooth body due to the large performance difference. There is no transition area between two different metal materials, and there is no real fusion with the metal material of the tooth body at the joint. It is easy to break or peel off under strong impact, which will cause the carbide head to lose its wrapping and support and be thrown out. Final pick scrapped

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