RU2460810C1 - Ploughshare strengthening method - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: during electromechanical processing on ploughshare surface there formed are parallel strengthening zones with hardening structures of high hardness level. Strengthening zones with depth of up to 3 mm and width of 3.5÷7 mm are located at an angle of 40÷55° to ploughshare blade at the distance between them of 10÷30 mm. As a result of the above method the additional materials are not consumed and further mechanical processing is not required.

EFFECT: increasing lifetime of ploughshares due to improving their strength characteristics and wear resistance to abrasive wear.

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Description

The invention relates to the field of metalworking, relates to methods of surface hardening of plowshares of plows of agricultural machines in order to increase their durability with abrasive wear.

Known methods of hardening plowshares (see Reliability and machine repair / V.V. Kurchatkin, N.F. Telnov, K.A. Achkasov et al .; Edited by V.V. Kurchatkin. - M .: Kolos, 2000. - 776 p.), In which surfacing of their surface with metals is used, having enhanced strength properties. However, when surfacing, there is a strong thermal effect on the metal, which leads to large deformations of parts, the use of additional materials significantly increases the cost of products.

There is a method of hardening plowshares of plows of medium-carbon and high-carbon steels by welding reinforcement (Patent No. 2274526 adopted as a prototype), in which a low-carbon electrode material is used as the deposited material, which is deposited on the working surface in the form of parallel rollers, each of which is applied from speed, providing the formation of a quenching structure, after cooling the previous one.

The method increases the wear resistance of parts due to the formation of solid barriers to the friction path of abrasive particles, which reduces the intensity of abrasive wear of hardened shares. The disadvantages of this method are the same.

A known method of hardening parts of medium-carbon and high-carbon steels (Patent No. 2270259 is also adopted as a prototype), including hardening by short-term high-temperature exposure to a current of 16 kA with applying stains of the contact in a checkerboard pattern or along reinforcement lines.

As a result of the application of this method, point hardened sections are formed, which increases the wear resistance of the parts; further machining and the consumption of additional materials are not required. However, this method increases the wear resistance in part, since only small areas undergo hardening.

Known methods for electromechanical hardening of machine parts (see Askinazi B.M. Hardening and restoration of parts by electromechanical processing. - L.: Mechanical Engineering. - 1989. - 184 pp. And Bagmutov V.P., Parshev S.N., Dudkina N. G., Zakharov IN Electromechanical processing: technological and physical fundamentals, properties, implementation. - Novosibirsk: Nauka, 2003. - 318 p.), In which a large current passes through the contact zone of the deforming electrode tool (roller) and the part density (10 ⁸ -10 ⁹ A / m ² ) and low (1-6 V) voltage, resulting in contacting a large amount of heat is released to the product’s surface, high-speed heating of the local surface microvolume with its simultaneous plastic deformation and subsequent intensive cooling due to heat dissipation inside the part occur, which leads to an increase in hardness, strength and wear resistance. The method significantly changes the physical and mechanical properties of the surface layer of products, which increases their wear resistance during abrasive friction.

The technical result of the invention is to increase the durability of the working bodies of agricultural machines by improving their strength characteristics and wear resistance to abrasive wear.

This result is achieved in that the hardening of the working surface of the plowshares is carried out by electromechanical treatment with a current density of up to 10 ⁹ A / m ² continuous hardened lines parallel to each other, and hardening is carried out to a depth of 3 mm, the hardening zones have a width of 3.5 ... 7 mm and are located at an angle of 40 ... 55 ° to the share blade with a distance between them of 10 ... 30 mm.

The drawing shows a simplified diagram of the proposed method of hardening plowshares, where 1 is a zone without hardening, 2 is a zone of hardening, 3 are mounting holes. The front side of the share is hardened by electromechanical treatment with a current density of up to 10 ⁹ A / m ² continuous lines parallel to each other, to a depth of 3 mm, the hardening zones have a width of 3.5 ... 7 mm and are located at an angle of 40 ... 55 ° to the share blade with a distance between them 10 ... 30 mm, for example, on a vertically milling machine. Compliance with the specified parameters of the strengthening of the ploughshare provides high wear resistance, the range values are associated with the friction conditions of the products.

The modes of electromechanical processing (current density, force of pressing the tool to the surface of the part, processing speed, material and shape of the tool are taken based on the tasks and requirements of the process.

Thus, when processing by this method, hardened alternating zones with a hardness of up to 10 GPa are formed on the ploughshare surface, which increases their wear resistance during abrasive friction.

Claims (1)

The method of hardening the working surface of the plowshare plows, including electromechanical processing of the plow surface at a current density of up to 10 ⁹ A / m ² continuous lines parallel to each other, forming hardening zones, characterized in that hardening is performed to a depth of 3 mm, hardening zones have a width of 3, 5 ÷ 7 mm and are located at an angle of 40 ÷ 55 ° to the share blade at a distance between them of 10 ÷ 30 mm.

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