RU2501986C2 - Method to manufacture fixed joint of hub-shaft type for steel parts (versions) - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: method to manufacture a fixed joint of hub-shaft type for steel parts, including formation of a coating by the method of electric corrosion alloying at least one of coupled surfaces of joined parts with their subsequent assembly, differing by the fact that on the inner surface of the hub in zones adjacent to its ends, using the method of electric corrosion alloying, they form a diffusion layer, and the sub-hub surface of the shaft is exposed to cementing by the method of electric corrosion alloying, afterwards a layer of soft anti-friction material is applied onto the cemented layer by the method of electric corrosion alloying, and then it is processed with the method of surface-plastic deformation, at the same time the thickness of the applied layer from soft anti-friction material and roughness of the coupled surfaces is provided due to selection of modes of electric corrosion alloying, the material of the electrode and the method of application of the layer of soft antifriction material.

EFFECT: increased fatigue strength of shafts of fixed joints, saving on nonferrous metals and simplified technology of hub manufacturing.

17 cl, 8 dwg

Description

The invention relates to mechanical engineering, in particular to the manufacture of rotors of turbines, compressors and pumps, shafts with gears of gears, axles and shafts of agricultural machines, etc.

One of the most common components in mechanisms and machines is a press connection or a connection with a guaranteed interference fit.

The most characteristic cases of failures in the operation of press and press-key connections are malfunctioning, fretting-fatigue damage and breakage due to fatigue. Therefore, improving the performance of these compounds is one of the most important tasks of ensuring the reliability and durability of machine parts.

Fixed joints of mating parts are characterized by the impossibility of their mutual movement. The immobility of the connection is ensured by interference. Connection strength is determined by fit and accuracy. Fixed joints can be made on press fit (guaranteed interference fit) or transition fit (fit or clearance).

The assembly of fixed surfaces can be carried out by pressing the shaft into the hole, heating the part that has the hole and covering the shaft, or by cooling the shaft [Zuev AA, Gurevich D.F. Technology of agricultural engineering. M .: Kolos, 1980, p. 219-220].

The peculiarity of press joints is that the details of these joints, even before the application of work loads, are in a stress state caused by the presence of interference on the seating surfaces. The summation of the operating stresses and the stresses from the interference can lead to a significant concentration of stresses in individual places of pairing. The reduction of the shaft endurance limit in the underbody occurs under the ends of the hub, as a result of stress concentration and fretting fatigue. The influence of these factors can be reduced by reducing the total stiffness of the hub, and especially at its ends, for example, by pressing rings of softer material onto the ends of the hub into rectangular grooves made on the bore diameter [L.T. Balatsky. Strength of press joints. K .: Technics, 1982. - S. 123-124, 128-129, prototype], (Fig. 1 ').

Figure 1 shows the press connection "hub 1 - shaft 3" with insert rings 2. The height of the ring (t) should be selected taking into account the interference in the connection and the transmitted load, which determines the amplitude of the relative slip of the hub 1 and shaft 3. The presence of rings 2 of more pliable materials in the zones of maximum contact pressures smooths out the peak of stresses and reduces the degree of damage during fretting corrosion.

The test results showed that the endurance limit of samples with a diameter of d = 20 mm from 40X steel with hubs with a diameter of D = 37 mm and a length of 90 mm, having rings of red copper M2, increases with clean bending with a frequency of 50 Hz by 2 times (from 150 to 300 MPa).

However, it is further noted that with significant press joint loads and insufficient ring width, as a result of crushing the contact surface of the ring, the end face of the hub can move to point A (Fig. 1). If this happens, then the endurance limit of such a compound may decrease, compared with pairing without rings, since the stiffness of the hub at the ends will increase.

A known method of electroerosive alloying (EEL), with which you can change the hardness of the metal surface:

- increase the hardness by applying to the surface of a material of higher hardness or by diffusion introduction into the surface layer of the necessary chemical elements from the environment or from the anode material;

- reduce hardness by applying softer materials to the surface;

- increase the hardness when processing non-hardened, but hardened material, using pulses with higher energy or longer, heating the metal slightly deeper than the total thickness of the deposited and diffusion layers [Lazarenko N.I. Electrospark alloying of metal surfaces. - M. Engineering, 1976. - p.19].

Compared to the hub, there are less possibilities for varying the structure for the underbody part of the shaft. One of the most common ways to increase fatigue resistance is to increase the diameter of the underbody with a smooth transition to thickening from the main diameter. Three cases can occur here: the end face of the hub hangs over the fillet (Fig. 1), the end face of the hub is flush with the end of the underside (l ₂ = 0) and the end of the hub does not reach the end of the underside (l ₂ is negative) [L. T. Balatsky. Strength of press joints. K .: Technique, 1982. - C.129-130]. In order to significantly increase the bearing capacity of press joints, a direction has recently been widely developed related to the introduction of soft and hard layers into the contact zone.

In [L.T. Balatsky. Strength of press joints. K .: Technika, 1982. - p.141] the author cites the results of the works of A. Tum and F. Wupderlich, in which a significant effect of increasing the endurance limit of shafts with pressed parts by cementation is noted. It was found that the endurance limit of samples with a diameter of 12 mm with pressed bushings was affected by their leash during quenching. After taking measures to prevent the leash, the endurance limit increased from 137.3 to 412.0 MPa. According to E. Lera, the endurance limit of cemented samples with a diameter of 60 mm in the press fitting has more than doubled.

Analysis of literary sources shows the absence of a single mechanism of protection against fretting corrosion. It was found that fretting corrosion of parts can be reduced or completely eliminated by changing the quality parameters of their surface layers, for example, by applying corrosion-resistant protective coatings of the required hardness, thickness and friction coefficient, firmly connected to the base of the part and not reducing their fatigue strength.

One of the most promising methods for the formation of surface layers of parts with the required properties is the method of electroerosive alloying (EEL). The method has a number of specific features, one of which is that the doping process can occur without transferring the anode material to the cathode surface and not form a material gain, for example, with an EEL using a graphite electrode [N. Lazarenko. Electrospark alloying of metal surfaces, - M .: Mechanical Engineering, 1976. - P.4].

The EEL method with a graphite electrode is based on the diffusion process (saturation of the surface layer of the part with carbon) and has some similarities with the type of chemical-thermal treatment - cementation.

Compared to conventional cementation, the method of cementing steel parts of EEL not only has all the advantages of the compared method, that is, the surface hardening of the part is carried out while maintaining the properties of its original material, but, in addition, it does not warp, and small-sized installations allow hardening to be performed on any available equipment. The performance of the process is 1-5 min / cm ² .

With an EEL with a graphite electrode, hardening of the surface of the part occurs due to diffusion-hardening processes, which involve local saturation with carbon at a sufficiently high temperature (up to 10,000 ° C), followed by rapid cooling to almost room temperature of the part itself.

Cementation of steel parts by electroerosive alloying (CEEL) can be distinguished in a separate direction, which allows to form surface layers of increased wear resistance on machine parts without changing the initial size of the part [Pat. 2337796. The Russian Federation. IPC V23H 9/00. The method of cementation of steel parts by electroerosive alloying / Martsinkovsky B.C., Tarelnik VB, Belous A.V .; declared 10/05/2006; publ. 10.04. 2008, Bull. No. 31. - 3 p., Prototype].

In CEEEL steel parts, the thickness of the hardened layer depends on the discharge energy and alloying time (process performance). With increasing discharge energy and doping time, the thickness of the hardened layer increases. At the same time, surface roughness also increases. So when EEL carbon medium-carbon alloy steel 40X (Ra = 0.5 μm) with a capacity of 5 min / cm ² at a discharge energy of 6.8 J, the thickness of the layer of high hardness is more than 1.15 mm The surface roughness in this case corresponds to Ra = 11.7-14.0 μm.

To reduce surface roughness after CEEL, as a rule, methods of surface plastic deformation (PPD) are used.

Among PPD methods, special attention is paid to: rolling around with a ball, roller and ultrasonic hardening - the method of non-abrasive ultrasonic finishing (BFFS).

Despite the fact that the subsequent processing of the BUFO significantly reduces the surface roughness, for many machine parts this is insufficient.

The technical problem to which the invention is directed is to increase the fatigue strength of the shafts of fixed joints. For this purpose, a method has been created for manufacturing a fixed joint such as a shaft-hub of steel parts, which, like the known method, includes forming a coating by electroerosive alloying, at least on one of the mating surfaces of the connected parts with their subsequent assembly, but in which, in accordance with with the claimed invention, on the inner surface of the hub in the areas adjacent to its ends, by the method of electroerosive alloying form an annular diffusion layer, while the thickness of the applied Loy of soft anti-friction material and provide a surface roughness due to the choice electroerosion doping regimes, the electrode material and a method of applying a layer of soft anti-friction material.

An annular diffusion layer 5-10 mm wide is formed by an electrode-tool made of copper or tin bronze at a discharge energy of 0.01-3.4 J on the surfaces of grooves made on the landing diameter of the hub. Moreover, an annular diffusion layer is formed on the surfaces of the hub grooves at a discharge energy of 0.01-0.5 J in air and at a discharge energy of 0.01-3.4 J in a protective argon atmosphere.

A method of manufacturing a fixed joint of the shaft-hub type of steel parts has been created, which, like the known method, includes forming a coating by electroerosive alloying, at least on one of the mating surfaces of the connected parts with their subsequent assembly, but in which, in accordance with the claimed by the invention, the access surface of the shaft is subjected to cementation by electroerosive alloying, after which a soft layer is applied to the cemented layer by electric erosion alloying ntifriktsionnogo material and then it is treated by surface-plastic deformation, the thickness of the applied layer of soft antifriction material and surface roughness due to the choice provide electroerosion doping regimes, the electrode material and a method of applying a layer of soft anti-friction material.

The entrance surface of the shaft is subjected to cementation by the EDM method with a graphite electrode at a discharge energy of 0.1-6.8 J, and the cemented access surface of the shaft is subjected to electrical discharge by silver or copper.

The cemented access surface of the shaft can be subjected to electroerosive alloying with a tin bronze electrode, thereby forming a soft antifriction layer up to 2.5 mm thick, and increasing the diameter of the entrance part of the shaft by 5.00 mm.

A transition radius (fillet) is formed in the area of the undercut surface of the shaft from the portion of the shaft of larger diameter to the portion of the shaft of normal diameter by reducing the discharge energy and / or increasing the force of surface-plastic deformation.

A method of manufacturing a fixed joint of the shaft-hub type of steel parts has been created, which, like the known method, includes forming a coating by electroerosive alloying, at least on one of the mating surfaces of the connected parts with their subsequent assembly, but in which, in accordance with the claimed the invention, on the inner surface of the hub in the areas adjacent to its ends, by the method of electroerosive alloying form a ring-shaped diffusion layer, and the accession surface of the shaft cementation is carried out by electroerosive alloying, after which a layer of soft antifriction material is applied to the cemented layer by electroerosive alloying, and then it is treated by the method of surface-plastic deformation, while the thickness of the applied layer of soft antifriction material and the roughness of the mating surfaces are ensured by choosing the modes of electroerosion alloying , electrode material and method for applying a layer of soft antifriction material.

An annular diffusion layer 5-10 mm wide is formed by an electrode-tool made of copper or tin bronze at a discharge energy of 0.01-3.4 J on the surfaces of grooves made on the landing diameter of the hub. Moreover, an annular diffusion layer is formed on the surfaces of the hub grooves at a discharge energy of 0.01-0.5 J in air and at a discharge energy of 0.01-3.4 J in a protective argon atmosphere.

It should be borne in mind that the width of the diffusion layer is determined by the dimensional parameters of the compound.

The entrance surface of the shaft is subjected to cementation by the EDM method with a graphite electrode at a discharge energy of 0.1-6.8 J, and the cemented access surface of the shaft is subjected to electrical discharge by silver or copper.

The cemented access surface of the shaft can be subjected to electroerosive alloying with a tin bronze electrode, thereby forming a soft antifriction layer up to 2.5 mm thick, and increasing the diameter of the entrance part of the shaft by 5.00 mm.

A transition radius (fillet) is formed in the area of the undercut surface of the shaft from the portion of the shaft of larger diameter to the portion of the shaft of normal diameter by reducing the discharge energy and / or increasing the force of surface plastic deformation

The above methods are aimed at solving one technical problem, namely, increasing the fatigue strength of the shafts of fixed joints, and solving the problem is based on the general principle, that is, on obtaining a high-quality wear-resistant layer with the required roughness, at least on one of the mating surfaces by electroerosive alloying. Therefore, we can conclude that these inventions are united by a single inventive concept and are variants of one way to solve one technical problem.

A description of the implementation of the invention is presented with reference to graphic materials, where:

Figure 1 'shows a schematic illustration of a press connection with insert rings: 1 - hub; 2 - an insert ring; 3 - shaft.

Figure 1 presents a schematic illustration of a press connection with an enlarged diameter of the underbody.

Figure 2 presents a schematic illustration of a hub with a diffusion layer of copper.

Figure 3 presents a schematic illustration of a hub with rounded ends.

Figure 4 presents the image of steel samples for studying the results of cementation by electroerosive alloying (CEEL) and electroerosive alloying (EEL): a - silver and b - copper.

5 is a schematic representation of a CEEL using a lathe.

Figure 6 presents the image of thin sections for metallographic and durometric studies.

Figure 7 presents the image of the microsection (a) and the distribution diagram of microhardness in the surface layer of 40X steel of sample No. 1 (b).

On Fig presents the image of the microsection (a) and the distribution of microhardness in the surface layer of 40X steel of sample No. 2 (b).

In accordance with the present invention, the inner surface of the hub adjacent to its rounded inner ends was machined. Moreover, on the surface of the hub of steel 20 formed a strong diffusion layer of copper or tin bronze (figure 2).

In the proposed embodiment, there is the possibility of using such a design feature, as the rounding of the inner ends of the hub, which provides such an additional positive effect as a decrease in its rigidity (figure 3).

Table 1 below shows the operating modes of the EDM-8 EDM unit, as well as data on the roughness and thickness of copper and tin bronze coatings on steel 20.

Electroerosive alloying of steel with 20 electrodes made of copper and tin bronze at the UILV-8 installation

Table 1 No.
regime Capacitance, microfarad Voltage Discharge energy, j Layer thickness mm Microroughness height Rz, mm copper bronze copper bronze one twenty 38.5 0.01 0.01 0.01 2 3 3 twenty 56.1 0.02 0.015 0.02 3 four 6 twenty 73.6 0,03 0.02 0,03 5 7 8 twenty 83,4 0.04 0,025 0.04 8 10 9 300 38.5 0.13 0,035 0.05 10 12 eleven 300 56.1 0.28 0.05 0,07 13 fifteen 12 300 62.8 0.35 0,07 0.08 fifteen 17 13 300 68.7 0.42 0.09 0.11 16 19 fourteen 300 73.6 0.49 0.11 0.13 17 21 fifteen 300 78.6 0.56 0.13 0.15 23 27 16 300 83,4 0.63 0.14 0.17 27 thirty

It should be noted that, starting from regime 15, when the discharge energy is 0.56 J, electrodes from both copper and tin bronze begin to oxidize more intensively, which leads to a decrease in the quality of the treated surface.

The quality of the formed layers when using high discharge energies can be improved by using a protective argon medium. Table 2 below shows data on the roughness and thickness of copper and tin bronze coatings, depending on the discharge energy, obtained with EEL of steel 20 using an Elitron-52A model in an argon protective medium.

Durometric analysis shows that when steel 20 is alloyed with copper and tin bronze both in air and in argon, the microhardness on the surface of the layer is, respectively, 850-900 MPa and 1050-1150 MPa. As it deepens, it gradually increases to the microhardness of the heat-affected zone (2500-3000 MPa), and then goes into the microhardness of the base metal 1750-1800 MPa. The thickness of the heat affected zone depends on the doping regime and is, for example, for a discharge energy of 0.56 J in air, 50 μm, and in an argon medium of 40 μm.

Dependence of the surface roughness and thickness of coatings of copper and tin bronze on the energy of the discharge with EEL steel 20 on the installation of the model "Elitron-52A" in a protective environment of argon

table 2 Discharge energy, j Productivity, min / cm Layer thickness mm Microroughness height Rz, mm copper bronze copper bronze 0.9 1,0 0.15 0.18 16 eighteen 2.83 0.5 0.17 0.35 23 25 3.4 0.5 0.21 0.53 27 31 6.8 0.5 0.23 1,5 39 67

The choice of the limiting values of the discharge energy for the deposition of copper and tin bronze is due to the nature of their interaction with deformable solid metals.

The lower limit of the discharge energy is limited by the efficiency of the method. An increase in the discharge energy above the upper limit when applying copper or tin bronze in air leads to more intense oxidation, burns appear, which negatively affects the formation of layers obtained by the electroerosion method.

In a neutral argon medium, oxidation is practically absent. However, an increase in the discharge energy to 6.8 J leads to a sharp increase in surface roughness (see Table 2).

Thus, on the basis of the conducted studies, it is possible to recommend the use of copper and tin bronze as alloying electrodes, which allows the formation of coatings on the steel surface 20 with a continuity of up to 100%. At the same time, the best coating quality (continuity, roughness, uniformity, etc.) is achieved by using a protective medium - argon.

In addition, the advantages of the proposed method include saving non-ferrous metals, as well as simplifying the manufacturing technology of the hub.

In accordance with the present invention, the undercut surface of a 40X steel shaft was machined.

The quality of the cemented layer of the shaft can be improved both by choosing the most rational processing modes, and by applying soft antifriction materials, for example, copper, silver, etc., to the cemented layer and subsequent processing of the BFVD.

Below is the methodology and results of the studies.

The performance of the EDM process, depending on the alloying mode, is presented in Table 3.

Performance of the cementation process by electroerosive alloying (CEL), depending on the alloying mode

Table 3 Discharge Energy (W _p ), J 0.1 0.31 0.53 0.9 2.83 3.4 6.8 EC performance, m / cm ² 2.0 1,0 1,0 1,0 0.5 0.5 0.5

CEEL was carried out on a portable EEL installation with a manual vibrator, providing a discharge energy in the range 0.1 ... 0.53 J of "Elitron-22A" and an electroerosion alloying unit of higher power - "Elitron-52A" with a discharge energy of up to 6.8 J.

The CEEL process was carried out automatically using a special device in various modes in the range of discharge energies (W _p ) from 0.1 to 6.8 J.

For research, we used special samples made of 40X steel in the form of a coil consisting of two disks with a diameter of 50 mm and a width of 10 mm, interconnected by a spacer with a diameter of 15 mm and having two technological sections of the same diameter (Fig. 4). The surface of the disks before the CEEL was ground to Ra = 0.5 μm. The samples were fixed in the lathe chuck, after which CEEL, silver and copper alloying and processing of the BUFO were performed (Fig. 5). At all stages of processing, the surface roughness was measured on a device profilograph profilometer mode. 201 factory "Caliber". Separate segments were cut out of the disks, in turn thin sections for metallographic and durometric studies were made (Fig. 6).

After manufacturing, the sections were examined with a Neofot-2 optical microscope, where the quality of the layer, its continuity, thickness and structure of the sublayer zones — the diffusion zone and the heat-affected zone — were evaluated. At the same time, a durometric analysis was carried out on the distribution of microhardness in the surface layer and along the depth of the thin section from the surface. Microhardness was measured on a PMT-3 microhardness meter by indentation of the diamond pyramid.

When CEEL details were used graphite electrodes of the brand EG-4 OST 229-83.

Below are the results of studies of the following series of samples of steel 40X:

- cementation (W _p = 2.83 J; with a productivity of 5 min / cm ² ); alloying with silver (W _p = 0.31 J; with a productivity of 1 min / cm); processing BUFO (sample No. 1);

- cementation (W _p = 2.83 J; with a productivity of 5 min / cm ² ); alloying with copper (W _p = 0.31 J; with a productivity of 1 min / cm); processing BUFO (sample No. 2).

The results of measuring the surface roughness of sample No. 1 after cementation and electroerosive alloying with silver are presented in table 4 and with subsequent processing of BUFD in table 5.

Roughness of the surface of sample No. 1 after cementation and EEL silver

Table 4 The value of the surface roughness at individual points, microns The average value of the roughness parameter, microns R _a 1.92 3.3 1.55 2,57 2.15 2.04 R _z R _a R _z 5.43 9.37 4.38 7.26 6.17 5.76 2.26 6.40

The surface roughness of sample No. 1 after cementation, EEL silver and processing BUFO

Table 5 The value of the surface roughness at individual points, microns The average value of the roughness parameter, microns R _a 0.59 0.86 1.27 0.47 1.33 0.76 0.59 R _z R _a R _z 1.68 2.44 3,59 1.33 3.76 2.14 1.68 0.88 2.49

It should be noted that with EEL silver, the diameter of the sample increased by 0.05 mm, and after treatment with BFU decreased by 0.03 mm.

Figure 7 shows a microsection, and the distribution of microhardness in sample No. 1 of steel 40X. As can be seen from the figure, a layer with a hardness of the order of 80-90 HV is located on the surface of the sample, which is lower than the microhardness of the base (220 HV) and a depth of up to 35 μm. Further, with deepening, the microhardness gradually increases and reaches a maximum value of 470 HV at a depth of ~ 60 μm, after which it again gradually decreases to a depth of 100 μm, at which the microhardness of the base corresponds.

The results of measuring the surface roughness of sample No. 2 after cementation and electroerosive alloying with copper are presented in table bis by subsequent processing of BUFO in table 7.

The surface roughness of sample No. 2 after cementation and EEL copper

Table 6 The value of the surface roughness at individual points, microns The average value of the roughness parameter, microns R _a 3.02 4.46 2,5 3.38 2.14 3.41 R _z R _a R _z 8.54 12.63 7.07 9.67 6.06 10,2 3.15 9.03

The surface roughness of sample No. 2 after cementation, EEL copper and processing BUFO

Table 7 The value of the surface roughness at individual points, microns The average value of the roughness parameter, microns R _a 0.55 0.65 0.91 0.62 0.87 0.71 0.51 R _z R _a R _z 3.05 2.40 2,35 2.64 2.48 3.01 3.25 0.80 3.19

On Fig depicts a microsection, and the distribution of microhardness in sample No. 2. As can be seen from the figure, a layer with a hardness of the order of 140-170 HV is located on the surface of the sample, which is lower than the microhardness of the base (220 HV) and a depth of up to 40 μm. Further, with deepening, the microhardness gradually increases and reaches a maximum value of 510 HV at a depth of ~ 75 μm, after which it again smoothly decreases to a depth of 120 μm and at which it corresponds to the microhardness of the base.

It was noted that with EEL with copper, the diameter of the sample increased by 0.04 mm, and after treatment with BFU it decreased by 0.02 mm.

Analyzing the studies performed, it can be said that when applying soft antifriction metals, for example, copper or silver to areas cemented by the EEL method, the surface of the part is formed of two layers:

- a layer of soft antifriction metal located outside; and

- a layer of hard wear-resistant metal below.

The application of a soft antifriction metal makes it possible to obtain a high-quality wear-resistant layer with the required roughness during subsequent processing of the BUFO.

The thickness of the applied layer of soft antifriction material can be adjusted due to the EEL mode, application method and electrode material. So, on the mechanized installation EIL - 9, using electrodes made of tin bronze, it is possible to form layers up to 2.5 mm, increasing the diameter of the underside of the shaft by 5.0 mm.

The radius of the transition (fillet) in the area from the thickened part of the shaft to the usual diameter can be formed:

- reducing the discharge energy;

- increasing break-in force.

The advantages of the proposed method include: saving metal in the manufacture of shafts with increased diameter, as well as simplifying the technology for their manufacture.

Claims (17)

1. A method of manufacturing a fixed joint such as a shaft-hub of steel parts, comprising forming a coating by electroerosive alloying, at least on one of the mating surfaces of the parts to be joined, followed by their assembly, characterized in that on the inner surface of the hub in areas adjacent to it the ends, by the method of electroerosive alloying form an annular diffusion layer, while the thickness of the applied layer of soft antifriction material and the roughness of the mating surfaces These are ensured by choosing the modes of electroerosive alloying, electrode material, and the method of applying a layer of soft antifriction material. 2. The method according to claim 1, characterized in that the annular diffusion layer with a width of 5-10 mm is formed by an electrode-tool made of copper or tin bronze with a discharge energy of 0.01-3.4 J on the surfaces of the grooves made on the landing diameter of the hub. 3. The method according to claim 1 or 2, characterized in that an annular diffusion layer is formed on the surfaces of the hub grooves at a discharge energy of 0.01-0.5 J in air. 4. The method according to claim 1 or 2, characterized in that an annular diffusion layer is formed on the surfaces of the hub grooves at a discharge energy of 0.01-3.4 J in a protective argon atmosphere. 5. A method of manufacturing a fixed joint such as a shaft-hub of steel parts, including forming a coating by electroerosive alloying, at least on one of the mating surfaces of the parts to be joined, followed by their assembly, characterized in that the approach surface of the shaft is subjected to cementation by electroerosive alloying, after whereby a layer of soft antifriction material is applied to the cemented layer by electroerosive alloying and then treated with a surface plastic deformation, while the thickness of the applied layer of soft antifriction material and the roughness of the mating surfaces are ensured by the choice of modes of electroerosive alloying, electrode material and the method of applying a layer of soft antifriction material. 6. The method according to claim 5, characterized in that the approach surface of the shaft is subjected to cementation by electroerosive alloying with a graphite electrode at a discharge energy of 0.1-6.8 J. 7. The method according to claim 5 or 6, characterized in that the cemented access surface of the shaft is subjected to electroerosive alloying with silver or copper. 8. The method according to claim 5 or 6, characterized in that the cemented access surface of the shaft is subjected to electroerosive alloying with a tin bronze electrode, and a soft antifriction layer is formed up to 2.5 mm thick and the diameter under the hub part of the shaft is increased by 5.00 mm . 9. The method according to claim 5, characterized in that a transition radius (fillet) is formed in the area near the shaft surface of the shaft from a portion of a shaft of a larger diameter to a portion of a shaft of a smaller diameter by reducing the discharge energy and / or increasing the force of surface plastic deformation. 10. A method of manufacturing a fixed joint such as a shaft-hub of steel parts, comprising forming a coating by electroerosive alloying, at least on one of the mating surfaces of the parts to be joined, followed by their assembly, characterized in that on the inner surface of the hub in areas adjacent to it at the ends, by the method of electroerosive alloying, an annular diffusion layer is formed, and the approach surface of the shaft is cemented by the method of electroerosive alloying, after which a cemented layer is applied by a method of electroerosive alloying to apply a layer of soft antifriction material, and then it is treated by the method of surface plastic deformation, while the thickness of the applied layer of soft antifriction material and the roughness of the mating surfaces are ensured by the choice of modes of erosion alloying, electrode material and the method of applying a layer of soft antifriction material. 11. The method according to claim 10, characterized in that the annular diffusion layer 5-10 mm wide is formed by a copper or tin bronze electrode with a discharge energy of 0.01-3.4 J on the surfaces of the grooves made on the landing diameter of the hub. 12. The method according to claim 10 or 11, characterized in that an annular diffusion layer is formed on the surfaces of the hub grooves at a discharge energy of 0.01-0.5 J in air. 13. The method according to claim 10 or 11, characterized in that an annular diffusion layer is formed on the surfaces of the hub grooves at a discharge energy of 0.01-3.4 J in a protective argon atmosphere. 14. The method according to claim 10, characterized in that the access surface of the shaft is subjected to cementation by electroerosive alloying with a graphite electrode at a discharge energy of 0.1-6.8 J. 15. The method according to claim 10 or 14, characterized in that the cemented access surface of the shaft is subjected to electroerosive alloying with silver or copper. 16. The method according to claim 10 or 14, characterized in that the cemented access surface of the shaft is subjected to electroerosive alloying with a tin bronze electrode, while forming a soft antifriction layer with a thickness of up to 2.5 mm and increasing the diameter of the underside of the shaft by 5.00 mm. 17. The method according to claim 10, characterized in that a transition radius (fillet) is formed in the area near the shaft surface of the shaft from a portion of a shaft of a larger diameter to a portion of a shaft of a smaller diameter by reducing the discharge energy and / or increasing the force of surface plastic deformation.

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