RU2710086C1 - Method of electrically polishing inner channel of metal part and device for its implementation - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to machine building and can be used for processing of channels, in particular, internal surfaces of artillery pieces, by electropolishing. Method involves movement of tool electrode along channel inner surface along its axis. Electrode-tool is an auger with a metal rod, the screw element of which is tightly pressed to the processed surface of the part and electrically insulated in contact with it. Processed part with screw is placed in granules medium, made from anion exchangers impregnated with electrolyte solution, contacting the treated surface of the part with the granules and bringing the screw into rotation, electric potential is supplied to processed part and granules, which provides ion removal of metal from processed part surface and its polishing in the medium of said granules and electropolishing to obtain a given roughness of inner surface channel parts.

EFFECT: invention provides improved quality and uniformity of polishing inner surfaces of channels of metal parts.

10 cl, 5 dwg

Description

The invention relates to the field of mechanical engineering and can be used for processing channels, for example, the internal surfaces of the trunks of artillery guns or small arms by electropolishing.

A known method of electrochemical-mechanical processing (AS USSR No. 1085734. IPC В23Р 1/04, Method of electrochemical-mechanical processing. Publ.: 04.15.1984.), Where the stock is taken along the length of the channel due to the shock reciprocating action of the tool.

The disadvantage of this method is the low quality of the surface treatment of the part, since mechanical force is applied to the surface layer of the material of the part.

A known method of electrochemical processing of holes and an electrode tool (patent RU No. 2166416, IPC V23H 5/06, publ. Bull. No. 13, 2001), which uses a bipolar cathode tool made of alternating abrasive and conductive bars on it the forming part, while the cathode-tool is simultaneously informed of rotation and vibration to ensure contact between the anode-part and the cathode-tool.

There is also known a method and apparatus for processing the inner surfaces of channels (RF patent No. 2251472. IPC B23H 5/06, publ.: Bull. No. 13, 2005). The method includes moving along the axis of processing of the rod with the electrode-tool. Moreover, the device for electrochemical-mechanical processing of channels includes a rod with an electrode tool containing a working part, a front guide and a calibrating element with slots.

The closest technical solution selected as a prototype of the method is a method of electropolishing polishing the inner surface of artillery guns or small arms barrels with an electrode-tool. (Patent DE4419864. IPC C25D 7/04. Uniform thickness internal chromium plating for gun barrels and chambers. 1995) The method uses an electrode-tool that is coaxially positioned relative to the inner surface of the barrel, by which its internal surface is processed when the electrolyte is fed into the barrel.

However, the known methods and devices do not provide high quality and uniformity of processing of the internal surfaces of the channels of metal parts.

The closest technical solution, selected as a prototype of the device, is an electrode tool for electrochemical processing of the internal channel of a metal part (RF patent No. 2588953, IPC B23H 5/06, publ. Bull. No. 19, 2016). The tool electrode comprises a housing made of an elastic material, provided with at least one electrode in the inner cavity and a device for reciprocating motion relative to the machined surface of the channel and pressed against the inner surface of the channel.

However, the known method (DE4419864) and the device (RF patent No. 2588953) do not provide high quality and uniform processing by polishing the inner surfaces of the channels of metal parts.

The task to which the invention is directed is to improve the quality and uniformity of polishing of the inner surfaces of the channels of metal parts by ensuring uniform interaction of the processing medium with the processed inner surface of the channel of the part.

The technical result of the invention is to improve the quality and uniformity of the processing of the internal surfaces of the channels of metal parts.

The technical result is achieved due to the fact that in the method of electropolishing the inner channel of a metal part, including moving the electrode-tool along the inner surface of the channel along its axis, in contrast to the prototype, a screw with a metal rod, the screw element of which is tight pressed to the workpiece surface and electrically insulated in contact with it, the workpiece with the screw is placed in the medium of granules made of anion exchangers, impregnated electrolyte solution, providing electrical conductivity of said granules and ion ablation of metal with removal of microprotrusions from its surface, the workpiece surface is contacted with said granules, while providing contact between said granules, the auger is rotated, which allows granules to move relative to the channel surface to be treated, fed to the workpiece and granules electric potential, providing ion ablation of metal from the workpiece surface of the part and e e polishing in the medium of said granules and electro-polishing is carried out to obtain a given roughness of the inner surface of the channel of the part.

In addition, you can use the following additional methods: granules are brought into vibrational motion from 50 ... 400 Hz, providing uniform washing with granules of the workpiece surface; apply a screw element of the screw, made of metal and coated with a layer of elastic dielectric material; apply a screw element of the screw made of an elastic dielectric material; apply a screw element of the screw, made in the form of a brush; ion exchange resins obtained on the basis of copolymerization of either polystyrene or polyacrylate and divinylbenzene are used as anion exchangers of the said granules, and the granule sizes are selected from the range from 0.1 to 1.1 mm, and electro polishing with granules is carried out by applying positive and negative electric particles to the granules a potential of 25 to 35 V or electro polishing with granules is carried out in a pulsed mode with a polarity reversal, with a pulse frequency range of 20 to 100 Hz, a pulse period of 50 μs to 10 μs, with a polarity current amplitude positive polarity during a +50 A pulse and their duration 0.4 to 0.8 μs, with a current amplitude of negative polarity during a pulse - 20 A, and their duration 0.2 to 0.4 μs, with a rectangular shape of current output pulses and duration of pauses between pulses from 49.6 μs to 9.2 μs; as the channel being processed, use the channel of artillery guns or small arms, and as electrolytes for impregnating the said granules from anion exchangers, use one of the following aqueous solutions: either NH ₄ F, concentration from 6 to 24 g / l, or NaF, concentration from 4 to 18 g / l, or KF concentration of 35 to 55 g / l, or a mixture of NH ₄ F   and KF with an NH ₄ F content of from 5 to 15 g / l and KF from 30 to 50 g / l, or a mixture of NaF   and KF with a NaF content of from 3 to 14 g / l and KF from 35 to 60 g / l, or a mixture of NH ₄ F   and NaF when the content of NH ₄ F is from 4 to 12 g / l and KF is from 35 to 55 g / l, or a mixture of NH ₄ F, NaF and KF when the content of NH ₄ F is from 3 to 9 g / l and KF - from 20 to 30 g / l, and NaF - from 10 to 25 g / l, or a mixture of NH ₄ F   and HF with an NH ₄ F content of from 5 to 15 g / l and HF from 3 to 5 g / l, or from 8 to 14% aqueous NaNO ₃ solution _, or in electrolytes of the compositions, wt.%: (NH ₄ ) ₂ SO ₄ - 5; Trilon B - 0.8, or containing sulfuric and phosphoric acid, a block copolymer of ethylene oxide and propylene and the sodium salt of sulfonated butyl oleate in the following ratio, wt.%:

Sulfuric acid - 10-30

Orthophosphoric acid - 40-80

Block copolymer of ethylene oxide and propylene - 0.05-1.1

Sodium salt of sulfonated butyl oleate - 0.01-0.05

Water - The rest.

The technical result is achieved due to the fact that the device for electropolishing the internal channel of a metal part contains a supply container and a container for receiving granules interconnected through a container for regenerating granules, holders of parts, a vibrator that provides vibrational movement of the said granules with a frequency of 50 ... 400 Hz, the electrodes of the electrode-tool in the form of screws with a metal rod, the screw elements of which are tightly pressed against the workpiece surface of the channel parts and electrical insulation ovans in the places of contact with the part, rotation drives of said electrode-tools made with the possibility of reverse rotation and imparting vibration and reciprocating motion to the electrode-tool.

The invention is illustrated by drawings, where in FIG. 1 shows the process of electropolishing with cylindrical channel anionite pellets by a screw electrode-tool (Fig. 1 a is a view of a channel with a screw electrode without filling with granules, Fig. 1 b is a view of a channel with a screw electrode when filling a channel with granules), Fig. 2 shows the process of polishing a cylindrical channel in 3D projection, in FIG. 3 shows a diagram of the operation of the installation with a closed cycle when feeding and correcting the properties of granules-anion exchangers, in FIG. 4 shows the process of polishing the inner surface of an artillery gun; FIG. 5 - channel surface of a part made of titanium alloy treated with anion exchangers. In figures 1-5 indicated: 1 - processed metal part with a channel; 2 - channel in the detail; 3 - auger with an electrode – tool; 4 - screw element of the screw; 5 - metal rod; 6 - anion-exchange granules: 7 - auger rotation drive; 8 - container filled with granules-anion exchangers; 9 - pipeline; 10 - capacity for the correction of granules; 11 - for receiving granules (container with spent granules); 12 - docking device with a seal; 13 - the processed surface of the channel. (The arrows indicate the direction of movement of the granules, a pair of arrows - the reciprocating movement of the screw-electrode-tool, round arrows - the direction of rotation of the screw).

The inventive method of electropolishing the inner channel 2 of the metal part 1 is as follows. The screw 3 with the electrode-tool in the form of a metal rod 5 (Fig. 1) is placed inside the machined channel 2 of the part 1, the screw 3 is rotated (Fig. 1a) and granules 6 are fed into the channel 2, which fill the machined cavity of the channel 2 for due to the rotation of the screw 3 (Fig.1b and Fig.2). A screw 3 is used with a metal rod-electrode 5, the screw element 4 of the screw 2 is tightly pressed against the workpiece surface 1. The electrode in the form of a metal rod 5 of the screw 3 is electrically insulated at the points of contact with the part 1. The processed section of the channel 2 is filled with granules 6, providing contact with the processed the surface of the part 1 with granules 6, while ensuring contact between the granules themselves 6. When polishing the channel 2, the screw 3 is rotated, moving the granules relative to the machined surface of the channel 2, serves on the workpiece 1 and granules 6, the electric potential that provides ionic ablation of metal from the treated surface of the part 1 and polishes it in the medium of granules 6 is electropolished to obtain the desired roughness of the inner surface of the channel 2 of the part 1. Granules 6, to ensure a more uniform washing of the treated surface of the part 1 can also be additionally driven into vibrational motion with a frequency of 50 ... 400 Hz. You can use the screw 3 with a screw element made either of metal and coated with a layer of elastic dielectric material, or made of elastic dielectric material, or made in the form of a brush (figure 4). As the granion anion exchangers 6, ion-exchange resins obtained based on the copolymerization of either polystyrene or polyacrylate and divinylbenzene are used. The sizes of the granules 6 are selected from the range from 0.1 to 1.1 mm. Electropolishing with granules 6 is carried out either by supplying a positive electric potential to the part, and negative electric potential from 25 to 35 V to the granules, or in pulsed mode with polarity reversal, with a pulse frequency range of 20 to 100 Hz, a pulse period of 50 μs to 10 μs, when the amplitude of the current of positive polarity during the pulse is +50 A and their duration is 0.4 to 0.8 μs, when the amplitude of the current of negative polarity during the pulse is 20 A, and their duration is 0.2 to 0.4 μs, with a rectangular shape output current pulses and pauses between pulses From 49.6 μs to 9.2 μs.

When processing the channel of an artillery gun or small arms, one of the following aqueous solutions is used as electrolytes for impregnating the said granules from anion exchangers: either NH ₄ F, concentration from 6 to 24 g / l, or NaF, concentration from 4 to 18 g / l, or KF with a concentration of 35 to 55 g / l, or a mixture of NH ₄ F   and KF with an NH ₄ F content of from 5 to 15 g / l and KF from 30 to 50 g / l, or a mixture of NaF   and KF with a NaF content of from 3 to 14 g / l and KF from 35 to 60 g / l, or a mixture of NH ₄ F   and NaF when the content of NH ₄ F is from 4 to 12 g / l and KF is from 35 to 55 g / l, or a mixture of NH ₄ F, NaF and KF when the content of NH ₄ F is from 3 to 9 g / l and KF - from 20 to 30 g / l, and NaF - from 10 to 25 g / l, or a mixture of NH ₄ F   and HF with an NH ₄ F content of from 5 to 15 g / l and HF from 3 to 5 g / l, or from 8 to 14% aqueous NaNO ₃ solution _, or in electrolytes of the compositions, wt.%: (NH ₄ ) ₂ SO ₄ - 5; Trilon B - 0.8, or containing sulfuric and phosphoric acid, a block copolymer of ethylene oxide and propylene and the sodium salt of sulfonated butyl oleate in the following ratio, wt.%:

Sulfuric acid - 10-30

Orthophosphoric acid - 40-80

Block copolymer of ethylene oxide and propylene - 0.05-1.1

Sodium salt of sulfonated butyl oleate - 0.01-0.05

Water - The rest.

To polish the inner channel 2 of the metal part 1, a device is used comprising interconnected by a pipe 9 (Fig. 3) through a container 10 for regenerating granules 6, a container 8 with filled granules-anion exchangers for feeding granules 6 and a container 11 for receiving granules, holders of parts, vibrator, providing vibrational movement of granules 6 with a frequency of 50 ... 400 Hz, electrode electrodes-tools in the form of screws 3 with a metal rod 5, the screw elements 4 of which are tightly pressed against the machined surface of the channel 2 parts 1 and are electrically insulated in places of contact with part 1, rotation drives 7 of the tool electrodes made with the possibility of reverse rotation and imparting vibration and reciprocating motion to the tool electrode.

The oscillatory motion of the electrically conductive granules 6 can provide a uniform effect on the entire machined surface of the channel 2 of the part 1 and thereby improve its quality and uniformity. In addition, due to the creation of homogeneous conditions for the entire volume of granules, a uniform flow of electrical processes is ensured, in particular, ion transfer during processing of channel 2 of part 1.

When implementing the method, the following processes occur. When the mass of the electrically conductive granules 6 fluctuates, they collide with the machined surface of the channel 2 of the part 1. In this case, collisions between the electrically conductive granules 6 also occur in the entire volume of the container, thereby creating uniform conditions for electrical processes. In this case, electrical processes, for example, when connecting the polarity of the part-anode, granules-cathode, between part 1 (anode) and electrically conductive granules 6 (cathode) occur due to the contact of the mass of granules 6 with each other and with the negative potential introduced into the mass of granules 6 rod electrode 5 (cathode). When electrically conductive granules 6 collide with microprotrusions on the treated surface of the channel 2 of part 1, ionic ablation of the material from microprotrusions occurs, as a result of which the surface is leveled, its roughness decreases, and the surface of the channel 2 of part 1 is polished.

If an artillery channel or small arms channel is used as the processed channel2, then, depending on the specific tasks, either the carbon deposit cleaning process, the grinding process, or the polishing process can be used as the type of processing used.

Examples.

End-to-end internal channels with a diameter of 40 mm and a length of 600 mm were subjected to processing in a part made of VT9 grade titanium alloy. An electrode-tool with a brush screw was inserted into the channel being processed, filling the channel with granules from 0.1 to 1.1 mm in size made of a sulfonated styrene-divinylbenzene copolymer. As an electrolyte-filler granules used an aqueous solution of a mixture of NH ₄ F   and KF with an NH ₄ F content of 6 g / L and KF of 33 g / L. They applied a positive voltage to the part, and a negative voltage to the granules (through the electrode of the container). The polishing process was carried out at a screw rotation speed of 3 to 100 rpm with continuous oscillatory motion of granules with an amplitude of 50 ... 400 Hz. The polishing process was carried out at a current density of 1.2 to 2.3 A / cm ² .

In addition, studies were carried out on the following modes of channel processing in parts from titanium alloys (VT-1, VT3-1, VT8), from nickel alloys (EK151-ID, EK152-ID, EP975-ID), from alloy steels (50A, 50RA, 30XH2MFA, 30XRA, 40X13). For a negative result during electropolishing, the processing mode was adopted, which gives a scatter of roughness values on the part surface of more than ΔRa 0.05 μm.

Channels with a diameter of 20 mm and a length of 300 mm were also machined in parts from steels 25KH3M3NBTSA-Sh, 0KHN3MFA.

Pellet vibration: 40 Hz (NR), 50 Hz (U.R.), 125 Hz (U.R.), 200 Hz (U.R.), 300 Hz (U.R.), 400 Hz (U.R.), 500Hz (N.R.).

Granule sizes: less than 0.1 mm (N.R.), 0.1 mm (U.R.), 0.6 mm (U.R.), 0.8 mm (U.R.), 1.1 mm (U.R.), 0, 14 mm (N.R.).

Used electrolytes for the impregnation of granules made of anion exchangers when processing parts from alloy steels:

1) NH ₄ F, concentration from 6 to 24 g / l (going beyond the limits of NH ₄ F concentrations from 6 to 24 g / l gives a negative result);

2) NaF, concentration from 4 to 18 g / l, (going beyond the concentration range from 4 to 18 g / l gives a negative result);

3) KF with a concentration of 35 to 55 g / l, (going beyond the concentration range of 35 to 55 g / l gives a negative result);

4) mixtures of NH ₄ F   and KF when the content of NH ₄ F is from 5 to 15 g / l (going beyond the concentration of NH ₄ F is from 5 to 15 g / l, gives a negative result) and KF is from 30 to 50 g / l (going beyond KF concentrations - from 30 to 50 g / l, gives a negative result),

5) mixtures of NaF   and KF with a NaF content of from 3 to 14 g / L (going beyond NaF concentrations from 3 to 14 g / L gives a negative result), and KF from 35 to 60 g / L (going beyond KF concentrations - from 35 to 60 g / l, gives a negative result),

6) mixtures of NH ₄ F   and NaF at an NH ₄ F content of from 4 to 12 g / l (going beyond NH ₄ F concentrations from 4 to 12 g / l gives a negative result) and KF from 35 to 55 g / l (going beyond KF concentrations - from 35 to 55 g / l, gives a negative result),

7) mixtures of NH ₄ F, NaF and KF with an NH ₄ F content of from 3 to 9 g / l (going beyond NH ₄ F concentrations from 3 to 9 g / l gives a negative result), and KF from 20 up to 30 g / l, (going beyond KF concentrations from 20 to 30 g / l gives a negative result), and NaF from 10 to 25 g / l (going beyond NaF concentrations from 10 to 25 g / l gives a negative result)

8) mixtures of NH ₄ F   and НF with the content of NH ₄ F - from 5 to 15 g / l (going beyond the concentration of NH ₄ F - from 5 to 15 g / l, gives a negative result), and НF - from 3 to 5 g / l (yield limits of HF concentrations from 3 to 5 g / l, gives a negative result),

9) from 8 to 14% aqueous NaNO ₃ solution (going beyond the limits of NaNO ₃ concentrations from 8 to 14% gives a negative result).

When processing parts from titanium alloys:

Anion exchange granules impregnated with an electrolyte composition of an aqueous solution of a mixture of NH ₄ F   and KF with an NH ₄ F content of from 8 to 14 g / l and KF from 36 to 48 g / l.

When processing parts from nickel alloys.

Details from nickel alloys of ZhS6U, ZhS32 brands. Granules impregnated with an electrolyte of the composition: an aqueous solution of ammonium fluoride salt with a concentration of 6 - 9.0 g / liter (5.0 g / liter (N.R.), 6.0 g / liter (U.R.), 7.0 g / liter (U.R.), 8.0 g / liter (U.R.), 10.0 g / liter (U.R.), 12.0 g / liter (N.R.)) and at a current density of 1.5 to 2.1 A / cm ² (1.3 A / cm ² (N.R.), 1.5 A / cm ² (U. R.), 1.6 A / cm ² (U.R.), 1.9 A / cm ² (U.R.), 2.1 A / cm ² (U.R.), 2.3 A / cm ² (N.R.)).

In all cases, anion exchangers were used - ion-exchange resins obtained on the basis of copolymerization of either polystyrene or polyacrylate and divinylbenzene. The brands of synthetic resin-based anion exchangers used in the present invention are: Anion exchanger 17-8СС, Anion exchanger PuroliteA520E, LewatitS 6328 A (based on styrene-divinylbenzene copolymer), “Lewatit M500”, “LewatitMonoPlus MK 51”, “Lewlitomite 68 CluiteMuitePuiteMU51 , Purolite A-860 (macroporous strongly basic anion exchange resin based on acrylates), anion exchange resin sulfonated styrene-divinylbenzene copolymer. The listed anion exchangers impregnated with the above electrolyte compositions showed a positive result when polishing parts from alloy steels, as well as titanium and nickel alloys.

In pulse mode with polarity reversal:

- pulse frequency range from 20 to 100 Hz: 15Hz (N.R.), 20Hz (U.R.), 40Hz (U.R.), 60Hz (U.R.), 80Hz (U.R.), 100Hz (U.R.), 120Hz (N.R.)

- pulse period from 50 μs to 10 μs ,: 60 μs (N.R.), 50 μs (U.R.), 40 μs (U.R.), 30 μs (U.R.), 20 μs ( U.R.), 10 μs (U.R.), 5 μs (N.R.);

- the amplitude of the current of positive polarity during the pulse +50 A and their duration 0.4 μs to 0.8 μs: 0.2 μs (N.R.), 0.4 μs (U.R.), 0.6 μs (U.R.), 0.8 μs (U.R.), 10.0 μs (N.R.);

- when the amplitude of the current of negative polarity during the pulse is 20 A, and their duration is 0.2 μs to 0.4 μs, 0.1 μs (N.R.), 0.2 μs (U.R.), 0, 3 μs (U.R.), 0.4 μs (U.R.), 0.5 μs (N.R.);

- with a rectangular shape of the output current pulses (U.R.),

- and the duration of pauses between pulses from 49.6 μs to 9.2 μs - (U.R.) out of range - (N.R.).

In the regime without changing polarity: electro polishing with granules was performed by supplying a positive electric potential to the component, and a negative electric potential from 25 to 35 V: 22 V (N.R.), 25 V (U.R.), 28 V (U.R) .), 30 V (U.R.), 35 V (U.R.), 40 V (N.R.).

Similar parts of alloy steels, titanium and nickel alloys with internal channels were processed by the prototype method (RF patent No. 2588953). The initial surface roughness of the channels was Ra 0.72 μm. After processing, the dispersion of roughness in different parts of the channel surface was: for the prototype from Ra 0.14 μm to Ra 0, 22 μm, for processed by the proposed method from Ra 0.10 μm to Ra 0, 12 μm.

Thus, the proposed method of polishing the inner channel of the metal part and the device for its implementation can improve the quality and uniformity of the processing of the inner surfaces of the channels of the metal parts.

Claims (12)

1. A method of electropolishing the inner channel of a metal part, including moving the tool electrode along the inner surface of the channel along its axis, characterized in that a screw is used as the electrode tool, with a metal rod, the screw element of which is tightly pressed against the workpiece surface of the part and is insulated in places of contact with it, the workpiece with the screw is placed in the medium of granules made of anion exchangers, impregnated with a solution of electrolyte, providing conductive These granules and ionic ablation of the metal with removal of microprotrusions from its surface make contact of the workpiece surface with the said granules, in which the screw is rotated to move the granules relative to the machined channel surface, and an electric potential providing ionic potential is supplied to the workpiece and granules ablation of metal from the workpiece surface and polishing it in the medium of said granules, while electro polishing is carried out until a predetermined ohovatosti inner channel surface parts. 2. The method according to p. 1, characterized in that the said granules result in a vibrational movement of 50-400 Hz, providing uniform washing with granules of the workpiece surface to be treated. 3. The method according to p. 1, characterized in that they use a screw element of the screw, made of metal and coated with a layer of elastic dielectric material. 4. The method according to p. 1, characterized in that they use a screw element of the screw made of an elastic dielectric material. 5. The method according to p. 4, characterized in that they use a screw element of the screw, made in the form of a brush. 6. The method according to any one of paragraphs. 1-5, characterized in that the ion exchange resins obtained on the basis of the copolymerization of polystyrene or polyacrylate and divinylbenzene are used as the anion exchangers of the said granules, the granule sizes being selected from the range from 0.1 to 1.1 mm, and the electropolishing with granules is carried out by feeding detail of the positive, and the granules of negative electric potential from 25 to 35 V. 7. The method according to any one of paragraphs. 1-5, characterized in that the ion exchange resins obtained on the basis of the copolymerization of polystyrene or polyacrylate and divinylbenzene are used as the anion exchangers of the said granules, the granule sizes being selected from the range from 0.1 to 1.1 mm, and the electropolishing with granules is carried out in a pulsed mode with a polarity reversal, for a pulse frequency range of 20 to 100 Hz, a pulse period of 50 μs to 10 μs, a current amplitude of positive polarity during a pulse of +50 A and a pulse duration of 0.4 to 0.8 μs, and a negative current amplitude polarity in about the pulse time - 20 A, and their duration 0.2 to 0.4 μs, with a rectangular shape of the output current pulses and the duration of the pauses between pulses from 49.6 μs to 9.2 μs. 8. The method according to p. 6, characterized in that the channel of the artillery gun or small arms used as the channel being processed, and one of the following aqueous solutions is used as electrolytes for impregnating the said granules from anion exchangers: or NH₄F, a concentration of 6 to 24 g / l, or NaF, a concentration of 4 to 18 g / l, or KF a concentration of 35 to 55 g / l, or a mixture of NH₄F and KF at NH₄F - from 5 to 15 g / l and KF - from 30 to 50 g / l, or a mixture of NaF and KF with a NaF content of from 3 to 14 g / l and KF from 35 to 60 g / l, or a mixture of NH₄F and NaF at NH₄F - from 4 to 12 g / l and KF - from 35 to 55 g / l, or a mixture of NH₄F, NaF and KF at NH₄F - from 3 to 9 g / l and KF - from 20 to 30 g / l, and NaF - from 10 to 25 g / l, or a mixture of NH₄F and HF at NH₄F - from 5 to 15 g / l and HF - from 3 to 5 g / l, or from 8 to 14% aqueous NaNO solution₃, or in electrolytes of the compositions, wt.%: (NH₄)₂SO₄ - 5; Trilon B - 0.8, or containing sulfuric and phosphoric acid, a block copolymer of ethylene and propylene oxides and the sodium salt of sulfonated butyl oleate in the following ratio, wt.%: Sulfuric acid 10-30 Orthophosphoric acid 40-80 Block copolymer of ethylene and propylene oxides 0.05-1.1 Sulfated Butyl Oleate Sodium Salt 0.01-0.05 Water Rest 9. The method according to claim 7, characterized in that the channel of the artillery gun or small arms used as the channel being processed, and one of the following aqueous solutions is used as electrolytes for impregnating the said granules from anion exchangers: or NH₄F, a concentration of 6 to 24 g / l, or NaF, a concentration of 4 to 18 g / l, or KF a concentration of 35 to 55 g / l, or a mixture of NH₄F and KF at NH₄F - from 5 to 15 g / l and KF - from 30 to 50 g / l, or a mixture of NaF and KF with a NaF content of from 3 to 14 g / l and KF from 35 to 60 g / l, or a mixture of NH₄F and NaF at NH₄F - from 4 to 12 g / l and KF - from 35 to 55 g / l, or a mixture of NH₄F, NaF and KF at NH₄F - from 3 to 9 g / l and KF - from 20 to 30 g / l, and NaF - from 10 to 25 g / l, or a mixture of NH₄F and HF at NH₄F - from 5 to 15 g / l and НF - from 3 to 5 g / l, or from 8 to 14% aqueous NaNO solution₃or in electrolytes of the compositions, wt.%: (NH₄)₂SO₄ - 5; Trilon B - 0.8, or containing sulfuric and phosphoric acid, a block copolymer of ethylene and propylene oxides and the sodium salt of sulfonated butyl oleate in the following ratio, wt.%: Sulfuric acid 10-30 Orthophosphoric acid 40-80 Block copolymer of ethylene and propylene oxides 0.05-1.1 Sulfated Butyl Oleate Sodium Salt 0.01-0.05 Water Rest 10. Device for electropolishing the inner channel of a metal part, characterized in that it contains a container for feeding and a container for receiving granules, interconnected through a container for regenerating granules, holders of parts, a vibrator that provides vibrational movement of said granules with a frequency of 50-400 Hz, electrode-tool in the form of a screw with a metal rod, the screw elements of which are made with the possibility of tight pressing against the workpiece surface of the channel of the part and are insulated at the contact points and with the part, and rotation drives of said electrode-tool, made with the possibility of reverse rotation and giving the electrode-tool vibration and reciprocating motion.

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