RU132083U1 - INSTALLATION FOR ELECTROLYTE-PLASMA TREATMENT OF METAL PRODUCTS - Google Patents

Abstract

1. Installation for electrolyte-plasma processing of metal products, containing at least one working capacity with electrolyte, a capacity for correcting electrolyte, a device for attaching workpieces and a power source for electrolytic-plasma processing, characterized in that in the processing zone of the working capacity inductors equipped with at least one power source for induction heating of products, while the working capacity is equipped with a lid with a device for creating a vacuum or excessively of pressure in said container for its germetizatsii.2. The installation according to claim 1, characterized in that it further comprises a pump for pumping the electrolyte, and the electrolyte correction capacity is equipped with a heat exchanger, and the working capacity and electrolyte correction capacity are configured to combine their volumes and create a common electrolyte circulation system. Installation according to claim 2, characterized in that an additional level sensor is added to the electrolyte correction tank. Installation according to claim 3, characterized in that it further comprises a dispersion filter for pumping the solution. Installation according to claim 4, characterized in that it further comprises a pre-loading chamber and a device for loading and removing products from the electrolyte. Installation according to claims 1-5, characterized in that the inductors are arranged to be placed in their cavities of the processed products, while the working capacity is a cathode, and the installation is additionally equipped with a control unit for stabilization and automation of the process.

Description

The utility model relates to the field of electrochemical processing of parts, in particular, to installations for electrolyte-plasma polishing of metal products, mainly from chromium-containing stainless steel alloys, as well as titanium and titanium alloys, and can be used in turbomachinery for processing working and guide vanes of steam turbines, blades of gas pumping units and compressors of gas turbine engines, in order to ensure the necessary physical, mechanical and operational properties of parts urbomashin, as well as a preparatory step before the ion-implantation surface modifying parts and application of protective ion-plasma coatings.

The working blades of the compressor of a gas turbine engine (GTE) and gas turbine installation (GTU), as well as steam turbines during operation, are exposed to significant dynamic and static loads, as well as corrosion and erosion destruction. Based on the performance requirements, high-alloy chromium, chromomolybdenum (CrMo), chromomolybdenum-vanadium (CrMoV) and other medium and high alloy steels are used for the manufacture of gas turbine compressor blades (for example, for steam turbine blades - steel grades 20X13 and 15X11MF, gas turbines - steel 20X13, AE 961). These steels are among the stainless steels with a Cr content of 11-14%, differing in the content of alloying elements: C, Mo, V. In addition, for the manufacture of gas compressor blades In turbines, titanium alloys are used, which, in comparison with technical titanium, have higher strength, including at high temperatures, while maintaining a sufficiently high ductility and corrosion resistance (for example, titanium alloys of the grades VT6, VT14, VT3-1, VT22 and other)

However, turbine blades of these steels and alloys are highly sensitive to stress concentrators. Therefore, defects formed in the manufacturing process of these parts are unacceptable, since they cause the occurrence of intense destruction processes. This causes problems when machining surfaces of turbomachine parts. In this regard, the development of methods for producing high-quality surfaces of turbomachine parts is a very urgent task.

The most promising methods for processing turbomachine blades are electrochemical methods of polishing surfaces [Griliches S.Ya. Electrochemical and chemical polishing: Theory and practice. Effect on the properties of metals. L., Mashinostroenie, 1987.], while the most interesting for the area under consideration are the methods of electrolyte-plasma polishing (EPP) of parts [for example, Patent GDR (DD) N 238074 (A1), cl. C25F 3/16, publ. 08/06/86., As well as Patent RB N 1132, cl. C25F 3/16, 1996, BHN 3].

A device is known (AS USSR No. 1039251, IPC С25F 7/00, 04.01.81) containing a bath for an electrolyte, a working electrode and an electrolyte circulation system, including a centrifugal pump with a nozzle for supplying electrolyte, a window with a nozzle for returning electrolyte.

There is also known a device for processing in electrolyte plasma (RF Patent No.2009212, IPC C 21 D 1/44, 03.15.94), containing a bath with electrolyte and a test electrode placed in it, a power source, the device is equipped with a possibility of movement relative to the test the electrode with a ferromagnetic rod magnetically closed with a test electrode through a magnetic circuit with two inductors, and a power supply unit electrically connected to one of the coils, and the other coil is electrically connected to the power source through a recording device and the reverse ligature.

The closest in technical essence is the electrolyte-plasma polishing unit selected as a prototype (RF Patent No. 2268326, IPC С21D 1/44, 03.15.94), containing pneumatic cylinders, a suspension with cartridges, two working baths, an electrolyte correction bath, a pump for pumping solution, column, clamps for fixing products, a pre-loading chamber, a diffusion filter for pumping a solution, characterized in that an electric heater, a heat exchanger and a level sensor are introduced into the electrolyte correction bath, and the body of the working bath is etsya cathode.

The main disadvantages of the known devices include the complexity, and in some cases the inability to ensure a reliable processing mode during the start of the process, as well as stabilization by temperature. As a result of this, the likelihood of defects significantly increases. These defects that occur on the surface of the part are inherited by the further processing process, which leads to significant unevenness in the processing of the part, thereby deteriorating its quality. This, in particular, is due to the fact that, during the period of entering the processing mode, fluctuations in the magnitude of the input electric power cause strong changes in the temperature regime on the surface of the part, which makes the process extremely unstable and increases the likelihood of defects, especially for the polishing process.

The task to which the claimed utility model is directed is to provide the possibility of choosing the optimal processing conditions and increasing the flexibility of the process due to the possibility of separately creating and controlling the parameters of a gas-vapor envelope and a plasma discharge in it, as well as reducing the values of working potentials between the part and the electrolyte necessary start the process and conduct processing.

The technical result is achieved by the fact that in the installation of electrolyte-plasma processing, containing at least one working capacity with electrolyte, a device for attaching workpieces and a power source for electrolytic-plasma processing, in contrast to the prototype in the working capacity, in the processing zone inductors are located, equipped with at least one power source for induction heating of parts, and the bath is made with the possibility of sealing, providing a pressure above or below atmospheric.

The technical result is also achieved by the fact that the installation further comprises a pump for pumping the electrolyte and a correction capacitance of the electrolyte equipped with a heat exchanger, the working capacity and correction capacity made with the possibility of combining their volumes and creating a common electrolyte circulation system; in addition, in addition, a level sensor may be introduced into the electrolyte correction capacity.

The technical result is also achieved by the fact that the installation may further comprise a dispersion filter for pumping the solution, as well as a pre-loading chamber and a device for loading and removing parts from the electrolyte.

The technical result is also achieved by the fact that the installation can additionally contain inductors made with the possibility of placing workpieces in their cavities, the working capacity is a cathode, and the installation has a control unit for stabilization and automation of the process.

The essence of the technical solution is illustrated by drawings. The figure shows the layout of the proposed installation.

Installation for electrolyte-plasma processing, contains a working capacity 1, a device for mounting workpieces 2, workpieces 3, inductors 4, electrolyte 5, correction capacity of electrolyte 6, a pump for pumping electrolyte 7, a device for creating a vacuum or overpressure 8 in the working capacity 1, pipes 9. The working capacity 1 is equipped with a cover that allows you to seal the working capacity 1. In the working capacity 1 is a device for supplying electrolyte and inductors 4 for heating the surface of the parts. The correction capacity of the electrolyte 6 is equipped with a heat exchanger and a level sensor. The installation is equipped with two power sources: a power source for conducting the process of electrolyte-plasma processing and a power source for induction heating, as well as a processing process control unit with a control panel. As containers 1 and 6 use containers made of a material resistant to electrolyte.

Installation of electrolyte-plasma processing works as follows. When the lid of the working container 1 is open, the workpieces 3 are installed in the device for fastening the processed products 2, fixed with clamps and lowered into the working container 1 filled with electrolyte 5. Then the lid of the working container is closed, the required pressure is created and parts are processed according to one of the following circuits.

1) processing according to the scheme: "preliminary induction heating of the part and the formation of a gas-vapor shell (PGO) - ignition of a plasma discharge in the formed PGO - exit to the processing mode with a gradual decrease in the fraction of induction heating of the part — the implementation of the processing without induction heating";

2) processing according to the scheme; “Preliminary induction heating of the part and the formation of PGO — ignition of a plasma discharge in the formed PGO — exit to the processing mode with a gradual transition of the induction heating of the part to the support mode”;

3) processing according to the scheme: “simultaneous induction heating of the part and supply of potential to the part both at the start of the process and during its implementation”.

4) processing according to the scheme: "induction heating of a part by high-frequency currents (HDTV), the formation of high-frequency plasma and processing only high-frequency (without supplying potential to the part").

5) processing according to the scheme: “induction heating of a part by high-frequency currents (HDTV), the formation of high-frequency plasma and processing together with high-frequency plasma when combined with the supply of (positive or negative) potential to the part”.

6) processing according to the scheme: “supplying potential to a part — the formation of PGO and ignition of a discharge in it” (similar to the prototype installation)

When using the above processing schemes, depending on the objectives, conditions and conditions are created that allow either electrolyte-plasma polishing of the parts, or the production of coatings, or the hardening of the parts, or their chemical-thermal treatment. To control the process, pressure is additionally regulated in the working capacity of the installation. Moreover, an increase in pressure contributes to an increase in the process temperature, and a decrease to a decrease in the process temperature.

When processing on the proposed installation according to the scheme:

“Preliminary induction heating of the part and the formation of a gas-vapor shell (PGO) - ignition of a plasma discharge in the formed PGO - access to the processing mode with a gradual decrease in the fraction of induction heating of the part — the implementation of the processing process without induction heating”, perform the following actions.

The metal part 3 to be treated is immersed in a container 1 with an aqueous solution of electrolyte 5, placed in the cavity of the inductor 4, induction heating of the part 3 until a vapor-gas shell is formed around the part, a positive voltage is applied to the part 3, and a negative voltage is applied to the electrolyte (anode treatment) or negative voltage to part 3, and positive (cathodic treatment) to electrolyte, due to which a plasma discharge is ignited between the workpiece and the electrolyte. Then, a transition to the processing mode is carried out with a gradual decrease in the fraction of induction heating of the part until it is completely turned off and the electrolyte-plasma processing process is carried out only by supplying potential to the part. Processing is carried out in an electrolyte medium while maintaining a vapor-gas shell around a part.

When carrying out electrolyte-plasma treatment using induction heating, the following processes occur. Under the influence of induction currents, the surface of the part is heated and a vapor-gas shell forms around it. Excess heat arising from the induction heating of the part and, in part, of the electrolyte is removed through the cooling system, while maintaining the desired process temperature. Under the action of electric voltage (electric potential between the part and the electrolyte), a discharge arises in the vapor-gas shell, which is an ionized electrolytic plasma, which ensures the flow of intensive chemical and electrochemical reactions between the treated part and the medium of the gas-vapor shell.

When a positive potential is applied to the part, during the course of these reactions, the surface of the part is anodized with the chemical etching of the formed oxide. Moreover, with anodic polarization, the vapor-gas layer consists of electrolyte vapors, anions, and gaseous oxygen. Since etching occurs mainly on microroughnesses, where a thin oxide layer is formed, and the anodizing processes continue, as a result of the combined action of these factors, the roughness of the treated surface decreases and, as a result, polishing of the latter occurs.

In the case of cathodic polarization, the vapor-gas shell around the part consists of electrolyte vapors, cations and hydrogen gas, therefore, along with the chemical interaction of cations with the material of the surface layer of the part, micro spark discharges occur in the gas-vapor shell, which leads to electroerosive and cavitation effects on the treated surface.

The process of electrolyte-plasma polishing on the proposed installation is as follows. After installation and fixing in the device for fastening the processed products 2 they are lowered into the working tank 1. Parts 3 are connected to the positive pole of the power source. The device for fastening the workpieces 2 are arranged so that the parts 3 are placed in the cavity of the inductors 4 (for protection against direct contact of the parts 3 with the inductor 4, guides made in the form of a truncated inverted cone without bottoms are placed in the cavity of the inductor). The negative pole of the power source is connected to the contacts located directly on the outer side of the wall of the working tank 1.

During the operation of the installation, the electrolyte circulates in the total volume of tanks 1 and 2. In tank 2, the chemical composition of the solution is corrected by introducing components, as well as to maintain a given range of solution temperatures. To maintain the working level of the electrolyte, a sensor is provided. The pump for pumping the solution directs the electrolyte from the correction tank 6 to the working tank 1. The control unit and the control panel are designed to set and maintain the specified parameters of the part processing process.

Example. Two batches of samples in the form of metal plates made of stainless steel 12X18P10T with dimensions of 50 × 20 × 2 mm with an initial roughness of R _a = 0.12 μm, were processed in two ways - according to the proposed and prototype.

According to the proposed option, the samples were immersed in a container with an aqueous solution of electrolyte, created a vacuum of 10 ^-1 mm Hg, and placed in the cavity of the inductor, induction heating was performed until a vapor-gas shell was formed around the part, then a positive voltage was applied to the plates, and to the electrolyte negative. Parts were machined in an electrolyte based on an aqueous solution of sodium hydrogencarbonate salt. The electrolyte was circulated cooled (the average process temperature was maintained at 45-60 ° C). In the prototype embodiment, similar process conditions were used, with the exception of induction heating of the samples.

The table shows the test results of samples made of stainless chromium-nickel steel.

Table Option No. No. According to the prototype According to the proposed method Concentration, r-ra wt.% Potential difference, V Height
microroughness after processing R _a , microns Note Concentration, r-ra wt.% Potential difference, V Height
microroughness after processing R _a , microns Note one 2 3 four 5 6 7 8 9 10 one one 5 twenty - The vapor-gas shell did not form 5 twenty 0.12 (-) 2 10 twenty - 10 twenty 0.11 (+) 3 fifteen twenty - fifteen twenty 0.12 (-) four twenty twenty - twenty twenty 0.11 (+)

2 5 5 thirty - The vapor-gas shell did not form 5 thirty 0.05 (+) 6 10 thirty - 10 thirty 0.05 (+) 7 fifteen thirty - fifteen thirty 0,03 (+) 8 twenty thirty - twenty thirty 0,03 (+) 3 9 5 one hundred - Process unstable 5 one hundred 0,03 (+) 10 10 one hundred - 10 one hundred 0.02 (+) eleven fifteen one hundred - fifteen one hundred 0.02 (+) 12 twenty one hundred - twenty one hundred 0.02 (+) four 13 5 200 0.08 (+) 5 200 0.02 (+) fourteen 10 200 0.08 (+) 10 200 0,03 (+) fifteen fifteen 200 0.06 (+) fifteen 200 0,03 (+) 16 twenty 200 0.06 (+) twenty 200 0.02 (+) 5 17 5 300 0.06 (+) 5 300 0,03 (+) eighteen 10 300 0.08 (+) 10 300 0.02 (+) 19 fifteen 300 0.06 (+) fifteen 300 0,03 (+) twenty twenty 300 0.04 (+) twenty 300 0.04 (+) one 2 3 four 5 6 7 8 9 10 6 21 5 400 0.06 (+) 5 400 0.04 (+) 22 10 400 0.06 (+) 10 400 0.04 (+) 23 fifteen 400 0.08 (+) fifteen 400 0.06 (+) 24 twenty 400 0.06 (+) twenty 400 0.06 (+) 7 25 5 500 - Microprotrusion reflow 5 500 - Microprotrusion reflow 26 10 500 - 10 500 - 27 fifteen 500 - fifteen 500 - 28 twenty 500 - twenty 500 -

The proposed installation, unlike the prototype, provides the opportunity to select the optimal processing conditions and allows to increase the flexibility of the process due to the possibility of separate creation and control of the parameters of the gas-vapor shell and plasma discharge in it, as well as lowering the potentials between the part and the electrolyte necessary to start the process and conducting processing. Due to this, the proposed installation can improve the quality of surface treatment of parts.

Claims (6)

1. Installation for electrolyte-plasma processing of metal products, containing at least one working capacity with electrolyte, a capacity for correcting electrolyte, a device for attaching workpieces and a power source for electrolytic-plasma processing, characterized in that in the processing zone of the working capacity inductors equipped with at least one power source for induction heating of products, while the working capacity is equipped with a lid with a device for creating a vacuum or excessively of pressure in said container for sealing it. 2. Installation according to claim 1, characterized in that it further comprises a pump for pumping the electrolyte, and the electrolyte correction tank is equipped with a heat exchanger, and the working capacity and electrolyte correction tank are made with the possibility of combining their volumes and creating a common electrolyte circulation system. 3. Installation according to claim 2, characterized in that an additional level sensor is introduced into the electrolyte correction capacity. 4. Installation according to claim 3, characterized in that it further comprises a dispersion filter for pumping the solution. 5. Installation according to claim 4, characterized in that it further comprises a pre-loading chamber and a device for loading and removing products from the electrolyte. 6. Installation according to claims 1-5, characterized in that the inductors are arranged to be placed in their cavities of the processed products, while the working capacity is a cathode, and the installation is additionally equipped with a control unit for stabilization and automation of the process.

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