RU2591919C1 - Metal parts zinc impregnation plant of - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention relates to technologies and devices for application of protective anti-corrosion coatings, can be used for corrosion-protective treatment of precision parts of fasteners for aviation, automobile and aerospace engineering and machine building. Metal parts diffusion zinc coating unit contains at least one working chamber with neck for loading of metal parts, covered with cover provided with adjustable elements connected to inert medium source, working chamber heating system, feed hopper with charge and loading tank with metal parts. Said plant is equipped with located in a single process line bath with electrolyte for galvanic application of metal under-layer metal from group of transition metals of periodic table and bath for treatment of protective zinc layer coated metal parts in phosphorus-containing electrolyte. Said heating system is composed of induction unit which generates heating by currents with frequency of 0.44-1 MHz to 850-880 °C, in which there is at least one said working chamber for arrangement of metal parts intended for obtaining protective zinc coating on them. Said induction unit is located between said baths.

EFFECT: production of superfine uniform coatings on non-uniform precision parts of fine fasteners, as well as improving coating quality, simplified design of said unit and reduced time of one process cycle.

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Description

The proposed device relates to the field of technologies and devices for applying protective anticorrosive coatings and can be used for corrosion-protective processing of precision fastener parts for aircraft, automotive, space technology and mechanical engineering.

In terms of technical nature, the installation closest to the claimed one (certificate No. 13376 priority of 08/30/1999 "Installation for diffusion galvanizing of metal parts", IPC С23С 10/28, publ. 10.04.2000, BI No. 10), containing a working chamber with a neck for loading of parts with a covered lid, a heating system for the working chamber, a feed hopper with a charge, a loading container with metal parts, the working chamber is connected to a vibrating system with the possibility of transmitting vibration throughout the chamber, the camera lid is made of two parts, one of which is located outside the chamber, hermetically closes the neck, and the other is mounted on the first with the possibility of moving to the bottom of the working chamber as a sealing element and coincides along the contour with the cross section of the chamber, while the installation is additionally connected to a vacuum system and an inert source medium, mainly inert gas, which is connected to the working chamber through a control element.

The disadvantages of this device are the complexity of the design (the presence of a composite cover, vibration system, etc.), a significant process time due to the use of a resistance furnace, the need to seal the mixture to ensure contact over the entire surface of the coated parts, the presence of a temperature gradient when heating the zinc mixture, low the efficiency of the installation.

The task of the authors of the invention is to develop a plant for diffusion galvanizing, providing ultra-thin uniform coatings on the complex precision parts of small fasteners, high quality coatings.

The technical results to which the claimed invention is directed are to provide conditions for obtaining ultra-thin uniform coatings on the highly specialized precision parts of small fasteners, improve the quality of the coating, simplify the design, reduce the time spent on one process cycle.

These technical results are achieved in that in a plant for diffusion galvanizing of metal parts, containing at least one working chamber with a neck for loading parts, a covered lid, a heating system for the working chamber, a feed hopper with a charge, a loading container with metal parts, at In this case, each working chamber is connected through a regulatory body to an inert medium source, the new one is that the heating system is made in the form of an induction unit that forms heating by currents with a frequency of 0.44-1 MHz up to 850-880 ° C, in which at least one working chamber is placed to accommodate metal parts intended for receiving a protective zinc coating on them, in addition, an induction heating system is located between, on the one hand, a bath with electrolyte for galvanic deposition a metal sublayer of a metal from the group of transition metals of the periodic system of elements, and on the other hand, with a bath for processing metal parts coated with a protective zinc layer in a phosphorus-containing electrolyte, which are combined Nena in a single process line.

The use of the heating system of the working chamber in the form of an induction unit eliminates the need for a vibroinstallation and a sealing element, which eliminates the need for a complex chamber lid. All this together leads to a simplification of the design. Also, the use of an induction unit as a heating system for the working chamber allows reducing the time of one process cycle and eliminating the temperature gradient when heating the zinc mixture, which leads to an improvement in the processability of the process and an increase in suitable products

Installation for diffusion galvanizing of metal parts (Fig. 1) contains a working chamber 1 with a neck for loading parts, a cover of the working chamber 2, which ensures the tightness of the working chamber, induction unit 3, source 4 of inert medium.

The heating system is made in the form of an induction unit 3, which forms heating by currents with a frequency of 0.44-1 MHz to 300-400 ° C.

The induction unit 3 contains an inductor 5, a magnetic circuit 6 and insulating gaskets 7.

The working chamber 1 is equipped with a neck for loading metal parts, is covered by a cover 2, adjustable elements for connecting to an inert medium source 4, has a heating system for the working chamber (induction unit 3), a feed hopper with a charge, a loading container with metal parts.

The working chamber 1 is installed in the cavity of the induction unit 3 and contains the parts loaded before installation in the induction unit 3.

The working chamber 1 is made of stainless steel of any brand.

As an induction unit 3, any industrial, newly developed installation for induction heating can be used, providing a volume sufficient to be placed inside one or more working chambers.

Additionally, the induction heating system 3 is located between, on the one hand, a bath with electrolyte 8 for galvanic deposition of a metal sublayer of metal from a group of transition metals of the periodic system of elements, and on the other hand, with a bath 9 for processing metal parts coated with a protective zinc layer in a phosphorus-containing electrolyte, which combined into a single production line (Fig. 2).

The installation for diffusion galvanizing of metal parts with several working chambers 1 (Fig. 2) is performed similarly to the first embodiment of the installation (Fig. 1).

Installation for diffusion galvanizing metal parts works as follows.

Previously, from a nutrient hopper (not shown in Fig. 1, 2), a charge based on zinc powder is loaded into the working chamber 1.

After preliminary preparation and cleaning of parts, they are placed in a bath 8 with an electrolyte for the galvanic deposition of a metal sublayer of metal from the group of transition metals of the periodic system of elements. Next, the prepared metal parts are moved from the position of the initial processing of the parts into the working chamber 1. In this case, contact of the charge particles with the surface of the metal parts occurs. The working chamber 1 through the regulatory body (not shown in Fig. 1) is connected to an inert medium source 4, the inert medium supply system is activated inside the chamber, after which the lid 2 is hermetically closed and the working chamber 1 is placed in the induction unit 3.

It was experimentally established that only in an inert environment can a uniform diffusion film of a zinc coating be formed.

This is a consequence of reducing the risk of the process of uncontrolled oxidation of zinc in the conditions of the proposed device.

After filling the working chamber 1 with an inert medium, the chamber 1 is closed with a lid 2, thereby preserving the inert atmosphere in the working chamber 1. At the end of the heat treatment process, the working chamber 1 is removed from the cavity of the induction unit 3. Then the working chamber 1 is opened, zinc-coated parts are removed and placed in a bath 9 for processing coated with a protective zinc layer of metal parts in a phosphorus-containing electrolyte. All these structural units are combined into a single technological line.

By analogy, the same actions are performed with other working chambers.

After that, each working chamber 1 is placed in an induction block 3, which provides heating of the zinc mixture in the working chambers to the required temperature (plus 300-400 C) for 1-2 minutes (instead of 1-2 hours as in the closest analogue), while the temperature gradient tends to zero. The working chambers 1 with coated parts can withstand during the estimated time, then removed from the induction unit 3 and cooled. Then remove the parts from the working chamber 1.

If necessary, tests are carried out for continuity of coating, bending, corrosion resistance, measurement of coating thickness.

Thus, when using the proposed device, the conditions for obtaining ultrathin uniform coatings on the complex-profile precision parts of small fasteners are provided, improving the quality of the coating, simplifying the design, reducing the time for one process cycle.

The possibility of industrial implementation of the proposed device is confirmed by the following examples.

Example 1. In laboratory conditions, the proposed diffusion galvanizing plant was tested on an experimental prototype assembled as shown in FIG. 1. Under the conditions of this example in FIG. 1 shows an embodiment of a plant for diffusion galvanizing of metal parts with one working chamber. The working chamber 2 with a neck and a cover 2 provided with sealing elements are made of steel grade ST3, the source 4 of inert medium is a cylinder filled with liquid nitrogen as an inert medium. As coated parts, the working chamber 1 is filled with steel parts of small fasteners. The induction unit 3 is a camera with a source, forming a heating chamber with currents with a frequency of 0.44-1 MHz.

In the working chamber 1 with a charge on the basis of finely divided zinc powder, equipped with heating means and a gas line connected to an inert gas source 4 for supplying an inert medium to the working chamber, the parts are loaded onto the surface of which a galvanic nickel sublayer is preliminarily applied in the bath 8 with electrolyte for galvanic metal coating. Then, a diffusion zinc coating is applied to these parts, while the parts are loaded directly into the working chamber when they are completely immersed in the mass of a zinc-containing charge. Then include the inert gas supply to the working chamber 1 and induction heating to 300 ° C.

Under the conditions of the proposed test of the proposed device there is a significant (2-3 times) reduction in the process of applying an ultrathin coating of diffusion zinc, the coating quality is significantly improved due to the absence of a temperature gradient in the zinc mixture, in addition, the efficiency of the installation due to the simultaneous coating of parts in several cameras.

Example 2. In FIG. 2 shows an embodiment of a plant for diffusion galvanizing of metal parts with several (in this case, three) working chambers 1.

As experiments have shown, when implementing the proposed device, the conditions for obtaining ultrathin uniform coatings on the complex-profile precision parts of small fasteners are provided, improving the quality of the coating, simplifying the design, reducing the time for one cycle of the process.

Claims (1)

A diffusion galvanizing installation for metal parts, comprising at least one working chamber with a neck for loading metal parts, a covered lid equipped with adjustable elements for connecting to an inert medium source, a heating system for the working chamber, a feed hopper with a charge, a loading container with metal parts characterized in that it is equipped with a bath with an electrolyte located in a single production line for the galvanic deposition of a metal sublayer of metal from groups s of transition metals of the periodic system of elements and the bath for processing metal parts coated with a protective zinc layer in a phosphorus-containing electrolyte, while the said heating system is made in the form of an induction block forming heating by currents with a frequency of 0.44-1 MHz to 850-880 ° C, which is placed at least one of the aforementioned working chamber for accommodating metal parts intended to receive a protective zinc coating on them, while said induction unit is located between the said van s.

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