RU2734604C1 - Method for brassing of patented wire for production of metal cord - Google Patents

Abstract

FIELD: electroplating.

SUBSTANCE: invention can be used for application of coating on steel wire used for production of metal cord. Method includes immersion with pressure rollers of wire in galvanic baths with electroplating copper plating and zinc coating and soluble anodes in form of copper and zinc granules, drawing of wire through baths with application of layers of copper and zinc and subsequent diffusion annealing to simple brass, at that before and after galvanic bath rotary mechanism and pendulum are provided, intended for screwing of drawn wire through galvanic baths relative to vertical wire axis by 30° in two sides, keeping center of wire axis fixed.

EFFECT: method of brassing allows creating a more uniform surface of brass wire, reducing and eliminating thickness difference of coating and creating a more uniform coating layer, reduced weight loss of the coating during wet drawing due to reduced damage of coating on peaks and poles, as well as creation of controlled application of coating on steel wire in compliance with application curve.

1 cl, 4 dwg

Description

The invention relates to the field of electroplating and can be used for coating steel wire used for the production of steel cord.

In production, they do not impose requirements on the thickness of the coating after galvanization and diffusion annealing, but impose only on the mass of the coating per kilogram of wire, therefore, the elimination of the coating defect, as the unevenness of the coating thickness, is an urgent task.

The known method of brass plating [1], which can be used for wire brass plating. The essence of the method: layers of copper and zinc are sequentially applied to the wire by electroplating, after which the first stage of interdiffusion is carried out by heating the wire to a temperature of 450-550 ° C, treated in a solution of phosphoric acid and copper sulfate and the second stage of interdiffusion is carried out by heating to a temperature of 300- 450 ° C, and the first stage of interdiffusion is stopped after reaching the β-phase in brass in the amount of 10-20%, and the second stage of interdiffusion is continued until the β-phase completely disappears [1].

In production [2, 3], a two-stage coating is applied to the wire in a stationary manner, without rolling the wire passing through the galvanizing baths and subsequent diffusion annealing.

The disadvantages of the known methods [1-3] are the following:

1) due to the close location of the lower part of the wire to the anode [4], the coating grows in the form of peaks, its thickness increases to 5-10 μm, relative to the upper part, where the coating has a thickness of 1 μm;

2) the coating has an undesirable relief other than the average coating curve (FIG. 1).

3) the thickness of the coating has poles and peaks, the excess coating is removed into brass chips.

The object of the invention is to eliminate the difference in coating thickness, to create a more uniform coating layer, to reduce the loss of coating mass during wet drawing, and also to provide a controlled coating of steel wire in accordance with the application curve of FIG.

To solve these problems, the method of brass plating of a patented wire for the production of steel cord includes immersing the wire with pinch rollers in galvanic baths with electrolytes of copper plating and zinc plating and soluble anodes in the form of copper and zinc granules, pulling the wire through baths with deposition of copper and zinc layers and subsequent diffusion annealing brass, while before and after the galvanic bath, a rotary mechanism and a pendulum are provided, designed to twist the drawn wire through the galvanic baths relative to the vertical axis of the wire by 30 ⁰ in two directions, keeping the center of the wire axis motionless.

Brassing is carried out in two consecutive baths with electrolyte, in the first bath a copper layer is applied, in the second a zinc layer.

The device consists of loop drives and pendulums, as well as a turntable, which turns the wire together with the drive synchronously at the entrance and exit from the bath, thereby compensating for the effect of wire twisting, distributing it over a long wire length to reduce the stresses from twisting.

The coating is carried out in the range of the mean coating curve. The graph represents the average surface area obtained with two-stage coating and subsequent diffusion annealing (FIG. 1).

An approximate diagram of the patenting and galvanizing line (Fig. 2) includes: an unwinding device (1), an annealing furnace (2), a cooling unit (3), a rotary storage mechanism and pendulum No. 1 (4), a copper plating bath (5) , an auxiliary rotary storage mechanism and a pendulum (6), a galvanizing bath (7), a diffusion annealing furnace (8) and a winding device (9).

The wire rolls around its axis along three points (Fig. 3): 30 ° and -30 °, which are maximum, and 0 ° - along the center of the wire cross-section (Fig. 4), along the bath with a copper anode, which is granules copper, zinc is applied from a solution previously dissolved in separate baths, and has little effect on the formation of peaks, repeating the surface relief of the copper coating. This allows for a smooth application of the coating on the site, distributing the coating corresponding to the peak in the usual static application mode over a large area of the wire surface, followed by diffusion annealing at 500-600 ° C. The rolling curve of the wire along the length of the copper plating baths is shown in FIG. 4.

The method of brass plating allows to create a more uniform surface of brass-plated wire, to reduce and eliminate differences in coating thickness and create a more uniform coating layer, to reduce the loss of coating mass during wet drawing due to less damage to the coating on peaks and poles, and also to create a controlled coating of steel wire in accordance with the application curve of Fig. 1.

LIST OF REFERENCES

1. Pat. 2048603 Russian Federation, IPC С23С 10/02. Wire brass plating method. SOUTH. Alekseev [and others]. Applicant and patentee "Oryol Steel Rolling Plant".

2. Alekseev Yu.G., Kuvaldin N.A. Steel cord for car tires. Moscow: Metallurgy, 1992.192 p.

3. Tsybulina A.A., Starikov A.K. Steel cord production. Moscow: Metallurgy, 1979.63 p.

4. Kurenkova TP, Voznaya V.I. Application of a scanning electron microscope equipped with a microanalysis system to investigate the quality of brass plating / Casting and metallurgy. 2010. No. 3 (56). S. 110-114.

Claims (1)

A method of brass plating of a patented wire for the production of a steel cord, including immersing wire pressure rollers in galvanic baths with electrolytes of copper and zinc plating and soluble anodes in the form of copper and zinc granules, pulling the wire through baths with deposition of copper and zinc layers and subsequent diffusion annealing, which is different from plain brass the fact that before and after the galvanic bath there is a rotary mechanism and a pendulum designed to twist the drawn wire through the galvanic baths relative to the vertical axis of the wire by 30 ° in two directions, keeping the center of the wire axis motionless.

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