JPS5884999A - Electrolytic pickling method for horizontally laid looped wire rod - Google Patents

Abstract

PURPOSE:To pickle looped wire rods uniformly over the entire circumference by conveying said wire rods into the tunnel of an electrolytic pickling cell using sulfuric acid and controlling the quantity of electric power supply on the charging side and discharging side respectively independently, thereby pickling the wire rods electrolytically. CONSTITUTION:Looped wire rods 1 are conveyed into an arrow direction with cathode feed rolls 2, 11 onto the tunnel 4 of an electrolytic pickling cell 3 using sulfuric acid 17 by means of a conveyor 6. Anodes 7, 9 and 8, 10 are provided in the opening part 5 in the central part of the tunnel 4 and are connected respectively to the rolls 2, 11 via DC electric power sources 13, 14. When the wire rods 1 are electrolytically pickled in this state, the front sides of the rods 1 have high current density and the front parts can be thoroughly pickled. In the central part, the right and left of the rods 1 have high current density and further on the outlet side, the rear parts of the rods 1 have high current density; therefore the rods 1 are pickled uniformly over the entire circumference.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for electrolytic pickling of metal wires, in particular a method for uniformly (double electrolytic pickling) (1) in which wires are placed horizontally in a loop on a striped conveyor and are continuously conveyed. be.

For example, when producing steel wire for automatic or semi-automatic welding, continuous primary wire drawing, annealing, pretreatment (including pickling),
It is manufactured through various processes such as plating, finishing wire drawing, and winding. In the special C2 pre-treatment process, in order to increase the efficiency of pickling, the wire is placed in a polymerized link state (loop shape) (2) and the pickling tank is conveyed horizontally on a conveyor (2). immersion method) has been put into practical use.

Hydrochloric acid is generally used in this dipping method C2, which dissolves the scale (iron oxide) on the wire surface generated during the annealing process in a short time, leaving no scale on the wire surface. This is because it has an excellent property of creating a uniform wire surface.

In particular, when hydrochloric acid is raised to a liquid @ 50C or more, the pickling ability increases and excellent properties are exhibited, but the evaporation of hydrochloric acid increases. Needless to say, this accelerates the aging of the pickling solution and increases the amount of hydrochloric acid consumed. Evaporated hydrochloric acid again? Do I need a device to collect the alkali neutralizer (caustic soda, etc.)? Will be using it a lot.

It is conceivable to use sulfuric acid, which does not easily evaporate, instead of hydrochloric acid in the above-mentioned immersion method, but sulfuric acid does not produce a wire surface as uniform as pickling with hydrochloric acid.

Therefore, an electrolytic pickling method using sulfuric acid as an electrolyte has been put into practical use.

Conventionally, the electrolytic pickling method uses a support trochanter (two wires) in which a single wire is run straight, the so-called strand method (hereinafter referred to as the strand method), and a metal wire that is completely bent to form a series of helical coils. There are two methods that have already been put into practical use: the so-called helico-filing method (hereinafter referred to as the "helicopiling method"), in which the robot is mounted and moved forward in the horizontal axis direction.These two methods each have the following problems. There is a point.

Regarding the strand method, it is difficult to improve the efficiency of acid theory work. In other words, in order to increase efficiency, the wire speed of the material to be pickled must be increased, and the length of the pickling tank must be increased. In addition, in the helicofoil method, the diameter is small (4+
It is extremely difficult to improve the efficiency of pickling work when the diameter is less than nφ). Therefore, an advantageous method for increasing the efficiency of pickling work even if the diameter is small is that loop-shaped wire rods that are conveyed horizontally (
We focused on electrolytic pickling (hereinafter referred to as the loop method). It goes without saying that the pickling process using the loop method is highly efficient because it is transported horizontally on a conveyor in a polymerized link state (loop shape).

In order to supply power by directly contacting electrodes at several locations within 10 m of one wire, it is relatively easy to uniformly pickle the surface of the wire. However, in electrolytic pickling of a horizontal loop-shaped wire, a single wire 10? Several K within FI
, it is impossible to supply electricity by directly contacting the electrodes, and the most important challenge is to easily supply electricity and provide a uniform pickled surface without variation. The question was how to obtain it.

This variation in the surface after pickling is caused by non-uniform current density, and in areas where pickling is insufficient, plating adhesion deteriorates, which adversely affects the quality of the product.

In detail, a small amount of scale remains in areas that are not sufficiently pickled, and when copper is plated in the next step, copper has extremely poor adhesion to the wire, and when the wire is drawn further after this, the diamond powder easily peels off and clogs. Die scratches, poor color tone, etc. are more likely to occur. In the case of wire rods for welding, copper powder peeled off during welding can be used in flexible conduit tubes with semi-automatic welding machines.
It becomes clogged inside the chip and causes deterioration in feeding performance.

The present invention was achieved as a result of various experiments and research conducted with the aim of improving the drawback of nonuniform pickling in electrolytic pickling using sulfuric acid mentioned above. This is a continuous electrolytic pickling method for a horizontally placed loop-shaped wire to obtain a plated wire with good adhesion without variation on the wire surface.

As shown in Figures 1 and 2, the solution in the electrolytic pickling tank is sulfuric acid, a tunnel as narrow as possible to transport the horizontally placed loop wire is built in the electrolytic pickling tank, and the electrolytic pickling power source is As two power sources, for example, a cathode feeding point is installed on the electrolytic pickling tank, that is, the entrance and exit sides of the looped wire into the tunnel, and an anode is installed in the opening in the center of the tunnel. It is characterized by controlling the amount of power supplied to each side power source independently.

First, all parts of the electrolytic pickling tank are powered, and with the upper part of the electrolyte tank open, power is supplied using a single power source from the cathode power supply points on both sides of the electrolytic pickling tank, on the loading and unloading sides, and then the anode power is supplied. When the wire rods were placed above and below a horizontally placed loop wire rod, as shown in FIG. 3, insufficient pickling occurred particularly on the left, right and rear sides of each loop C in the traveling direction of the loop wire rod.

Therefore, the power supply is as described above (one power supply is used, and if the tunnel is set up so that the thickness of the liquid layer is uniform from the inlet side to the outlet side, the front and left and right parts of each loop are sufficiently thick as shown in Figure 4. Pickling was carried out, but the rear part was not sufficiently pickled.

Next, without providing a tunnel in the electrolytic solution tank, from the cathode power supply points on both sides of the electrolytic pickling tank inlet and outlet sides to the anode in the center?
When two power sources are used and the amount of power supplied is controlled independently, as shown in Figure 5, the front and rear of each loop are thoroughly pickled.
The left and right parts were insufficiently pickled.

Finally, as shown in Fig. 1, a narrow tunnel through which the wire can pass is provided in the electrolytic pickling tank, and electrodes are placed.
In the case of power supply control, as shown in FIG. 6, pickling is carried out uniformly and sufficiently at the front, rear, left and right sides of each loop, that is, the entire circumference of each loop.

Providing the tunnels shown in FIGS. 1 and 2 in electrolytic pickling of horizontal loop wire rods that are continuously conveyed means that the loop wire rod 1, the electrolyte sulfuric acid 17, the anode It controls the flow of current to the plates 7 to 10, and in particular increases the current flowing through the loop-shaped wires, making it possible to strengthen the pickling of the left and right portions of each loop.

The reason for controlling the two power supplies is that the power supply 13 on the carry-in side contributes to strengthening the pickling of the front part of each loop, and the power supply 14 on the carry-out side contributes to strengthening the pickling of the rear part of each loop.

If we change the angle and explain this in terms of current density, in the process of the looped wire moving all the way through the electrolytic pickling tank, on the entrance side of the electrolytic pickling tank, the front part of each loop has a high current. The front part of each loop is sufficiently pickled, and as the looped wire moves, the high current density also moves, and when the looped wire reaches the center of the tank, the high current density also increases from the front of each loop to the left and right. Move to part. Furthermore, when the looped wire moves to the exit side of the electrolytic pickling tank, the high current density also reaches the rear of each loose. As described above, the present invention is an electrolytic pickling method that enables uniform pickling over the entire circumference of a loop-shaped wire.

Next, the present invention will be explained in detail with reference to Drawing 12.

FIG. 1 is a side view showing an example of the electrolytic pickling method of the present invention in which a horizontally placed loop-shaped wire is continuously conveyed and electrolytically pickled, and FIG. 2 is a front view.

In FIGS. 1 and 2, 1 is a loop-shaped wire being conveyed;
2 is a cathode power supply roller on the wire carrying side, 3 is an electrolytic pickling tank, 4 is
is a tunnel arranged in the pickling tank and capable of transporting a loop-shaped wire; 5 is an opening provided in the center of the tunnel; 6 is a transport conveyor; 7, 8°; 9.10 is an anode plate; 11 is a wire transport A side cathode electrification roller 12 indicates the direction in which the loop-shaped wire is conveyed. Reference numerals 13 and 14 indicate a DC power supply, 15 and 16 a variable resistor, and 17 a sulfuric acid electrolyte.

In FIGS. 3 to 6, n indicates the traveling direction of the loop-shaped wire, whereas 18 indicates the front part, 19 indicates the right side, ridge 21 indicates the left side, and the surface of the loop-shaped wire after pickling. It is a drawing showing a state.

In the conventional technique, that is, in FIG. 1, the power supply to the power supply rollers 2 and 11 is common and cannot be controlled independently, and the loop-shaped wire is fully electrolytically pickled (no tunnel)! −
Considering this, as shown in Figure 3, the front part of No. 18 was well pickled;
19, 20. The left side of 21 and the right side of the rear ζ are insufficiently pickled.

Next, in Figure 1-C, if the power supply to the power supply rollers 2 and 11 is common and the loop-shaped wire is electrolytically pickled without controlling each one individually (with tunnel), The left and right parts of section 19.21 are well pickled.
Insufficient pickling at the rear of the car.

In addition, in FIG. 1, when the power supply to the power supply rollers 2 and 11 is not shared and is controlled individually, and the loop-shaped wire is electrolytically pickled (without tunnel), as shown in FIG. The rear part of Toka was well pickled, but the left and right parts of 19.20 were poorly pickled.

In the present invention, in order to eliminate the drawbacks of the prior art, the power supply to the power supply rollers 2 and 11 shown in FIG. When the loop-shaped wire is fully electrolytically pickled, the entire circumference of each loop is uniformly pickled as shown in FIG.

Next, examples of the present invention will be shown together with comparative examples.

Electrolytic pickling conditions Electrolytic pickling wire material: Steel wire for welding Wire diameter 2. Q! 111
φ loop diameter SOO■lφ Under the above conditions, single power supply (no tunnel, with tunnel) and 2
Table 1 shows the scale removal judgment results in the conveying direction of the looped wire rod, which were performed using the power supply control method (the above is the conventional method) and the method of the present invention with "2 power supply control and 10 tunnels". Table 2 shows the determination results of plating adhesion at positions corresponding to the scale removal determination positions, and Table 3 shows the results of product appearance color tone determination.

As shown in Table 1, the electrolytic pickling method of the present invention removes scale 5 more uniformly than the conventional method, which is a great improvement. Furthermore, the plating adhesion shown in Table 2 was also improved. Furthermore, as shown in Table 3, it was also observed that the color tone of the product was much improved compared to the conventional method.

Although the present invention has been explained above using a cathodic pickling method, it can also be applied to an anodic pickling method if necessary.

[Brief explanation of drawings]

FIG. 1 is a side view showing an example of a sortie pickling tank suitable for carrying out the method of the present invention, and FIG. 2 is a front view. Figure 3,
FIG. 4, FIG. 5, and FIG. 6 are explanatory diagrams showing the pickling state of the loop-shaped wire. DESCRIPTION OF SYMBOLS 1... Loop-shaped wire rod, 2... Cathode power supply roller on the wire carrying-in side, 3... Plating tank, 4... Tunnel, 5...
・Opening in the center of the tunnel, 6...Transportation conveyor,
7-IQ... Anode plate, 11... Wire discharge side cathode power supply roller, 12... Direction of loop-shaped wire, 13-14
...DC power supply, 15-16...Variable resistance, 17...
- Sulfuric acid, 18... Front part of the loop with respect to the direction of loop-shaped wire rod movement, 19... Right part, 20... Rear part, 21...
Left part, n... traveling direction of the loop-shaped wire. Patent applicant representative Patent attorney Tomoyuki Yafuki (and 1 other person)

Claims (1)

[Claims] Electrolytic pickling method for horizontally placed loop wire rods that are continuously conveyed: Second, the liquid in the electrolytic pickling tank is sulfuric acid, and a tunnel is provided in the electrolytic pickling tank to allow the loop wire rod to be transported. Electrolysis of a horizontally placed loop-shaped wire, characterized in that electrolytic pickling is carried out by independently (= controlling) the amount of power supplied to the power supply electrode of the wire to be electrolyzed, which is provided at the carrying-in side and carrying-out (1111) to the electrolytic pickling tank. Pickling method.