JP3211407B2 - Electrode for alloy plating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alloy plating electrode used for applying alloy plating to a strip surface.

[0002]

2. Description of the Related Art When an alloy plating is applied to the surface of a strip, as shown in FIG. 5, electrodes 2a and 2b are arranged near the surface of a strip X which comes into contact with a conductor roll 3 and passes through a plating bath. And plating by electroplating. At this time, the jet headers 10a, 10b are placed on the entrance or exit sides of the electrodes 2a, 2b.
(Provided only on the outlet side in the drawing), and a jet is sent between the strip X and the electrodes 2a and 2b (at this time, a flow along the flow of the strip X is a forward flow, and a flow opposite thereto is opposed The composition of the alloy is controlled by controlling the relative flow velocity between the jet and the strip X.

[0003]

However, in the above configuration, the flow velocity distribution between the strip X and the electrodes 2a, 2b differs between the jet headers 10a, 10b and the opposite side as shown in FIG. As a result, as shown in FIG. 7, the alloy composition in the plating film becomes non-uniform in the depth direction of the plating layer, which is not preferable in plating performance.

As a preventive measure, Japanese Patent Laid-Open No. 62-2113
No. 99, as shown in FIG.
It proposes a configuration in which rectifying plates 20a and 20b are arranged between 2a and 2b. However, in this configuration, the distance between the strip X and the electrodes 2a and 2b is increased, resulting in a disadvantage that the plating voltage is increased.

The present invention has been made in view of the above-mentioned problems of the prior art, and provides a configuration in which the flow velocity distribution in the electrode longitudinal direction between the strip electrodes can be made uniform. The purpose of this is to make the alloy composition uniform.

[0006]

Therefore, the structure of the present invention is an improvement of the structure of the electrode, in which the jet discharge port is provided inside.
At the alloy plating electrode to be stored, the jet flows
The discharge port, which is the counter flow, is inclined with respect to the electrode surface.
The angle is 30 ° or less, and the width of the mouth slit is
Formed to be 2/3 to 1 of the distance between the strip and
The basic feature is that you have done it.

[0007] The above-described configuration was created based on the elucidation of the cause of the above-mentioned problem in the prior art, and the elucidated cause will be described in detail below.

When a jet is applied to the surface of the strip X by the jet headers 10a and 10b as shown in FIG. 5, the jet not only includes the jet ejected from the tip of the header nozzle but also entrains the plating solution around the tip of the nozzle. The strip X and the electrodes 2a, 2b in a non-rectified state including eddy currents.
It will flow in the opposite direction. Therefore,
The eddy current or the like becomes a resistance, and the flow velocity gradually decreases.

At this time, the greater the difference in the distance between the strip X and the electrodes 2a, 2b with respect to the slit width at the nozzle tip of the jet headers 10a, 10b, the greater the amount of surrounding plating solution involved, The tendency becomes remarkable.

Therefore, it is also effective to make the jet flow into a rectifying state without eddy currents by the rectifying plates 20a and 20b as described above.
Then, as described above, the distance between the strip X and the electrodes 2a and 2b becomes large, and a new problem occurs in that the plating voltage becomes high.

The inventors of the present invention have examined a configuration in which the flow of the jet between the strip X and the electrodes 2a and 2b can be rectified without using such a configuration of the current plate. When the outlet was provided, it was found that, under certain conditions, the flow of the jet flow was in a rectified state, which led to the creation of the configuration of the present invention.

In the present invention , first, the direction of the jet outlet is
The generation of the entrainment flow was suppressed by setting the jet flow to be a counter flow with the flow of the strip . Thereby, the flow velocity distribution in the longitudinal direction of the electrode can be made uniform.

From the experimental results described later, it has been found that setting the slit width of the discharge port to 2/3 to 1 times the distance between the strip and the electrode has a remarkable effect on the uniformity of the flow velocity distribution. .

[0014] Further, from the experiment described later, the electrode surface
If the discharge port inclination angle with respect to is 30 ° or less,
Most of the plating solution spouting from the discharge port
It flows between trips, and the flow in that part is rectified
It is clear that the
It was decided to adopt also about the composition of. That is,
Ming is based on the combination of these optimal conditions.
Thus, the flow velocity distribution in the electrode longitudinal direction is made uniform.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described in detail.

FIG. 1 is an explanatory view showing the structure of one embodiment of the electrodes 2a and 2b of the present invention provided in an alloy electroplating tank for strip X. In the figure, reference numeral 3 denotes a conductor roll, and reference numerals 4a and 4b denote headers for supplying a plating solution to jet outlets 1a and 1b to be described later.

As shown in FIG. 1, for each electrode surface of the 1 m long electrodes 2a and 2b disposed in parallel on the upper and lower surfaces of the strip X, a jet outlet is provided on the rear side of the flow of the strip X. 1a and 1b are provided, and the plating solution supplied from the headers 4a and 4b is ejected so as to face the flow of the strip X.

With the above configuration, the strip X and both electrodes 1a and
Each distance to 1b is set to 15mm, and the outlet 1
The set angle of each of the electrode surfaces a and 1b and the slit width thereof were initially set to 30 ° and 10 mm, respectively.

The alloy composition in the depth direction of the plating layer obtained at this time is stable at a substantially constant value as shown in FIG.

Next, the present inventors changed the slit width of the jet outlets 1a and 1b to 3 mm and 15 mm, and carried out plating without changing other conditions. FIG. 3 shows the discharge port 1 at that time.
The flow velocity distribution from a, 1b to the entrance direction of each electrode 2a, 2b is shown. In this figure, 1/5, 2/3, and 1/1 represent the slit width / the distance between the electrode and the strip (that is, 1/5 indicates that the slit width is 3 mm, and 2/3 indicates the same.)
For 10 mm, 1/1 is for 15 mm). As can be seen from the figure, when the slit width of the discharge ports 1a and 1b is set to 2/3 to 1 times the distance between the electrode and the strip, the strip X
It can be seen that the flow velocity distribution between the electrodes 2a and 2b is substantially constant.

On the other hand, the slit width was set again to 10 mm, and instead, the set angle of the discharge ports 1a and 1b was changed between 10 ° and 90 °, and plating was performed. FIG. 4 shows the ratio of the flow rate between the electrode and the strip / the flow rate at the discharge port for each set angle at that time. As is clear from the figure, when the setting angle is set to 30 ° or less, most of the plating solution ejected from the discharge ports 1a and 1b flows directly between the electrode and the strip, and the flow in that part is It can be seen that the state has been rectified.

[0022]

According to the electrode structure of the present invention described in detail above, since the jet outlet is provided in the electrode itself, unnecessary protrusion is eliminated, the distance between the electrode and the strip can be reduced, and the voltage can be increased. Basic that plating is not required
The effect is recognized, as well as the direction and inclination of the discharge port.
The angle and mouth slit width have been selected to optimal conditions.
Since the flow between the electrode and the strip is kept in a rectified state, the alloy composition in the depth direction of the plating layer of the product becomes uniform, and a product of good quality can be manufactured.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of an electrode of the present invention provided in an alloy electroplating bath of a strip.

FIG. 2 is a graph showing an alloy composition in a depth direction of a plating layer of a product obtained by the configuration of this example.

FIG. 3 is a graph showing a flow velocity distribution in a longitudinal direction of an electrode when a slit width of a discharge port is changed in the configuration of the present embodiment.

FIG. 4 is a graph showing the ratio of the flow rate between the electrode and the strip to the flow rate of the jet when the setting of the inclination angle of the discharge port is changed in the configuration of the present embodiment.

FIG. 5 is an explanatory view showing a configuration of a conventional apparatus when an alloy plating is applied to the surface of a strip.

FIG. 6 shows electrodes and electrodes when alloy plating is performed according to a conventional configuration.
It is a graph which shows the flow velocity distribution of the jet which flows between strips.

FIG. 7 is a graph showing an alloy composition in a depth direction of a plating layer of a product obtained by the conventional configuration.

FIG. 8 is an explanatory diagram of a conventional configuration in which a flow velocity distribution of a jet is made uniform by a flow regulating plate.

[Explanation of symbols]

 1a, 1b Discharge port 2a, 2b Electrode 3 Conductor roll 4a, 4b Header X strip

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) C25D 5/08 C25D 7/06 C25D 17/00 C25D 17/12

Claims (1)

(57) [Claims] 1. An alloy plating electrode having a built-in jet outlet, in which a jet flows in a direction opposite to a flow of a strip.
The outlet has an inclination angle of 30 ° or less with respect to the electrode surface,
And the width of the mouth slit is the distance between the electrode and the strip.
An electrode for alloy plating, wherein the electrode is formed so as to have a thickness of 2/3 to 1 .