JP2000290800A - Method and apparatus for electrolytic cleaning of steel strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for electrolytically cleaning a steel strip which can prevent excessive adhesion of Si at an edge portion of the steel strip applicable in an actual operation. SOLUTION: When electrolytically cleaning a cold rolled steel strip in an alkaline detergent bath, the effective width of electrodes 2a, 2b is set to the value of the cold rolled steel strip 3;
(Effective width of electrode−Width of cold rolled steel strip) / 2/2
Make it within the range of 50 mm to +50 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for electrolytically cleaning steel strip in a process of manufacturing a cold-rolled steel strip.

[0002]

2. Description of the Related Art Rolling oil,
Machine oil, scale, iron powder, dust, dust, etc. are attached. For a type requiring surface cleanliness, for example, for a plated original plate, annealing is performed after cleaning the surface with an electrolytic cleaning line.

As shown in FIG. 1, the electrolytic cleaning apparatus of the electrolytic cleaning line is provided with a plurality of pairs of electrodes 2a and 2b installed in a tank of an alkaline solution 1 in a running direction of a steel strip 3. Electric current is applied between the pair of electrodes 2a and 2b through the steel strip 3 to generate bubbles of hydrogen or oxygen from the steel strip 3, and the steel strip 3 is washed.

The alkali used for the alkaline solution 1 is generally sodium orthosilicate, and when washed with an electrolytic cleaning device, electrodeposited Si adheres to the surface of the steel strip 3 after the cleaning. This electrodeposited Si has an effect of preventing adhesion of the steel strip 3 during the annealing process,
Excessive electrodeposited Si is oxidized in the annealing process to form Si oxide, and a temper color is generated, and the plating appearance and corrosion resistance are adversely affected in the plating process.

[0005]

In the electrolytic cleaning apparatus, the electrode width is widened in accordance with the maximum steel strip width in order to foam the steel strip having different widths over the entire width thereof.
Current concentrates on the edge of the. Therefore, a large amount of electrodeposited Si adheres to the edge portion. For this reason, a temper color occurs at the edge portion during the annealing process, and plating unevenness occurs at the edge portion during the plating process.

Japanese Patent Application Laid-Open No. 54-14339 proposes a method in which the area of the electrode near the edge is larger on the cathode than on the anode in order to prevent abnormal adhesion of the edge of the electrodeposited Si in the cleaning process. ing.

When the cleaning operation is continued, dirt and ions in the alkaline solution are attracted to and adhere to the electrodes 2a and 2b having different polarities, and the voltage between the electrodes 2a and 2b increases. Therefore, the controller 4 performs an operation of reversing the polarities of the electrodes 2a and 2b at regular intervals to dissolve the deposits and reduce the increased voltage.

In an actual operation, it is necessary to repeat this operation. However, in the method described in Japanese Patent Application Laid-Open No. 54-14339, since the polarity of the anode and the cathode must be fixed, a practical proposal is made. is not.

An object of the present invention is to provide a method and an apparatus for electrolytically cleaning a steel strip which can be applied in actual operation and can prevent excessive adhesion of Si at the edge of the steel strip in consideration of the above problems. .

[0010]

Means of the present invention for solving the above problems are as follows.

(1) When electrolytically cleaning a cold-rolled steel strip in an alkaline detergent bath, the effective width of the electrode is defined as (effective electrode width-cold-rolled steel strip width) / 2 with respect to the cold-rolled steel strip width. To -350 mm
A method for electrolytically cleaning a steel strip, wherein the thickness is within the range of +50 mm (first invention).

(2) In the above (1), by changing the electrode width, (effective width of electrode−width of cold-rolled steel strip) / 2 is -350 mm.
A method for electrolytically cleaning steel strip, characterized in that the thickness is within the range of +50 mm (second invention).

(3) In the above (1), an insulator edge mask is provided on the electrode surface on the side of the edge portion in the electrode width direction, and (effective width of electrode−width of cold rolled steel strip) / 2 is −350 mm to +350 mm.
An electrolytic cleaning method for a steel strip, characterized in that it is within a range of 50 mm (third invention).

(4) In the above (1), a conductive member is provided so as to oppose the electrode surface on the edge side in the electrode width direction of the pair of electrodes installed in the running direction of the steel strip. (Effective width-cold rolled steel strip width) / 2 is -350 mm to +50 mm
2. The electrolytic cleaning method for a steel strip according to claim 1, wherein the conductive members provided at the edges of the pair of electrodes are disposed so as to be able to conduct with each other.
invention).

(5) An apparatus for electrolytically cleaning a cold-rolled steel strip by passing an electric current between a pair of electrodes installed in a steel strip running direction in an electrolytic tank, wherein the pair installed in the steel strip running direction. A conductive member is installed so as to face the electrode surface on the width direction edge side of each electrode of the electrodes, and the conductive members installed on the edge portions of the pair of electrodes are arranged so as to be able to conduct with each other. Characteristic electrolytic cleaning equipment for steel strip.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION If the electrodeposited Si at the edge of a steel strip is too large, it causes temper color in the annealing step and uneven plating in the plating step. According to the findings of the present inventors, the unevenness of plating is more conspicuous than that of temper color.
Therefore, in order to prevent the above-mentioned defects, it is necessary to equalize the amount of electrodeposited Si on the surface of the steel strip to the extent that plating unevenness does not become a problem. In the electrolytic cleaning device, the greater the amount of electricity flowing through the steel strip, the greater the amount of electrodeposited Si. Therefore, electrodeposited Si
In order to make the amount uniform, it is important to make the current flowing on the steel strip surface uniform.

FIG. 2 shows the state of the current distribution in the width direction of the steel strip in the electrolytic cleaning apparatus. As shown in (a), when the electrode width is wider than the steel strip width, current concentrates on the edge of the steel strip 3. On the other hand, as shown in FIG.
When the protruding portion of the electrode 2 is reduced from both ends of the steel strip 3, the current concentration at the edge of the steel strip 3 can be reduced.

FIG. 3 is a diagram showing the result of simulating the current density distribution in the steel strip width direction when a current of 1 kA per unit length is applied. When the electrode width is 300 mm wider on one side than the steel strip width, the edge portion has a current density about 3.5 times that of the center portion. On the other hand, when the electrode width and the steel strip width are the same, the edge portion is at the center portion. It is less than twice the current density. If the electrode width is further reduced, the current density at the edge can be further reduced. However, if the electrode width is too narrow, the current at the edge becomes insufficient, and poor cleaning occurs at the edge. Therefore, in order to prevent the occurrence of temper color at the time of annealing and the occurrence of plating unevenness at the time of plating while securing necessary cleaning properties at the edge portion, it is necessary to set the electrode width to an appropriate range with respect to the steel strip width. is there.

The present inventors have conducted various investigations on the appropriate electrode width. As a result, when the width of the electrode (hereinafter referred to as the effective width of the electrode) at which good current is conducted between the electrode and the steel strip is smaller than the width of the steel strip, the distance between the electrode edge and the steel strip edge is 350 m.
m, that is, (effective width of electrode−steel strip width) / 2 is −350.
When the effective width of the electrode is wider than the steel strip width, the distance between the electrode edge part and the steel strip edge part exceeds 50 mm, that is, when the effective width of the electrode is larger than the steel strip width, that is, When (effective width-steel strip width) / 2 exceeds 50 mm,
It was found that excessive Si adhered to the edge of the steel strip, and temper color during annealing and uneven plating during plating were likely to occur. Therefore, while securing the necessary cleaning properties,
In order to prevent the occurrence of temper color during annealing and uneven plating during plating, the effective width of the electrode is set to -350 mm to +50 mm with respect to the steel strip width.
Must be within the range.

In a normal electrode, since the steel strip is favorably energized over the entire width of the electrode, the effective width of the electrode coincides with the electrode width.
The width of the electrode may satisfy the above range with respect to the width of the cold-rolled steel strip (second invention).

Instead of adjusting the width of the electrode itself, the width of the electrode that allows good conduction with the steel strip may be adjusted. For example, an insulator edge mask may be provided on the electrode surface on the side of the edge in the electrode width direction, so that electricity is not conducted to the steel strip at the electrode edge (third invention). Further, a conductive member is installed facing the electrode surface on each electrode width direction edge portion side of the pair of electrodes installed in the steel strip running direction, and the conductive member installed on the edge portion of the pair of electrodes is provided. The electrodes may be arranged so as to be able to conduct electricity, electricity is conducted between the electrode and the conductive member at the electrode edge portion, and electricity is conducted between the electrode and the steel strip at the center of the electrode where the conductive member is not provided ( 4th invention, 5th invention). In this case, the effective width of the electrode refers to the electrode width of the portion where the edge mask is not provided in the third invention, and refers to the electrode width of the portion where the conductive member is not arranged to face in the fourth invention.

In the present invention, since there is no restriction on the polarity switching of the electrodes, the present invention can be easily applied in the operation of the present invention.

Hereinafter, the present invention will be further described. First, a case will be described in which the electrode width is adjusted to (steel width of electrode−cold rolled steel strip width) / 2 within the range of −350 mm to +50 mm with respect to the steel strip width.

Normally, in the electrolytic tank of the electrolytic cleaning apparatus, as shown in FIG. 1, a plurality of pairs of electrodes 2a and 2b are installed in the running direction of the steel strip. FIG. 4 shows one of a plurality of electrode pairs in the electrolytic tank. In FIG. 4, a pair of electrodes 2a, 2a installed above and below a steel strip 3 are installed with the same polarity, and a pair of electrodes 2b, 2b having different polarities with respect to the electrodes 2a, 2a are arranged adjacent thereto. Have been.
When the electrode 2a is a positive electrode, the electrode 2b becomes a negative electrode, and the current flows in a path of the electrode 2a → the steel strip 3 → the electrode 2b. At this time, hydrogen bubbles are generated from the surface of the steel strip 3 near the electrode 2a, and oxygen bubbles are generated from the surface of the steel strip 3 near the electrode 2b.
The width of the electrodes 2a and 2b is larger than the width of the steel strip 3 by (electrode width−
(Cold rolled steel strip width) / 2 is adjusted within the range of -350 mm to +50 mm. By setting the electrode width as described above, current concentration at the edge portion of the steel strip 3 is eliminated, and necessary cleaning properties can be secured, and occurrence of temper color at the time of annealing and uneven plating at the time of plating can be prevented. .

In the apparatus shown in FIG. 4, when the range of the width of the steel strip to be cleaned is wide, it is advantageous from the viewpoint of productivity if the electrode width can be adjusted according to the width of the steel strip. 5 to 8 show examples in which the electrode width is arranged so as to be adjustable according to the steel strip width.
Note that FIGS. 5 to 9 show a state in which one of the plurality of electrodes disposed on the upper side of the steel strip is viewed from above.

In FIG. 5, the electrode 11 is a set of divided electrodes 1 having a comb-shaped uneven portion extending in the width direction of the steel strip.
1a and 11b, and the electrodes 11a and 11b
Are arranged so as to be movable in the width direction of the steel strip. When the width of the steel strip 3 is narrow, the electrodes 11a and 11b move toward the center of the steel strip, and as shown in FIG. It can be moved to a position where a flat surface is formed. When the width of the steel strip 3 is large, the electrodes 11a and 11b are changed from the state shown in FIG.
They move in a direction away from each other, resulting in a state as shown in FIG. As shown in (a), the width of the electrode 11 in a state where the protrusion of one electrode is completely mounted in the recess of the other electrode is W1, and as shown in (b), the protrusion of one electrode is the other. Assuming that the width of the electrode 11 in the state where the mounting is started in the concave portion of the electrode is W2, the width (effective width) W of the electrode 11 is changed to W1 to W2 by moving the electrodes 11a and 11b in the width direction of the steel strip 3.
It can be adjusted freely within the range. In the present apparatus, when the width range of the steel strip 3 to be cleaned is wide, the electrode 1 is adjusted according to the width of the steel strip 3.
The width W of the electrode 11 can be freely adjusted within the range defined in the present invention with respect to the width of the steel strip by adjusting the width direction positions of 1a and 11b.

In FIG. 6, the electrode 11 is a fixed electrode 11c.
(Width W1) and auxiliary electrode 11 rotatable about axis 13.
d (width W3). When the width of the steel strip 3 is narrow, the auxiliary electrode 11d is rotated and disposed above the fixed electrode 11c, and the auxiliary electrode 11d is not used, as shown in FIG. When the width of the steel strip 3 is large, as shown in (b), the auxiliary electrode 11d and the fixed electrode 11c are disposed so as to form the same electrode surface. When the auxiliary electrode 11d is not used, the width of the electrode 11 is W1, and when the auxiliary electrode 11d is used, the width of the electrode can be increased from W1 to W1 + 2 × W3.

In FIG. 7, the electrode 11e is arranged rotatably around the shaft 14. When the electrode 11e is rotated by 90 degrees from the state of (a) to the state of (b), the electrode 11e
Can be increased from W1 to W4.

In FIG. 8, the corner of the electrode 11e shown in FIG. 7 is formed in an arc shape. The electrode may have such a shape as necessary.

In FIG. 9, an auxiliary electrode 11g (width W3) is provided on both sides of the main electrode 11f (width W1), and the main electrode 11f and the auxiliary electrode 11g are provided so as to be capable of controlling current independently of each other. Has been established. When the width of the steel strip 3 is narrow, (a)
As shown in FIG. 7, only the main electrode 11f is used, and the auxiliary electrode 11f is used.
Do not use g. When the width of the steel strip 3 is large, as shown in (b), the main electrode 11f and the auxiliary electrode 11g are used together. When the main electrode 11f and the auxiliary electrode 11g are used together, the width of the electrode 11 can be increased from W1 to W1 + 2 × W3.

Next, a case where an insulator edge mask is provided on the electrode surface on the edge portion side in the electrode width direction will be described.

FIG. 10 shows one of a plurality of pairs of electrodes in the electrolytic tank, similarly to FIG. In FIG.
4 except that an insulating edge mask 5 is attached to the surface of each of the electrodes 2a and 2b placed above and below the steel strip 3 on the side of each width direction edge portion facing the steel strip 3. It has a similar configuration.

In the apparatus shown in FIG. 10, as shown in FIG.
Electric conduction between the electrode surface on which the insulator edge mask 5 is installed and the steel strip 3 is not performed. Assuming that the width of the electrode 2 (2a, 2b) is W1 and the width of the edge mask 5 is W3, the effective width W of the electrode is the width W1-2 × W3 of the electrode on which the edge mask 5 is not installed. In the present apparatus, the effective width W of the electrode is set within a range of -350 mm to +50 mm with respect to the width of the cold-rolled steel strip with respect to the width of the cold-rolled steel strip.

In the apparatus shown in FIG. 10, it is advantageous if the effective width of the electrode can be adjusted according to the width of the steel strip.
FIG. 12 shows an example of a device provided so that the effective width of the electrode can be adjusted. In the apparatus of FIG. 12, the edge mask 5 is disposed so as to be movable in the width direction of the steel strip 3 by the shift arm 6. Assuming that the width of the electrode 2 is W0, the effective width W of the electrode 2 is reduced by adjusting the amount of movement of the edge mask 5 toward the central portion in the steel strip width direction and the amount of extraction toward the steel strip edge. Can be adjusted freely within the range not exceeding.

Next, a case where a conductive member is provided so as to face the electrode surface on the edge portion side in the electrode width direction will be described.

FIG. 13 shows one of a plurality of pairs of electrodes in the electrolytic tank of the electrolytic cleaning apparatus as in FIG. 4, and each electrode on the width direction edge portion side of the pair of electrodes 2a and 2b. The configuration is the same as that of FIG. 4 except that a conductive member 7 of a conductor is provided facing the surface. In FIG. 13, electrodes 2a, 2a, 2b, and 2b are provided above and below a steel strip 3, and a conductive member 7 connects the electrodes 2a to 2b on the edge portions between the upper and lower electrodes 2a and 2b. It is arranged to penetrate. The conductive member 7 may be provided so as to penetrate between all the electrodes in the electrolytic tank provided in the traveling direction of the steel strip 3.

In the apparatus shown in FIG. 13, as shown in FIG.
At portions protruding from both sides of the steel strip 3, a current flows between the electrode 2 and the conductive member 7. Therefore, the paired electrodes 2
In the portion facing the steel strip 3 between a and 2b, a current flows through the route of the electrode 2a → the steel strip 3 → the electrode 2b,
In the portion protruding from both edges of the steel strip 3, current flows through the route of the electrode 2a → the conductive member 7 → the electrode 2b, so that the current can be prevented from being concentrated on the edge of the steel strip 3. In this case, the distance between the conductive members 7 disposed on both sides of the steel strip 3 is W
7, the effective width W of the electrode 2 is equal to the distance W between the conductive members 7.
It becomes 7. Therefore, in the present apparatus, the effective width W of the electrode 2 is set to (effective width of electrode W−cold rolled steel strip width) / 2 within a range of −350 mm to +50 mm with respect to the cold rolled steel strip width.

FIG. 15 shows an example of the cross-sectional shape of the conductive member 7. (A) is a case where the cross section of the conductive member 7 is rectangular. To more effectively suppress the current concentration at the steel strip edge,
(B) As shown in FIG.
To the steel strip 3) as shown in (c).
A shape that surrounds the edge is effective. For the conductive member 7, a material having a lower electric resistance is more effective.
As in the case of FIG. 12, a means for moving the conductive member 7 in the width direction of the steel strip may be provided, and the conductive member 7 may be moved in the width direction of the steel strip to adjust the effective width W of the electrode 2. .

[0039]

EXAMPLES (Example 1) A cold-rolled steel strip was charged into an electrolytic cleaning line, cleaned by an electrolytic cleaning apparatus provided with electrodes having a constant width, and then annealed and temper rolled. Galvanized in an electric galvanizing line. The cleaning degree of the steel strip after cleaning and the plating appearance of the steel strip after plating were examined. The degree of cleaning of the steel strip was measured by adhering a cellophane tape to the edge portion of the surface of the steel strip after cleaning and peeling it off again.

：: good (small dirt) ×: bad (small dirt) As for the plating appearance, the average value of the width w of the plating unevenness at the edge portion generated in the form shown in FIG. Was passed, and those exceeding 7 mm were rejected.

FIG. 17 shows the result of the investigation. As can be seen from FIG. 17, when the electrode width is within the range of the present invention with respect to the steel strip width, both the degree of cleaning and the plating appearance are good, but the electrode width is out of the range of the present invention with respect to the steel strip width. And the degree of cleaning and plating appearance are inferior.

(Embodiment 2) The position of the edge mask is changed to adjust the effective width of the electrode by using an electrolytic cleaning apparatus in which an insulating edge mask is provided at the edge of the electrode, and after the cold rolling. Was cleaned, tempered, rolled and galvanized in the same manner as in Example 1, and the cleaning degree of the steel strip after cleaning and the plating appearance of the steel strip after plating were examined.

FIG. 18 shows the result of the investigation. In FIG. 18, the electrode exposure width is an electrode width (effective electrode width) of a portion where the edge mask is not provided.

As can be seen from FIG. 18, when the electrode exposure width is within the range of the present invention relative to the steel strip width, both the degree of cleaning and the plating appearance are good, but the electrode exposure width is smaller than the steel strip width. If it is out of the range of the present invention, either the degree of cleaning or the plating appearance is inferior.

(Embodiment 3) FIG.
The rectangular conductive member shown in FIG.
× 50 mm), the distance between the conductive member and the steel strip was set to 10 mm ((effective width of electrode−steel strip width) / 2 = 10 mm), and the steel strip after cold rolling was used. Was washed, temper-rolled, and galvanized in the same manner as in Example 1, and the cleaning degree of the steel strip after cleaning and the plating appearance of the steel strip after plating were examined. Regarding the plating appearance, the occurrence rate of plating unevenness (the ratio of the length of the portion where the plating unevenness having a width of 7 mm or more occurred) was further investigated. For comparison, the same investigation was performed for the case where the conductive member was not provided. Table 1 shows the survey results.

[0046]

[Table 1]

As can be seen from Table 1, the example of the invention in which the effective width of the electrode satisfies the scope of the present invention with respect to the width of the steel strip has a significantly improved degree of edge unevenness as compared with the comparative example using no conductive member. ing.

[0048]

According to the present invention, excessive adhesion of Si at the edge of the steel strip can be prevented, and the occurrence of temper color during annealing and edge unevenness during plating can be prevented. It is easy to apply the present invention to electrolytic cleaning of steel strip in an actual electrolytic cleaning line.

[Brief description of the drawings]

FIG. 1 is a diagram showing a main part of electrolytic treatment equipment of a conventional electrolytic cleaning line.

FIGS. 2A and 2B are diagrams illustrating a state of current distribution in a steel strip width direction in the electrolytic cleaning equipment. FIG. 2A shows a case where the electrode width is wider than the steel strip width, and FIG. The case where the protruding portion of the electrode is further reduced is shown.

FIG. 3 is a view showing a simulation result of a current density distribution in a steel strip width direction when a current of 1 kA per unit length is applied.

FIG. 4 is a perspective view showing a main part of an electrode structure of an electrolytic cleaning apparatus for adjusting an effective width of an electrode by changing an electrode width in the present invention.

FIG. 5 is a diagram showing a first example of an electrode structure in which the electrode width can be changed in the device of FIG.

FIG. 6 is a diagram showing a second example of the electrode structure in which the electrode width can be changed in the device of FIG.

FIG. 7 is a diagram showing a third example of the electrode structure in which the electrode width can be changed in the device of FIG. 4;

FIG. 8 is a diagram showing an example of an electrode shape in which a corner portion is formed in an arc shape in FIG. 7;

FIG. 9 is a diagram showing a fourth example of the electrode structure in which the electrode width can be changed in the device of FIG. 4;

FIG. 10 is a perspective view showing a main part of an electrode structure of an electrolytic cleaning apparatus for adjusting an effective width of an electrode by installing an insulator edge mask in the present invention.

FIG. 11 is a view for explaining a state of a current distribution in a steel strip width direction in the electrolytic cleaning equipment when an insulator edge mask is installed.

FIG. 12 is a diagram showing an example in which the edge mask is arranged so as to be movable in the width direction in the apparatus of FIG. 10;

FIG. 13 is a perspective view showing a main part of an electrode structure of an electrolytic cleaning apparatus in which a conductive member is provided so as to face an electrode surface on an edge portion side in an electrode width direction in the present invention.

FIG. 14 is a view for explaining a state of a current distribution in a steel strip width direction in the electrolytic cleaning equipment when a conductive member is installed.

FIG. 15 is a view showing an example of the shape of a conductive member used in the apparatus shown in FIG. 13;

FIG. 16 is a view showing a state of occurrence of plating unevenness after electrogalvanizing.

FIG. 17 is a diagram showing a relationship between a difference between an electrode width and a steel strip width, plating appearance, and cleaning degree in Example 1.

FIG. 18 is a diagram showing a relationship between a difference between an electrode exposure width and a steel strip width, plating appearance, and cleaning degree in Example 2.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Alkaline solution 2, 2a, 2b Electrode 3 Steel strip 4 Controller 5 Edge mask 6 Shift arm 7 Conductive member 11, 11a-11g Electrode

Claims (5)

[Claims] When the cold-rolled steel strip is electrolytically washed in an alkaline detergent bath, the effective width of the electrode is determined by the width of the cold-rolled steel strip.
(Effective width of electrode-width of cold rolled steel strip) / 2 is -350 mm to +
An electrolytic cleaning method for a steel strip, characterized in that the thickness is within a range of 50 mm. 2. The electrolytic cleaning of a steel strip according to claim 1, wherein the width of the electrode is changed so that (effective width of the electrode−width of the cold-rolled steel strip) / 2 is in the range of −350 mm to +50 mm. Method. 3. An insulator edge mask is provided on the electrode surface on the edge side in the electrode width direction to make (effective width of electrode−cold rolled steel strip width) / 2 within the range of −350 mm to +50 mm. The method for electrolytically cleaning steel strip according to claim 1, wherein: 4. A conductive member is installed facing an electrode surface on a width direction edge side of each electrode of a pair of electrodes installed in a running direction of a steel strip, and (effective width of electrode−cold rolled steel). Obi width) /
2 is set within a range of -350 mm to +50 mm, and conductive members provided at edges of the pair of electrodes are arranged so as to be able to conduct with each other.
The electrolytic cleaning method for a steel strip according to the above. 5. An apparatus for electrolytically cleaning a cold-rolled steel strip by passing an electric current between a pair of electrodes installed in a steel strip running direction in an electrolytic tank, wherein the pair installed in the steel strip running direction is provided. A conductive member is provided so as to face an electrode surface on the width direction edge portion side of each electrode of the electrodes to be formed, and the conductive members provided at the edge portions of the paired electrodes are arranged so as to be able to conduct with each other. Steel strip electrolytic cleaning equipment.