JP3078385B2 - Manufacturing method of double-sided electroplated steel sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a double-sided electroplated steel sheet.

[0002]

2. Description of the Related Art In general, a double-sided electroplated steel sheet is formed by plating one side of a steel sheet in a preceding cell to form a first plating and then plating the other side in a subsequent cell by forming a second plating. In the manufacture of, a pre-plating surface is infiltrated with a plating solution while a pre-plating is formed in a cell at a preceding stage.

[0003]

However, in the infiltration of the post-plated surface by such a method, the plating adhesion of the post-plated surface after the post-plating is not good, or the post-plated surface is not formed during the formation of the pre-plated surface. However, there has been a problem that the plating solution component is deposited on the rolls in contact with the rolls, which causes a flaw.

An object of the present invention is to solve the above problems and to provide a method for producing a flawless double-sided electroplated steel sheet having excellent plating adhesion.

[0005]

According to the present invention, in order to attain the above object, according to the present invention, a pre-plating solution containing an acid and zinc ions is used on one surface of a steel sheet in a preceding cell. Plating is performed to form a pre-plating, and in a subsequent subsequent cell, the other side of the steel sheet contains acid and zinc ions.
In the method for producing a double-sided electroplated steel sheet which is subjected to plating using a post-plating solution having the post-plating , the post-plating surface is formed with the pre- plating solution while forming the pre-plating in the preceding cell. Production of a double-sided electroplated steel sheet characterized by infiltrating the post-plated surface with an acid constituting the post- plating solution before entering the cell at the post- stage A method is provided.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

FIG. 1 is a schematic diagram showing an example of a radial cell used in the method of the present invention. Such a radial cell is usually used for the production of a double-sided electroplated steel sheet.

The cell is composed of a preceding cell 3 and a succeeding cell 4, and the number of cells is not limited to that shown in FIG. 1. The preceding cell 3 and the succeeding cell 4 can be replaced with arbitrary ones as necessary. A number can be provided.

In the following description, a case where the material to be plated is a steel strip will be described, but a steel plate can be similarly electroplated on both sides.

The steel strip 6 is conveyed from the right side of FIG. 1 and passes through a conductor roll 5 provided in each plating bath, while one side of the steel strip 6 is applied to one surface of the steel strip 6 in the preceding cell 3 .
Plating is performed using a pre-plating solution containing zinc and zinc ions to form pre-plating. During this pre-plating, the conductor roll 5 of each preceding cell 3 is placed
The acid spray 1 constituting the first plating solution is performed, and the unplated surface (post-plating surface) of the steel strip 6 constitutes the first plating solution.
Soaked in acid.

[0011] The pre-plated steel strip 6 is subsequently conveyed to the subsequent cell 4, but before entering the latter cell 4, the steel strip 6 is again transferred by the acid spray 2 constituting the post-plating solution. After the plating surface is infiltrated with the acid constituting the post-plating solution , post-plating is performed in each plating bath while passing through the conductor roll 5 of the cell 4 at each subsequent stage.

According to the present invention, previously during plating to form, after infiltrating the post plating surface with acid constituting the above plating solution, post plating solution post plated surface still in front of the rear plating
, So that the plating surface (iron surface) after plating before plating is extremely activated, and the plating adhesion becomes extremely good.

[0013] At this time, in advance during the "infiltration by previous plating after - after plating before the formation of acid", continuously ahead plated
It may be infiltrated with an acid constituting the solution and / or the post-plating solution , may be soaked with some other liquid if necessary, or may be dried.

Post-plating solution after post-plating surface before post-plating formation
Although the appropriate acid concentration and the appropriate infiltration time for infiltration with the acid constituting the composition vary depending on the type of plating, it is usually pH 0.1.
5 to 2.0, for example, in the case of Zn-Ni alloy plating, pH
Is preferably about 1 or 3 seconds or more.

If the acid concentration of the post-plating solution is too low, the effect of acid infiltration will not be obtained, and if the acid concentration is too high, the pre-plated surface will be dissolved when the acid reaches the pre-plated surface.

If the spraying time is too short, the oxide film on the iron surface cannot be sufficiently removed, and there is no effect of acid infiltration. Of course,
It is possible to shorten the time by devising the concentration.

While the pre-plating is being formed in the preceding cell, the acid concentration of the pre-plating solution that infiltrates the post-plated surface also varies depending on the type of plating, but is usually between pH 1.5 and 1.5.
At 4.0, for example, in the case of a Zn—Ni alloy plating, the pH is preferably 2-3.

If the acid concentration of the first plating solution is too low, poor energization may occur when the rear plating surface is in contact with the energizing roll.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to embodiments.

Example 1 Using the radial cell shown in FIG. 1, a plating solution shown in Table 1 was used.
(Common to first plating solution and post plating solution) , steel strip (SPCC, 0.75mm thickness x 150 ) under cleaning conditions and plating conditions
0 mm width) was plated on both sides. Table 2 shows the p of each spray liquid.
H and the results are shown. Note that hydrochloric acid was used as a spray solution other than the plating solution in Table 2. The overall judgment was ：: good,
Δ: Somewhat good, ×: Bad.

[0021]

[Table 1]

[0022]

[Table 2]

From Table 2, it can be seen that when the former cell acid spray was pH = 7, Zn (OH) ₂ was precipitated on the energizing roll,
It was good when ≦ 3.

When the acid spray pH before the latter cell was pH = 2, slight peeling of the plating was observed, but the overall judgment was good. Further, when pH = 1 and pH = 0, the results were good.

[0025]

As described above, the present invention is configured as described above, so that the pre- plating solution and the infiltration solution for the post-plating surface during the formation of the pre-plating surface in the preceding cell are used.
Since the acid constituting the post-plating solution is used, there is no adverse effect on the post-plating surface and the roll in contact with the post-plating surface, and no influence on the deterioration of the pre-plating solution and / or the post- plating solution. Thus, a high-quality double-sided electroplated steel sheet having excellent plating adhesion can be manufactured.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a radial cell used in the method of the present invention.

[Explanation of symbols]

 Reference Signs List 1 acid spray on the front cell side 2 acid spray on the input side of the rear cell 3 cell in the front stage 4 cell in the rear stage 5 Conductor roll (electrical roll) 6 Steel plate (steel strip)

Claims (1)

(57) [Claims] (1) An acid is added to one surface of a steel sheet in a preceding cell.
And a plating using a pre-plating solution containing zinc ions to form a pre-plating, and in a subsequent subsequent cell, the other surface of the steel sheet contains acid and zinc ions.
In a method for producing a double-sided electroplated steel sheet in which plating is performed by using a post-plating solution to form a post-plating, a post-plating surface is formed by the pre- plating solution while forming the pre-plating in the preceding cell. After infiltration with acid,
The method for producing a double-sided electroplated steel sheet further comprises infiltrating the post-plated surface with an acid constituting the post- plating solution before entering the post- stage cell.