Electroplated steel plate production control process for controlling edge thickening

Abstract

The invention discloses an electroplated steel plate production control process which comprises the following steps: acquiring a target plating layer thickness based on a plating layer type; and based on the target coating thickness, the strip steel running speed and the current density in the electroplating process are adjusted at the same time. The production control process of the electroplated steel plate also adjusts the running speed and the current density of the strip steel in the electroplating process according to the following formula: I = (alpha * h * M * V) / (Y * eta) based on the target coating thickness, wherein alpha represents a correction coefficient; h represents the target coating thickness, and the unit parameter is [mu] m; m represents the coating metal influence coefficient, the unit parameter is (A.h) / m < 3 >, and the coating metal influence coefficient = coating metal density / coating metal electrochemical equivalent; v represents the running speed of the strip steel, and the unit parameter is m / min; y represents an anode plate coefficient of electroplating; eta represents the current efficiency.

Description

Technical Field

[0001] The present invention relates to a steel plate production process, and particularly to a production process of electroplated steel plates. Background Art

[0002] In an electroplating production line, under normal processes, that is, when the anode plate and the strip are placed regularly, compared with the middle part of the strip, the curvature of the strip edge is larger, and the surface charge density is greater, resulting in a greater electric field strength at the strip edge. Eventually, the current density corresponding to the strip edge is greater, and further, the coating deposited on the strip edge is thicker than that in the middle part of the strip.

[0003] This problem has not been well solved in the current strip electroplating production control process.

[0004] Existing research mainly focuses on the electrode current control system of soluble anodes, the number of anode plates, and gradient current regulation. There is no solution in the prior art for adjusting the specific current density of electroplated strips. Summary of the Invention

[0005] The purpose of the present invention is to provide a production control process for electroplated steel plates to control edge thickening. This process solves the problem of edge thickening of the coating by controlling the current density and the strip running speed, and improves the coating thickness uniformity in the width direction of the strip. The electroplated steel plate prepared according to this process has uniform coating thickness in the width direction and excellent surface quality.

[0006] To achieve the above purpose, the present invention provides a production control process for electroplated steel plates to control edge thickening, including the steps of:

[0007] Based on the coating type, obtain the target coating thickness;

[0008] Based on the target coating thickness, simultaneously adjust the strip running speed and the current density during electroplating.

[0009] Further, in the production control process of electroplated steel plates of the present invention, when electroplating tin, the target coating thickness is set to 0.15 - 1 μm, then the strip running speed is controlled to be 200 - 380 m / min, and the current density is controlled to be 10 - 60 A / dm 2 .

[0010] Further, in the production control process of electroplated steel plates of the present invention, when electroplating nickel, the target coating thickness is set to 0.3 - 4 μm, then the strip running speed is controlled to be 30 - 150 m / min, and the current density is controlled to be 5 - 20 A / dm 2 .

[0011] Further, in the electroplated steel sheet production control process of the present invention, when electro-galvanizing, the target coating thickness is set to 3 - 15 μm, then the strip running speed is controlled to be 50 - 180 m / min, and the current density is controlled to be 8 - 30 A / dm 2 .

[0012] Further, in the electroplated steel sheet production control process of the present invention, based on the target coating thickness, the strip running speed and current density during electroplating are adjusted according to the following formula:

[0013] I = (α × h × M × V) / (Y × η)

[0014] Wherein, α represents the correction coefficient; h represents the target coating thickness, and its unit parameter is μm; M represents the coating metal influence coefficient, and its unit parameter is (A·h) / m 3 , the coating metal influence coefficient = coating metal density / electro - chemical equivalent of the coating metal; V represents the strip running speed, and its unit parameter is m / min; Y represents the anode plate coefficient of electroplating; η represents the current efficiency.

[0015] Further, in the electroplated steel sheet production control process of the present invention, the value of the current efficiency is 80 - 98%.

[0016] Further, in the electroplated steel sheet production control process of the present invention, the value of α is 2.4×10 -4 -7.5×10 -4 .

[0017] Further, in the electroplated steel sheet production control process of the present invention, when electro - tinning, the value of α is 4.8×10 -4 -7.5×10 -4 .

[0018] Further, in the electroplated steel sheet production control process of the present invention, when electro - nickel plating, the value of α is 3.1×10 -4 -4.8×10 -4 .

[0019] Further, in the electroplated steel sheet production control process of the present invention, when electro - galvanizing, the value of α is 2.4×10 -4 -3.1×10 -4 .

[0020] The electroplated steel sheet production control process of the present invention has the following advantages and beneficial effects:

[0021] The electroplated steel sheet production control process of the present invention can reduce the production cost of electroplated steel sheets, and at the same time can improve the surface quality of electroplated steel sheets.

[0022] The electroplated steel plate production control process of the present invention can reduce the degree of thickening of the coating at the edge of the steel plate and improve the yield rate.

[0023] The electroplated steel plate production control process of the present invention can not only reduce energy consumption, but also improve the weldability of the edges of wide electroplated steel plates while avoiding spatter in the strip weld, thus achieving better economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A comparison diagram of the coating uniformity effect along the width direction of the steel strip according to Example 2 of the present invention is shown.

[0025] Figure 2 A comparison diagram of the coating uniformity effect along the width direction of the strip steel of Example 6 of the present invention is shown.

[0026] Figure 3 A comparison diagram of the coating uniformity effect along the width direction of the strip steel of Example 9 of the present invention is shown. DETAILED DESCRIPTION

[0027] The electroplated steel plate production control process described in the present invention will be further explained and illustrated below in conjunction with specific embodiments and drawings in the specification. However, such explanation and illustration do not constitute an improper limitation on the technical solution of the present invention.

[0028] For electroplated steel strip, the surface charge density at different locations on the strip surface mainly depends on the surface curvature at that location. The greater the surface curvature, the easier it is to accumulate charges, resulting in a higher current density. In actual production, since the surface curvature of the strip edge is greater than that of the middle of the strip, the corresponding current density at the strip edge is greater, resulting in a thicker coating deposited at the strip edge than in the middle of the strip, resulting in uneven coating distribution, poor strip coiling, poor welding, and a large amount of waste of coating metal.

[0029] In order to control the coating thickness at the edge of the strip, the following formula (1) can be obtained based on Faraday's first law and Faraday's second law:

[0030] G=K×J×t×η

[0031] Where: G is the thickness of the single-sided coating, K is the electrochemical equivalent of the coating metal, J is the current density, t is the electroplating time, and η is the cathode current efficiency.

[0032] It can be concluded from the formula that the single-sided coating thickness G is proportional to the current density J. Therefore, in general, the coating thickness can be reduced by reducing the current density, or by reducing the electroplating time and increasing the strip running speed.

[0033] However, through research, the inventors found that the above formula has certain limitations and a limited scope of application. At the same time, the edge plating thickness deviation obtained by using the above formula is relatively large, and the problem of thickening at the edge of the plating has not been well solved.

[0034] To solve the above problems, the present invention provides a production control process for electroplated steel sheets, which includes the steps of:

[0035] Based on the type of plating, obtain the target plating thickness;

[0036] Based on the target plating thickness, simultaneously adjust the strip running speed and current density during electroplating.

[0037] In some specific embodiments, when electroplating tin, the target plating thickness is set to 0.15 - 1 μm, then the strip running speed is controlled to be 200 - 380 m / min, and the current density is controlled to be 10 - 60 A / dm 2 .

[0038] In some specific embodiments, when electroplating nickel, the target plating thickness is set to 0.3 - 4 μm, then the strip running speed is controlled to be 30 - 150 m / min, and the current density is controlled to be 5 - 20 A / dm 2 .

[0039] In some specific embodiments, when electroplating zinc, the target plating thickness is set to 3 - 15 μm, then the strip running speed is controlled to be 50 - 180 m / min, and the current density is controlled to be 8 - 30 A / dm 2 .

[0040] In the present invention, for different types of plating, on the premise of setting the plating thickness, the current density can be controlled according to the change of the strip running speed, so as to achieve the control of the uniformity in the width direction of the plating.

[0041] Examples 1 - 10

[0042] To illustrate the preferred embodiments of this case, the specific process parameters adopted in the preferred Examples 1 - 10 of the present invention are shown in Table 1.

[0043] Table 1.

[0044] Number Plating method Coating thickness (μm) Strip running speed (m / min) <![CDATA[Current density (A / dm 2 )]]> Example 1 Tin plating 0.15 380 10 Example 2 Tin plating 0.15 330 13.9 Example 3 Tin plating 0.5 300 28.2 Example 4 Tin plating 1.0 200 60 Example 5 Nickel plating 0.3 150 5 Example 6 Nickel plating 1 50 6.32 Example 7 Nickel plating 4 30 20 Example 8 Zinc plating 3 180 8 Example 9 Zinc plating 5 80 14.05 Example 10 Zinc plating 15 50 30

[0045] Through further research, the inventors found that by comprehensively considering the relationship between the plating weight of the electroplated strip, the width of the steel sheet, and the strip running speed, as well as the relationship between the current density and the plating thickness, the following formula (2) was obtained:

[0046]

[0047] Wherein: α is the correction coefficient, h is the coating thickness, and its unit parameter is μm; M is the coating metal influence coefficient (coating metal density / electro - chemical equivalent of the coating metal), and its unit parameter is (A·h) / m 3 ; V is the speed of the process section, and its unit parameter is m / min; Y is the anode plate coefficient (anode plate height × number of anode plate groups); η is the current efficiency.

[0048] It can be obtained from the formula that the current density is directly proportional to the coating thickness, coating metal density, and strip running speed, and inversely proportional to the electro - chemical equivalent of the coating metal ions, anode plate height, number of anode plates put into use, and cathode current efficiency.

[0049] Thus, it can be seen that based on the above formula, when Y, η, α, and M are known, for a set coating thickness h, the strip running speed V and current density I can be adjusted.

[0050] In order to make the above process more accurate in actual production, in the electroplated steel sheet production control process of the present invention, the current efficiency is controlled between 80 - 98%; the correction coefficient α is controlled between 2.4×10 -4 -7.5×10 -4 .

[0051] In some specific embodiments, when electroplating tin, the correction coefficient α can be controlled between 4.8×10 -4 -7.5×10 -4 .

[0052] In some specific embodiments, when electroplating nickel, the correction coefficient α can be controlled between 3.1×10 -4 -4.8×10 -4 .

[0053] In some specific embodiments, when electroplating zinc, the correction coefficient α can be controlled between 2.4×10 -4 -3.1×10 -4 .

[0054] Examples 2, 6, 9

[0055] To embody the preferred embodiments of this case, the preferred Examples 2, 6, 9 of the present invention further use formula (2) to more precisely adjust the current density and strip running speed within the process parameter range defined by the present invention. Table 2 shows the values of each parameter in formula (2) in Examples 2, 6, 9.

[0056] Table 2.

[0057]

[0058] In order to prove the implementation effect of the preferred embodiment 2, Figure 1 A comparison diagram of the coating uniformity effect along the width direction of the steel strip according to Example 2 of the present invention is shown.

[0059] like Figure 1 As shown, the coating thickness of the tinplate produced in Example 2 (new process) using the process implemented by the present invention is compared with that produced under the condition of no current density adjustment (original process). It can be seen that the edge thickening of the strip using the process implemented by the present invention is less than 10%, which is 16% higher than that under the initial current density condition.

[0060] At the same time, in order to prove the implementation effect of the preferred embodiment 6, Figure 2 A comparison diagram of the coating uniformity effect along the width direction of the strip steel of Example 6 of the present invention is shown.

[0061] like Figure 2 As shown, the coating thickness of the nickel-plated plate of Example 6 (new process) prepared by the implementation process of the present invention is compared with that of the nickel-plated plate produced under the condition of no current density adjustment (original process). It can be seen that the edge thickening of the strip using the implementation process of the present invention is less than 10%, which is 15% higher than that under the initial current density condition.

[0062] In addition, in order to prove the implementation effect of the preferred embodiment 9, Figure 3 A comparison diagram of the coating uniformity effect along the width direction of the strip steel of Example 9 of the present invention is shown.

[0063] like Figure 3 As shown, the coating thickness of the galvanized sheet produced in Example 9 (new process) using the process implemented by the present invention is compared with that produced under the condition of no current density adjustment (original process). It can be seen that the edge thickening of the strip using the process implemented by the present invention is less than 10%, which is 11% higher than that under the initial current density condition.

[0064] It should be noted that the above-listed embodiments are only specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and similar changes or modifications made therewith can be directly derived or easily associated with by those skilled in the art from the contents disclosed in the present invention, and all should belong to the protection scope of the present invention.

Claims

1. A production control process for electroplated steel sheets used to control edge thickening, characterized in that, Including the steps of: Obtaining the target coating thickness based on the coating type; Based on the target coating thickness, simultaneously adjusting the strip running speed and current density during electroplating.

2. The production control process for electroplated steel sheets according to claim 1, characterized in that, When electroplating tin, if the target coating thickness is set to 0.15 - 1 μm, the strip running speed is controlled to be 200 - 380 m / min, and the current density is controlled to be 10 - 60 A / dm 2 .

3. The production control process for electroplated steel sheets according to claim 1, characterized in that, When electroplating nickel, if the target coating thickness is set to 0.3 - 4 μm, the running speed of the strip steel is controlled to be 30 - 150 m / min, and the current density is controlled to be 5 - 20 A / dm 2 .

4. The production control process for electroplated steel sheets according to claim 1, characterized in that, When electrogalvanizing, if the target coating thickness is set to 3 - 15 μm, the strip running speed is controlled to be 50 - 180 m / min, and the current density is controlled to be 8 - 30 A / dm 2 .

5. The production control process for electroplated steel sheets according to claim 1, characterized in that, Based on the target coating thickness, adjusting the strip running speed and current density during electroplating according to the following formula: Among them, α represents the correction coefficient; h represents the target coating thickness, and its unit parameter is μm; M represents the coating metal influence coefficient, and its unit parameter is (A·h) / m 3 , coating metal influence coefficient = coating metal density / electro - chemical equivalent of coating metal; V represents the strip running speed, and its unit parameter is m / min; Y represents the anode plate coefficient of electroplating; η represents the current efficiency.

6. The production control process for electroplated steel sheets according to claim 5, characterized in that, The value of current efficiency is 80-98%.

7. The production control process for electroplated steel sheets according to claim 5, characterized in that, The value of α ranges from 2.4×10 -4 to -7.5×10 -4 .

8. The production control process for electroplated steel sheets according to claim 7, characterized in that, When electroplating tin, the value of α is 4.8×10 -4 -7.5×10 -4 .

9. The production control process for electroplated steel sheets according to claim 7, characterized in that, When electroplating nickel, the value of α is 3.1×10 -4 -4.8×10 -4 .

10. The production control process for electroplated steel sheets according to claim 7, characterized in that, When electroplating zinc, the value of α is 2.4×10 -4 - 3.1×10 -4 .

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