Electrogalvanized steel sheet having high peak count and thick zinc coating, and manufacturing method therefor

Abstract

Disclosed in the present invention is an electrogalvanized steel sheet having a high peak count and a thick zinc coating, comprising a steel substrate and an electrogalvanized zinc layer plated on a surface of the steel substrate, wherein the surface roughness profile skewness Rskb of the steel substrate is greater than or equal to 0.1, and the surface peak count Pcs of the electrogalvanized zinc layer is greater than or equal to 75 / cm. Further disclosed in the present invention is a manufacturing method for an electrogalvanized steel sheet having a high peak count and a thick zinc coating, comprising the steps: performing peak removal treatment on a textured surface of a roll of a temper mill, so that the roll has a profile skewness parameter Rsk≤-0.5; performing temper rolling on the steel substrate by means of the roll; and electrogalvanizing the steel substrate having undergone temper rolling to obtain the electrogalvanized steel sheet having a high peak count and a thick zinc coating. The electrogalvanized steel sheet having a high peak count and a thick zinc coating and the manufacturing method therefor according to the present invention solve the problem of excessive attenuation in surface morphology parameters, and can effectively ensure that the surface morphology parameters still exhibit a high peak count indicator after electrogalvanizing, thereby improving the stamping and coating effects of thick-zinc electrogalvanized steel sheets at user ends.

Description

High peak value number thick zinc layer electro-galvanized steel sheet and manufacturing method thereof TECHNICAL FIELD

[0001] The present application relates to a steel sheet and a manufacturing method thereof, and in particular to a plated steel sheet and a manufacturing method thereof. BACKGROUND

[0002] Electro-galvanized steel sheets are often applied to high surface quality requirements of automobile outer plates due to good stamping stability and few surface quality defects.

[0003] However, the surface morphology of the electro-galvanized steel sheet has an important influence on the stamping and coating effect. In order to maintain good stamping stability and coating appearance of the material, the steel sheet is usually required to have a roughened surface with a certain roughness and a high peak value number. Reasonable roughness is conducive to forming a good lubricating interface between the steel sheet and the die, and the higher the peak value number, the finer the roughened microstructure of the material surface, and the better the surface quality after coating.

[0004] The surface micro-morphology of the electro-galvanized steel sheet mainly comes from the rolling and smoothing process in the previous process, and the roughened texture is imprinted on the surface of the steel substrate by the rolling roller, and then electro-galvanizing is performed. However, due to the filling effect in the zinc deposition process, the surface morphology of the steel sheet usually decays to a certain extent after electro-galvanizing. Some high-grade automobile steel sheets have high requirements for the surface peak value number to ensure good coating effect, and the steel sheet with high peak value number has a more fine surface microstructure, so the decay after electro-galvanizing is more serious. At the same time, the galvanizing amount of high-grade automobile steel sheets is often thick to ensure good corrosion resistance, and the thicker the galvanizing amount, the more serious the decay of the surface roughened morphology of the steel sheet after electro-galvanizing.

[0005] Therefore, the production of high peak value number thick zinc layer electro-galvanized steel sheet is extremely difficult. There are Chinese patent documents in the prior art that inhibit the surface morphology decay of high peak value number thick zinc layer electro-galvanized steel sheet during the electro-galvanizing process, including:

[0006] For example, the Chinese patent document with the publication number CN115976597A and the publication date of April 18, 2023, and the name of "A steel sheet for automobile outer plate and a preparation method thereof" discloses a steel sheet for automobile outer plate and a preparation method thereof, which mentions controlling the electro-galvanizing solution pH value, electro-galvanizing solution temperature, zinc ion concentration, electro-galvanizing speed, and smoothing roller roughness to inhibit the surface morphology parameter decay during the electro-galvanizing process. Although the morphology parameter index of the electro-galvanized steel sheet is improved to a certain extent, the decay problem of the high peak value number thick zinc layer electro-galvanized steel sheet is not completely solved, because compared with the conventional electro-galvanized steel sheet, the high peak value number thick zinc layer electro-galvanized steel sheet has high peak value number and large galvanizing amount, and it is still difficult to fully solve the decay problem during the electro-galvanizing process by adjusting only the electro-galvanizing process and the smoothing roller roughness. SUMMARY

[0007] One of the purposes of the present application is to provide a high peak number thick zinc layer electro-galvanized steel sheet which solves the problem of excessive surface topography parameter decay of the conventional thick zinc layer electro-galvanized steel sheet, and can effectively ensure that the surface topography parameter after electro-galvanizing still has a high peak number index, thereby improving the use effect of the thick zinc layer electro-galvanized steel sheet during stamping and coating.

[0008] In order to achieve the above-mentioned purpose, the present application provides a high peak number thick zinc layer electro-galvanized steel sheet, which comprises a steel substrate and an electro-galvanized zinc layer plated on the surface of the steel substrate, wherein the surface roughness profile skewness Rsk b of the steel substrate is greater than or equal to 0.1, and the surface peak number Pc s of the electro-galvanized zinc layer is greater than or equal to 75 pieces / cm.

[0009] The present inventors have found through a large number of experimental observations that the surface profile skewness parameter Rsk b of the steel plate substrate surface topography characteristic parameter has an important influence on the decay effect during electroplating, and the greater the profile skewness Rsk b , i.e. the more the sharp peak shape of the steel plate surface topography, the smaller the surface roughness and peak number decay after electroplating. The reason is that the sharp peak is less likely to be filled in the electroplating process than the pit, so it can more effectively inhibit the decay of the topography parameter during electroplating. In addition, the present inventors have found through a large number of experimental verifications that when the Rsk b of the steel plate surface is controlled to be 0.1 or more, the decay of the surface roughness and peak number parameters of the steel plate during electroplating can be effectively inhibited.

[0010] Further, in the high peak number thick zinc layer electro-galvanized steel sheet according to the present application, the surface roughness Ra s of the electro-galvanized zinc layer is 0.9 μm to 1.4 μm.

[0011] In some embodiments, in the high peak number thick zinc layer electro-galvanized steel sheet according to the present application, the surface roughness Ra b of the steel substrate is 1.00 to 1.40 μm.

[0012] Further, in the high peak number thick zinc layer electro-galvanized steel sheet according to the present application, the surface roughness Ra s of the electro-galvanized zinc layer satisfies the following condition: Ra b of the steel substrate at the corresponding position is less than or equal to 0.1 μm. b -Ra s ≤0.1 μm.

[0013] In some embodiments, in the high peak count thick zinc layer electrogalvanized steel sheet according to the present application, the surface peak count Pc of the steel substrate is b ≥ 80 counts / cm. In some embodiments, in the high peak count thick zinc layer electrogalvanized steel sheet according to the present application, the surface peak count Pc of the steel substrate is b 80 to 100 counts / cm. In some embodiments, in the high peak count thick zinc layer electrogalvanized steel sheet according to the present application, the surface peak count Pc of the steel substrate is b 81 to 96 counts / cm.

[0014] In some embodiments, in the high peak count thick zinc layer electrogalvanized steel sheet according to the present application, the surface peak count Pc of the electrogalvanized zinc layer is s 75 to 100 counts / cm. In some embodiments, in the high peak count thick zinc layer electrogalvanized steel sheet according to the present application, the surface peak count Pc of the electrogalvanized zinc layer is s 78 to 92 counts / cm.

[0015] Further, in the high peak count thick zinc layer electrogalvanized steel sheet according to the present application, the surface peak count Pc of the electrogalvanized zinc layer is s the surface peak count Pc of the steel substrate at the corresponding position thereof b satisfies Pc b - Pc s ≤ 10 counts / cm.

[0016] Further, in the high peak count thick zinc layer electrogalvanized steel sheet according to the present application, the average zinc plating amount of one side of the steel substrate is ≥ 40 g / m 2 , such as 40 to 100 g / m 2 , 40 to 80 g / m 2 , or 40 to 60 g / m 2 .

[0017] Further, in the high peak count thick zinc layer electrogalvanized steel sheet according to the present application, the surface roughness profile skewness Rsk of the steel substrate is b ≥ 0.2. In the present application, by controlling the surface roughness profile skewness Rsk of the steel substrate to be ≥ 0.2, the attenuation effect of the thick zinc layer steel sheet during the zinc plating process can be further weakened. b

[0018] In some embodiments, in the high peak count thick zinc layer electrogalvanized steel sheet according to the present application, the surface roughness profile skewness Rsk of the steel substrate is b 0.1 to 0.6. In some embodiments, in the high peak count thick zinc layer electrogalvanized steel sheet according to the present application, the surface roughness profile skewness Rsk of the steel substrate is b ​is 0.2-0.6. In some embodiments, in the high-peak-count thick zinc layer electro-galvanized steel sheet according to the present application, the profile skewness Rsk of the surface roughness of the steel substrate is 0.24-0.56. b is 0.24-0.56.

[0019] Another object of the present application is to provide a method for manufacturing a high-peak-count thick zinc layer electro-galvanized steel sheet, which can provide a high-peak-count thick zinc layer electro-galvanized steel sheet that solves the problem of excessive decay of surface topography parameters of conventional thick zinc layer electro-galvanized steel sheets, and effectively ensures that the surface topography parameters after electro-galvanizing still have a high peak count index, thereby improving the use effect of the thick zinc layer electro-galvanized steel sheet during stamping and painting.

[0020] To achieve the above object, the present application provides a method for manufacturing a high-peak-count thick zinc layer electro-galvanized steel sheet, comprising the steps of:

[0021] (1) performing a peak-removing treatment on the surface of the roughened skin pass mill roll to make the profile skewness parameter Rsk of the roll ≤-0.5;

[0022] (2) performing skin pass rolling on the steel substrate using the roll: controlling the skin pass elongation ≥0.6%;

[0023] (3) electro-galvanizing the skin-passed steel substrate to obtain a high-peak-count thick zinc layer electro-galvanized steel sheet.

[0024] In this context, the roughening treatment refers to a certain roughening treatment on the surface of the roll. Through the roughening treatment, a uniform and fine micro-convex structure can be formed on the surface of the roll, and these micro-convex structures can be copied to the surface of the rolled material during rolling, thereby forming corresponding micro-structures on the surface of the rolled product. The roll surface roughening treatment technology well known in the art can be used to implement the present application, and these technologies include sand blasting roughening technology, laser roughening technology, and electric spark roughening technology, etc. Sand blasting roughening is a technology that uses high-speed sand particles to impact the surface of the roll to form a rough surface. Laser roughening is a technology that uses a high-energy laser beam to instantaneously melt or vaporize the surface of the roll, and then solidify to form a micro-convex structure with a specific shape and size. Electric spark roughening is a technology that uses the electric spark discharge phenomenon between the electrode and the surface of the roll to locally melt and solidify the surface of the roll, thereby forming a rough surface.

[0025] In this context, the peak-removing treatment refers to a polishing peak-removing treatment on the profile of the roughened roll surface by physical or chemical methods. Exemplary physical methods include sand belt polishing, and exemplary chemical methods include electrolytic polishing. In this context, the specific process of the peak-removing treatment (i.e., the polishing peak-removing treatment) is not particularly limited, as long as the profile skewness parameter Rsk of the roll obtained finally is ≤-0.5.

[0026] Since the surface profile of the steel plate is imprinted by the roughened roll, and the roll and the surface profile of the steel plate have complementary convex and concave, the Rsk value of the surface of the steel plate tends to be positive when the surface profile skewness Rsk of the roll is controlled to be negative. Meanwhile, the small invalid peaks on the surface of the roll are removed by the peak-removing treatment, which slows down the roughness attenuation of the roll during use.

[0027] In some embodiments, the profile skewness Rsk of the finally obtained roll is in the range of -0.5 to -0.90. In some embodiments, the profile skewness Rsk of the finally obtained roll is in the range of -0.5 to -0.82.

[0028] In the present application, the peak-removing treatment can make the Rsk value of the roll surface more negative, combined with a larger flat elongation rate, so that a higher profile skewness Rsk value can be imprinted on the surface of the steel plate, combined with the control of the electroplating process parameters, so that the profile attenuation during the electroplating zinc process is controllable, and a high-peak-value thick zinc layer electroplated zinc steel plate with small attenuation degree is obtained.

[0029] In the present application, when the flat elongation rate is too small, the transfer and replication ratio of the surface profile of the work roll of the flattening machine to the surface of the steel plate is insufficient, and it is difficult to ensure the Rsk value of the surface of the steel plate. b Therefore, in the present application, the flat elongation rate is controlled to be ≥0.6%. In some embodiments, the flat elongation rate is controlled to be 0.6-2.0%. In some embodiments, the flat elongation rate is controlled to be 0.6-1.5%. In some embodiments, the flat elongation rate is controlled to be 0.6-1.0%.

[0030] The key of the manufacturing method described in the present application is the peak-removing treatment on the surface of the roll and the use of a larger flat elongation rate, wherein the peak-removing treatment can make the Rsk value of the roll surface more negative, combined with a larger flat elongation rate, so that a higher profile skewness Rsk value can be imprinted on the surface of the steel plate, combined with the control of the electroplating process parameters, so that the profile attenuation during the electroplating zinc process is controllable, and a high-peak-value thick zinc layer electroplated zinc steel plate with small attenuation degree is obtained.

[0031] Further, in step (1) of the manufacturing method described in the present application, the surface roughness of the roll after the peak-removing treatment is 2.0-4.0 μm.

[0032] Further, in step (1) of the manufacturing method described in the present application, the number of surface peaks of the despiking-processed roll is ≥ 95 peaks / cm. In some embodiments, the number of surface peaks of the despiking-processed roll is 95-150 peaks / cm. In some embodiments, the number of surface peaks of the despiking-processed roll is 95-135 peaks / cm. In some embodiments, the number of surface peaks of the despiking-processed roll is 95-133 peaks / cm.

[0033] In some embodiments, in step (2), after the steel substrate is subjected to the skin pass rolling using the roll, the surface roughness profile skewness Rsk b of the obtained steel substrate is ≥ 0.1; in some embodiments, the surface roughness profile skewness Rsk b of the obtained steel substrate is 0.1-0.6; in some embodiments, the surface roughness profile skewness Rsk b of the obtained steel substrate is 0.2-0.6; in some embodiments, the surface roughness profile skewness Rsk b of the obtained steel substrate is 0.24-0.56.

[0034] In some embodiments, in step (2), after the steel substrate is subjected to the skin pass rolling using the roll, the surface peak number Pc b of the obtained steel substrate is ≥ 80 peaks / cm; in some embodiments, the surface peak number Pc b of the obtained steel substrate is 80-100 peaks / cm; in some embodiments, the surface peak number Pc b of the obtained steel substrate is 81-96 peaks / cm.

[0035] In some embodiments, in step (2), after the steel substrate is subjected to the skin pass rolling using the roll, the surface roughness Ra b of the obtained steel substrate is 1.00-1.40 μm.

[0036] In the present application, by controlling the surface roughness and the surface peak number of the despiking-processed roll, it is further advantageous to control the surface roughness Ra s of the electrogalvanized steel sheet to be between 0.9 μm and 1.4 μm, and the surface peak number Pc s to be ≥ 75 peaks / cm. In some embodiments, the surface peak number Pc s of the electrogalvanized steel sheet is 75-100 peaks / cm.

[0037] Further, in step (3) of the manufacturing method described in the present application, the temperature of the plating solution is controlled to be 48-53°C.

[0038] The inventors found through data statistics and a large number of experiments that the temperature of the electroplating solution has a significant inverse correlation with the roughness attenuation after electroplating. The inventors further found that the zinc layer deposited on the surface of the steel plate tends to grow horizontally with the increase of the temperature of the electroplating solution, which makes the zinc coating change from rough to bright, that is, the surface morphology attenuation during electroplating increases. Therefore, under the condition that the process conditions permit, reasonably reducing the temperature of the electroplating solution can effectively inhibit the morphology attenuation after electroplating. When the temperature of the electroplating solution is too low, it will cause the defect of silk spot on the surface of the steel plate. Therefore, preferably, in step (3) of the manufacturing method, the temperature of the electroplating solution can be controlled to be between 48-53℃.

[0039] Compared with the prior art, the high-peak-value thick zinc layer electroplated zinc steel plate and the manufacturing method thereof have the following advantages and beneficial effects:

[0040] The high-peak-value thick zinc layer electroplated zinc steel plate and the manufacturing method thereof solve the problem of excessive surface morphology parameter attenuation of the thick zinc layer electroplated zinc steel plate in the prior art, and can effectively ensure that the surface morphology parameter after electroplating zinc still has a high peak value index, thereby improving the stamping and coating use effect of the thick zinc layer electroplated zinc steel plate at the user end. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 shows the surface three-dimensional profile of the steel substrate in Example 1 of the present application. DETAILED DESCRIPTION

[0042] The high-peak-value thick zinc layer electroplated zinc steel plate and the manufacturing method thereof will be further explained and described in combination with the specific description of the drawings and examples, but the explanation and description do not constitute undue limitation on the technical solutions of the present application.

[0043] Examples 1-5 and Comparative Examples 1-4

[0044] The high-peak-value thick zinc layer electroplated zinc steel plate of Examples 1-5 of the present application is prepared by the following steps:

[0045] (1) Roller surface treatment: the roller is subjected to roughening treatment, and then the surface of the roughened skin pass mill roller is subjected to peak removal treatment (for example, sand belt polishing) to make the profile skewness parameter Rsk≤-0.5 of the roller.

[0046] (2) The steel substrate is subjected to skin pass rolling using the roller: the skin pass elongation is controlled to be ≥0.6%.

[0047] (3) The skin-passed steel substrate is subjected to electroplating zinc (the average zinc plating amount of a single side is between 40-80g / m 2 ), to obtain a high-peak-value thick zinc layer electroplated zinc steel plate.

[0048] In some embodiments, the temperature of the electroplating solution can be controlled between 48-53°C.

[0049] The rollers of Comparative Examples 1-3 were not subjected to desharpening after roughening, and the flat elongation of Comparative Example 4 did not meet the design requirements of the present application.

[0050] Table 1 lists the specific process parameters of the high-peak-count-thick-zinc-layer electroplated zinc steel sheets of Inventive Examples 1-5 and the comparative steel sheets of Comparative Examples 1-4.

[0051] Table 1.

[0052] The high-peak-count-thick-zinc-layer electroplated zinc steel sheets of Inventive Examples 1-5 and the comparative steel sheets of Comparative Examples 1-4 were tested, and the test results are listed in Table 2. Among them:

[0053] The roughness, peak count, and roughness profile skewness described in the present application are defined in GB / T 3505 and GB / T 2523 standards, and the sampling length for roughness measurement is specified as 2.5 mm, and the upper and lower cutoff lines for peak count are ±0.5 μm.

[0054] The surface topography parameters of the steel substrate at the corresponding position described in the present application are measured after the surface of the electroplated zinc steel sheet is de-zinced, and the surface de-zincing method is to dissolve the zinc layer using an acid solution, and the acid solution is prepared by adding 5-20% concentration of dilute hydrochloric acid solution and 2-5 g / L of hexamethylenetetramine corrosion inhibitor. The role of hydrochloric acid is to dissolve the zinc layer on the surface of the steel sheet, and the role of the corrosion inhibitor is to weaken the corrosion effect of hydrochloric acid on the steel sheet substrate.

[0055] The surface of the steel substrate after removing the zinc plating layer is cleaned and dried, and the roughness, peak count, and roughness profile skewness are measured using a Malvern PS10 roughness meter. The roughness, peak count, and roughness profile skewness of the surface of the zinc plating layer are also measured using a Malvern PS10 roughness meter.

[0056] Table 2 lists the implementation effects of the high-peak-count-thick-zinc-layer electroplated zinc steel sheets of Inventive Examples 1-5 and the comparative steel of Comparative Examples 1-4.

[0057] Table 2.

[0058] As can be seen from the above Table 2, the surface roughness profile skewness Rsk of the steel substrate of each Inventive Example is greater than 0.2. At the same time, the average zinc plating amount of the electroplated zinc steel sheets of Inventive Examples 1-5 is greater than or equal to 40 g / m b of the thick zinc plating layer, the surface peak count Pc of the zinc plating layer is ≥75 pieces / cm, and the surface roughness Ra of the electroplated zinc layer is ≤0.8 μm. 2 s s ​​The surface roughness Ra of the steel substrate at the corresponding position is between 0.9 pm and 1.4 pm s The surface roughness Ra of the steel substrate at the corresponding position is between 0.9 pm and 1.4 pm b The surface roughness Ra of the steel substrate at the corresponding position is between 0.9 pm and 1.4 pm b The surface roughness Ra of the steel substrate at the corresponding position is between 0.9 pm and 1.4 pm s The surface peak number Pc of the steel substrate at the corresponding position is less than 0.1 pm s The surface peak number Pc of the steel substrate at the corresponding position is less than 0.1 pm b The surface peak number Pc of the steel substrate at the corresponding position is less than 0.1 pm b The surface peak number Pc of the steel substrate at the corresponding position is less than 0.1 pm s The surface peak number Pc of the steel substrate at the corresponding position is less than 0.1 pm

[0059] In addition, the three-dimensional profile of the surface of the steel substrate of Example 1 was observed using an Olympus OLS4100 three-dimensional laser confocal microscope, with a field size of 640 pm*640 pm, and the surface three-dimensional morphology profile of the steel substrate was obtained as shown in FIG. 1.

[0060] As can be seen from FIG. 1, the surface three-dimensional morphology of the steel substrate is mostly in the form of peaks, and few in the form of valleys. This surface structure feature can make it more difficult to be filled by the zinc layer after galvanizing, thereby effectively reducing the surface morphology parameter attenuation during the electroplating process.

[0061] It should be noted that the combination of the technical features in the present case is not limited to the combination mode described in the claims of the present case or the combination mode described in the specific embodiments. All technical features described in the present case can be freely combined or combined in any way, unless contradictory to each other.

[0062] It should be noted that the above-mentioned embodiments are only specific embodiments of the present application. Obviously, the present application is not limited to the above-mentioned embodiments, and similar changes or modifications made by those skilled in the art based on the disclosure of the present application are directly derived or easily conceived, and all should belong to the protection scope of the present application.

Claims

1. A high peak value number thick zinc layer electroplated zinc plated steel sheet comprising a steel substrate and an electroplated zinc layer plated on the surface of the steel substrate, characterized in that, the surface roughness profile skewness Rsk of the steel substrate b ≥ 0.1, the surface peak count Pc of the electro-galvanizing layer s ≥ 75 / cm.

2. The high peak value number thick zinc layer electro-galvanized steel sheet as claimed in claim 1, characterized in that, The surface roughness Ra of the electro-galvanizing layer s is 0.9 μm - 1.4 μm.

3. The high peak value number thick zinc layer electro-galvanized steel sheet as claimed in claim 1, characterized in that, The surface roughness Ra of the steel substrate b is 1.00 to 1.40 μm.

4. The high peak count zinc layer electro-galvanised steel sheet according to anyone of claims 1 to 3, characterized in that, surface roughness Ra of the galvannealed layer s surface roughness of the steel substrate at its corresponding location Ra b satisfies Ra b -Ra s ≤ 0.1 μm.

5. The high peak count zinc layer electro-galvanised steel sheet according to anyone of claims 1 to 4, characterized in that, the surface peak count Pc of the steel substrate b ≥ 80 / cm, such as 80-100 / cm or 81-96 / cm.

6. The high peak count zinc layer electro-galvanised steel sheet according to anyone of claims 1 to 5, characterized in that, the surface peak count Pc of the electro-galvanized layer s the surface peak count of the steel substrate at its corresponding position Pc b satisfies Pc b -Pc s ≤ 10 cm-1.

7. The high peak value number thick zinc layer electro-galvanized steel sheet as claimed in claim 1, characterized in that, The average amount of zinc plating on one side of the steel substrate is ≥ 40 g / m 2 , preferably 40-100 g / m 2 , more preferably 40-80 g / m 2 , more preferably 40-60 g / m 2 .

8. The high peak value number thick zinc layer electro-galvanized steel sheet as claimed in claim 1, characterized in that, the surface roughness profile skewness Rsk of the steel substrate b ≥ 0.2; or the Rsk b is 0.1-0.6, 0.2-0.6 or 0.24-0.

56.

9. The method of producing a high peak value number thick zinc layer electroplated zinc steel sheet according to any one of claims 1 to 8, characterized by, The method comprises the steps of: (1) performing peak-removing treatment on the surface of the roughened skin pass mill roller to make the profile skewness parameter Rsk of the roller ≤-0.5; (2) performing skin pass rolling on the steel base plate by using the roller: controlling the skin pass elongation ≥0.6%; (3) performing electro-galvanizing on the skin-passed steel base plate to obtain high-peak-count-thickness zinc layer electro-galvanized steel plate.

10. The production method according to claim 9, wherein In step (1), the surface roughness of the roller after peak-removing treatment is 2.0-4.0 μm.

11. The production method according to claim 9, wherein In step (1), the surface peak count of the roller after peak-removing treatment is ≥95 / cm.

12. The production method according to claim 9, wherein In step (2), after performing skin pass rolling on the steel base plate by using the roller, the surface roughness profile skewness of the obtained steel base plate is Rsk b ≥ 0.1, such as 0.1-0.6, 0.2-0.6 or 0.24-0.

56.

13. The production method according to claim 9, wherein In step (2), the steel substrate is subjected to flat rolling using a pair of rolls, and the steel substrate obtained after the flat rolling has a surface peak number Pc b ≥ 80 pieces / cm, such as 80 to 100 pieces / cm or 81 to 96 pieces / cm.

14. The production method according to claim 9, wherein In step (2), the surface roughness Ra of the steel substrate obtained after the steel substrate is subjected to the skin pass rolling in step (2) is 0.5 to 1.5 μm. b is 1.00 to 1.40 μm.

15. The production method according to claim 9, wherein In step (3), the temperature of the electro-galvanizing solution is controlled at 48-53℃.

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