Production method of fingerprint-resistant electro-galvanized steel plate

Abstract

The invention discloses a production method of a fingerprint-resistant electro-galvanized steel sheet, which comprises the following steps: in the process of producing a fingerprint-resistant product by an electro-galvanizing unit, controlling the running speed of strip steel to be 80-120mpm according to different steel types and specifications, and controlling the thickness of a fingerprint-resistant film of a finished product by controlling the rotating speed ratio of a lifting roller to a coating roller of a roller coater and the drying temperature. The rotating speed ratio of a lifting roller to a coating roller of the roller coater is controlled to be 60 / 120-70 / 140; according to the method, a complex treatment process is not needed, the steel plate which is good in fingerprint resistance and corrosion resistance and high in smoothness can be obtained, meanwhile, the chromium-free fingerprint-resistant liquid is adopted, and pollution to the environment is avoided; and stable and efficient production of the fingerprint-resistant electro-galvanized steel in the electro-galvanizing process can be guaranteed, and the fingerprint-resistant film is uniform in coating, consistent in thickness, consistent in surface brightness and good in application performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of galvanized sheet production, and particularly relates to a production method of fingerprint-resistant electro-galvanized steel sheet. Background Art

[0002] Electro-galvanizing belongs to high-end products in coil plates, and the demand for electro-galvanized products is developing towards higher standards and more personalized requirements. At present, with the development of the economy and the improvement of the national income level, the demand for large-size LCD TVs is increasing. Compared with hot-dip galvanizing, electro-galvanized products have great advantages in terms of surface quality, performance stability, weldability, etc. When the cost permits, users are more inclined to use electro-galvanized products.

[0003] Fingerprint-resistant steel sheets are widely used in the electronics and electrical industries due to their excellent fingerprint resistance, conductivity and corrosion resistance. At the same time, as household appliances, it is necessary to avoid the sweat stains on the hands of workers remaining on the surface of household appliances. This requires a method to ensure that there are no usage marks on household appliances during long-term use. At the same time, the double-layer synergistic effect of the electro-galvanized layer and the fingerprint-resistant layer can effectively improve the compactness and adhesion of the film layer, so that the high-performance electro-galvanized environmental protection fingerprint-resistant board formed after coating and curing has excellent corrosion resistance, painting performance, fingerprint resistance, alkali resistance, water resistance, surface smoothness and corrosion resistance. At the same time, the use of chromium-free fingerprint-resistant liquid will not cause environmental pollution. Summary of the Invention

[0004] In order to solve many problems existing in the prior art and facilitate wide application in the household appliance industry, the present invention provides a production method of fingerprint-resistant electro-galvanized steel sheet. This electro-galvanized steel sheet can obtain a steel sheet with fingerprint resistance, corrosion resistance and high smoothness without complex treatment processes. At the same time, the use of chromium-free fingerprint-resistant liquid will not cause environmental pollution.

[0005] In order to achieve the above-mentioned invention purpose, the present invention provides a production method of fingerprint-resistant electro-galvanized steel sheet. The production method includes process steps such as slab heating, rough rolling, finish rolling, laminar cooling, coiling, cold rolling, electro-galvanizing, etc. Among them,

[0006] ① Place the continuous casting slab in a walking beam reheating furnace for heating, and keep it at 1180°C - 1220°C for 40 - 80 minutes; after the slab is taken out of the furnace, perform high-pressure water descaling, and then perform rough rolling. The temperature before entering the roughing mill is ≥1150°C.

[0007] Furthermore, the chemical composition mass content of the continuous casting slab is C: 0.05% - 0.08%, Si: 0.03% - 0.05%, Mn: 0.20% - 0.40%, P≤0.030%, S≤0.030%, Alt: 0.020% - 0.025%, and the balance is iron and unavoidable impurities.

[0008] Furthermore, after the continuous casting billet is taken out of the furnace and descaled with high-pressure water, it is then rough-rolled. The temperature before entering the roughing mill is ≥1150°C; the temperature of the intermediate billet after rough rolling is ≥950°C, and then it enters the finishing mill for rolling. The finishing rolling temperature is 870°C - 930°C; after laminar cooling, it is coiled, and the coiling temperature is 670°C - 730°C; the cold rolling reduction rate is controlled at ≥75%.

[0009] ② Place the electro-galvanized substrate in the electro-galvanizing unit, and ensure that the running speed of the strip is controlled at 80 - 120 mpm according to the control plan;

[0010] ③ After surface cleaning in the electro-galvanizing unit, it enters the electroplating bath to control the upper and lower surfaces of the zinc layer, and control the single-sided zinc layer thickness at 10 - 20 g / m 2 ;

[0011] ④ The strip passes through the electro-galvanized roll coater, and the rotational speed ratio of the lifting roller and the coating roller is adjusted to 60 / 120 - 70 / 140 (about 1:2), and the coating roller pressure is 150 - 170 kg;

[0012] ⑤ After passing through the roll coater, it is dried in an infrared drying oven. The drying temperature is 90°C - 110°C, and a chromium-free anti-fingerprint solution is coated on the surface after electro-galvanizing.

[0013] Furthermore, a chromium-free anti-fingerprint solution is coated on the surface of the electro-galvanizing unit after electro-galvanizing. The main components of the chromium-free anti-fingerprint solution are resin, silane, inorganic salt, corrosion inhibitor, titanium dioxide, water, etc.

[0014] A fingerprint-resistant electro-galvanized steel sheet produced by the above method.

[0015] Furthermore, the thickness of the fingerprint-resistant electro-galvanized steel sheet is 0.5 - 1.2 mm, and its chemical composition mass content is C: 0.0015% - 0.0020%, Si: 0.02% - 0.03%, Mn: 0.15% - 0.17%, P ≤ 0.015%, S ≤ 0.010%, Alt: 0.030% - 0.035%, N ≤ 0.0028%, and the balance is iron and inevitable impurities.

[0016] Furthermore, the thickness of the fingerprint-resistant film of the fingerprint-resistant electro-galvanized steel sheet is ≥1.0 μm, and the surface corrosion resistance is 72-hour neutral salt spray, and the white rust area ≤ 5%.

[0017] Compared with the prior art, the beneficial effects of the present invention:

[0018] The present invention can obtain a steel plate with good fingerprint resistance, corrosion resistance and high gloss without a complex treatment process. At the same time, a chromium-free fingerprint-resistant solution is used, which will not pollute the environment. This production method can ensure the stable and efficient production of fingerprint-resistant electro-galvanized steel in the electro-galvanizing process. The fingerprint-resistant film is evenly coated, with a consistent thickness and a consistent surface brightness, and has good application performance, which is convenient for application in the household appliance industry. Detailed implementation manners

[0019] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited in any way. To avoid repetition, in the following embodiments, the raw materials are all commercially available products unless otherwise specified, and the methods used are all conventional methods unless otherwise specified.

[0020] Example 1

[0021] A production method of a fingerprint-resistant electro-galvanized steel plate, the production method comprising the following steps:

[0022] ① Place the continuous casting billet in a walking beam reheating furnace for heating, hold at 1200 °C for 40 min to dissolve a large amount of alloy.

[0023] The chemical composition mass content of the continuous casting billet is C: 0.08%, Si: 0.05%, Mn: 0.40%, P: 0.020%, S: 0.020%, Alt: 0.020%, and the balance is iron and inevitable impurities.

[0024] After the billet is taken out of the furnace, it is descaled with high-pressure water and then rough-rolled. The temperature before entering the roughing mill is 1150 °C; the temperature of the intermediate billet after roughing is 950 °C, and then it enters the finishing mill for rolling. The final rolling temperature is 870 °C; it is coiled after laminar flow cooling, and the coiling temperature is 670 °C; the cold rolling reduction rate is controlled at 75%.

[0025] ② The electro-galvanized substrate ensures that the running speed of the strip is controlled at 90 mpm in the electro-galvanizing unit according to the control plan.

[0026] ③ After surface cleaning in the electro-galvanizing unit, it enters the electroplating bath, and the thickness of the zinc layer on the upper and lower surfaces is controlled to be 20 g / m on one side. 2 .

[0027] ④ The strip passes through the electro-galvanized roll coater, and the rotation speed ratio of the lifting roller and the coating roller is adjusted to 70 / 140, and the pressure of the coating roller is 165 kg.

[0028] ⑤ After passing through the roll coater, it is dried in an infrared drying oven, and the drying temperature is 95 °C.

[0029] After electro-galvanizing, the electro-galvanizing unit coats a chromium-free fingerprint-resistant solution on the surface. The main components of the chromium-free fingerprint-resistant solution are resin, silane, inorganic salt, corrosion inhibitor, titanium dioxide and water.

[0030] Example 1: The fingerprint-resistant electro-galvanized steel sheet produced by the above method has the following chemical composition by mass percentage: C: 0.0018%, Si: 0.03%, Mn: 0.17%, P: 0.015%, S: 0.010%, Alt: 0.030%, N: 0.0028%, and the balance is iron and unavoidable impurities; the surface of the fingerprint-resistant electro-galvanized steel sheet ensures uniform fingerprint-resistant liquid, without surface defects. The thickness of the fingerprint-resistant film on the upper surface of the strip on the operator side is 1.23 μm, the thickness of the fingerprint-resistant film on the upper surface at the middle position of the strip is 1.3 μm, and the thickness of the fingerprint-resistant film on the upper surface of the strip on the drive side is 1.11 μm; the thickness of the fingerprint-resistant film on the lower surface of the strip on the operator side is 1.4 μm, the thickness of the fingerprint-resistant film on the lower surface at the middle position of the strip is 1.38 μm, and the thickness of the fingerprint-resistant film on the lower surface of the strip on the drive side is 1.21 μm. The surface is dense and defect-free, and the surface corrosion resistance is 72-hour neutral salt spray, with the white rust area being 3.8%.

[0031] Example 2

[0032] A production method of a fingerprint-resistant electro-galvanized steel sheet, the production method comprising the following steps:

[0033] ① Place the continuous casting billet in a walking beam reheating furnace for heating, hold at 1180 °C for 80 min to dissolve a large amount of alloy.

[0034] The chemical composition of the continuous casting billet by mass percentage is: C: 0.06%, Si: 0.04%, Mn: 0.20%, P: 0.018%, S: 0.019%, Alt: 0.024%, and the balance is iron and unavoidable impurities.

[0035] After the billet is taken out of the furnace, it is descaled by high-pressure water and then rough-rolled. The temperature before entering the roughing mill is 1170 °C; the temperature of the intermediate billet after rough rolling is 960 °C, and then it enters the finishing mill for rolling, and the finishing temperature is 930 °C; after laminar flow cooling, it is coiled, and the coiling temperature is 730 °C; the cold rolling reduction rate is controlled at 78%.

[0036] ② The electro-galvanized substrate in the electro-galvanizing unit ensures that the running speed of the strip is controlled at 105 mpm according to the control plan.

[0037] ③ After surface cleaning in the electro-galvanizing unit, it enters the electroplating bath to control the upper and lower surfaces of the zinc layer, and the single-sided zinc layer thickness is 20 g / m 2 .

[0038] ④ The strip passes through the electro-galvanizing roll coater, and the rotation speed ratio of the lifting roll and the coating roll is adjusted to 65 / 130, and the coating roll pressure is 160 kg.

[0039] ⑤ After passing through the roll coater, it is dried in an infrared drying oven, and the drying temperature is 100 °C.

[0040] The electro-galvanizing unit coats a chromium-free anti-fingerprint solution on the surface after electro-galvanizing. The main components of the chromium-free anti-fingerprint solution are resin, silane, inorganic salts, corrosion inhibitor, titanium dioxide and water.

[0041] The anti-fingerprint electro-galvanized steel sheet produced by the method in Example 2. The mass content of the chemical composition of the anti-fingerprint electro-galvanized steel sheet is C: 0.0016%, Si: 0.02%, Mn: 0.16%, P: 0.014%, S: 0.008%, Alt: 0.032%, N: 0.0020%, and the balance is iron and inevitable impurities; there are no defects on the surface of the anti-fingerprint electro-galvanized steel sheet. The thickness of the anti-fingerprint film on the upper surface of the strip on the operator side is 1.26μm, the thickness of the anti-fingerprint film on the upper surface at the middle position of the strip is 1.21μm, and the thickness of the anti-fingerprint film on the upper surface of the strip on the drive side is 1.21μm; the thickness of the anti-fingerprint film on the lower surface of the strip on the operator side is 1.31μm, the thickness of the anti-fingerprint film on the lower surface at the middle position of the strip is 1.33μm, and the thickness of the anti-fingerprint film on the lower surface of the strip on the drive side is 1.22μm; the surface is dense and defect-free, and the surface corrosion resistance is 72 hours of neutral salt spray, and the area of white rust is 4.2%.

[0042] For any person skilled in the art, without departing from the scope of the technical solution of the present invention, many possible changes and modifications can be made to the technical solution of the present invention by using the technical content disclosed above, or modified into equivalent embodiments with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for producing a fingerprint-resistant electrogalvanized steel sheet, characterized in that: The production method comprises the steps of heating the ingot, rough rolling, finishing rolling, laminar cooling and coiling, and electrogalvanizing, wherein: ① Place the continuous casting billet in a walking beam heating furnace and heat it at 1180℃~1220℃ for 40~80min; after the billet is taken out of the furnace, it is descaled by high-pressure water and then rough rolled. The temperature before entering the rough rolling mill is ≥1150℃; ② The running speed of the strip steel in the electrogalvanizing unit is controlled at 80-120mpm; ③ After the surface of the electrogalvanizing unit is cleaned, it enters the electroplating tank and controls the thickness of the single-sided zinc layer to 10-20g / m 2 ; ④ After the strip passes through the electrogalvanizing roller coater, adjust the speed ratio of the feeding roller and the coating roller to 60 / 120-70 / 140, and the coating roller pressure to 150-170kg; ⑤ After passing through the roller coater, it is dried in an infrared drying oven at a temperature of 90℃~110℃. After electro-galvanizing, the surface is coated with chrome-free fingerprint-resistant liquid.

2. The production method according to claim 1, characterized in that Step ① The chemical composition mass content of the continuous casting billet is C: 0.05%-0.08%, Si: 0.03%-0.05%, Mn: 0.20%-0.40%, P≤0.030%, S≤0.030%, Alt: 0.020%-0.025%, and the remainder is iron and unavoidable impurities.

3. The production method according to claim 1, characterized in that After rough rolling, the temperature of the intermediate billet is ≥950°C, and then it enters the finishing rolling unit for rolling, with the final rolling temperature being 870°C to 930°C; after laminar cooling, it is coiled, with the coiling temperature being 670°C to 730°C.

4. The production method according to claim 1, characterized in that Step ⑤: The main components of the chrome-free anti-fingerprint liquid are resin, silane, inorganic salt, corrosion inhibitor, titanium dioxide and water.

5. A fingerprint-resistant electrogalvanized steel sheet produced by the method as claimed in claim 1.

6. The fingerprint-resistant electrogalvanized steel sheet according to claim 5, characterized in that: The chemical composition mass content of the fingerprint-resistant electrogalvanized steel sheet is C: 0.0015% to 0.0020%, Si: 0.02% to 0.03%, Mn: 0.15% to 0.17%, P≤0.015%, S≤0.010%, Alt: 0.030% to 0.035%, N≤0.0028%, and the remainder is iron and unavoidable impurities.

7. The fingerprint-resistant electrogalvanized steel sheet according to claim 5, characterized in that: The anti-fingerprint film thickness of the electro-galvanized steel sheet is ≥1.0 μm, the surface corrosion resistance is 72h neutral salt spray, and the white rust area is ≤5%.