Preparation method of super-hydrophobic corrosion-resistant coating based on X80 steel surface

Abstract

The invention discloses a preparation method of a super-hydrophobic corrosion-resistant coating based on an X80 steel surface, and belongs to the technical field of corrosion-resistant super-hydrophobic coatings. The method comprises the following steps: polishing an X80 steel sample through abrasive paper, then carrying out acid pickling activation treatment, then carrying out dip plating in an acidic copper sulfate solution to form a copper layer, exposing in air to oxidize to form a copper oxide film, and finally modifying with a fluorosilane solution and heating and curing to form the super-hydrophobic coating. The coating has excellent waterproof, antifouling and anti-corrosion performance, and the service life of X80 steel equipment is effectively prolonged. The preparation method is simple, low in cost and suitable for industrial scale production, and a new solution is provided for surface corrosion prevention of the X80 steel.

Description

Technical Field

[0001] The invention relates to the technical field of corrosion-resistant super-hydrophobic coatings, and in particular to a method for preparing a super-hydrophobic corrosion-resistant coating based on an X80 steel surface. Background Art

[0002] X80 steel is a high-strength, high-toughness steel that is widely used in pipelines, storage tanks and other equipment in the oil, natural gas, chemical and other industries. However, due to its long-term exposure to harsh environments such as high temperature, high pressure, and chemical corrosive liquids during use, its surface is prone to corrosion and wear, which seriously affects the normal operation and service life of the equipment. Therefore, how to improve the corrosion resistance of X80 steel and extend its service life has become an important topic of current research.

[0003] As a new type of anti-corrosion technology, super-hydrophobic coating forms a microstructure with nano-scale roughness on the metal surface, so that water droplets present a larger contact angle on its surface, thereby achieving super-hydrophobicity. Super-hydrophobic coating has excellent waterproof, anti-fouling and anti-corrosion properties, and can effectively prevent the erosion of metal surfaces by moisture, chemicals, etc. in the environment, thereby greatly improving the corrosion resistance and service life of metal materials. Therefore, the present invention provides a method for preparing a super-hydrophobic coating with a simple process and good performance based on X80 steel. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a super hydrophobic corrosion-resistant coating based on the surface of X80 steel, so as to solve the problem of insufficient anti-corrosion performance of X80 steel in the background technology.

[0005] To achieve the above object, the present invention provides a method for preparing a super hydrophobic corrosion-resistant coating on the surface of X80 steel, comprising the following steps: S1. Surface treatment of X80 steel samples; S2, immersing the surface treated X80 steel sample in a concentrated sulfuric acid solution for activation treatment; S3, taking out the X80 steel sample and placing it in an acidic copper sulfate solution a for immersion plating, and then taking it out and immersing it in an acidic copper sulfate solution b for immersion plating; S4, take out the X80 steel sample, rinse it, dry it, and expose it to air for oxidation; S5, immersing the oxidized X80 steel sample in a fluorosilane solution for surface modification; S6, heating to remove bound water, thereby obtaining a super hydrophobic corrosion-resistant coating; In S3, the specific composition of the acidic copper sulfate solution is: 30.0 ml / L of concentrated H2SO4, 80.0 g / L of copper sulfate, and 100 g / L of citric acid; The specific composition of acidic copper sulfate b solution is 30.0 ml / L concentrated H2SO4, 60.0 g / L copper sulfate, and 8 g / L sodium chloride.

[0006] Preferably, the specific operation of S1 is: grinding the X80 steel sample using sandpaper #80-#2000, then rinsing with deionized water and ethanol and drying.

[0007] Preferably, in S2, the concentration of the concentrated sulfuric acid solution is 10wt%; and the activation treatment time is 15s.

[0008] Preferably, in S3, the immersion plating time in the acidic copper sulfate solution a is 30 s; the immersion plating time in the acidic copper sulfate solution b is 30 s, 50 s or 70 s.

[0009] Preferably, in S4, the solvents used for rinsing are deionized water and ethanol; and the time of exposure to air is 0.1 h, 1 h and 12 h.

[0010] Preferably, in S5, the fluorosilane solution is prepared by dissolving 3.0 wt % of perfluorooctyltriethoxysilane, 3.0 wt % of water and 1.5 wt % of glacial acetic acid in an ethanol solution and stirring for 4 hours.

[0011] Preferably, in S5, the immersion time in the fluorosilane solution is 30 minutes.

[0012] Preferably, in S6, heating is performed at 120° C. for 30 min.

[0013] In the preparation process of the super-hydrophobic and corrosion-resistant coating, the copper layer deposition is the electron reduction of copper ions on the activated steel surface. Citric acid and sodium chloride affect the deposition by complexation and activation of the matrix respectively, laying the foundation for the follow-up. The formation of copper oxide is due to the reaction of the copper layer with oxygen, and the oxidation time determines its subsequent modification effect. The fluorosilane modification is the condensation of the ethoxy group with the hydroxyl group on the surface of copper oxide after hydrolysis in the acetic acid-water-ethanol system. The low surface energy groups such as perfluorooctyl are arranged in a directional manner to reduce the surface energy. Each step synergistically achieves super-hydrophobic and corrosion-resistant properties.

[0014] Therefore, the present invention provides a kind of preparation method of super hydrophobic corrosion-resistant coating based on X80 steel surface, by optimizing copper sulfate solution, can improve the stability and bonding force of copper coating, and maintain a certain roughness; fluorosilane solution components are improved, the low surface energy modification time is shortened, and the hydrophobicity and durability of coating are enhanced; by controlling immersion plating time and oxidation time, the effective regulation of coating thickness, structure and bonding force is achieved. The method is simple, low cost and suitable for large-scale production.

[0015] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a surface morphology of the super-hydrophobic coating obtained in Example 3 of the present invention; Figure 2 This is a diagram showing the surface hydrophobicity of the super-hydrophobic coating prepared in Example 2 of the present invention; Figure 3 This is a surface morphology of the super-hydrophobic coating prepared in Example 2 of the present invention after being immersed in a 3.5% NaCl solution for 8 hours; Figure 4 This is a surface morphology of the super hydrophobic coating prepared in Example 2 of the present invention after being immersed in a 3.5% NaCl solution for 8 hours and the corrosion products are removed. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further described below by means of the accompanying drawings and embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Any other changes, modifications, substitutions, combinations, simplifications made without violating the spirit and principle of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention. In addition, it should be understood that after reading the content of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application and belong to the scope of protection of the present invention.

[0018] Reference to "embodiment" herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The term "embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or association with other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the various technical features mentioned in the embodiments can be combined in any way to form a corresponding implementable technical solution.

[0019] Unless otherwise defined, the technical terms used in this document have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms in this document is only for describing specific embodiments and is not intended to limit this application.

[0020] In the present invention, the specific preparation methods of acidic copper sulfate solution a and acidic copper sulfate solution b are as follows: a) adding deionized water into a reaction vessel, then adding concentrated sulfuric acid and copper sulfate, and stirring until completely dissolved; b) The obtained solution is divided into two parts, citric acid is added to one part to form an acidic copper sulfate a solution, and sodium chloride is added to the other part to form an acidic copper sulfate b solution.

[0021] In the present invention, the specific preparation method of the fluorosilane solution is as follows: a) adding ethanol into a reaction vessel; b) Add perfluorooctyltriethoxysilane, water and glacial acetic acid to ethanol and stir for 4 hours until completely dissolved to obtain a fluorosilane solution.

[0022] Unless otherwise specified in the present invention, the reagents, instruments, equipment, etc. used in the following examples are all reagents, instruments, and equipment commonly used by technicians in this field.

[0023] Example 1 This embodiment provides a method for preparing a super hydrophobic corrosion-resistant coating on the surface of X80 steel, which specifically comprises the following steps: S1. Prepare X80 steel samples, grind them with #2000 sandpaper, then rinse them with deionized water and ethanol and blow dry them.

[0024] S2. Immerse the X80 steel sample in a 10wt% concentrated sulfuric acid solution and activate it for 15s.

[0025] S3. After taking out the X80 steel sample, immediately place it in acidic copper sulfate solution a for immersion plating for 30 seconds, and then quickly immerse it in acidic copper sulfate solution b for immersion plating for 30 seconds.

[0026] S4. Take out the X80 steel sample, rinse it with deionized water and ethanol, and blow it dry. Then expose the sample to air for 0.1 h to oxidize the surface and form a copper oxide film.

[0027] S5. Soak the oxidized X80 steel sample in a fluorosilane solution for 30 minutes for surface modification.

[0028] S6. Heat the sample at 120°C for 30 min to remove bound water and obtain a superhydrophobic coating.

[0029] Example 2 This embodiment provides a method for preparing a super hydrophobic corrosion-resistant coating on the surface of X80 steel, which specifically comprises the following steps: S1. Prepare X80 steel samples, grind them with #2000 sandpaper, then rinse them with deionized water and ethanol and blow dry them.

[0030] S2. Immerse the X80 steel sample in a 10wt% concentrated sulfuric acid solution and activate it for 15s.

[0031] S3. After taking out the X80 steel sample, immediately place it in acidic copper sulfate solution a for immersion plating for 30 seconds, and then quickly immerse it in acidic copper sulfate solution b for immersion plating for 50 seconds.

[0032] S4. Take out the X80 steel sample, rinse it with deionized water and ethanol, and blow it dry. Then expose the sample to air for 1 hour to oxidize the surface and form a copper oxide film.

[0033] S5. Soak the oxidized X80 steel sample in a fluorosilane solution for 30 minutes for surface modification.

[0034] S6. Heat the sample at 120°C for 30 min to remove bound water and obtain a superhydrophobic coating.

[0035] Example 3 This embodiment provides a method for preparing a super hydrophobic corrosion-resistant coating on the surface of X80 steel, which specifically comprises the following steps: S1. Prepare X80 steel samples, grind them with #2000 sandpaper, then rinse them with deionized water and ethanol and blow dry them.

[0036] S2. Immerse the X80 steel sample in a 10wt% concentrated sulfuric acid solution and activate it for 15s.

[0037] S3. After taking out the X80 steel sample, immediately place it in acidic copper sulfate solution a for immersion plating for 30 seconds, and then quickly immerse it in acidic copper sulfate solution b for immersion plating for 70 seconds.

[0038] S4. Take out the X80 steel sample, rinse it with deionized water and ethanol, and blow it dry. Then expose the sample to air for 12 hours to oxidize the surface and form a copper oxide film.

[0039] S5. Soak the oxidized X80 steel sample in a fluorosilane solution for 30 minutes for surface modification.

[0040] S6. Heat the sample at 120°C for 30 min to remove bound water and obtain a superhydrophobic coating.

[0041] The hydrophobicity and corrosion resistance of the product prepared in the embodiment of the present invention were tested.

[0042] 1. Contact angle Figure 1 This is a surface morphology of the super-hydrophobic coating obtained in Example 3 of the present invention. Its rough morphology provides gas retention gaps for super-hydrophobic performance and reduces the contact area between the liquid and solid phases. Figure 2 3 is a diagram showing the surface hydrophobicity of the super-hydrophobic coating prepared in Example 2 of the present invention. It can be seen that the super-hydrophobic coating prepared in Example 2 has good super-hydrophobic properties, and the hydrophobic angle reaches 158°.

[0043] 2. Corrosion resistance Figure 3This is a surface morphology of the super hydrophobic coating obtained in Example 2 of the present invention after being immersed in a 3.5% NaCl solution for 8 hours. The surface microstructure after corrosion can be clearly observed from the figure. After a certain period of corrosion, the surface presents an uneven corrosion state, and there are obvious differences in corrosion areas. Some areas show a relatively dense accumulation of corrosion products, and these corrosion product clusters are of different sizes and irregular shapes. Some smaller corrosion products are interconnected to form a mesh-like structure, which may be caused by the unevenness of local chemical reactions during the corrosion process.

[0044] Figure 4 The surface morphology of the super hydrophobic coating prepared in Example 2 of the present invention after being immersed in 3.5% NaCl solution for 8 hours and then removing the corrosion products is presented. Overall, the surface is much better than when it is covered with corrosion products ( Figure 3 ) shows its own structural characteristics more clearly. After the surface is corroded, a certain degree of microscopic roughness is still retained, and some tiny convex and concave structures can be seen. These structures may be the remnants of the original microstructure formed in the process of preparing the coating. They are affected to a certain extent in the corrosion process, but still maintain a certain degree of integrity. This shows that the coating plays a certain protective role on the substrate during the corrosion process, so that the original microstructure of the substrate is not completely destroyed.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for preparing a super hydrophobic corrosion-resistant coating on an X80 steel surface, characterized in that: The following steps are involved: S1. Surface treatment of X80 steel samples; S2, immersing the surface treated X80 steel sample in a concentrated sulfuric acid solution for activation treatment; S3, taking out the X80 steel sample and placing it in an acidic copper sulfate solution a for immersion plating, and then taking it out and immersing it in an acidic copper sulfate solution b for immersion plating; S4, take out the X80 steel sample, rinse it, dry it, and expose it to air for oxidation; S5, immersing the oxidized X80 steel sample in a fluorosilane solution for surface modification; S6, heating to remove bound water, thereby obtaining a super hydrophobic corrosion-resistant coating; In S3, the specific composition of the acidic copper sulfate solution is: 30.0 ml / L of concentrated H2SO4, 80.0 g / L of copper sulfate, and 100 g / L of citric acid; The specific composition of acidic copper sulfate b solution is 30.0 ml / L concentrated H2SO4, 60.0 g / L copper sulfate, and 8 g / L sodium chloride.

2. A method for preparing a super hydrophobic corrosion-resistant coating based on an X80 steel surface according to claim 1, characterized in that: The specific operation of S1 is: grinding the X80 steel sample with sandpaper #80-#2000, then rinsing with deionized water and ethanol and drying.

3. The method for preparing a super hydrophobic corrosion-resistant coating based on the surface of X80 steel according to claim 1, characterized in that: In S2, the concentration of the concentrated sulfuric acid solution is 10wt%; the activation treatment time is 15s.

4. The method for preparing a super hydrophobic corrosion-resistant coating on an X80 steel surface according to claim 1, characterized in that: In S3, the immersion plating time in the acidic copper sulfate solution a is 30 s; the immersion plating time in the acidic copper sulfate solution b is 30 s, 50 s or 70 s.

5. The method for preparing a super hydrophobic corrosion-resistant coating on an X80 steel surface according to claim 1, characterized in that: In S4, the solvents used for rinsing were deionized water and ethanol; the exposure time to air was 0.1 h, 1 h, and 12 h.

6. The method for preparing a super hydrophobic corrosion-resistant coating on an X80 steel surface according to claim 1, characterized in that: In S5, the fluorosilane solution is prepared by dissolving 3.0 wt % of perfluorooctyltriethoxysilane, 3.0 wt % of water and 1.5 wt % of glacial acetic acid in an ethanol solution and stirring for 4 h.

7. The method for preparing a super hydrophobic corrosion-resistant coating on the surface of X80 steel according to claim 1, characterized in that: In S5, the immersion time in the fluorosilane solution is 30 minutes.

8. The method for preparing a super hydrophobic corrosion-resistant coating on the surface of X80 steel according to claim 1, characterized in that: In S6, heating is performed at 120°C for 30 minutes.

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