High-temperature steam oxidation resistant coating slurry, coating, and preparation method therefor

Abstract

The present application provides a high-temperature steam oxidation resistant coating slurry, a coating, and a preparation method therefor. The high-temperature steam oxidation resistant coating slurry is obtained by mixing a solid phase component and a liquid phase component in a ratio of 10 g:(3-7) mL. In parts by mass, the solid-phase component comprises: 50-60 parts of aluminum powder, 5-15 parts of silicon powder, 10-20 parts of aluminum oxide powder, and 5-35 parts of an MXene material; and the liquid-phase component comprises an aluminum dihydrogen phosphate solution, chromium trioxide, and sodium silicate, wherein the ratio of aluminum dihydrogen phosphate solution, chromium trioxide, and sodium silicate is 100 mL:(10-30) g:(5-15) mL. The coating is prepared from the described coating slurry. The present application improves the crack resistance and high-temperature steam oxidation resistance of the coating.

Description

A coating slurry resistant to high-temperature water vapor oxidation, the coating and its preparation method

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411586199.0, filed on November 8, 2024, entitled "A Coating Slurry, Coating and Preparation Method Thereof Resistant to High Temperature Water Vapor Oxidation", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application belongs to the field of material surface coating technology, specifically relating to a coating slurry, coating and preparation method for resisting high temperature water vapor oxidation. Background Technology

[0004] In thermal power units, boilers operate in high-temperature environments. With the development of ultra-supercritical power generation technology, the temperature and pressure of steam inside the boiler are constantly increasing, causing the inner wall of the boiler to be oxidized by steam to form an oxide layer. The formation of the oxide layer reduces the effective contact area between the heated surface of the inner wall of the boiler and the steam, thereby reducing the heat exchange efficiency. The peeling off of the oxide layer may block the pipes, causing the steam flow in the pipes to be obstructed, which in turn leads to overheating and tube rupture.

[0005] There are two existing technologies for improving the resistance to steam oxidation in austenitic steel used in boilers: grain refinement and shot peening of the inner wall. Both methods enable the austenitic steel to rapidly grow a protective Cr2O3 film, which possesses antioxidant properties. However, in steam above 600°C, Cr2O3 exhibits poor stability and is prone to peeling off, further increasing the risk of pipe blockage and rupture. Furthermore, with increasing service life, the Cr content in the austenitic steel will become insufficient for the growth of the Cr2O3 film, leading to an accelerated decline in the boiler's oxidation resistance. Therefore, these two methods only improve oxidation resistance in the initial stages and do not fundamentally solve the problem.

[0006] To further address the oxidation problem, high-temperature water vapor oxidation-resistant coating technology has emerged. This coating is a special type of coating used to protect the substrate from oxidation in high-temperature water vapor environments. It prevents the substrate from being oxidized and corroded in such environments, thus extending the substrate's service life.

[0007] Silicon-modified aluminide coatings are one type of coating resistant to high-temperature steam oxidation. However, due to the significant difference in thermal expansion coefficients between the aluminide coating and the substrate, substantial stress is generated during boiler start-up and shutdown, leading to cracking and even peeling of the coating. Furthermore, the high-temperature steam oxidation resistance of existing silicon-modified aluminide coatings still needs improvement. Summary of the Invention

[0008] To address the problems of the prior art, this application provides a coating slurry, a coating, and a method for preparing the same that are resistant to high-temperature water vapor oxidation, thereby improving the coating's crack resistance and resistance to high-temperature water vapor oxidation.

[0009] This application is achieved through the following technical solution:

[0010] This application provides a coating slurry resistant to high-temperature water vapor oxidation. The coating slurry is obtained by mixing a solid phase component and a liquid phase component in a ratio of 10g:(3-7)mL. By mass, the solid phase component includes: 50-60 parts of aluminum powder, 5-15 parts of silicon powder, 10-20 parts of alumina powder, and 5-35 parts of MXene material. The liquid phase component includes aluminum dihydrogen phosphate solution, chromium trioxide, and water glass. The ratio of aluminum dihydrogen phosphate solution, chromium trioxide, and water glass is 100mL:(10-30)g:(5-15)mL.

[0011] Optionally, the solid phase component, by mass parts, includes: 50-60 parts of aluminum powder, 5-15 parts of silicon powder, 10-20 parts of alumina powder, and 15-25 parts of MXene material.

[0012] Optionally, the MXene material is a multilayer Ti2CT. x MXene powder, multilayer Nb2CT x MXene powder or multilayer Mo2CT x MXene powder.

[0013] The method for preparing the high-temperature water vapor oxidation-resistant coating slurry described in this application includes:

[0014] (1) Aluminum powder, silicon powder, alumina powder and MXene powder are ball-milled and mixed to obtain a solid phase component;

[0015] (2) Add chromium trioxide to aluminum dihydrogen phosphate solution, stir until dissolved, then add water glass and stir to obtain liquid phase component;

[0016] (3) Mix the solid phase component and the liquid phase component, and ball mill them to obtain the coating slurry.

[0017] Optionally, the ball milling in step (1) is wet ball milling, and the solvent used in wet ball milling is ethanol.

[0018] This application also provides a coating resistant to high-temperature water vapor oxidation, which is prepared by coating a substrate with a coating slurry resistant to high-temperature water vapor oxidation as described above.

[0019] Optionally, the matrix is ​​boiler steel, such as austenitic steel.

[0020] The method for preparing the high-temperature water vapor oxidation resistant coating described in this application includes:

[0021] (1) The coating slurry is coated onto the surface of the substrate and dried to form a coating precursor on the substrate;

[0022] (2) Curing the coating precursor;

[0023] (3) Under argon protection, the cured coating precursor is heat-treated to obtain the coating.

[0024] Optionally, in the method for preparing the coating resistant to high-temperature water vapor oxidation, the substrate is pretreated before step (1): the substrate surface is cleaned, dried, and then preheated.

[0025] Optionally, in the method for preparing the coating resistant to high-temperature water vapor oxidation, in step (2), the curing temperature is 300-400℃ and the curing time is 30-50min.

[0026] Optionally, in the preparation method of the coating resistant to high temperature water vapor oxidation, in step (3), the heat treatment temperature is 900-1100℃ and the time is 10-20min.

[0027] Compared with the prior art, this application has the following beneficial effects:

[0028] This application incorporates MXene material into the coating slurry. MXene is a type of two-dimensional material with a graphene-like structure. After the coating slurry forms a coating, the two-dimensional structure of MXene increases the diffusion path of water vapor within the coating, thereby delaying the oxidation process of the substrate by high-temperature water vapor and improving the substrate's resistance to high-temperature water vapor oxidation. Furthermore, the lamellar structure of MXene can induce crack deflection, causing the crack to change direction during propagation. This deflection process requires more energy, thus effectively inhibiting the crack propagation rate. The boundaries of the MXene lamellars can effectively impede dislocation movement. By hindering dislocation movement, the lamellar structure of MXene can reduce crack initiation and propagation. Therefore, the lamellar structure of MXene can improve the crack resistance of the coating and prevent coating fracture and detachment.

[0029] Furthermore, this application optimized the amount of MXene material added through research. When 15 to 25 parts of MXene material are added to the solid phase component, the effect of resisting high-temperature water vapor oxidation is better. Too little or too much MXene material added is not conducive to improving the effect of resisting high-temperature water vapor oxidation. Attached Figure Description

[0030] Figure 1 is a cross-sectional morphology diagram of the coating prepared in Example 3 of this application.

[0031] Figure 2 is a cross-sectional morphology diagram of the coating after thermal shock testing of the sample of Example 3 of this application.

[0032] Figure 3 shows the cross-sectional morphology of the coating after thermal shock testing of the sample of Comparative Example 1 of this application. Detailed Implementation

[0033] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application.

[0034] It should be noted that the process equipment or apparatus not specifically mentioned in the following embodiments are all conventional equipment or apparatus in the art.

[0035] It should be noted that the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or apparatuses. Furthermore, unless otherwise stated, the numbering of each method step is merely a convenient tool for identifying each method step, and not intended to limit the order of the method steps or define the scope of this application. Changes or adjustments to their relative relationships, without substantially altering the technical content, shall also be considered within the scope of this application.

[0036] The high-temperature water vapor oxidation slurry described in this application is obtained by mixing a solid phase component and a liquid phase component in a ratio of 10g:(3-7)mL; by mass parts, the solid phase component includes: 50-60 parts of aluminum powder, 5-15 parts of silicon powder, 10-20 parts of alumina powder, and 5-35 parts of MXene material; the liquid phase component includes aluminum dihydrogen phosphate solution, chromium trioxide, and water glass; wherein, the ratio of aluminum dihydrogen phosphate solution, chromium trioxide, and water glass is 100mL:(10-30)g:(5-15)mL.

[0037] MXene is a type of two-dimensional material with a graphene-like structure. Applying MXene to the coating of this application increases the diffusion path of water vapor within the coating, thereby delaying the oxidation process of the substrate by high-temperature water vapor and improving the overall resistance of the substrate to high-temperature water vapor oxidation. Furthermore, the two-dimensional structure of MXene also improves the crack resistance of the coating, preventing it from cracking and peeling off. The layered structure of MXene gives the coating a certain degree of flexibility and ductility; and the strong covalent bond between titanium and carbon elements makes Ti2CT... x MXene has excellent mechanical properties, which provides a good foundation for crack resistance in coatings.

[0038] In some specific embodiments of this application, the MXene material is a multilayer Ti2CT. x MXene powder, multilayer Nb2CT x MXene powder or multilayer Mo2CT x MXene powder.

[0039] In this application, the concentration of the aluminum dihydrogen phosphate solution can be 20% to 50%, and the concentration of the aluminum dihydrogen phosphate solution used in the embodiments of this application is 25%.

[0040] The method for preparing the high-temperature water vapor oxidation-resistant coating slurry described in this application includes:

[0041] (1) Preparation of solid components: Aluminum powder, silicon powder, alumina powder and multilayer MXene powder are ball-milled and mixed to obtain solid components;

[0042] (2) Preparation of liquid phase component: Chromium trioxide is added to aluminum dihydrogen phosphate solution and stirred until completely dissolved. Then water glass is added and stirred to obtain liquid phase component;

[0043] (3) Preparation of coating slurry: Mix the solid phase component and the liquid phase component, and ball mill to obtain the coating slurry.

[0044] This application also provides a coating resistant to high-temperature water vapor oxidation, the preparation method of which includes:

[0045] (1) The coating slurry is coated onto the surface of the substrate and dried to form a coating precursor on the substrate;

[0046] (2) Curing the coating precursor;

[0047] (3) Under argon protection, the cured coating precursor is heat-treated to obtain the coating.

[0048] In some specific embodiments of this application, the substrate is pretreated in advance: the substrate surface is cleaned, dried, and then preheated.

[0049] The cleaning methods may include: first rinsing the substrate with a high-pressure water gun, and then cleaning with alcohol.

[0050] The preheating specifically involves preheating at 200–250°C for 10–20 minutes, preferably at 220°C for 15 minutes.

[0051] In some specific embodiments of this application, in step (2), the curing temperature is 300-400℃ and the curing time is 30-50min.

[0052] In some specific embodiments of this application, in step (3), the heat treatment temperature is 900-1100℃ and the time is 10-20min.

[0053] The coating for resisting high-temperature steam oxidation described in this application is used for corrosion protection of the inner wall of boiler flow components in thermal power units. The substrate is boiler steel, such as austenitic steel.

[0054] The samples used in the following examples and comparative examples of this application are austenitic steel Super304H, and the MXene material used was purchased from Xi'an Qiyue Biotechnology Co., Ltd.

[0055] Example 1

[0056] Step 1, Preparation of coating slurry:

[0057] (1) Preparation of solid components: Weigh out 55 parts aluminum powder, 10 parts silicon powder, 15 parts alumina powder, and 5 parts multilayer Ti2CT by mass. x MXene powder was prepared by adding the weighed material into a ball mill, adding ethanol as solvent, and ball milling at 500 r / min for 3 h, followed by drying to obtain a solid phase component. The zirconia balls used in the ball mill had diameters of Φ5 and Φ10, and the mass ratio of Φ5 to Φ10 zirconia balls was 7:3.

[0058] (2) Preparation of liquid phase component: Take 100 mL of 25% aluminum dihydrogen phosphate solution and place it in a 90℃ water bath. Add 15 g of chromium trioxide to the aluminum dihydrogen phosphate solution and stir until completely dissolved. Then add 10 mL of water glass, stir thoroughly, and filter the residue to obtain the liquid phase component.

[0059] (3) Preparation of coating slurry: The solid phase component and the liquid phase component were stirred and mixed for 2 hours according to the solid-liquid ratio of 10g:5mL, and then ball milled for 3 hours to obtain the coating slurry.

[0060] Step 2, Coating Preparation:

[0061] (1) Sample surface pretreatment: First, rinse the sample with a high-pressure water gun, then clean it with alcohol, dry it at 80℃ for 15 min, and then preheat it at 220℃ for 15 min.

[0062] (2) Coating slurry application: The above-prepared coating slurry is uniformly applied to the surface of the sample and allowed to air dry for 24 hours.

[0063] (3) Curing of coating: The sample obtained in step (2) was cured at 350℃ for 40 min;

[0064] (4) Heat treatment: The sample obtained in step (3) is kept at 1000℃ for 15 minutes under argon protection to obtain a coating.

[0065] Example 2

[0066] Step 1, Preparation of coating slurry:

[0067] (1) Preparation of solid components: Weigh out 55 parts aluminum powder, 10 parts silicon powder, 15 parts alumina powder, and 15 parts multilayer Ti2CT by mass. x MXene powder was prepared by adding the weighed material into a ball mill, adding ethanol as solvent, and ball milling at 500 r / min for 3 h, followed by drying to obtain a solid phase component. The zirconia balls used in the ball mill had diameters of Φ5 and Φ10, and the mass ratio of Φ5 to Φ10 zirconia balls was 7:3.

[0068] (2) Preparation of liquid phase component: Take 100 mL of 25% aluminum dihydrogen phosphate solution and place it in a 90℃ water bath. Add 15 g of chromium trioxide to the aluminum dihydrogen phosphate solution and stir until completely dissolved. Then add 10 mL of water glass, stir thoroughly, and filter the residue to obtain the liquid phase component.

[0069] (3) Preparation of coating slurry: The solid phase component and the liquid phase component were stirred and mixed for 2 hours according to the solid-liquid ratio of 10g:5mL, and then ball milled for 3 hours to obtain the coating slurry.

[0070] Step 2, Coating Preparation:

[0071] (1) Sample surface pretreatment: First, rinse the sample with a high-pressure water gun, then clean it with alcohol, dry it at 80℃ for 15 min, and then preheat it at 220℃ for 15 min.

[0072] (2) Coating slurry application: The above-prepared coating slurry is uniformly applied to the surface of the sample and allowed to air dry for 24 hours.

[0073] (3) Curing of coating: The sample obtained in step (2) was cured at 350℃ for 40 min;

[0074] (4) Heat treatment: The sample obtained in step (3) is kept at 1000℃ for 15 minutes under argon protection to obtain a coating.

[0075] Example 3

[0076] Step 1, Preparation of coating slurry:

[0077] (1) Preparation of solid components: Weigh out 55 parts aluminum powder, 10 parts silicon powder, 15 parts alumina powder, and 20 parts multilayer Ti2CT by mass. x MXene powder was prepared by adding the weighed material into a ball mill, adding ethanol as solvent, and ball milling at 500 r / min for 3 h, followed by drying to obtain a solid phase component. The zirconia balls used in the ball mill had diameters of Φ5 and Φ10, and the mass ratio of Φ5 to Φ10 zirconia balls was 7:3.

[0078] (2) Preparation of liquid phase component: Take 100 mL of 25% aluminum dihydrogen phosphate solution and place it in a 90℃ water bath. Add 15 g of chromium trioxide to the aluminum dihydrogen phosphate solution and stir until completely dissolved. Then add 10 mL of water glass, stir thoroughly, and filter the residue to obtain the liquid phase component.

[0079] (3) Preparation of coating slurry: The solid phase component and the liquid phase component were stirred and mixed for 2 hours according to the solid-liquid ratio of 10g:5mL, and then ball milled for 3 hours to obtain the coating slurry.

[0080] Step 2, Coating Preparation:

[0081] (1) Sample surface pretreatment: First, rinse the sample with a high-pressure water gun, then clean it with alcohol, dry it at 80℃ for 15 min, and then preheat it at 220℃ for 15 min.

[0082] (2) Coating slurry application: The above-prepared coating slurry is uniformly applied to the surface of the sample and allowed to air dry for 24 hours.

[0083] (3) Curing of coating: The sample obtained in step (2) was cured at 350℃ for 40 min;

[0084] (4) Heat treatment: The sample obtained in step (3) is kept at 1000℃ for 15 minutes under argon protection to obtain the coating (as shown in Figure 1).

[0085] Example 4

[0086] Step 1, Preparation of coating slurry:

[0087] (1) Preparation of solid components: Weigh out 55 parts aluminum powder, 10 parts silicon powder, 15 parts alumina powder, and 25 parts multilayer Ti2CT by mass. xMXene powder was prepared by adding the weighed material into a ball mill, adding ethanol as solvent, and ball milling at 500 r / min for 3 h, followed by drying to obtain a solid phase component. The zirconia balls used in the ball mill had diameters of Φ5 and Φ10, and the mass ratio of Φ5 to Φ10 zirconia balls was 7:3.

[0088] (2) Preparation of liquid phase component: Take 100 mL of 25% aluminum dihydrogen phosphate solution and place it in a 90℃ water bath. Add 15 g of chromium trioxide to the aluminum dihydrogen phosphate solution and stir until completely dissolved. Then add 10 mL of water glass, stir thoroughly, and filter the residue to obtain the liquid phase component.

[0089] (3) Preparation of coating slurry: The solid phase component and the liquid phase component were stirred and mixed for 2 hours according to the solid-liquid ratio of 10g:5mL, and then ball milled for 3 hours to obtain the coating slurry.

[0090] Step 2, Coating Preparation:

[0091] (1) Sample surface pretreatment: First, rinse the sample with a high-pressure water gun, then clean it with alcohol, dry it at 80℃ for 15 min, and then preheat it at 220℃ for 15 min.

[0092] (2) Coating slurry application: The above-prepared coating slurry is uniformly applied to the surface of the sample and allowed to air dry for 24 hours.

[0093] (3) Curing of coating: The sample obtained in step (2) was cured at 350℃ for 40 min;

[0094] (4) Heat treatment: The sample obtained in step (3) is kept at 1000℃ for 15 minutes under argon protection to obtain a coating.

[0095] Example 5

[0096] Step 1, Preparation of coating slurry:

[0097] (1) Preparation of solid components: Weigh out 55 parts aluminum powder, 10 parts silicon powder, 15 parts alumina powder, and 35 parts multilayer Ti2CT by mass. x MXene powder was prepared by adding the weighed material into a ball mill, adding ethanol as solvent, and ball milling at 500 r / min for 3 h, followed by drying to obtain a solid phase component. The zirconia balls used in the ball mill had diameters of Φ5 and Φ10, and the mass ratio of Φ5 to Φ10 zirconia balls was 7:3.

[0098] (2) Preparation of liquid phase component: Take 100 mL of 25% aluminum dihydrogen phosphate solution and place it in a 90℃ water bath. Add 15 g of chromium trioxide to the aluminum dihydrogen phosphate solution and stir until completely dissolved. Then add 10 mL of water glass, stir thoroughly, and filter the residue to obtain the liquid phase component.

[0099] (3) Preparation of coating slurry: The solid phase component and the liquid phase component were stirred and mixed for 2 hours according to the solid-liquid ratio of 10g:5mL, and then ball milled for 3 hours to obtain the coating slurry.

[0100] Step 2, Coating Preparation:

[0101] (1) Sample surface pretreatment: First, rinse the sample with a high-pressure water gun, then clean it with alcohol, dry it at 80℃ for 15 min, and then preheat it at 220℃ for 15 min.

[0102] (2) Coating slurry application: The above-prepared coating slurry is uniformly applied to the surface of the sample and allowed to air dry for 24 hours.

[0103] (3) Curing of coating: The sample obtained in step (2) was cured at 350℃ for 40 min;

[0104] (4) Heat treatment: The sample obtained in step (3) is kept at 1000℃ for 15 minutes under argon protection to obtain a coating.

[0105] Example 6

[0106] Step 1, Preparation of coating slurry:

[0107] (1) Preparation of solid components: Weigh out 50 parts aluminum powder, 15 parts silicon powder, 20 parts alumina powder, and 20 parts multilayer Nb2CT by mass. x MXene powder was prepared by adding the weighed material into a ball mill, adding ethanol as solvent, and ball milling at 500 r / min for 3 h, followed by drying to obtain a solid phase component. The zirconia balls used in the ball mill had diameters of Φ5 and Φ10, and the mass ratio of Φ5 to Φ10 zirconia balls was 7:3.

[0108] (2) Preparation of liquid phase component: Take 100 mL of 25% aluminum dihydrogen phosphate solution and place it in a 90℃ water bath. Add 10 g of chromium trioxide to the aluminum dihydrogen phosphate solution and stir until completely dissolved. Then add 15 mL of water glass, stir thoroughly, and filter the residue to obtain the liquid phase component.

[0109] (3) Preparation of coating slurry: The solid phase component and the liquid phase component were stirred and mixed for 2 hours according to the solid-liquid ratio of 10g:3mL, and then ball milled for 3 hours to obtain the coating slurry.

[0110] Step 2, Coating Preparation:

[0111] (1) Sample surface pretreatment: First, rinse the sample with a high-pressure water gun, then clean it with alcohol, dry it at 80℃ for 15 min, and then preheat it at 220℃ for 15 min.

[0112] (2) Coating slurry application: The above-prepared coating slurry is uniformly applied to the surface of the sample and allowed to air dry for 24 hours.

[0113] (3) Curing of coating: The sample obtained in step (2) was cured at 400℃ for 30 min;

[0114] (4) Heat treatment: The sample obtained in step (3) is kept at 1100℃ for 10 min under argon protection to obtain a coating.

[0115] Example 7

[0116] Step 1, Preparation of coating slurry:

[0117] (1) Preparation of solid components: Weigh out 60 parts aluminum powder, 5 parts silicon powder, 10 parts alumina powder, and 20 parts multilayer Mo2CT by mass. x MXene powder was prepared by adding the weighed material into a ball mill, adding ethanol as solvent, and ball milling at 500 r / min for 3 h, followed by drying to obtain a solid phase component. The zirconia balls used in the ball mill had diameters of Φ5 and Φ10, and the mass ratio of Φ5 to Φ10 zirconia balls was 7:3.

[0118] (2) Preparation of liquid phase component: Take 100 mL of 25% aluminum dihydrogen phosphate solution and place it in a 90℃ water bath. Add 30 g of chromium trioxide to the aluminum dihydrogen phosphate solution and stir until completely dissolved. Then add 5 mL of water glass, stir thoroughly, and filter the residue to obtain the liquid phase component.

[0119] (3) Preparation of coating slurry: The solid phase component and the liquid phase component were stirred and mixed for 2 hours according to the solid-liquid ratio of 10g:7mL, and then ball milled for 3 hours to obtain the coating slurry.

[0120] Step 2, Coating Preparation:

[0121] (1) Sample surface pretreatment: First, rinse the sample with a high-pressure water gun, then clean it with alcohol, dry it at 80℃ for 15 min, and then preheat it at 220℃ for 15 min.

[0122] (2) Coating slurry application: The above-prepared coating slurry is uniformly applied to the surface of the sample and allowed to air dry for 24 hours.

[0123] (3) Curing of coating: The sample obtained in step (2) is cured at 300℃ for 50 min;

[0124] (4) Heat treatment: The sample obtained in step (3) is kept at 900℃ for 20 minutes under argon protection to obtain a coating.

[0125] Comparative Example 1

[0126] The difference from Example 3 is that no multilayer Ti2CT is added to the solid phase component. x MXene powder.

[0127] Comparative Example 2

[0128] The difference from Example 3 is that 50 parts of multilayer Ti2CT were added to the solid phase component. x MXene powder.

[0129] The coatings obtained in each embodiment and comparative example were tested for their resistance to water vapor oxidation at temperatures of 600℃ and 650℃, respectively. The test results are shown in Table 1 and Table 2.

[0130] Table 1. Mass change data of the sample in water vapor at 600℃ (mg / cm³) 2 )

[0131] Table 2. Mass change data of samples in water vapor at 650℃ (mg / cm³) 2 )

[0132] As can be seen from Tables 1 and 2, compared with the uncoated samples, the mass changes of the coated samples (Examples 1-7 and Comparative Examples 1-2) were all reduced, indicating that the coating provided a certain degree of resistance to water vapor oxidation. Compared with samples without multilayer Ti2CT... x Compared to Comparative Example 1, which used MXene powder, the sample mass changes in Examples 1-7 of this application were all reduced, indicating that multilayer Ti2CT... x The addition of MXene powder further enhances the sample's resistance to water vapor oxidation. This is because Ti2CT... x The layered structure of MXene increases the diffusion path of water vapor, thereby slowing down the oxidation process of water vapor on the sample matrix.

[0133] Comparing Examples 1-5, it can be seen that in multilayer Ti2CT x When the amount of MXene powder added is less than 20 parts, the water vapor oxidation resistance of the sample coating increases with the multilayer Ti2CT. x The effect of increasing MXene powder content gradually increases when multilayer Ti2CT is added. x When the amount of MXene powder added exceeds 20 parts, the water vapor oxidation resistance of the sample coating increases with the multilayer Ti2CT. x The increasing amount of MXene powder gradually decreases, indicating that the multilayer Ti2CT... x The amount of MXene powder added has a certain influence on the water vapor oxidation resistance of the sample coating. (Multilayer Ti2CT) xWhen the amount of MXene powder added is low, its effect is weak; however, when the amount added is high, it affects the density of the coating, leading to a weakening of its antioxidant effect. Comparative Example 2, due to the addition of excessive multilayer Ti2CT... x MXene powder significantly weakens the resistance to water vapor oxidation. Therefore, multilayer Ti2CT x The amount of MXene powder added should be controlled at 20 parts.

[0134] In accordance with the thermal shock test standards of Shanghai Boiler Factory, the thermal shock performance of the coating was tested at 700℃ / 10min, with 30 thermal shock cycles. The results are shown in Figures 2 and 3.

[0135] As shown in Figure 2, after 30 thermal shock cycles, the coating of the sample in Example 3 of this application remained largely intact, and no cracks were observed under a microscopic examination; as shown in Figure 3, without the addition of Ti2CT... x The coating of the comparative example 1 sample of MXene showed slight cracks. This is due to Ti2CT. x The layered structure of MXene gives the coating a certain degree of flexibility and ductility; and due to the strong covalent bonding between titanium and carbon, Ti2CT... x MXene has excellent mechanical properties, which provides a good foundation for crack resistance in coatings.

Claims

1. A coating slurry resistant to high-temperature water vapor oxidation, characterized in that, The coating slurry is obtained by mixing solid phase components and liquid phase components in a ratio of 10g:(3-7)mL; The solid phase component comprises, by mass parts: 50-60 parts aluminum powder, 5-15 parts silicon powder, 10-20 parts alumina powder, and 5-35 parts MXene material; The liquid phase components include aluminum dihydrogen phosphate solution, chromium trioxide and water glass; wherein the ratio of aluminum dihydrogen phosphate solution, chromium trioxide and water glass is 100mL:(10~30)g:(5~15)mL.

2. The coating slurry resistant to high-temperature water vapor oxidation according to claim 1, characterized in that, The solid phase component comprises, by mass parts: 50-60 parts aluminum powder, 5-15 parts silicon powder, 10-20 parts alumina powder, and 15-25 parts MXene material.

3. The coating slurry resistant to high-temperature water vapor oxidation according to claim 1, characterized in that, The MXene material is a multilayer Ti2CT. x MXene powder, multilayer Nb2CT x MXene powder or multilayer Mo2CT x MXene powder.

4. The method for preparing the coating slurry resistant to high-temperature water vapor oxidation according to any one of claims 1 to 3, characterized in that, include: (1) Aluminum powder, silicon powder, alumina powder and MXene powder are ball-milled and mixed to obtain a solid phase component; (2) Add chromium trioxide to aluminum dihydrogen phosphate solution, stir until dissolved, then add water glass and stir to obtain liquid phase component; (3) Mix the solid phase component and the liquid phase component, and ball mill them to obtain the coating slurry.

5. The method for preparing the coating slurry resistant to high-temperature water vapor oxidation according to claim 4, characterized in that, The ball milling in step (1) is wet ball milling, and the solvent used in wet ball milling is ethanol.

6. A coating resistant to high-temperature water vapor oxidation, characterized in that, It is prepared by coating a substrate with the high-temperature water vapor oxidation slurry as described in any one of claims 1 to 3.

7. The coating resistant to high-temperature water vapor oxidation according to claim 6, characterized in that, The substrate is boiler steel.

8. The method for preparing the coating resistant to high-temperature water vapor oxidation as described in claim 6, characterized in that, include: (1) The coating slurry is coated onto the surface of the substrate and dried to form a coating precursor on the substrate; (2) Curing the coating precursor; (3) Under argon protection, the cured coating precursor is heat-treated to obtain the coating.

9. The method for preparing a coating resistant to high-temperature water vapor oxidation according to claim 8, characterized in that, In step (2), the curing temperature is 300-400℃ and the curing time is 30-50min.

10. The method for preparing a coating resistant to high-temperature water vapor oxidation according to claim 8, characterized in that, In step (3), the heat treatment temperature is 900-1100℃ and the time is 10-20min.

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