Cr / ni-cr-based high-temperature- and corrosion-resistant coating material, and coating layer, preparation method therefor and use thereof

Abstract

The present application relates to surface corrosion protection of flow components in thermal power plant units and discloses a Cr / Ni-Cr-based high-temperature- and corrosion-resistant coating material, and a coating layer, a preparation method therefor, and a use thereof. The coating material comprises a solid phase component and a liquid phase component. The solid phase component comprises, in percentage by mass, 40-80% of Cr, 5-30% of Ni, 2-20% of Fe, 1-3% of Al, 1-6% of Ti, 0.5-4% of Zr, and 0-3% of Co; the liquid phase component comprises aluminum dihydrogen phosphate, sodium silicate, and a curing agent. The preparation method comprises: spraying the Cr / Ni-Cr-based high-temperature- and corrosion-resistant coating material onto a surface of a preheated pipe, drying and curing the material, and sintering at 850-1050ºC to form a Cr / Ni-Cr-based high-temperature- and corrosion-resistant coating layer. The coating layer prepared by the method enables a metal material to exhibit excellent performance in terms of high-temperature resistance, corrosion resistance, wear resistance, fatigue resistance and the like, thereby improving the reliability and prolonging the service life.

Description

A Cr / Ni-Cr based high-temperature corrosion resistant coating material, coating, preparation method and application

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411586249.5, filed on November 8, 2024, entitled "A Cr / Ni-Cr-based High-Temperature Corrosion Resistant Coating Material, Coating, Preparation Method and Application", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application belongs to the field of surface corrosion protection technology for circulating components of thermal power plant units, specifically relating to a Cr / Ni-Cr based high-temperature corrosion resistant coating material, coating, preparation method and application. Background Technology

[0004] Corrosion of high-aspect-ratio flow passage components used in high-temperature fields such as power, energy storage, and petrochemicals has become a common industry problem and technical pain point restricting the safe operation of the entire energy equipment sector, resulting in huge losses. Taking the power industry as an example, pipe blockage and rupture accidents caused by oxide scale on the inner wall of flow passage components account for more than 50% of boiler non-shutdown accidents, leading to an increase in unit operating costs and material costs of more than 20%. Studies have shown that high-temperature coatings have significant effects on solving oxidation corrosion, wear, and high-temperature ablation of components; however, existing high-temperature coating technologies are mostly used for hot-end components such as aero-engine blades, rotors, and turbine disks, which are characterized by high temperature, short action time, and small size. For the high aspect ratio structural characteristics, high temperature, long-term, and low-stress service environment of flow passage components in energy equipment, existing coating technologies are no longer applicable.

[0005] Austenitic steel superheater / reheater tubes in thermal power boilers are key components in ultra-supercritical units, responsible for recovering energy from coal-fired flue gas, heating steam, and achieving energy conversion. They are the parts of the boiler that withstand the highest pressure, temperature, and harshest operating environment. Calculations show that the outer wall temperature of the tubes needs to reach 640-680℃ to achieve the steam parameters required for a 620℃-class ultra-supercritical secondary unit. Since there are currently no alloys available domestically or internationally for 600 / 620 / 620℃ secondary reheat ultra-supercritical units, austenitic steel remains one of the preferred materials for the final stage superheater / reheater. While austenitic steel can meet various mechanical and thermophysical performance requirements during service at higher temperatures, its oxidation resistance is significantly reduced under 650℃ steam conditions. The high steam oxidation rate limits the possibility of austenitic steel operating at even higher temperatures.

[0006] To improve the steam oxidation resistance of austenitic steel, grain refinement and internal shot peening techniques are commonly used. These techniques alter the microstructure of the pipe's inner wall, enabling the alloy to rapidly grow the Cr2O3 film required for oxidation resistance. However, Cr2O3 exhibits poor stability in steam above 600°C, and the loosening of the oxide film caused by volatile products can lead to oxide film peeling, further resulting in pipe blockage and rupture. Furthermore, the Cr content in the alloy matrix is ​​relatively low; as service time increases, when the Cr required for oxide film growth is not replenished, the alloy's oxidation resistance will decline sharply. Therefore, these two techniques can only improve the alloy's oxidation resistance in the short term during the initial service period and cannot fundamentally solve the problems of oxidation and oxide film peeling. Summary of the Invention

[0007] To overcome the problem that existing technologies cannot improve the oxidation resistance of alloys in the long term, the purpose of this application is to provide a Cr / Ni-Cr based high-temperature corrosion resistant coating material, coating, preparation method and application. The coating prepared by this method can make the metal material exhibit excellent performance in terms of high temperature resistance, corrosion resistance, wear resistance and fatigue resistance, thereby improving reliability and extending service life.

[0008] To achieve the above objectives, this application adopts the following technical solution:

[0009] A Cr / Ni-Cr based high-temperature corrosion resistant coating material, comprising a solid phase component and a liquid phase component;

[0010] The solid phase components, by mass percentage, include 40-80% Cr, 5-30% Ni, 2-20% Fe, 1-3% Al, 1-6% Ti, 0.5-4% Zr, and 0-3% Co.

[0011] The liquid phase components include aluminum dihydrogen phosphate, water glass, and a curing agent.

[0012] A further improvement of this application is that the ratio of solid phase component to liquid phase component is 10g:1-5mL.

[0013] A further improvement of this application is that the curing agent is a mixture of magnesium oxide and chromium trioxide; the ratio of aluminum dihydrogen phosphate solution, water glass, chromium trioxide and magnesium oxide is 100mL:12-25mL:20-25g:5-12g, and the mass concentration of aluminum dihydrogen phosphate solution is 37.5%.

[0014] A further improvement of this application is that the solid phase components, by mass percentage, include 60-79% Cr, 10-30% Ni, 5-20% Fe, 1-2% Al, 2-4% Ti, 2-4% Zr, and 1-3% Co.

[0015] A further improvement of this application is that, by mass percentage, it comprises 60-70% Cr, 10-24% Ni, 10-20% Fe, 1-2% Al, 2-4% Ti, 2-3% Zr, and 1-2% Co.

[0016] A method for preparing a Cr / Ni-Cr based high-temperature corrosion resistant coating includes the following steps:

[0017] The Cr / Ni-Cr based high-temperature corrosion resistant coating material is sprayed onto the preheated pipe surface, dried, cured, and sintered at 850-1050℃ to form a Cr / Ni-Cr based high-temperature corrosion resistant coating.

[0018] A further improvement of this application is that the preheating temperature is 200-220℃ and the time is 30-40 minutes;

[0019] The spraying pressure is 0.5-2.0 MPa, and the spraying thickness is 0.1-1.0 mm.

[0020] A further improvement of this application is that the curing temperature is 200-300℃ and the curing time is 24-60h;

[0021] The sintering time is 8-15 minutes.

[0022] A Cr / Ni-Cr based high-temperature corrosion resistant coating, wherein the coating has a double-layer structure, a thickness of 20-42 μm, and an aluminum atomic mass content of 20%-35%.

[0023] Application of a Cr / Ni-Cr based high-temperature corrosion resistant coating in the flow components of thermal power units.

[0024] Compared with the prior art, this application has at least the following beneficial technical effects:

[0025] This application employs a solid-phase component containing Ni and Cr, which is sprayed onto the pipe surface to form a Cr / Ni-Cr-based high-temperature corrosion resistant coating. Due to the high Cr content, the pipe's oxidation resistance is improved. In this application, Ti and Zr can form chemical bonds with oxygen atoms on the substrate surface, thereby enhancing the adhesion between the coating and the substrate. This coating improves the pipe's resistance to high-temperature water vapor oxidation and its ability to prevent oxide layer peeling by altering the oxidation behavior and oxide structure of the pipe wall.

[0026] Furthermore, the Ni and Co metal elements in this application can improve the hardness and toughness of the coating, making it more wear-resistant and impact-resistant. Attached Figure Description

[0027] Figure 1 is a cross-sectional morphology photograph of the tough, high-temperature steam oxidation resistant coating prepared under the parameters of Example 1 of this application;

[0028] Figure 2 is a cross-sectional morphology photograph of the tough, high-temperature steam oxidation resistant coating prepared under the parameters of Example 2 of this application;

[0029] Figure 3 is a cross-sectional morphology photograph of the tough, high-temperature steam oxidation resistant coating prepared under the parameters of Example 3 of this application;

[0030] Figure 4 shows the aluminum element distribution of the tough, high-temperature steam oxidation resistant coating prepared under the parameters of Example 4 of this application. Detailed Implementation

[0031] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this application. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0032] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0034] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0035] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0036] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0037] It should also be understood that the terminology used in this application specification is for the purpose of describing particular embodiments only and is not intended to limit the application. As used in this application specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0038] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0039] The accompanying drawings illustrate various structural schematics according to embodiments disclosed in this application. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0040] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0041] The method for preparing the Cr / Ni-Cr based high-temperature corrosion resistant coating of this application includes the following steps:

[0042] 1) Solid raw materials: by mass percentage, including 40-80% Cr, 5-30% Ni, 2-20% Fe, 1-3% Al, 1-6% Ti, 0.5-4% Zr, and 0-3% Co.

[0043] The above raw materials are mixed according to the mass percentage, then wet ball milled and dried to obtain a solid phase component;

[0044] Optionally, by mass percentage, it includes 60-79% Cr, 10-30% Ni, 5-20% Fe, 1-2% Al, 2-4% Ti, 2-4% Zr, and 1-3% Co.

[0045] Further optionally, by mass percentage, it includes 60-70% Cr, 10-24% Ni, 10-20% Fe, 1-2% Al, 2-4% Ti, 2-3% Zr, and 1-2% Co.

[0046] In this application, Ti and Zr can form chemical bonds with oxygen atoms on the substrate surface, thereby enhancing the adhesion between the coating and the substrate.

[0047] Furthermore, Ni and Co metal elements can improve the hardness and toughness of the coating, making it more wear-resistant and impact-resistant.

[0048] 2) Liquid phase raw materials: aluminum dihydrogen phosphate solution, water glass and curing agent;

[0049] Aluminum dihydrogen phosphate, water glass, and a curing agent are mixed, stirred thoroughly, reacted, and then filtered to obtain the liquid phase. The ratio of aluminum dihydrogen phosphate solution, water glass, chromium trioxide, and magnesium oxide is 100 mL: 12–25 mL: 20–25 g: 5–12 g, and the mass concentration of the aluminum dihydrogen phosphate solution is 37.5%.

[0050] 3) Mix the solid phase component and the liquid phase component at a ratio of 10g:1-5mL to obtain a slurry;

[0051] 4) Spray the slurry onto the surface of austenitic steel pipes in the boiler of the thermal power unit, clean - preheat - spray the slurry - dry - cure - heat treatment - residue treatment;

[0052] Specifically, cleaning: After rinsing with a high-pressure water gun, rinse with alcohol or acetone.

[0053] Preheating: Preheat at 200-220℃ for 30-40 minutes to improve adhesion;

[0054] Spraying: Spraying pressure 0.5-2.0MPa, spraying thickness 0.1-1.0mm, slurry coverage not less than 98%;

[0055] Drying: Allow to air dry naturally for 24-40 hours to prevent the coating from cracking;

[0056] Curing: Cur at 200-300℃ for 24-60 hours;

[0057] Heat treatment (high-temperature sintering): Sinter at 850-1050℃ for 8-15 minutes under inert gas protection;

[0058] Residue treatment: Rinse with a high-pressure water gun or high-pressure airflow and then air dry naturally.

[0059] The coating prepared in this application has the following characteristics: the coating structure is a double layer with a thickness of 20-42 μm and an aluminum atomic mass content of 20%-35%.

[0060] Resistance to steam oxidation: After 1000 hours of oxidation in a pure water steam environment at 600℃, the coating's weight gain due to oxidation was 0.06157 mg / cm³. 2 The oxidation rate is 6.2 × 10⁻⁶. -5 mg / (cm 2 The oxidative weight gain of the parent material was 2.91814 mg / cm³ (·h). 2 Oxidation rate 3.6 × 10 - 4 mg / (cm 2 • h); After oxidation in a pure water vapor environment at 650℃ for 1000 h, the oxidation weight gain of the coating was 0.08163 mg / cm³. 2 The oxidation rate is 8.2 × 10⁻⁶. -5 mg / (cm 2 The oxidative weight gain of the parent material was 3.50178 mg / cm³ (·h). 2 Oxidation rate 5.8 × 10 - 4 mg / (cm 2 •h). The coating's resistance to steam oxidation is 50-70 times higher than that of the base material.

[0061] The austenitic steel pipes in this application are made of materials such as TP304H, TP347H, Super304H, TP347HFG, HR3C, or nickel-iron based alloys.

[0062] Example 1

[0063] The material of the austenitic steel pipe is TP347H.

[0064] The method for preparing the Cr / Ni-Cr based high-temperature corrosion resistant coating of this application includes the following steps:

[0065] 1) Solid raw materials, by mass percentage, include 40% Cr, 30% Ni, 20% Fe, 3% Al, 5% Ti, 2% Zr and 0% Co.

[0066] The above raw materials are mixed according to the mass percentage, then wet ball milled and dried to obtain a solid phase component;

[0067] 2) Liquid raw materials, including aluminum dihydrogen phosphate solution, water glass and curing agent;

[0068] Aluminum dihydrogen phosphate solution, water glass, and curing agent were mixed, stirred thoroughly, reacted, and then filtered to obtain the liquid phase. The ratio of aluminum dihydrogen phosphate solution, water glass, chromium trioxide, and magnesium oxide was 100 mL:12 mL:20 g:12 g, and the mass concentration of the aluminum dihydrogen phosphate solution was 37.5%.

[0069] 3) The solid phase component and the liquid phase component are mixed at a ratio of 10g:1mL to obtain a slurry;

[0070] 4) After spraying the slurry onto the surface of the austenitic steel pipe and cleaning it with a high-pressure water gun, rinse it with alcohol or acetone. Then, preheat it at 200℃ for 40 minutes before spraying. The spraying pressure is 0.5MPa, the spraying thickness is 0.1mm, and the slurry coverage is not less than 98%. Allow it to air dry naturally for 24 hours, cure it at 200℃ for 60 hours, and finally sinter it at 900℃ for 13 minutes under inert gas protection. After rinsing off the residue with a high-pressure water gun or high-pressure airflow, allow it to air dry naturally.

[0071] Referring to Figure 1, it can be seen that a single-layer coating morphology is formed on the surface of the pipe. The coating structure is clear, the organization is uniform, and it is metallurgically bonded to the pipe. The coating thickness is about 27 μm, and a small amount of precipitated phase is formed near the coating.

[0072] Example 2

[0073] The material of the austenitic steel pipe is TP347H.

[0074] The method for preparing the Cr / Ni-Cr based high-temperature corrosion resistant coating of this application includes the following steps:

[0075] 1) Solid raw materials: by mass percentage, including 80% Cr, 12.5% ​​Ni, 2% Fe, 1% Al, 1% Ti, 0.5% Zr and 3% Co.

[0076] The above raw materials are mixed according to the mass percentage, then wet ball milled and dried to obtain a solid phase component;

[0077] 2) Liquid raw materials, including aluminum dihydrogen phosphate solution, water glass and curing agent;

[0078] Aluminum dihydrogen phosphate solution, water glass, and curing agent were mixed, stirred thoroughly, reacted, and then filtered to obtain the liquid phase. The ratio of aluminum dihydrogen phosphate solution, water glass, chromium trioxide, and magnesium oxide was 100 mL: 25 mL: 25 g: 5 g, and the mass concentration of the aluminum dihydrogen phosphate solution was 37.5%.

[0079] 3) The solid phase component and the liquid phase component are mixed at a ratio of 10g:2mL to obtain a slurry;

[0080] 4) After spraying the slurry onto the surface of the austenitic steel pipe and cleaning it with a high-pressure water gun, rinse it with alcohol or acetone. Then, preheat it at 220℃ for 30 minutes before spraying. The spraying pressure is 1.5MPa, the spraying thickness is 0.4mm, and the slurry coverage is not less than 98%. Allow it to air dry naturally for 25 hours, then cure it at 300℃ for 24 hours. Finally, sinter it at 1000℃ for 10 minutes under inert gas protection. After rinsing off the residue with a high-pressure water gun or high-pressure airflow, allow it to air dry naturally.

[0081] The coating prepared in this application has the following characteristics: the coating structure is a double layer with a thickness of 20-42 μm and an aluminum atomic mass content of 20%-35%.

[0082] Referring to Figure 2, it can be seen that the coating on the pipe surface has a single-layer morphology, a uniform coating structure, a metallurgical bond with the pipe, and no obvious precipitated phases. The coating thickness is about 36 μm.

[0083] Example 3

[0084] The austenitic steel pipe is made of Super304H.

[0085] The method for preparing the Cr / Ni-Cr based high-temperature corrosion resistant coating of this application includes the following steps:

[0086] 1) Solid raw materials: by mass percentage, including 60% Cr, 15% Ni, 15% Fe, 2% Al, 3% Ti, 4% Zr and 1% Co.

[0087] The above raw materials are mixed according to the mass percentage, then wet ball milled and dried to obtain a solid phase component;

[0088] 2) Liquid raw materials, including aluminum dihydrogen phosphate solution, water glass and curing agent;

[0089] Aluminum dihydrogen phosphate solution, water glass, and curing agent were mixed, stirred thoroughly, reacted, and then filtered to obtain the liquid phase. The ratio of aluminum dihydrogen phosphate solution, water glass, chromium trioxide, and magnesium oxide was 100 mL: 15 mL: 22 g: 7 g, and the mass concentration of the aluminum dihydrogen phosphate solution was 37.5%.

[0090] 3) The solid phase component and the liquid phase component are mixed at a ratio of 10g:3mL to obtain a slurry;

[0091] 4) After spraying the slurry onto the surface of the austenitic steel pipe and rinsing it with a high-pressure water gun, rinse it with alcohol or acetone. Then, preheat it at 210℃ for 35 minutes before spraying. The spraying pressure is 1MPa, the spraying thickness is 0.7mm, and the slurry coverage is not less than 98%. Allow it to air dry naturally for 30 hours, then cure it at 210℃ for 55 hours. Finally, under inert gas protection, sinter it at 950℃ for 12 minutes. After rinsing off the residue with a high-pressure water gun or high-pressure airflow, allow it to air dry naturally.

[0092] The coating prepared in this application has the following characteristics: the coating structure is a double layer with a thickness of 20-42 μm and an aluminum atomic mass content of 20%-35%.

[0093] Referring to Figure 3, it can be seen that the coating on the pipe surface has a single-layer morphology, with a uniform coating structure, clear interface, metallurgical bonding with the pipe, and no obvious precipitated phases. The coating thickness is about 29 μm.

[0094] Example 4

[0095] The material of the austenitic steel pipe is TP347HFG.

[0096] The method for preparing the Cr / Ni-Cr based high-temperature corrosion resistant coating of this application includes the following steps:

[0097] 1) Solid raw materials: by mass percentage, including 60% Cr, 14% Ni, 20% Fe, 1% Al, 2% Ti, 2% Zr and 1% Co.

[0098] The above raw materials are mixed according to the mass percentage, then wet ball milled and dried to obtain a solid phase component;

[0099] 2) Liquid raw materials, including aluminum dihydrogen phosphate solution, water glass and curing agent;

[0100] Aluminum dihydrogen phosphate solution, water glass, and curing agent were mixed, stirred thoroughly, reacted, and then filtered to obtain the liquid phase. The ratio of aluminum dihydrogen phosphate solution, water glass, chromium trioxide, and magnesium oxide was 100 mL: 20 mL: 23 g: 10 g, and the mass concentration of the aluminum dihydrogen phosphate solution was 37.5%.

[0101] 3) The solid phase component and the liquid phase component are mixed at a ratio of 10g:5mL to obtain a slurry;

[0102] 4) After spraying the slurry onto the surface of the austenitic steel pipe and cleaning it with a high-pressure water gun, rinse it with alcohol or acetone. Then, preheat it at 205℃ for 35 minutes before spraying. The spraying pressure is 2MPa, the spraying thickness is 0.5mm, and the slurry coverage is not less than 98%. Allow it to air dry naturally for 30 hours, then cure it at 250℃ for 50 hours. Finally, under inert gas protection, sinter it at 850℃ for 15 minutes. After rinsing off the residue with a high-pressure water gun or high-pressure airflow, allow it to air dry naturally.

[0103] Referring to Figure 4, it can be seen that a single-layer coating morphology is formed on the surface of the pipe, with a coating thickness of about 17 μm. The coating is metallurgically bonded to the pipe, and although the interface between the coating and the substrate is relatively blurred, it can still be distinguished.

[0104] Example 5

[0105] The material of the austenitic steel pipe is HR3C.

[0106] The method for preparing the Cr / Ni-Cr based high-temperature corrosion resistant coating of this application includes the following steps:

[0107] 1) Solid raw materials: by mass percentage, including 79% Cr, 10% Ni, 5% Fe, 1% Al, 2% Ti, 2% Zr and 1% Co.

[0108] The above raw materials are mixed according to the mass percentage, then wet ball milled and dried to obtain a solid phase component;

[0109] 2) Liquid raw materials, including aluminum dihydrogen phosphate solution, water glass and curing agent;

[0110] Aluminum dihydrogen phosphate solution, water glass, and curing agent were mixed, stirred thoroughly, reacted, and then filtered to obtain the liquid phase. The ratio of aluminum dihydrogen phosphate solution, water glass, chromium trioxide, and magnesium oxide was 100 mL: 22 mL: 20 g: 11 g, and the mass concentration of the aluminum dihydrogen phosphate solution was 37.5%.

[0111] 3) The solid phase component and the liquid phase component are mixed at a ratio of 10g:4mL to obtain a slurry;

[0112] 4) After spraying the slurry onto the surface of the austenitic steel pipe and cleaning it with a high-pressure water gun, rinse it with alcohol or acetone. Then, preheat it at 215℃ for 35 minutes before spraying. The spraying pressure is 0.5MPa, the spraying thickness is 0.8mm, and the slurry coverage is not less than 98%. Allow it to air dry naturally for 30 hours, then cure it at 270℃ for 30 hours. Finally, sinter it at 1050℃ for 8 minutes under inert gas protection. After rinsing off the residue with a high-pressure water gun or high-pressure airflow, allow it to air dry naturally.

[0113] Example 6

[0114] The material of austenitic steel pipe is a nickel-iron based alloy.

[0115] The method for preparing the Cr / Ni-Cr based high-temperature corrosion resistant coating of this application includes the following steps:

[0116] 1) Solid raw materials: by mass percentage, including 60% Cr, 29% Ni, 5% Fe, 1% Al, 2% Ti, 2% Zr and 1% Co.

[0117] The above raw materials are mixed according to the mass percentage, then wet ball milled and dried to obtain a solid phase component;

[0118] 2) Liquid raw materials, including aluminum dihydrogen phosphate solution, water glass and curing agent;

[0119] Aluminum dihydrogen phosphate solution, water glass, and curing agent were mixed, stirred thoroughly, reacted, and then filtered to obtain the liquid phase. The ratio of aluminum dihydrogen phosphate solution, water glass, chromium trioxide, and magnesium oxide was 100 mL: 24 mL: 24 g: 8 g, and the mass concentration of the aluminum dihydrogen phosphate solution was 37.5%.

[0120] 3) The solid phase component and the liquid phase component are mixed at a ratio of 10g:2.5mL to obtain a slurry;

[0121] 4) After spraying the slurry onto the surface of the austenitic steel pipe and cleaning it with a high-pressure water gun, rinse it with alcohol or acetone. Then, preheat it at 220℃ for 32 minutes before spraying. The spraying pressure is 1.2MPa, the spraying thickness is 0.2mm, and the slurry coverage is not less than 98%. Allow it to air dry naturally for 40 hours, then cure it at 230℃ for 40 hours. Finally, sinter it at 900℃ for 12 minutes under inert gas protection. After rinsing off the residue with a high-pressure water gun or high-pressure airflow, allow it to air dry naturally.

[0122] Example 7

[0123] The austenitic steel pipe is made of Super304H.

[0124] The method for preparing the Cr / Ni-Cr based high-temperature corrosion resistant coating of this application includes the following steps:

[0125] 1) Solid raw materials: by mass percentage, including 62% Cr, 15% Ni, 10% Fe, 2% Al, 4% Ti, 4% Zr and 3% Co.

[0126] The above raw materials are mixed according to the mass percentage, then wet ball milled and dried to obtain a solid phase component;

[0127] 2) Liquid raw materials, including aluminum dihydrogen phosphate solution, water glass and curing agent;

[0128] Aluminum dihydrogen phosphate solution, water glass, and curing agent were mixed, stirred thoroughly, reacted, and then filtered to obtain the liquid phase. The ratio of aluminum dihydrogen phosphate solution, water glass, chromium trioxide, and magnesium oxide was 100 mL:18 mL:20 g:9 g, and the mass concentration of the aluminum dihydrogen phosphate solution was 37.5%.

[0129] 3) The solid phase component and the liquid phase component are mixed at a ratio of 10g:4.5mL to obtain a slurry;

[0130] 4) After spraying the slurry onto the surface of the austenitic steel pipe and cleaning it with a high-pressure water gun, rinse it with alcohol or acetone. Then, preheat it at 207℃ for 37 minutes before spraying. The spraying pressure is 1.7MPa, the spraying thickness is 0.9mm, and the slurry coverage is not less than 98%. Allow it to air dry for 27 hours, cure it at 265℃ for 28 hours, and finally sinter it at 1020℃ for 9 minutes under inert gas protection. After rinsing off the residue with a high-pressure water gun or high-pressure airflow, allow it to air dry naturally.

[0131] Example 8

[0132] The austenitic steel pipe is made of Super304H.

[0133] The method for preparing the Cr / Ni-Cr based high-temperature corrosion resistant coating of this application includes the following steps:

[0134] 1) Solid raw materials: by mass percentage, including 60% Cr, 15% Ni, 15% Fe, 2% Al, 3% Ti, 4% Zr and 1% Co.

[0135] The above raw materials are mixed according to the mass percentage, then wet ball milled and dried to obtain a solid phase component;

[0136] 2) Liquid raw materials, including aluminum dihydrogen phosphate solution, water glass and curing agent;

[0137] Aluminum dihydrogen phosphate solution, water glass, and curing agent were mixed, stirred thoroughly, reacted, and then filtered to obtain the liquid phase. The ratio of aluminum dihydrogen phosphate solution, water glass, chromium trioxide, and magnesium oxide was 100 mL: 21 mL: 25 g: 10 g, and the mass concentration of the aluminum dihydrogen phosphate solution was 37.5%.

[0138] 3) The solid phase component and the liquid phase component are mixed at a ratio of 10g:3.5mL to obtain a slurry;

[0139] 4) After spraying the slurry onto the surface of the austenitic steel pipe and cleaning it with a high-pressure water gun, rinse it with alcohol or acetone. Then, preheat it at 218℃ for 32 minutes before spraying. The spraying pressure is 1MPa, the spraying thickness is 0.6mm, and the slurry coverage is not less than 98%. Allow it to air dry naturally for 32 hours, then cure it at 285℃ for 26 hours. Finally, under inert gas protection, sinter it at 880℃ for 13 minutes. After rinsing off the residue with a high-pressure water gun or high-pressure airflow, allow it to air dry naturally.

[0140] Example 9

[0141] The austenitic steel pipe is made of Super304H.

[0142] The method for preparing the Cr / Ni-Cr based high-temperature corrosion resistant coating of this application includes the following steps:

[0143] 1) Solid raw materials: by mass percentage, including 60% Cr, 10% Ni, 20% Fe, 2% Al, 3% Ti, 3% Zr and 2% Co.

[0144] The above raw materials are mixed according to the mass percentage, then wet ball milled and dried to obtain a solid phase component;

[0145] 2) Liquid raw materials, including aluminum dihydrogen phosphate solution, water glass and curing agent;

[0146] Aluminum dihydrogen phosphate solution, water glass, and curing agent were mixed, stirred thoroughly, reacted, and then filtered to obtain the liquid phase. The ratio of aluminum dihydrogen phosphate solution, water glass, chromium trioxide, and magnesium oxide was 100 mL: 25 mL: 25 g: 11 g, and the mass concentration of the aluminum dihydrogen phosphate solution was 37.5%.

[0147] 3) The solid phase component and the liquid phase component are mixed at a ratio of 10g:2.5mL to obtain a slurry;

[0148] 4) After spraying the slurry onto the surface of the austenitic steel pipe and rinsing it with a high-pressure water gun, rinse it with alcohol or acetone. Then, preheat it at 200℃ for 40 minutes before spraying. The spraying pressure is 2MPa, the spraying thickness is 1mm, and the slurry coverage is not less than 98%. Allow it to air dry naturally for 40 hours, then cure it at 295℃ for 24 hours. Finally, under inert gas protection, sinter it at 1050℃ for 8 minutes. After rinsing off the residue with a high-pressure water gun or high-pressure airflow, allow it to air dry naturally.

[0149] The foregoing has shown and described the basic principles, main features, and advantages of this application. It will be apparent to those skilled in the art that this application is not limited to the details of the exemplary embodiments described above, and that this application can be implemented in other specific forms without departing from the spirit or basic characteristics of this application. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this application. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0150] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of this application and should not be used to limit the scope of protection of this application. Any modifications made to the technical solutions based on the technical concept proposed in this application fall within the scope of protection of the claims of this application.

Claims

1. A Cr / Ni-Cr based high-temperature corrosion resistant coating material, characterized in that, Includes solid phase components and liquid phase components; The solid phase components, by mass percentage, include 40-80% Cr, 5-30% Ni, 2-20% Fe, 1-3% Al, 1-6% Ti, 0.5-4% Zr, and 0-3% Co. The liquid phase components include aluminum dihydrogen phosphate, water glass, and a curing agent.

2. The Cr / Ni-Cr based high-temperature corrosion resistant coating material according to claim 1, characterized in that, The ratio of solid phase component to liquid phase component is 10g:1-5mL.

3. The Cr / Ni-Cr based high-temperature corrosion resistant coating material according to claim 1, characterized in that, The curing agent is a mixture of magnesium oxide and chromium trioxide; the ratio of aluminum dihydrogen phosphate solution, water glass, chromium trioxide and magnesium oxide is 100mL:12-25mL:20-25g:5-12g, and the mass concentration of aluminum dihydrogen phosphate solution is 37.5%.

4. The Cr / Ni-Cr based high-temperature corrosion resistant coating material according to claim 1, characterized in that, The solid phase components, by mass percentage, include 60-79% Cr, 10-30% Ni, 5-20% Fe, 1-2% Al, 2-4% Ti, 2-4% Zr, and 1-3% Co.

5. The Cr / Ni-Cr based high-temperature corrosion resistant coating material according to claim 1, characterized in that, By mass percentage, it includes 60-70% Cr, 10-24% Ni, 10-20% Fe, 1-2% Al, 2-4% Ti, 2-3% Zr, and 1-2% Co.

6. A method for preparing a Cr / Ni-Cr based high-temperature corrosion resistant coating as described in any one of claims 1-5, characterized in that, Includes the following steps: The Cr / Ni-Cr based high-temperature corrosion resistant coating material is sprayed onto the preheated pipe surface, dried, cured, and sintered at 850-1050℃ to form a Cr / Ni-Cr based high-temperature corrosion resistant coating.

7. The method for preparing the Cr / Ni-Cr based high-temperature corrosion resistant coating according to claim 6, characterized in that, The preheating temperature is 200-220℃, and the time is 30-40 minutes; The spraying pressure is 0.5-2.0 MPa, and the spraying thickness is 0.1-1.0 mm.

8. The method for preparing the Cr / Ni-Cr based high-temperature corrosion resistant coating according to claim 1, characterized in that, The curing temperature is 200-300℃, and the time is 24-60 hours; The sintering time is 8-15 minutes.

9. A Cr / Ni-Cr based high-temperature corrosion resistant coating prepared by the method according to any one of claims 4-8, characterized in that, The coating has a double-layer structure with a thickness of 20-42 μm and an aluminum atomic mass content of 20%-35%.

10. The application of a Cr / Ni-Cr based high-temperature corrosion resistant coating prepared by the method according to any one of claims 4-8 in the flow components of a thermal power unit.

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