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

Abstract

The invention belongs to the technical field of heat-engine plant unit circulation component surface corrosion prevention, and discloses a Cr / Ni-Cr-based high-temperature-corrosion-resistant coating material, a coating, a preparation method and application, the coating material comprises a solid-phase component and a liquid-phase component, the solid-phase component comprises, 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, water glass and a curing agent. And the Cr / Ni-Cr-based high-temperature-corrosion-resistant coating material is sprayed to the preheated pipeline surface, dried, cured and sintered at the temperature of 850-1050 DEG C, and the Cr / Ni-Cr-based high-temperature-corrosion-resistant coating is formed. According to the coating prepared through the method, the metal material can show excellent performance in the aspects of high temperature resistance, corrosion resistance, abrasion resistance, fatigue resistance and the like, the reliability is improved, and the service life is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of surface corrosion protection of circulating components of thermal power plant units, and specifically relates to a Cr / Ni-Cr-based high-temperature corrosion resistant coating material, a coating, a preparation method and an application thereof. Background Art

[0002] The corrosion of large aspect ratio flow components used in high temperature fields such as electricity, energy storage, and petrochemicals has become a common industry problem and technical pain point that restricts the safe production and operation of the entire energy equipment, resulting in huge losses. Taking the power industry as an example, pipe blockage and pipe burst accidents caused by scale problems on the inner wall of the flow components account for more than 50% of boiler non-stop accidents, resulting in an increase of more than 20% in the operating cost and material cost of the unit. Studies have shown that high-temperature coatings have obvious effects in solving the problems of component oxidation corrosion, wear, and high-temperature ablation; however, existing high-temperature coating technologies are mostly used for hot end components such as aircraft engine blades, rotors, and turbine disks with high temperatures, short action times, and small sizes. For the characteristics of large aspect ratio structural characteristics, high temperature, long time, and low stress service environment of energy equipment flow components, the existing coating technology is no longer applicable.

[0003] Austenitic steel superheater tubes for thermal power boilers are key components in ultra-supercritical units responsible for recovering coal flue gas energy, heating steam, and realizing energy conversion. They are the parts of the boiler that bear the highest pressure, temperature, and harsh service environment. According to calculations, the temperature of the outer wall of the tube must reach 640-680℃ to make the steam parameters meet the requirements of 620℃ ultra-supercritical secondary units. Since there are no alloys available for 600 / 620 / 620℃ secondary reheating ultra-supercritical units at home and abroad, austenitic steel is still one of the preferred materials for the final superheater of the unit; at higher temperatures, although austenitic steel can meet various mechanical and thermal properties during service, its oxidation resistance is greatly reduced under 650℃ steam conditions, and the higher steam oxidation rate limits the possibility of austenitic steel serving at higher temperatures.

[0004] In order to improve the steam oxidation resistance of austenitic steel, the grain refinement and inner wall shot peening technology are generally adopted. These two technologies change the inner wall structure of the tube, so that the alloy can quickly grow the Cr required for oxidation resistance. 2 O 3 But Cr 2 O 3The stability in steam above 600℃ is poor, and the loose oxide film caused by volatile products will cause the oxide film to peel off, and further lead to pipe blockage and pipe explosion accidents; in addition, the Cr content in the alloy matrix is ​​relatively low. As the service time increases, when the Cr content required for the growth of the oxide film cannot be replenished, the oxidation resistance of the alloy will also drop sharply. Therefore, the two technologies can only improve the oxidation resistance of the alloy in a short period of time at the beginning of service, and cannot fundamentally solve the problems of alloy oxidation and oxide film peeling. Summary of the invention

[0005] In order to overcome the problem in the prior art that the oxidation resistance of alloys cannot be improved for a long time, the purpose of the present invention is to provide a Cr / Ni-Cr-based high-temperature corrosion-resistant coating material, coating, preparation method and application. The coating prepared by the method can enable metal materials to exhibit excellent performance in terms of high temperature resistance, corrosion resistance, wear resistance, fatigue resistance, etc., thereby improving reliability and extending service life.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A Cr / Ni-Cr based high temperature corrosion resistant coating material, comprising a solid phase component and a liquid phase component;

[0008] The solid phase components include 40-80% Cr, 5-30% Ni, 2-20% Fe, 1-3% Al, 1-6% Ti, 0.5-4% Zr and 0-3% Co by mass percentage;

[0009] The liquid phase components include aluminum dihydrogen phosphate, water glass and a curing agent.

[0010] A further improvement of the present invention is that the usage ratio of the solid phase component to the liquid phase component is 10g:1-5mL.

[0011] A further improvement of the present invention is that the curing agent is a mixture of magnesium oxide and chromium trioxide; the ratio of the 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%.

[0012] A further improvement of the present invention is that the solid phase components include 60-79% Cr, 10-30% Ni, 5-20% Fe, 1-2% Al, 2-4% Ti, 2-4% Zr and 1-3% Co by mass percentage.

[0013] A further improvement of the present invention is 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.

[0014] A method for preparing a Cr / Ni-Cr based high temperature corrosion resistant coating comprises the following steps:

[0015] The Cr / Ni-Cr based high temperature corrosion resistant coating material is sprayed onto the preheated pipeline surface, dried, cured, and sintered at 850-1050°C to form a Cr / Ni-Cr based high temperature corrosion resistant coating.

[0016] A further improvement of the present invention is that the preheating temperature is 200-220°C and the time is 30-40 minutes;

[0017] The spraying pressure is 0.5-2.0MPa, and the spraying thickness is 0.1-1.0mm.

[0018] A further improvement of the present invention is that the curing temperature is 200-300°C and the curing time is 24-60h;

[0019] The sintering time is 8-15min.

[0020] A Cr / Ni-Cr based high temperature corrosion resistant coating has a double layer structure, a thickness of 20-42 mu m and an aluminum atomic mass content of 20%-35%.

[0021] The invention discloses an application of a Cr / Ni-Cr based high temperature corrosion resistant coating in circulation components of a thermal power unit.

[0022] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0023] In the present invention, a solid phase component containing Ni and Cr is used to form a Cr / Ni-Cr-based high temperature corrosion resistant coating on the surface of the pipeline by spraying. Due to the high Cr content, the oxidation resistance of the pipeline can be improved; Ti and Zr in the present invention can form chemical bonds with oxygen atoms on the surface of the substrate, thereby enhancing the bonding force between the coating and the substrate. The coating of the present invention improves the pipeline's resistance to high temperature steam oxidation and the ability to resist oxidation layer peeling by changing the oxidation behavior and oxide structure of the pipeline wall.

[0024] Furthermore, the Ni and Co metal elements in the present invention can improve the hardness and toughness of the coating, making it more wear-resistant and impact-resistant. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a cross-sectional morphology photograph of a tough high-temperature steam oxidation resistant coating prepared under the parameters of Example 1 of the present invention;

[0026] Figure 2 This is a cross-sectional morphology photograph of a tough high-temperature steam oxidation resistant coating prepared under the parameters of Example 2 of the present invention;

[0027] Figure 3 This is a cross-sectional morphology photograph of a tough high-temperature steam oxidation resistant coating prepared under the parameters of Example 3 of the present invention;

[0028] Figure 4 The aluminum element distribution of the tough high-temperature steam oxidation resistant coating prepared under the parameters of Example 4 of the present invention. DETAILED DESCRIPTION

[0029] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0030] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0031] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0032] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0034] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0035] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0036] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0037] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0038] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0039] The preparation method of the Cr / Ni-Cr based high temperature corrosion resistant coating of the present invention comprises the following steps:

[0040] 1) Solid raw material: 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.

[0041] The above raw materials are mixed according to mass percentage, and then wet ball milled and dried to obtain a solid phase component;

[0042] Preferably, 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.

[0043] More preferably, the alloy comprises 60-70% Cr, 10-24% Ni, 10-20% Fe, 1-2% Al, 2-4% Ti, 2-3% Zr and 1-2% Co by mass percentage.

[0044] In the present invention, Ti and Zr can form chemical bonds with oxygen atoms on the surface of the substrate, thereby enhancing the bonding force between the coating and the substrate.

[0045] Furthermore, Ni and Co metal elements can improve the hardness and toughness of the coating, making it more wear-resistant and impact-resistant.

[0046] 2) Liquid raw materials: aluminum dihydrogen phosphate solution, water glass and curing agent;

[0047] Aluminum dihydrogen phosphate, water glass and curing agent are mixed, stirred evenly, reacted and filtered to obtain a liquid phase component. 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 aluminum dihydrogen phosphate solution is 37.5%.

[0048] 3) Mix the solid phase component and the liquid phase component according to 10 g: 1-5 mL to obtain a slurry;

[0049] 4) Spray the slurry onto the surface of the austenitic steel pipeline of the thermal power unit boiler, clean - preheat - slurry spray - dry - solidify - heat treatment - residue treatment;

[0050] Specifically, cleaning: rinse with a high-pressure water gun, then rinse with alcohol or acetone;

[0051] Preheating: Preheat at 200-220℃ for 30-40min to improve adhesion;

[0052] Spraying: spraying pressure 0.5-2.0MPa, spraying thickness 0.1-1.0mm, slurry coverage not less than 98%;

[0053] Drying: Use natural air drying for 24-40 hours to avoid cracking of the coating;

[0054] Curing: Curing at 200-300℃ for 24-60h;

[0055] Heat treatment (high temperature sintering): sinter at 850-1050℃ for 8-15min under inert gas protection;

[0056] Residue disposal: Rinse with high-pressure water gun or high-pressure air flow and then air dry naturally.

[0057] The coating prepared by the present invention has the following results: the coating structure is a double-layer structure, the thickness is 20-42 μm, and the aluminum atomic mass content is 20%-35%.

[0058] Steam oxidation resistance: After oxidation in a 600℃ pure steam environment for 1000h, the coating's oxidation weight gain is 0.06157mg / cm 2 , the oxidation rate is 6.2×10 -5 mg / (cm 2 h), the oxidation weight gain of the parent material is 2.91814 mg / cm 2 , oxidation rate 3.6×10 -4 mg / (cm 2 h); Oxidation in 650℃ pure water vapor environment for 1000h, the oxidation weight gain of the coating is 0.08163mg / cm 2 , the oxidation rate is 8.2×10 -5 mg / (cm 2 h), the oxidation weight gain of the parent material is 3.50178 mg / cm 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.

[0059] The material of the austenitic steel pipeline in the present invention is: TP304H, TP347H, Super304H, TP347HFG, HR3C or nickel-iron based alloy.

[0060] Example 1

[0061] The material of austenitic steel pipe is TP347H.

[0062] The preparation method of the Cr / Ni-Cr based high temperature corrosion resistant coating of the present invention comprises the following steps:

[0063] 1) The solid raw material includes, by mass percentage, 40% Cr, 30% Ni, 20% Fe, 3% Al, 5% Ti, 2% Zr and 0% Co.

[0064] The above raw materials are mixed according to mass percentage, and then wet ball milled and dried to obtain a solid phase component;

[0065] 2) Liquid raw materials, including aluminum dihydrogen phosphate solution, water glass and curing agent;

[0066] The aluminum dihydrogen phosphate solution, water glass and curing agent are mixed, stirred evenly, reacted and filtered to obtain a liquid phase component, wherein the ratio of the aluminum dihydrogen phosphate solution, water glass, chromium trioxide and magnesium oxide is 100 mL: 12 mL: 20 g: 12 g, and the mass concentration of the aluminum dihydrogen phosphate solution is 37.5%.

[0067] 3) Mix the solid phase component and the liquid phase component at a ratio of 10 g: 1 mL to obtain a slurry;

[0068] 4) Spray the slurry onto the surface of the austenitic steel pipe, rinse it with a high-pressure water gun, then rinse it with alcohol or acetone, and then preheat it at 200°C 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%. Dry it naturally for 24 hours, cure it at 200°C for 60 hours, and finally, sinter it at 900°C for 13 minutes under inert gas protection; rinse the residue with a high-pressure water gun or high-pressure airflow and then dry it naturally.

[0069] See also Figure 1 It can be seen that a single-layer coating morphology is formed on the surface of the pipeline. The coating structure is clear, the organization is uniform, and it is metallurgically bonded to the pipeline. The coating thickness is about 27μm, and a small amount of precipitated phase is formed near the coating.

[0070] Example 2

[0071] The material of austenitic steel pipe is TP347H.

[0072] The preparation method of the Cr / Ni-Cr based high temperature corrosion resistant coating of the present invention comprises the following steps:

[0073] 1) Solid raw material: by mass percentage, including 80% Cr, 12.5% ​​Ni, 2% Fe, 1% Al, 1% Ti, 0.5% Zr and 3% Co.

[0074] The above raw materials are mixed according to mass percentage, and then wet ball milled and dried to obtain a solid phase component;

[0075] 2) Liquid raw materials, including aluminum dihydrogen phosphate solution, water glass and curing agent;

[0076] The aluminum dihydrogen phosphate solution, water glass and curing agent are mixed, stirred evenly, reacted, and filtered to obtain a liquid phase component. The ratio of the aluminum dihydrogen phosphate solution, water glass, chromium trioxide and magnesium oxide is 100 mL: 25 mL: 25 g: 5 g, and the mass concentration of the aluminum dihydrogen phosphate solution is 37.5%.

[0077] 3) Mix the solid phase component and the liquid phase component at a ratio of 10 g: 2 mL to obtain a slurry;

[0078] 4) Spray the slurry onto the surface of the austenitic steel pipe, rinse it with a high-pressure water gun, then rinse it with alcohol or acetone, and then preheat it at 220°C 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%. Air dry it naturally for 25 hours, cure it at 300°C for 24 hours, and finally, sinter it at 1000°C for 10 minutes under inert gas protection; rinse the residue with a high-pressure water gun or high-pressure airflow and then air dry it naturally.

[0079] The coating prepared by the present invention has the following results: the coating structure is a double-layer structure, the thickness is 20-42 μm, and the aluminum atomic mass content is 20%-35%.

[0080] See also Figure 2 It can be seen that the coating on the pipeline surface is a single-layer morphology, the coating structure is uniform, it is metallurgically bonded to the pipeline, no obvious precipitation phase is produced, and the coating thickness is about 36μm.

[0081] Example 3

[0082] The material of austenitic steel pipe is Super304H.

[0083] The preparation method of the Cr / Ni-Cr based high temperature corrosion resistant coating of the present invention comprises the following steps:

[0084] 1) Solid raw materials: by mass percentage, including 60% Cr, 15% Ni, 15% Fe, 2% Al, 3% Ti, 4% Zr and 1% Co.

[0085] The above raw materials are mixed according to mass percentage, and then wet ball milled and dried to obtain a solid phase component;

[0086] 2) Liquid raw materials, including aluminum dihydrogen phosphate solution, water glass and curing agent;

[0087] The aluminum dihydrogen phosphate solution, water glass and curing agent are mixed, stirred evenly, reacted and filtered to obtain a liquid phase component, wherein the ratio of the aluminum dihydrogen phosphate solution, water glass, chromium trioxide and magnesium oxide is 100 mL: 15 mL: 22 g: 7 g, and the mass concentration of the aluminum dihydrogen phosphate solution is 37.5%.

[0088] 3) Mix the solid phase component and the liquid phase component at a ratio of 10 g:3 mL to obtain a slurry;

[0089] 4) Spray the slurry onto the surface of the austenitic steel pipe, rinse it with a high-pressure water gun, then rinse it with alcohol or acetone, and then preheat it at 210°C 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%. Natural air drying is used for 30 hours, and it is cured at 210°C for 55 hours. Finally, under the protection of inert gas, it is sintered at 950°C for 12 minutes; rinse the residue with a high-pressure water gun or high-pressure airflow and then dry it naturally.

[0090] The coating prepared by the present invention has the following results: the coating structure is a double-layer structure, the thickness is 20-42 μm, and the aluminum atomic mass content is 20%-35%.

[0091] See also Figure 3 It can be seen that the coating on the pipeline surface is a single-layer morphology with a uniform coating structure and a clear interface. It is metallurgically bonded to the pipeline and no obvious precipitation phase is produced. The coating thickness is about 29 μm.

[0092] Example 4

[0093] The material of austenitic steel pipe is TP347HFG.

[0094] The preparation method of the Cr / Ni-Cr based high temperature corrosion resistant coating of the present invention comprises the following steps:

[0095] 1) Solid raw materials: by mass percentage, including 60% Cr, 14% Ni, 20% Fe, 1% Al, 2% Ti, 2% Zr and 1% Co.

[0096] The above raw materials are mixed according to mass percentage, and then wet-milled and dried to obtain a solid phase component;

[0097] 2) Liquid raw materials, including aluminum dihydrogen phosphate solution, water glass and curing agent;

[0098] The aluminum dihydrogen phosphate solution, water glass and curing agent are mixed, stirred evenly, reacted, and filtered to obtain a liquid phase component. The ratio of the aluminum dihydrogen phosphate solution, water glass, chromium trioxide and magnesium oxide is 100 mL: 20 mL: 23 g: 10 g, and the mass concentration of the aluminum dihydrogen phosphate solution is 37.5%.

[0099] 3) Mix the solid phase component and the liquid phase component at a ratio of 10 g:5 mL to obtain a slurry;

[0100] 4) Spray the slurry onto the surface of the austenitic steel pipe, rinse it with a high-pressure water gun, then rinse it with alcohol or acetone, and then preheat it at 205°C 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%. Dry it naturally for 30 hours, cure it at 250°C for 50 hours, and finally, sinter it at 850°C for 15 minutes under inert gas protection; rinse the residue with a high-pressure water gun or high-pressure airflow and then dry it naturally.

[0101] See also Figure 4 It can be seen that a single-layer coating morphology is formed on the surface of the pipeline. The coating thickness is about 17 μm, which is metallurgically bonded to the pipeline. Although the interface between the coating and the substrate is relatively fuzzy, it can still be identified.

[0102] Example 5

[0103] The material of austenitic steel pipe is HR3C.

[0104] The preparation method of the Cr / Ni-Cr based high temperature corrosion resistant coating of the present invention comprises the following steps:

[0105] 1) Solid raw material: by mass percentage, including 79% Cr, 10% Ni, 5% Fe, 1% Al, 2% Ti, 2% Zr and 1% Co.

[0106] The above raw materials are mixed according to mass percentage, and then wet-milled and dried to obtain a solid phase component;

[0107] 2) Liquid raw materials, including aluminum dihydrogen phosphate solution, water glass and curing agent;

[0108] The aluminum dihydrogen phosphate solution, water glass and curing agent are mixed, stirred evenly, reacted and filtered to obtain a liquid phase component, wherein the ratio of the aluminum dihydrogen phosphate solution, water glass, chromium trioxide and magnesium oxide is 100 mL: 22 mL: 20 g: 11 g, and the mass concentration of the aluminum dihydrogen phosphate solution is 37.5%.

[0109] 3) Mix the solid phase component and the liquid phase component at a ratio of 10 g:4 mL to obtain a slurry;

[0110] 4) Spray the slurry onto the surface of the austenitic steel pipe, rinse it with a high-pressure water gun, then rinse it with alcohol or acetone, and then preheat it at 215°C 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%. Natural air drying is used for 30 hours, and it is cured at 270°C for 30 hours. Finally, under the protection of inert gas, it is sintered at 1050°C for 8 minutes; rinse the residue with a high-pressure water gun or high-pressure airflow and then dry it naturally.

[0111] Example 6

[0112] Austenitic steel pipes are made of a nickel-iron based alloy.

[0113] The preparation method of the Cr / Ni-Cr based high temperature corrosion resistant coating of the present invention comprises the following steps:

[0114] 1) Solid raw materials: by mass percentage, including 60% Cr, 29% Ni, 5% Fe, 1% Al, 2% Ti, 2% Zr and 1% Co.

[0115] The above raw materials are mixed according to mass percentage, and then wet ball milled and dried to obtain a solid phase component;

[0116] 2) Liquid raw materials, including aluminum dihydrogen phosphate solution, water glass and curing agent;

[0117] The aluminum dihydrogen phosphate solution, water glass and curing agent are mixed, stirred evenly, reacted and filtered to obtain a liquid phase component, wherein the ratio of the aluminum dihydrogen phosphate solution, water glass, chromium trioxide and magnesium oxide is 100 mL: 24 mL: 24 g: 8 g, and the mass concentration of the aluminum dihydrogen phosphate solution is 37.5%.

[0118] 3) Mix the solid phase component and the liquid phase component at a ratio of 10 g: 2.5 mL to obtain a slurry;

[0119] 4) Spray the slurry onto the surface of the austenitic steel pipe, rinse it with a high-pressure water gun, then rinse it with alcohol or acetone, and then preheat it at 220°C 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%. Natural air drying is used for 40 hours, and it is cured at 230°C for 40 hours. Finally, under the protection of inert gas, it is sintered at 900°C for 12 minutes; rinse the residue with a high-pressure water gun or high-pressure airflow and then dry it naturally.

[0120] Example 7

[0121] The material of austenitic steel pipe is Super304H.

[0122] The preparation method of the Cr / Ni-Cr based high temperature corrosion resistant coating of the present invention comprises the following steps:

[0123] 1) Solid raw materials: by mass percentage, including 62% Cr, 15% Ni, 10% Fe, 2% Al, 4% Ti, 4% Zr and 3% Co.

[0124] The above raw materials are mixed according to mass percentage, and then wet ball milled and dried to obtain a solid phase component;

[0125] 2) Liquid raw materials, including aluminum dihydrogen phosphate solution, water glass and curing agent;

[0126] The aluminum dihydrogen phosphate solution, water glass and curing agent are mixed, stirred evenly, reacted and filtered to obtain a liquid phase component, wherein the ratio of the aluminum dihydrogen phosphate solution, water glass, chromium trioxide and magnesium oxide is 100 mL: 18 mL: 20 g: 9 g, and the mass concentration of the aluminum dihydrogen phosphate solution is 37.5%.

[0127] 3) Mix the solid phase component and the liquid phase component according to 10 g:4.5 mL to obtain a slurry;

[0128] 4) Spray the slurry onto the surface of the austenitic steel pipe, rinse it with a high-pressure water gun, then rinse it with alcohol or acetone, and then preheat it at 207°C 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%. Natural air drying is used for 27 hours, and it is cured at 265°C for 28 hours. Finally, under the protection of inert gas, it is sintered at 1020°C for 9 minutes; rinse the residue with a high-pressure water gun or high-pressure airflow and then dry it naturally.

[0129] Example 8

[0130] The material of austenitic steel pipe is Super304H.

[0131] The preparation method of the Cr / Ni-Cr based high temperature corrosion resistant coating of the present invention comprises the following steps:

[0132] 1) Solid raw materials: by mass percentage, including 60% Cr, 15% Ni, 15% Fe, 2% Al, 3% Ti, 4% Zr and 1% Co.

[0133] The above raw materials are mixed according to mass percentage, and then wet-milled and dried to obtain a solid phase component;

[0134] 2) Liquid raw materials, including aluminum dihydrogen phosphate solution, water glass and curing agent;

[0135] The aluminum dihydrogen phosphate solution, water glass and curing agent are mixed, stirred evenly, reacted and filtered to obtain a liquid phase component, wherein the ratio of the aluminum dihydrogen phosphate solution, water glass, chromium trioxide and magnesium oxide is 100 mL: 21 mL: 25 g: 10 g, and the mass concentration of the aluminum dihydrogen phosphate solution is 37.5%.

[0136] 3) Mix the solid phase component and the liquid phase component at a ratio of 10 g:3.5 mL to obtain a slurry;

[0137] 4) Spray the slurry onto the surface of the austenitic steel pipe, rinse it with a high-pressure water gun, then rinse it with alcohol or acetone, and then preheat it at 218°C 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%. Natural air drying is used for 32 hours, and it is cured at 285°C for 26 hours. Finally, under the protection of inert gas, it is sintered at 880°C for 13 minutes; rinse the residue with a high-pressure water gun or high-pressure airflow and then dry it naturally.

[0138] Example 9

[0139] The material of austenitic steel pipe is Super304H.

[0140] The preparation method of the Cr / Ni-Cr based high temperature corrosion resistant coating of the present invention comprises the following steps:

[0141] 1) Solid raw materials: by mass percentage, including 60% Cr, 10% Ni, 20% Fe, 2% Al, 3% Ti, 3% Zr and 2% Co.

[0142] The above raw materials are mixed according to mass percentage, and then wet ball milled and dried to obtain a solid phase component;

[0143] 2) Liquid raw materials, including aluminum dihydrogen phosphate solution, water glass and curing agent;

[0144] The aluminum dihydrogen phosphate solution, water glass and curing agent are mixed, stirred evenly, reacted and filtered to obtain a liquid phase component, wherein the ratio of the aluminum dihydrogen phosphate solution, water glass, chromium trioxide and magnesium oxide is 100 mL: 25 mL: 25 g: 11 g, and the mass concentration of the aluminum dihydrogen phosphate solution is 37.5%.

[0145] 3) Mix the solid phase component and the liquid phase component at a ratio of 10 g: 2.5 mL to obtain a slurry;

[0146] 4) Spray the slurry onto the surface of the austenitic steel pipe, rinse it with a high-pressure water gun, then rinse it with alcohol or acetone, and then preheat it at 200°C for 40 minutes before spraying. The spraying pressure is 2MPa, the spraying thickness is 1mm, and the slurry coverage is not less than 98%. Natural air drying is used for 40 hours, and it is cured at 295°C for 24 hours. Finally, under the protection of inert gas, it is sintered at 1050°C for 8 minutes; rinse the residue with a high-pressure water gun or high-pressure airflow and then dry it naturally.

[0147] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0148] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A Cr / Ni-Cr based high temperature corrosion resistant coating material, characterized in that: It includes solid phase components and liquid phase components; The solid phase components include 40-80% Cr, 5-30% Ni, 2-20% Fe, 1-3% Al, 1-6% Ti, 0.5-4% Zr and 0-3% Co by mass percentage; 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 dosage ratio of the solid phase component to the 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 the 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 include 60-79% Cr, 10-30% Ni, 5-20% Fe, 1-2% Al, 2-4% Ti, 2-4% Zr and 1-3% Co in percentage by mass.

5. The Cr / Ni-Cr based high temperature corrosion resistant coating material according to claim 1, characterized in that: Calculated 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 according to any one of claims 1 to 5, characterized in that: The following steps are involved: The Cr / Ni-Cr based high temperature corrosion resistant coating material is sprayed onto the preheated pipeline surface, dried, cured, and sintered at 850-1050°C 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 30-40min; The spraying pressure is 0.5-2.0MPa, and the spraying thickness is 0.1-1.0mm.

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 curing time is 24-60h; The sintering time is 8-15min.

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

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

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