Spent fuel wear-resistant coating, preparation method thereof and spent fuel container

Abstract

The invention discloses a spent fuel wear-resistant coating, a preparation method thereof and a spent fuel container, the spent fuel container is used for transporting or storing spent fuel, the surface of the spent fuel container is provided with the wear-resistant coating, and the wear-resistant coating comprises a bonding layer and a lubricating layer from near to far from the surface of a substrate, the bonding layer comprises Al and A and does not comprise graphite, the lubricating layer comprises Al, A and nickel-coated graphite, and therefore the problems that in the prior art, a coating is insufficient in hardness, low in bonding strength, poor in abrasion resistance and too high in cost are effectively solved; and the reliability and the service life of the spent fuel container in a complex service environment are remarkably improved, the friction coefficient and the abrasion loss are reduced, and a more reliable guarantee is provided for safe transportation and long-term storage of the spent fuel.

Description

Technical Field

[0001] This invention relates to the field of spent fuel transportation protection, specifically to a spent fuel wear-resistant coating, its preparation method, and a spent fuel container. Background Technology

[0002] Existing dry transport and storage containers for spent fuel consist of a cylindrical body, a basket (containing the contents), and a siphon exhaust system. The cylindrical body is generally a cylindrical cavity structure that can hold the contents container or the fuel assembly basket. The inner wall of the cylinder is in direct contact with the contents container or basket. The inner surface isolation layer of the cylinder is an important part of the spent fuel transport and storage container, and its service environment is extremely complex: First, the inner surface of the cylinder is in direct contact with the storage tank (containing the contents) and is under pressure for a long time. Under accident conditions, the maximum compressive stress can reach 60MPa. Second, after the lid is opened, it will come into contact with the hot and humid atmosphere, resulting in corrosion. Third, the alternating rise and fall of temperature (-40℃~150℃) causes a significant decrease in the performance of the inner surface. Fourth, during transportation and hoisting, it will come into contact with the contents and undergo multiple frictions, resulting in damage and exposure of the carbon steel material of the cylinder, causing iron ion contamination. Currently, the widely used linings are all stainless steel linings. These stainless steel linings must be designed and manufactured in accordance with the standards of nuclear safety level 1 equipment. Non-destructive testing personnel and welders must meet the standard requirements of HAF602 and HAF603. The design thickness is up to 25mm, which has the disadvantages of high manufacturing cost and high raw material cost.

[0003] Aluminum and aluminum alloy-based metal-ceramic composite coatings offer advantages such as low cost, good formability, high bonding strength, excellent deposition efficiency, and strong corrosion resistance. However, these coatings suffer from low hardness and insufficient load-bearing capacity, often resulting in insufficient wear resistance under actual friction conditions. On the other hand, while introducing nickel-coated graphite self-lubricating phases into the coating helps achieve friction reduction and self-lubrication effects, it typically weakens the overall bonding strength of the coating.

[0004] Patent document CN116752076A discloses wear-resistant self-lubricating materials, wear-resistant self-lubricating composite coatings, their preparation methods, and mechanical metal parts. One type of wear-resistant self-lubricating material, by mass fraction, comprises the following components: 10%–20% nickel-coated graphite powder; 10%–20% spherical alumina powder; and the balance being copper-aluminum alloy powder. However, it does not further address the issue of improving the hardness, load-bearing capacity, and wear resistance of the inner surface isolation layer of the spent fuel dry transport and storage container while maintaining good bonding strength.

[0005] Patent document CN221858283U discloses an oxygen-free copper rod that reduces adjacent wear, and the oxygen-free copper rod body is also provided with an anti-slip structure. The wear-resistant coating can be an alumina coating or a silicon nitride coating. The anti-slip structure adopts a concave-convex layer and a fine pore structure design, and its surface is provided with a lubricating layer. The lubricating layer is a fixed lubricant, such as graphite and molybdenum disulfide; however, it does not solve the problem of improving the hardness, load-bearing capacity and wear resistance of the inner surface isolation layer of the spent fuel dry transport and storage container while maintaining good bonding strength.

[0006] In summary, neither of the two existing patents mentioned above has solved the problem of improving the hardness, load-bearing capacity, and wear resistance of the inner surface isolation layer of the spent fuel dry transport and storage container while maintaining good bonding strength. Summary of the Invention

[0007] Based on the above-mentioned technical problems, this invention proposes a wear-resistant coating for spent fuel, its preparation method, and a spent fuel container, which solves the problem of improving the hardness, load-bearing capacity, and wear resistance of the inner surface isolation layer of the spent fuel dry transport and storage container while maintaining good bonding strength.

[0008] To achieve the above objectives, this invention proposes a wear-resistant coating for spent fuel, a method for preparing the coating, and a spent fuel container.

[0009] A worn-resistant coating for spent fuel includes an adhesive layer and a lubricating layer extending from the substrate surface towards the substrate. The adhesive layer is composed of Al and A. And excluding graphite, the material composition of the lubricating layer includes Al and A. And nickel-coated graphite.

[0010] Furthermore, the A in the adhesive layer The mass percentage of Al is 35%-45%; the mass percentage of Al is 55%-65%.

[0011] Furthermore, the A in the lubrication layer The mass percentage of the material is 25%-35%; the mass percentage of Al is 35%-50%; and the mass percentage of the nickel-coated graphite is Ni / Gr, which is 20%-30%.

[0012] Furthermore, in the nickel-coated graphite, Ni accounts for 55%-65% of the total mass of the nickel-coated graphite, and Gr accounts for 35%-45% of the total mass of the nickel-coated graphite.

[0013] Furthermore, the thickness of the adhesive layer is 470μm-580μm; the thickness of the lubricating layer is 250μm-500μm.

[0014] Furthermore, the thickness of the lubricating layer is 450μm-480μm.

[0015] A method for preparing a wear-resistant coating for spent fuel containers as described above, comprising: S1: Degrease, remove rust, and roughen the base surface of the container by sandblasting to achieve a surface roughness Ra of 1.5μm-3.0μm; S2: Add the adhesive layer material to the equipment and spray 2-4 layers according to the spraying parameters of the adhesive layer to form the adhesive layer; S3: Add the lubricating layer material to the equipment, and spray 1-2 layers onto the surface of the adhesive layer according to the spraying parameters of the lubricating layer to form the lubricating layer.

[0016] Furthermore, before step S1, the procedure also includes: The adhesive layer comprises the Al powder and the A The powder is mixed in a three-dimensional mixer for 3-5 hours to obtain the binder layer raw material; the components of the lubricating layer include the Al powder and the A The powder and the nickel-coated graphite powder are mixed in a three-dimensional mixer for 3-5 hours to obtain the lubricating layer raw material; the adhesive layer raw material and the lubricating layer raw material are dried at 80℃-120℃ for 2-4 hours respectively.

[0017] Furthermore, the sandblasting roughening includes: The compressed air pressure of the sandblasting machine is 0.70MPa-0.85MPa, and the sandblasting particles are 80 mesh irregular A. The sandblasting angle is 45°-60°, the sandblasting distance is 25mm-30mm, and the spray gun moving speed is 25mm / s-35mm / s.

[0018] Furthermore, the spraying parameters of the adhesive layer include: Working gas pressure: 2.5MPa-3.5MPa; gas temperature: 300℃-450℃; spraying distance: 10mm-30mm; spray gun moving speed: 80mm / s-100mm / s.

[0019] Furthermore, the spraying parameters of the lubricating layer include: Working gas pressure: 2.5MPa-3.5MPa; gas temperature: 300℃-450℃; spraying distance: 10mm-30mm; spray gun moving speed: 80mm / s-120mm / s.

[0020] Furthermore, the turntable speed of the device is 0.8 rpm.

[0021] A spent fuel container for transporting or storing spent fuel, characterized in that an abrasion-resistant coating as described above is provided on the inner wall surface or the outer substrate.

[0022] Based on the above technical solution, the present invention has at least the following beneficial effects: 1. This invention proposes a wear-resistant coating for spent fuel, its preparation method, and a spent fuel container. Through a unique coating structure design and preparation method, significant technical effects are achieved. The wear-resistant coating consists of an adhesive layer and a lubricating layer. The adhesive layer is composed of Al and A. The composition is graphite-free, ensuring higher bonding strength in the adhesive layer and preventing a decrease in overall coating strength due to graphite introduction. This design ensures extremely high bonding strength between the coating and the container substrate, effectively resisting mechanical shocks and frictional wear that may occur during transportation and storage. Simultaneously, the lubricating layer introduces Al and A into the adhesive layer. The combination of nickel-coated graphite and other materials not only provides excellent self-lubricating properties and significantly reduces the coefficient of friction, but the uniform distribution of nickel-coated graphite further enhances the coating's wear resistance and corrosion resistance. In terms of preparation methods, the application of high-pressure cold spraying technology, combined with precise control of spraying parameters, ensures the uniform deposition of the bonding and lubricating layers, achieving high-quality coating formation. This combination of coating structure and preparation method effectively solves the problems of insufficient coating hardness, low bonding strength, poor wear resistance, and excessive cost in existing technologies. It also significantly improves the reliability and service life of spent fuel containers in complex service environments, reduces the coefficient of friction and wear, and provides a more reliable guarantee for the safe transportation and long-term storage of spent fuel.

[0023] 2. This invention proposes a wear-resistant coating for spent fuel, its preparation method, and a spent fuel container. By precisely controlling the mass percentage of each component in the adhesive layer and lubrication layer, experimental verification has shown that a significant improvement in coating performance has been achieved. Specifically, in the adhesive layer, A... The specific Al mass percentage setting gives the adhesive layer high strength and good oxidation resistance, while maintaining sufficient toughness to effectively resist mechanical impact and frictional wear; the A content in the lubricating layer... The mass percentages of Al and nickel-coated graphite (Ni / Gr) ensure lubrication performance while significantly reducing the coefficient of friction and wear through the self-lubricating properties of nickel-coated graphite. Simultaneously, the addition of nickel enhances the coating's hardness and wear resistance. Specifically, the mass ratio of Ni to Gr in nickel-coated graphite is 55%-65% and 35%-45%, respectively. This ratio allows the nickel to uniformly coat the graphite, maximizing the graphite's lubricating effect while avoiding its negative impact on coating strength, thus achieving a balance between strength and lubrication performance.

[0024] 3. This invention proposes a wear-resistant coating for spent fuel, its preparation method, and a spent fuel container. The process design involves spraying 2 to 4 layers of adhesive layer with a thickness of 500μm-550μm, and spraying 1 to 2 layers of lubrication layer with a thickness of 250μm-500μm. This design ensures the uniformity of coating thickness and optimizes the overall performance of the coating through reasonable layer number control. It ensures that the coating meets the requirements of wear resistance and lubrication while having sufficient thickness to buffer mechanical impact and resist corrosion.

[0025] 4. This invention proposes a wear-resistant coating for spent fuel, its preparation method, and a spent fuel container. By finely roughening the substrate surface through sandblasting, the bonding strength between the coating and the substrate is significantly improved, providing a solid foundation for the coating's firm adhesion. Simultaneously, the use of high-pressure cold spraying technology and precise control of spraying parameters achieves uniform deposition of the adhesive and lubricating layers, ensuring uniform coating thickness and composition distribution. Furthermore, drying and mixing the powder before spraying further improves the coating's quality and performance stability. These process optimizations work together to enable the coating to exhibit excellent wear resistance, corrosion resistance, and self-lubricating properties under complex operating conditions, significantly improving the overall performance and service life of the spent fuel container and reducing maintenance costs. Attached Figure Description

[0026] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 A magnified micrograph of a cross-section of a wear-resistant coating for a spent fuel container according to one embodiment is shown. Figure 2 A morphology diagram of aluminum powder according to one embodiment is shown; Figure 3 A morphology diagram of alumina powder according to one embodiment is shown; Figure 4 A morphology diagram of nickel-coated graphite powder of one embodiment is shown; Figure 5 A surface morphology diagram of a wear-resistant coating for a spent fuel container according to one embodiment is shown. Figure 6 An enlarged view of the surface morphology of a wear-resistant coating for a spent fuel container according to one embodiment is shown. Figure 7 A magnified micrograph of a cross-section of the wear-resistant coating on a spent fuel container according to another embodiment is shown; Figure 8 A magnified micrograph of a cross-section of the wear-resistant coating on a spent fuel container according to another embodiment is shown; Figure 9A magnified micrograph of a cross-section of a wear-resistant coating on a spent fuel container is shown. Figure 10 A magnified micrograph of a cross-section of the wear-resistant coating on another comparative spent fuel container is shown. Figure 11 A schematic diagram showing the variation of the friction coefficient of the wear-resistant coating in different embodiments and comparative examples is shown; Figure 12 Schematic diagrams showing the overall frictional properties of wear-resistant coatings in different embodiments and comparative examples are provided. Figure 13 A schematic diagram of a bonding strength test process according to one embodiment is shown; Figure 14 Schematic diagrams showing the bonding strength properties of wear-resistant coatings in different embodiments and comparative examples are provided. Detailed Implementation

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] The present invention will be further described in detail below with reference to specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed by the present invention. The term "comprising" indicates the presence of a feature, but does not exclude the presence or addition of one or more other features. The terms "lateral," "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the purpose of 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 the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] In this description, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0030] Example 1

[0031] This invention proposes a wear-resistant coating for spent fuel, its preparation method, and a spent fuel container.

[0032] In this preferred embodiment, a worn-resistant coating for spent fuel is as follows: Figure 1 As shown, the substrate surface includes an adhesive layer and a lubricating layer from near to far. The adhesive layer is composed of Al and A. And excluding graphite, the material composition of the lubricating layer includes Al and A. Nickel-coated graphite; the adhesive layer thickness is 565 μm, and the lubricant layer thickness is 478 μm; the mass percentage of Al in the adhesive layer is 65%, and A... The mass percentage is 35%; A in the lubricating layer The mass percentage of Ni is 35%, the mass percentage of Al is 35%, and the mass percentage of nickel-coated graphite is 30%. In the nickel-coated graphite, Ni accounts for 65% of the total mass of the nickel-coated graphite, and Gr accounts for 35% of the total mass of the nickel-coated graphite. In specific implementations, the wear-resistant coating may contain a small amount of impurities, the mass percentage of which is less than 0.05%, and the impact on the wear-resistant coating is negligible. In this invention, "Gr" refers to graphene in nickel-coated graphite.

[0033] Furthermore, such as Figure 5 The image shown is a surface morphology diagram of a spent fuel wear-resistant coating in this embodiment. Figure 6 The diagram shown is a surface morphology method diagram, which includes nickel-coated graphite after spraying.

[0034] Furthermore, in this embodiment, a method for preparing a wear-resistant coating for spent fuel includes: S1: The base surface of the container is degreased, derusted, and roughened by sandblasting to achieve a surface roughness Ra of 1.5μm; S2: Add the adhesive layer material to the equipment and spray two layers according to the spraying parameters of the adhesive layer to form the adhesive layer; S3: Add the lubricating material to the equipment, and spray two layers onto the surface of the adhesive layer according to the spraying parameters of the lubricating layer to form the lubricating layer.

[0035] Specifically, in this embodiment, before step S1, the method further includes: weighing 130g of aluminum powder and 70g of A using a balance. Powder mixture as raw material for the binder layer; weigh 70g aluminum powder and 70g A using a balance. The powder and 60g of nickel-coated graphite powder were mixed as the raw material powder for the lubricating layer, wherein the median particle size (D50) of the aluminum powder was 30μm (purity ≥99.0%). The powder has a particle size of approximately 40 μm (purity ≥ 99.0%), and the nickel-coated graphite powder has a particle size of approximately 48 μm (purity ≥ 98.0%); the method of claim 7, characterized in that, before step S1, it further includes: mixing the Al powder and the A powder, which are components of the adhesive layer. The powder is mixed in a three-dimensional mixer to obtain the binder layer raw material; the components of the lubricating layer include the Al powder and the A The powder and the nickel-coated graphite powder are mixed in a three-dimensional mixer for 4 hours to obtain the lubricating layer raw material; the bonding layer raw material and the lubricating layer raw material are dried at 80°C for 4 hours.

[0036] Furthermore, such as Figure 2 The image shown is a morphology diagram of the aluminum powder in this embodiment. Figure 3 The figure shown is A in this embodiment. Morphology of the powder, such as Figure 4 The image shown is a morphology diagram of the nickel-coated graphite powder in this embodiment.

[0037] Furthermore, the equipment can be a cold spray coating device.

[0038] Specifically, in step S1 of this embodiment, the ductile iron surface is sequentially polished with 300-grit tungsten carbide sandpaper, ultrasonically cleaned in an ethanol solution, and then cleaned with 80-grit polygonal A sandpaper under a gas pressure of 0.80 MPa. A 45° sandblasting process is performed at a distance of 25 mm and a moving speed of 25 mm / s to remove the oxide layer from the surface of the metal substrate material.

[0039] Specifically, in step S2 of this embodiment, the spraying parameters for the adhesive layer are: working gas pressure 3MPa, gas temperature 450℃, spraying distance 20mm, and spray gun moving speed 100mm / s.

[0040] Specifically, in step S3 of this embodiment, the spraying parameters for the lubricating layer are: working gas pressure 3MPa, gas temperature 450℃, spraying distance 20mm, and spray gun moving speed 120mm / s.

[0041] Furthermore, the turntable speed of the device is 0.8 rpm.

[0042] Specifically, in this embodiment, the following is obtained: Figure 1 The wear-resistant coating shown in the SEM image was tested using a Vickers hardness tester. The average micro Vickers hardness was measured to be 55 HV. 0.5 The wear-resistant coating prepared in this embodiment was subjected to a bonding strength test, and the average bonding strength of the wear-resistant coating prepared in this embodiment was measured to be 43.59 MPa. The wear-resistant coating prepared in this embodiment was also subjected to a tribological test, and the coefficient of friction between the wear-resistant coating prepared in this embodiment and the friction pair Si3N4 microspheres was measured. The test process is as follows: Figure 13 As shown, its average coefficient of friction is 0.768, the wear track depth is 0.112 mm, and the wear rate is 0.421. 10 -3 / Nm.

[0043] A spent fuel container, wherein the inner wall surface or the outer substrate is provided with a wear-resistant coating formed by spraying in the above steps.

[0044] Furthermore, corrosion resistance tests were conducted on the spent fuel containers with the wear-resistant coating. The containers were sprayed in a salt spray chamber for 24 hours at an operating temperature of (35±2)℃. Before the test, the coating samples were ultrasonically cleaned with acetone and protected with a peelable film on the back and sides. First, a NaCl solution for creating the salt spray environment was prepared by dissolving NaCl in water to prepare a NaCl solution with a concentration of 50±5 g / L, which was then filtered and sealed. The containers were placed in the salt spray chamber, and the test time was set for a total of 1008 hours. Samples were taken out for testing at cycles of 0h, 168h, 336h, 504h, 672h, 840h, 864h, 888h, 912h, 936h, 960h, 984h, and 1008h. The test results showed that the coating was undamaged, indicating that the coating has good corrosion resistance.

[0045] Example 2

[0046] A type of wear-resistant coating for spent fuel, such as Figure 7 As shown, the substrate surface includes an adhesive layer and a lubricating layer from near to far. The adhesive layer is composed of Al and A. And excluding graphite, the material composition of the lubricating layer includes Al and A. And nickel-coated graphite; the adhesive layer thickness is 477 μm, and the lubricating layer thickness is 454 μm. In other embodiments, the adhesive layer thickness can be 470 μm ± 5 μm, and the lubricating layer thickness can be 500 μm ± 5 μm; the mass percentage of Al in the adhesive layer is 60%, and A The mass percentage of Al in the lubricating layer is 40%; the mass percentage of Al in the lubricating layer is 50%. The mass percentage of nickel-coated graphite is 30%, and the mass percentage of nickel-coated graphite is 20%. In the nickel-coated graphite, the mass of Ni accounts for 60% of the total mass of the nickel-coated graphite, and the mass of Gr accounts for 40% of the total mass of the nickel-coated graphite. In specific implementations, the wear-resistant coating may contain a small amount of impurities, the mass percentage of which is less than 0.05%, and the impact on the wear-resistant coating is negligible.

[0047] Furthermore, in this embodiment, a method for preparing a wear-resistant coating for spent fuel includes: S1: Degrease, remove rust, and roughen the base surface of the container by sandblasting to make its surface roughness Ra 3μm; S2: Add the adhesive layer material to the equipment and spray two layers according to the spraying parameters of the adhesive layer to form the adhesive layer; S3: Add the lubricating material to the equipment, and spray two layers onto the surface of the adhesive layer according to the spraying parameters of the lubricating layer to form the lubricating layer.

[0048] Specifically, in this embodiment, before step S1, the method further includes: weighing 120g of aluminum powder and 80g of A using a balance. The powder mixture is used as the raw material for the binder layer. 100g of aluminum powder and 60g of A are weighed using a balance. The powder was mixed with 40g of nickel-coated graphite powder as the raw material powder for the lubricating layer, wherein the median particle size (D50) of the aluminum powder was 30μm (purity ≥99.0%). The powder has a particle size of approximately 50 μm (purity ≥ 99.0%), and the nickel-coated graphite powder has a particle size of approximately 52 μm (purity ≥ 98.0%); the binder layer comprises the Al powder and the A... The powder was mixed in a three-dimensional mixer for 5 hours to obtain the binder layer raw material; the components of the lubricating layer included the Al powder and the A The powder and the nickel-coated graphite powder are mixed in a three-dimensional mixer for 5 hours to obtain the lubricating layer raw material; the binder layer raw material and the lubricating layer raw material are dried at 120°C for 4 hours.

[0049] Specifically, in step S1 of this embodiment, the ductile iron surface is sequentially polished with 300-grit tungsten carbide sandpaper, ultrasonically cleaned in an ethanol solution, and then cleaned with 80-grit polygonal A sandpaper under a gas pressure of 0.85 MPa. A 60° sandblasting process is performed at a distance of 30 mm and a moving speed of 35 mm / s to remove the oxide layer from the surface of the metal substrate material.

[0050] Specifically, in step S2 of this embodiment, the spraying parameters for the adhesive layer are: working gas pressure 2.5MPa, gas temperature 300℃, spraying distance 10mm, and spray gun moving speed 80mm / s.

[0051] Specifically, in step S3 of this embodiment, the spraying parameters for the lubricating layer are: working gas pressure 2.5MPa, gas temperature 300℃, spraying distance 10mm, and spray gun moving speed 80mm / s.

[0052] Furthermore, the turntable speed of the device is 0.8 rpm.

[0053] Specifically, in this embodiment, the following is obtained: Figure 7 The wear-resistant coating shown in the SEM image was tested using a Vickers hardness tester. The average micro Vickers hardness was measured to be 48 HV. 0.5The wear-resistant coating prepared in this embodiment was subjected to a bonding strength test, and the average bonding strength of the wear-resistant coating prepared in this embodiment was measured to be 43.44 MPa. The wear-resistant coating prepared in this embodiment was also subjected to a tribological test, and the coefficient of friction between the wear-resistant coating prepared in this embodiment and the friction pair Si3N4 microspheres was measured. The test process is as follows: Figure 13 As shown, its average coefficient of friction is 0.799, the wear track depth is 0.115 mm, and the wear rate is 0.424. 10 -3 / Nm.

[0054] A spent fuel container, wherein the inner wall surface or the outer substrate is provided with a wear-resistant coating formed by spraying in the above steps.

[0055] Furthermore, corrosion resistance tests were conducted on the spent fuel containers with the wear-resistant coating. The containers were sprayed in a salt spray chamber for 24 hours at an operating temperature of (35±2)℃. Before the test, the coating samples were ultrasonically cleaned with acetone and protected with a peelable film on the back and sides. First, a NaCl solution for creating the salt spray environment was prepared by dissolving NaCl in water to prepare a NaCl solution with a concentration of 50±5 g / L, which was then filtered and sealed. The containers were placed in the salt spray chamber, and the test time was set for a total of 1008 hours. Samples were taken out for testing according to the periodic pattern of 0h, 168h, 336h, 504h, 672h, 840h, 864h, 888h, 912h, 936h, 960h, 984h, and 1008h. The test results showed that the coating was undamaged, indicating that the coating has good corrosion resistance.

[0056] Example 3

[0057] A type of wear-resistant coating for spent fuel, such as Figure 8 As shown, the substrate surface includes an adhesive layer and a lubricating layer from near to far. The adhesive layer is composed of Al and A. And excluding graphite, the material composition of the lubricating layer includes Al and A. And nickel-coated graphite; the adhesive layer thickness is 537 μm, and the lubricating layer thickness is 281 μm. In other embodiments, the adhesive layer thickness can be 580 μm ± 5 μm, and the lubricating layer thickness can be 250 μm ± 5 μm; the mass percentage of Al in the adhesive layer is 55%, and A The mass percentage of A in the lubricating layer is 45%; The mass percentage of Ni is 25%, the mass percentage of Al is 50%, and the mass percentage of nickel-coated graphite is 25%. In the nickel-coated graphite, Ni accounts for 55% of the total mass of the nickel-coated graphite, and Gr accounts for 45% of the total mass of the nickel-coated graphite. In specific implementations, the wear-resistant coating may contain a small amount of impurities, the mass percentage of which is less than 0.05%, and the impact on the wear-resistant coating is negligible.

[0058] Furthermore, in this embodiment, a method for preparing a wear-resistant coating for spent fuel includes: S1: Degrease, remove rust, and roughen the base surface of the container by sandblasting to make its surface roughness Ra 2μm; S2: Add the adhesive layer material to the equipment, and spray two layers according to the spraying parameters of the adhesive layer. In other embodiments, adjust the spraying parameters to spray four layers to form the adhesive layer. S3: Add the lubricating layer material to the equipment, and spray one layer onto the surface of the adhesive layer according to the spraying parameters of the lubricating layer to form the lubricating layer.

[0059] Specifically, in this embodiment, before step S1, the method further includes: weighing 110g of aluminum powder and 90g of A using a balance. The powder mixture is used as the raw material for the binder layer. 100g of aluminum powder and 50g of A are weighed using a balance. The powder and 50g of nickel-coated graphite powder were mixed as the raw material powder for the lubricating layer, wherein the median particle size (D50) of the aluminum powder was 30μm (purity ≥99.0%). The powder has a particle size of approximately 35 μm (purity ≥ 99.0%), and the nickel-coated graphite powder has a particle size of approximately 45 μm (purity ≥ 98.0%); the binder layer comprises the Al powder and the A... The powder is mixed in a three-dimensional mixer for 3 hours to obtain the binder layer raw material; the components of the lubricating layer include the Al powder and the A The powder and the nickel-coated graphite powder are mixed in a three-dimensional mixer to obtain the lubricating layer material; the bonding layer material and the lubricating layer material are dried at 80°C for 4 hours.

[0060] Specifically, in step S1 of this embodiment, the ductile iron surface is sequentially polished with 300-grit tungsten carbide sandpaper, ultrasonically cleaned in an ethanol solution, and then cleaned with 80-grit polygonal A sandpaper under a gas pressure of 0.70 MPa. A 60° sandblasting process is performed at a distance of 25 mm and a moving speed of 30 mm / s to remove the oxide layer from the surface of the metal substrate material.

[0061] Specifically, in step S2 of this embodiment, the spraying parameters for the adhesive layer are: working gas pressure 3.5MPa, gas temperature 450℃, spraying distance 30mm, and spray gun moving speed 85mm / s. In other embodiments, it can also be 150mm / s.

[0062] Specifically, in step S3 of this embodiment, the spraying parameters for the lubricating layer are: working gas pressure 3.5MPa, gas temperature 450℃, spraying distance 30mm, and spray gun moving speed 110mm / s.

[0063] Furthermore, the turntable speed of the device is 0.8 rpm.

[0064] Specifically, in this embodiment, the following is obtained: Figure 8 The wear-resistant coating shown in the SEM image was tested using a Vickers hardness tester. The average micro Vickers hardness was measured to be 43 HV. 0.5 The wear-resistant coating prepared in this embodiment was subjected to a bonding strength test, and the average bonding strength of the wear-resistant coating prepared in this embodiment was measured to be 42.21 MPa. The wear-resistant coating prepared in this embodiment was also subjected to a tribological test, and the coefficient of friction between the wear-resistant coating prepared in this embodiment and the friction pair Si3N4 microspheres was measured. The test process is as follows: Figure 13 As shown, its average coefficient of friction is 0.855, the wear track depth is 0.127 mm, and the wear rate is 0.544. 10 -3 / Nm.

[0065] A spent fuel container, wherein the inner wall surface or the outer substrate is provided with a wear-resistant coating formed by spraying in the above steps.

[0066] Furthermore, corrosion resistance tests were conducted on the spent fuel containers with the wear-resistant coating. The containers were sprayed in a salt spray chamber for 24 hours at an operating temperature of (35±2)℃. Before the test, the coating samples were ultrasonically cleaned with acetone and protected with a peelable film on the back and sides. First, a NaCl solution for creating the salt spray environment was prepared by dissolving NaCl in water to prepare a NaCl solution with a concentration of 50±5 g / L, which was then filtered and sealed. The containers were placed in the salt spray chamber, and the test time was set for a total of 1008 hours. Samples were taken out for testing at cycles of 0h, 168h, 336h, 504h, 672h, 840h, 864h, 888h, 912h, 936h, 960h, 984h, and 1008h. The test results showed that the coating was undamaged, indicating that the coating has good corrosion resistance.

[0067] Comparative Example 1

[0068] Instead of using the adhesive layer and lubricating layer of this invention, only a single adhesive layer coating is provided, wherein A The mass percentage of aluminum powder is 30%, and the mass percentage of Al is 70%. Using the preparation method described in Example 1 above, 140g of aluminum powder and 60g of Al were weighed using a balance. The powder is used to degrease, derust, and roughen the base surface of the container by sandblasting, so that its surface roughness Ra is 1.5μm. The raw material powder is added to the equipment and sprayed in 4 layers according to the spraying parameters in Example 1, which will not be repeated here, to form a wear-resistant coating.

[0069] Furthermore, the wear-resistant coating in this comparative example was subjected to performance testing, and its SEM image is shown below. Figure 9 As shown, the layer thickness is 1068 μm. The hardness of the dual-layer functional integrated coating prepared in the example was measured using a Vickers hardness tester, and the average micro Vickers hardness was found to be 35 HV. 0.5 The coating was subjected to friction and wear tests to determine the coefficient of friction between the wear-resistant coating prepared in this embodiment and the friction pair Si3N4 microspheres. The test process is as follows: Figure 13 As shown, its average coefficient of friction is 1.148, the wear track depth is 0.175 mm, and the wear rate is 0.715. 10 -3 / Nm.

[0070] Comparative Example 2

[0071] Instead of using the adhesive layer and lubricating layer of this invention, only a single-layer lubricating coating is provided, wherein A The mass percentage of aluminum powder is 20%, the mass percentage of Al is 60%, and the mass percentage of nickel-coated graphite is 20%. Using the preparation method described in Example 1 above, 120g of aluminum powder and 40g of Al were weighed using a balance. The powder and 40g of nickel-coated graphite powder are mixed as raw material powder. The base surface of the container is degreased, derusted and roughened by sandblasting to make its surface roughness Ra 1.5μm. The raw material powder is added to the equipment and sprayed in 4 layers according to the spraying parameters in Example 1, which will not be repeated here, to form a lubricating coating.

[0072] Furthermore, the wear-resistant coating in this comparative example was subjected to performance testing, and its SEM image is shown below. Figure 10 As shown, the layer thickness is 749 μm. The hardness of the dual-layer functional integrated coating prepared in the example was measured using a Vickers hardness tester, and the average micro Vickers hardness was measured to be 38 HV. 0.5 The coating was subjected to friction and wear tests to determine the coefficient of friction between the wear-resistant coating prepared in this embodiment and the friction pair Si3N4 microspheres. The test process is as follows: Figure 13As shown, its average coefficient of friction is 0.879, the wear track depth is 0.135 mm, and the wear rate is 0.623. 10 -3 / Nm.

[0073] like Figure 11 The figure shows a comparison of the friction coefficients of Example 1, Example 2 and Comparative Example 1, where a is the friction coefficient curve of the wear-resistant coating in Example 1 as a function of time, b is the friction coefficient curve of the wear-resistant coating in Example 2 as a function of time, and d is the friction coefficient curve of the wear-resistant coating in Comparative Example 1 as a function of time. It can be seen that compared with Comparative Example 1, the friction coefficients of the wear-resistant coatings in Example 1 and Example 2 of the present invention are significantly reduced.

[0074] like Figure 12 The figure shows a comparison of the overall friction performance of Examples 1, 2, 3, 1, and 2. The average friction coefficient, wear depth, and wear rate of Examples 1 and 2 are lower than those of Comparative Example 1. This result indicates that the wear resistance of the wear-resistant coatings in Examples 1, 2, and 3 is significantly improved compared to Comparative Example 1 and 2. When spent fuel is transported or stored in containers, containers coated with the wear-resistant coatings prepared in Examples 1, 2, and 3 are less likely to break due to friction or collision, thus preventing damage to the container body.

[0075] like Figure 14 The diagram shows a comparison of the bonding strength performance of Embodiment 1, Example 2, Example 3, Comparative Example 1, and Comparative Example 2. The bonding strengths of Embodiment 1, Example 2, and Example 3 are 43.59 MPa, 43.44 MPa, and 42.21 MPa, respectively, which are all higher than the 33.37 MPa and 23.66 MPa of Comparative Example 1 and Comparative Example 2. This indicates that the wear-resistant coatings prepared in the embodiments have a higher bonding strength with the substrate and are less likely to fall off. Therefore, the wear-resistant coatings retain longer on the spent fuel container.

[0076] In summary, as can be seen from the above description, the embodiments of the present invention achieve the following technical effects: 1. This invention proposes a wear-resistant coating for spent fuel, its preparation method, and a spent fuel container. Through a unique coating structure design and preparation method, significant technical effects are achieved. The wear-resistant coating consists of an adhesive layer and a lubricating layer. The adhesive layer is composed of Al and A. The composition is graphite-free, ensuring higher bonding strength in the adhesive layer and preventing a decrease in overall coating strength due to graphite introduction. This design ensures extremely high bonding strength between the coating and the container substrate, effectively resisting mechanical shocks and frictional wear that may occur during transportation and storage. Simultaneously, the lubricating layer introduces Al and A into the adhesive layer. The combination of nickel-coated graphite and other materials not only provides excellent self-lubricating properties and significantly reduces the coefficient of friction, but the uniform distribution of nickel-coated graphite further enhances the coating's wear resistance and corrosion resistance. In terms of preparation, the application of high-pressure cold spraying technology, combined with precise control of spraying parameters, ensures the uniform deposition of the adhesive and lubricating layers, achieving high-quality coating formation. This combination of coating structure and preparation method effectively solves the problems of insufficient coating hardness, low bonding strength, poor wear resistance, and excessive cost in existing technologies. It also significantly improves the reliability and service life of spent fuel containers in complex service environments, reduces the coefficient of friction and wear, and provides a more reliable guarantee for the safe transportation and long-term storage of spent fuel.

[0077] 2. This invention proposes a wear-resistant coating for spent fuel, its preparation method, and a spent fuel container. By precisely controlling the mass percentage of each component in the adhesive layer and lubrication layer, experimental verification has shown that a significant improvement in coating performance has been achieved. Specifically, in the adhesive layer, A... The specific Al mass percentage setting gives the adhesive layer high strength and good oxidation resistance, while maintaining sufficient toughness to effectively resist mechanical impact and frictional wear; the A content in the lubricating layer... The mass percentages of Al and nickel-coated graphite (Ni / Gr) ensure lubrication performance while significantly reducing the coefficient of friction and wear through the self-lubricating properties of nickel-coated graphite. Simultaneously, the addition of nickel enhances the coating's hardness and wear resistance. Specifically, the mass ratio of Ni to Gr in nickel-coated graphite is 55%-65% and 35%-45%, respectively. This ratio allows the nickel to uniformly coat the graphite, maximizing the graphite's lubricating effect while avoiding its negative impact on coating strength, thus achieving a balance between strength and lubrication performance.

[0078] 3. This invention proposes a wear-resistant coating for spent fuel, its preparation method, and a spent fuel container. The process design involves spraying 2 to 4 layers of adhesive layer with a thickness of 500μm-550μm, and spraying 1 to 2 layers of lubrication layer with a thickness of 250μm-500μm. This design ensures the uniformity of coating thickness and optimizes the overall performance of the coating through reasonable layer number control. It ensures that the coating meets the requirements of wear resistance and lubrication while having sufficient thickness to buffer mechanical impact and resist corrosion.

[0079] 4. This invention proposes a wear-resistant coating for spent fuel, its preparation method, and a spent fuel container. By finely roughening the substrate surface through sandblasting, the bonding strength between the coating and the substrate is significantly improved, providing a solid foundation for the coating's firm adhesion. Simultaneously, the use of high-pressure cold spraying technology and precise control of spraying parameters achieves uniform deposition of the adhesive and lubricating layers, ensuring uniform coating thickness and composition distribution. Furthermore, drying and mixing the powder before spraying further improves the coating's quality and performance stability. These process optimizations work together to enable the coating to exhibit excellent wear resistance, corrosion resistance, and self-lubricating properties under complex operating conditions, significantly improving the overall performance and service life of the spent fuel container and reducing maintenance costs.

[0080] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0081] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0082] It should be noted that, in the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

Claims

1. A wear-resistant coating for spent fuel containers, characterized in that, Starting from the substrate surface and extending outwards, the layers include an adhesive layer and a lubricating layer. The adhesive layer is composed of Al and A. And excluding graphite, the material composition of the lubricating layer includes Al and A. And nickel-coated graphite.

2. The wear-resistant coating according to claim 1, characterized in that, The A in the adhesive layer The mass percentage of the substance is 35%-45%; the mass percentage of Al is 55%-65%; and the mass percentage of impurity elements is 0.1%-0.5%.

3. The wear-resistant coating according to claim 1, characterized in that, A in the lubricating layer The mass percentage of the material is 25%-35%; the mass percentage of Al is 35%-50%; and the mass percentage of the nickel-coated graphite is Ni / Gr, which is 20%-30%.

4. The wear-resistant coating according to claim 1, characterized in that, In the nickel-coated graphite, Ni accounts for 55%-65% of the total mass of the nickel-coated graphite, and Gr accounts for 35%-45% of the total mass of the nickel-coated graphite.

5. The wear-resistant coating according to claim 1, characterized in that, The thickness of the adhesive layer is 470μm-580μm; The thickness of the lubricating layer is 250μm-500μm.

6. The wear-resistant coating according to claim 5, characterized in that, The thickness of the lubricating layer is 450μm-480μm.

7. A method for preparing a wear-resistant coating for spent fuel containers as described in any one of claims 1-6, characterized in that, include: S1: Degrease, remove rust, and roughen the base surface of the container by sandblasting to achieve a surface roughness Ra of 1.5μm-3.0μm; S2: Add the adhesive layer material to the equipment and spray 2-4 layers according to the spraying parameters of the adhesive layer to form the adhesive layer; S3: Add the lubricating layer material to the equipment, and spray 1-2 layers onto the surface of the adhesive layer according to the spraying parameters of the lubricating layer to form the lubricating layer.

8. The method according to claim 7, characterized in that, Before step S1, the method further includes: The adhesive layer comprises the Al powder and the A The powder is mixed in a three-dimensional mixer for 3-5 hours to obtain the binder layer material; The components of the lubricating layer include the Al powder and the A The powder and the nickel-coated graphite powder are mixed in a three-dimensional mixer for 3-5 hours to obtain the lubricating layer raw material; The adhesive layer material and the lubricating layer material are dried at 80℃-120℃ for 2h-4h respectively.

9. The method according to claim 7, characterized in that, The sandblasting roughening includes: The compressed air pressure of the sandblasting machine is 0.70MPa-0.85MPa, and the sandblasting particles are 75-80 mesh A. The sandblasting angle is 45°-60°, the sandblasting distance is 25mm-30mm, and the spray gun moving speed is 25mm / s-35mm / s.

10. The method according to claim 7, characterized in that, The spraying parameters for the adhesive layer include: Working gas pressure: 2.5MPa-3.5MPa; gas temperature: 300℃-450℃; spraying distance: 10mm-30mm; spray gun moving speed: 80mm / s-100mm / s.

11. The method according to claim 7, characterized in that, The spraying parameters for the lubricating layer include: Working gas pressure: 2.5MPa-3.5MPa; gas temperature: 300℃-450℃; spraying distance: 10mm-30mm; spray gun moving speed: 80mm / s-120mm / s.

12. The method according to claim 7, characterized in that, The turntable speed of the equipment is 0.8 rpm.

13. A spent fuel container for transporting or storing spent fuel, characterized in that, The inner wall surface or the outer substrate is provided with a wear-resistant coating for spent fuel containers as described in any one of claims 1-6.

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