A surface treatment method for a refractory element alloy molten salt vapor corrosion resistant layer

Abstract

The present application relates to the field of molten salt corrosion, in particular to a surface treatment method of a refractory element alloy molten salt vapor corrosion resistant layer. The method comprises the following steps: (1) infiltrating Si atoms and Al atoms on the surface of the refractory element alloy part, forming an X n (Si, Al) m composite compound layer, X is a refractory element or an alloy thereof; (2) performing pre-oxidation treatment on the refractory element alloy part with Si atoms and Al atoms infiltrated on the surface, forming a SiO2 / Al2O3 composite oxide layer on the surface. The present application solves the problem that the existing technology cannot provide effective protection for the refractory element alloy in the molten salt vapor environment, and the problems that it is difficult to simultaneously achieve the insulation of molten salt vapor and the inhibition of refractory element oxidation, and the protective layer is prone to cracking and failure due to the oxidation of refractory elements, and is suitable for the corrosion protection of refractory element alloy structural parts in the molten salt nuclear reactor fuel salt dry reprocessing device under the chloride molten salt vapor environment.

Description

Technical Field

[0001] This invention relates to the field of molten salt corrosion, specifically to a surface treatment method for a refractory element alloy resistant molten salt vapor corrosion layer, which is particularly suitable for corrosion protection of refractory element alloy structural components in a chloride molten salt vapor environment in a dry reprocessing unit for fuel salt in a molten salt nuclear reactor. Background Technology

[0002] Molten halide salts (primarily chlorides) serve as fuel solvents and coolants in various molten salt reactor (MSR) concepts, and also as electrolytes in the electrochemical separation process of spent fuel. Molten salt vacuum distillation and recovery units are used to separate fission products (FP) and minor actinides (MA) generated during operation, as well as recyclable resources (233U, Pu). These units are essential for maintaining the core's criticality; therefore, molten salt reactor system design is typically accompanied by online or offline reprocessing. A major challenge in the use of molten salt vacuum distillation and recovery units is the corrosion of structural materials caused by these extreme environments. In nuclear reactor systems, dense oxide layers are typically used as corrosion barriers. For example, in liquid lead alloy-cooled reactors, the oxide layer formed on the surface of structural materials effectively reduces corrosion caused by the liquid metal coolant. However, in molten salt nuclear reactors, the commonly used alloy is nickel-based Hastelloy. In molten chloride salt systems, the reaction of chloride ions with the metal makes it thermodynamically difficult for an oxide barrier to form.

[0003] Molten halide salt corrosion occurs through active dissolution, lacking an oxide layer formation mechanism; instead, it employs a so-called "fluxing" mechanism. This involves a synergistic process of alternating chloride dissolution and oxide formation, which degrades the metal, thus exacerbating the degradation. Furthermore, the dissolution of small amounts of oxygen in the molten salt vapor, while causing metal oxidation, fails to form a complete oxide layer, further intensifying the formation and shedding of oxides and halides. In more extreme high-temperature service environments, nickel-based alloys exhibit significant softening due to their melting point limitations. Therefore, alloys of refractory elements with higher melting points become ideal candidates. However, refractory elements are also susceptible to oxide and chloride dissolution corrosion. Therefore, maintaining metal stability in extremely high-temperature environments (above 900 degrees Celsius) is a crucial issue that needs to be addressed in the selection of spent fuel reprocessing vessels for molten salt reactors.

[0004] Preparing a MoSi2 protective layer on a metal surface can effectively protect the alloy from oxidation in ultra-high temperature air environments. The principle is that after MoSi2 oxidizes, it forms a SiO2 layer, which isolates oxygen from direct contact with the metal substrate, thus achieving high-temperature oxidation protection. However, this method requires first spraying Mo powder onto the metal surface, creating an interface between the metal and the MoSi2 layer, which can lead to poor adhesion between the coating and the substrate. Furthermore, the preparation process is complex, requiring high-vacuum equipment and consumables such as Ar gas protection. The coating preparation process is complex and expensive, and there are limitations on the shape of the workpiece, making it difficult to uniformly coat complex-shaped workpieces with Mo powder.

[0005] Patent CN117265531A discloses a molten salt corrosion resistant coating comprising a gradient-structured nickel-rhenium inner layer and its preparation method. The coating consists of a gradient-structured nickel-rhenium inner layer and a pure nickel outer layer, with the substrate limited to high-temperature alloys such as GH3535 and Inconel-617. Its core design objective is to hinder element interdiffusion between the coating and the substrate, rather than addressing the synergistic problem of oxidation and corrosion of refractory elements in molten salt environments. From a protective principle perspective, both the nickel-rhenium inner layer and the pure nickel outer layer are metallic phases, easily dissolved by halide ions in high-temperature molten salts, making long-term stable protection above 900°C impossible. Furthermore, its preparation requires complex processes such as electroplating and physical vapor deposition, demanding sophisticated equipment and making it unsuitable for complex-shaped refractory alloy components. Patent CN118792611A discloses a method for preparing a chloride-resistant molten salt corrosion layer on the surface of high-temperature alloys. Targeting high-temperature alloys such as austenitic stainless steel or nickel-based alloys, the method uses a single aluminizing process to prepare the chloride-resistant molten salt corrosion layer. From an elemental perspective, it relies solely on Al to form the Al2O3 protective layer. However, Al alone cannot inhibit the oxidation of refractory elements. If this process is applied to refractory alloys, the refractory elements will preferentially oxidize to form large oxide particles, resulting in a discontinuous and easily cracked Al2O3 layer; furthermore, the aluminizing process requires argon protection. This solution is only suitable for molten salt corrosion environments at 800℃ under Ar protection and cannot meet the ultra-high temperature requirements of spent fuel reprocessing containers in molten salt nuclear reactors.

[0006] In summary, existing technologies cannot solve the oxidation-corrosion problem of refractory alloys in molten salt steam environments above 900℃. It is necessary to develop a surface treatment method that is suitable for refractory alloys, has excellent protective performance, and is simple to process. Summary of the Invention

[0007] The purpose of this invention is to provide a surface treatment method for a refractory element alloy resistant to molten salt vapor corrosion layer, which solves the problem that the prior art cannot provide effective protection against corrosion and softening of refractory element alloys in molten salt vapor environment, as well as the problem that it is difficult to simultaneously isolate molten salt vapor and inhibit the oxidation of refractory elements, and that the coating is prone to cracking and failure due to oxidation of refractory elements.

[0008] The technical solution of this invention is:

[0009] A surface treatment method for a refractory element alloy resistant to molten salt vapor corrosion layer includes the following steps:

[0010] (1) Si and Al atoms are diffused into the surface of refractory alloy parts to form X on the metal surface. n (Si,Al) m A composite compound layer, where X is a refractory element or its alloy;

[0011] (2) For refractory alloy parts with Si and Al atoms infiltrated on the surface, a pre-oxidation treatment is performed to form a SiO2 / Al2O3 composite oxide layer on the surface.

[0012] The surface treatment method for the refractory element alloy resistant salt vapor corrosion layer, wherein the refractory element is one or more of titanium, vanadium, niobium, molybdenum, tantalum, and tungsten.

[0013] The surface treatment method for the refractory element alloy resistant salt vapor corrosion layer involves infiltrating Si and Al atoms into the surface of the refractory element alloy component, and includes the following steps:

[0014] (1) Preparation of coating powder, the coating powder is composed of the following components by mass percentage: silicon powder 15~18wt%, Al-Si x The powder consists of 15-18 wt% powder, 4-5 wt% CeO2 powder, 14-15 wt% NaF powder, and 45-50 wt% spherical Al2O3 powder. The components are mixed and placed in a ball mill jar. The mixture is ball milled for 24-48 hours to obtain a uniformly mixed coated powder as a penetrant.

[0015] (2) Embed the refractory alloy parts into an alumina crucible containing coated powder, cover the crucible and seal it with ceramic glue, place the crucible in a muffle furnace for heat treatment, raise the temperature from room temperature to the target temperature at a rate of 5℃ / min to 10℃ / min, the heat treatment temperature is 1150 to 1250℃, the treatment time is 2 to 6 hours, and then cool the furnace to room temperature.

[0016] The surface treatment method for the refractory element alloy resistant salt vapor corrosion layer, Al-Si x The powder is an aluminum-silicon alloy powder, with a silicon content of 10-30 at%, and a powder diameter of 1-5 μm.

[0017] The surface treatment method for the refractory element alloy resistant salt vapor corrosion layer uses silicon powder with a particle size of 1~3μm, CeO2 powder with a particle size of 1~30μm, NaF powder with a particle size of 1~10μm, and spherical Al2O3 powder with a particle size of 40~50μm.

[0018] The surface treatment method for the refractory element alloy resistant salt vapor corrosion layer uses a bicomponent ceramic adhesive, which consists of a liquid binder and a powder filler. The mass ratio of the powder filler to the liquid binder is 1:1 to 1.5:1. The composition and content of each component are as follows:

[0019] The liquid binder phase consists of 40-60 wt% liquid sodium silicate and 40-60 wt% water, with the modulus of the liquid sodium silicate being 3.22; the powder filler consists of 70-90 wt% MgO powder and 10-30 wt% Al2O3 powder, with the particle size of the MgO powder being 1-5 μm and the particle size of the Al2O3 powder being 3-10 μm; ceramic adhesive is used for two-stage sealing, with the second application performed after the first application has completely cured.

[0020] The surface treatment method for the refractory element alloy resistant salt vapor corrosion layer involves pre-oxidizing refractory element alloy components with Si and Al atoms infiltrated on the surface to form a SiO2 / Al2O3 composite oxide layer, including the following steps:

[0021] (1) Remove the refractory alloy parts from the coating powder and ultrasonically clean them in alcohol;

[0022] (2) Place the refractory alloy parts in a muffle furnace at 1150~1250℃ and oxidize them in air for 15~30 minutes.

[0023] The surface treatment method for the refractory element alloy resistant salt vapor corrosion layer involves forming an X-shaped layer from the inside to the outside of the refractory element alloy component. n (Si,Al) m Composite compound layer and SiO2 / Al2O3 composite oxide layer.

[0024] The surface treatment method for the refractory element alloy resistant salt vapor corrosion layer, X n (Si,Al) m In the composite compound layer, n=1, m=1~2; with the sum of Si atoms and Al atoms being 100%, the proportion of Si atoms is 95~98%, and the proportion of Al atoms is 2~5%.

[0025] The surface treatment method for the refractory element alloy resistant salt vapor corrosion layer, X n (Si,Al) m The thickness of the composite compound layer is 20~30μm, and the thickness of the SiO2 / Al2O3 composite oxide layer is 8~12μm.

[0026] The design concept of this invention is:

[0027] 1. Innovation in the principle of refractory element alloys resisting corrosion by molten halide. In a molten salt steam environment, refractory element alloys can react rapidly with chloride ions, and in actual oxygen-containing conditions, oxidation-chlorination behavior will rapidly cyclically occur. Utilizing a quartz-state SiO2 layer, direct contact between the refractory element alloy matrix material and molten chloride salts is effectively isolated. Because the quartz-state SiO2 layer covers the grain boundaries, the diffusion of halide ions through the grain boundaries into the material matrix is ​​significantly slowed down. SiO2 and gaseous chloride ions do not react kinetically. Taking a temperature of 1000℃, standard conditions, and a solid activity of 1 as an example, the possible reactions of SiO2 in a trace oxygen environment are as follows:

[0028] SiO2(cristobalite)+2Cl2→SiCl4(g)+O2(g)

[0029] The standard Gibbs energy of formation for this reaction is: ΔG 1273K° ≈+187.1 kJ / mol (K°≈2.1×10 -8 This formation energy is positive, meaning it cannot be a spontaneous reaction. The corrosion behavior is solely due to the interaction of SiO2 and O. 2- The reaction produces silicate SiO3. 2- And it dissolves slowly.

[0030] 2. Innovative Principle of SiO2 Protective Layer Preparation. Refractory elements are generally prone to oxidation. If only Si atoms are diffused into their surface through a halide activation reaction, the refractory elements in the matrix will also be oxidized during subsequent oxidation reactions and encapsulated in a quartz-state SiO2 layer. Due to the large size of the oxide particles, this increases the surface roughness of the metal, making it difficult for SiO2 to effectively cover the metal surface. Therefore, this invention proposes to simultaneously diffuse Si and Al into the surface of refractory element alloys.

[0031] The large particles formed after the oxidation of refractory elements will inhibit the formation of a continuous oxide protective layer of SiO2 on the metal surface after the oxidation of Si elements. However, the addition of Al elements can effectively inhibit the oxidation of refractory elements, thereby promoting the formation of SiO2 film.

[0032] The standard Gibbs formation energy of Al oxidation is much lower than that of refractory elements, meaning that Al will oxidize preferentially over refractory elements. After Si oxidation forms a SiO2 protective layer, O diffuses into the matrix via lattice diffusion, with the O concentration decreasing as the diffusion depth increases. After Al oxidation, the O content in the matrix is ​​lower than the O concentration required for refractory element oxidation, thus preventing the refractory elements in the matrix from oxidizing. This, in turn, promotes the formation of a continuous and complete protective layer after Si oxidation. Small amounts of Al oxidation produce smaller particles of Al2O3, which can be completely coated by SiO2. The spherical Al2O3 is easier to flow and does not affect the film formation of quartz-state SiO2.

[0033] A short pre-oxidation process does not consume all the infiltrated Si / Al atoms, but it can effectively form a SiO2 protective layer. Therefore, during the molten salt vapor corrosion of the pre-oxidized components, Si / Al elements will continue to absorb active oxygen elements that diffuse from molten halides through the SiO2 lattice and pass through the SiO2 protective layer. As halide ions dissolve and corrode the SiO2 protective layer, the SiO2 protective layer continues to grow.

[0034] This method uses a simple approach to generate a Si / Al composite compound layer in situ on the surface of a refractory element alloy. The Si / Al composite compound layer and the base metal are a metallurgical bonding layer formed by diffusion transition, and there is no two-phase interface between them. Therefore, the Si / Al composite compound layer has a strong bonding force with the base metal, and the Si / Al composite compound is not easy to fall off due to the difference in thermal expansion coefficients.

[0035] The advantages and beneficial effects of this invention are:

[0036] 1. This invention eliminates the need to spray Mo powder onto the metal surface. It achieves the direct formation of a complete SiO2 quartz layer on the surface of refractory element alloys using a simple method, conventional equipment, and inexpensive raw materials.

[0037] 2. The raw materials used in this invention are all readily available standardized products, which is conducive to stable production.

[0038] 3. The Al-Si used in this invention x Using powdered aluminum as the Al source for the reaction effectively avoids the explosive properties of aluminum powder, significantly improving the safety factor of the preparation process, and does not cause impurity contamination. The Al-Si ratio can be adjusted as needed. x The Si content in the powder is adjusted to match the thermal expansion coefficient and volume difference between the Si / Al composite compound and the matrix, resulting in a tighter bond between the Si / Al composite compound layer and the matrix, and reducing cracking of the corrosion-resistant layer caused by thermal expansion.

[0039] 4. This invention utilizes a bicomponent ceramic adhesive to seal alumina containers, eliminating the need for vacuum heating equipment and an inert gas protective atmosphere, thus greatly simplifying the process, shortening the preparation time, and significantly reducing the preparation cost. Attached Figure Description

[0040] Figure 1 Cross-sectional morphology of a refractory high-entropy alloy sheet treated by the present invention after corrosion by molten salt steam (45LiCl-55KCl) at 950℃ for 100h.

[0041] Figure 2Cross-sectional morphology of a refractory high-entropy alloy sheet that has not been treated according to this invention after being etched by molten salt steam (45LiCl-55KCl) at 950℃ for 100h.

[0042] Figure 3 The refractory high-entropy alloy described in the examples, after incorporating Si / Al elements, yields X. n (Si,Al) m Composite compound layer.

[0043] Figure 4 The refractory high-entropy alloy described in the examples, after pre-oxidation treatment, yields a SiO2 / Al2O3 composite oxide layer. Detailed Implementation

[0044] The present invention will now be further described in detail with reference to embodiments and accompanying drawings.

[0045] Example (Refractory High-Entropy Alloy Nb) 40 Ta 20 Mo 15 W 10 Ti 15 )

[0046] In this embodiment, a surface treatment method for a refractory element alloy resistant to molten salt vapor corrosion includes the following steps:

[0047] (1) Metal sample preparation:

[0048] With refractory high-entropy alloy Nb 40 Ta 20 Mo 15 W 10 Ti 15 Taking (at%) as an example, its surface is subjected to molten salt vapor corrosion resistance treatment. The specific steps are as follows: a circular alloy sheet with a diameter of 30 mm and a thickness of 2 mm is prepared by wire electrical discharge machining. The electrical discharge machining residue on the surface is removed with 400 grit sandpaper, and then polished with 800 grit sandpaper to obtain the refractory high entropy alloy sheet to be treated.

[0049] (2) Preparation of coated powder:

[0050] The following raw materials were mixed: 7 g of silicon powder with a particle size of 3 micrometers, 7 g of Al-12Si powder with a particle size of 2 micrometers (Si 12at%, Al 88at%), 6 g of NaF powder with a particle size of 5 micrometers, 20 g of spherical alumina powder with a particle size of 45 micrometers, and 2 g of CeO2 powder with a particle size of 4 micrometers. The mixture was placed in a ball mill jar, and Al2O3 ball milling balls were used. The ball milling speed was 300 r / min, the ball-to-material mass ratio was 10:1, and the mixture was ball milled for 48 hours to obtain a uniformly mixed coating powder as a penetrant.

[0051] (3) Pour the mixed coating powder into an alumina crucible, then place the refractory high-entropy alloy sheet in it, and then completely cover the alloy sheet with the coating powder. Cover the crucible and seal it with bicomponent ceramic adhesive. The adhesive application process is two-stage. After the first application of adhesive has completely cured, the second application of adhesive is performed.

[0052] In this embodiment, the bicomponent ceramic adhesive is composed of a liquid binder phase and a powder filler, with a mass ratio of powder filler to liquid binder phase of 1.2:1. The composition and content of each component are as follows: the liquid binder phase is composed of 55wt% liquid sodium silicate and 45wt% water, and the modulus of liquid sodium silicate is 3.22; the powder filler is composed of 80wt% MgO powder and 20wt% Al2O3 powder, with the particle size of MgO powder being 1~5μm and the particle size of Al2O3 powder being 3~10μm.

[0053] (4) The sealed alumina crucible was placed in a muffle furnace for heat treatment. The temperature was raised from room temperature to the target temperature at a rate of 6°C / min, the heat treatment temperature was 1200°C, and the treatment time was 3 hours. The furnace was then cooled to room temperature. A composite compound layer of refractory high-entropy alloy, Si atoms, and Al atoms was formed on the surface of the refractory high-entropy alloy sheet. Figure 3 As shown, X is obtained after infiltrating Si / Al elements into a refractory high-entropy alloy. n (Si,Al) m The composite compound layer (n=1, m=2) has a Si atom ratio of 97.08% and an Al atom ratio of 2.92% based on the sum of Si atoms and Al atoms being 100%, and the thickness of the composite compound layer is 25 μm.

[0054] (5) Remove the heat-treated refractory high-entropy alloy sheet from the alumina crucible, ultrasonically clean it in alcohol for 5 minutes, dry it in a dryer at 80°C, preheat the muffle furnace to 1200°C, place the refractory high-entropy alloy sheet infiltrated with Si / Al elements directly into the muffle furnace chamber, and perform pre-oxidation treatment in air for 30 minutes. After removal, allow it to cool naturally to room temperature. Figure 4 As shown, after pre-oxidation treatment, a refractory high-entropy alloy sheet with a SiO2 / Al2O3 composite oxide layer formed on the surface of the composite compound layer is obtained, and the thickness of the SiO2 / Al2O3 composite oxide layer is 10μm.

[0055] (6) The pre-oxidized refractory high-entropy alloy sheet was etched in 45LiCl-55KCl (wt%) molten salt vapor. The specific etching process was as follows: 45LiCl-55KCl mixed salt powder was placed in a graphite jar, and the refractory high-entropy alloy sheet to be tested was completely embedded in the mixed salt powder. The graphite jar was placed in a stainless steel jar, and the jar body and lid of the stainless steel jar were sealed by welding. All operations were carried out in a glove box protected by Ar gas to create a micro-oxygen environment. The welded stainless steel jar was taken out and placed in a muffle furnace heated to 950℃ for etching for 100 hours. After removal, it was cooled to room temperature by air.

[0056] like Figure 1 As shown, after 100 hours of molten salt steam corrosion at 950℃, the cross-sectional view of the refractory high-entropy alloy sheet shows that a complete and dense SiO2 / Al2O3 composite oxide layer has been formed on the alloy surface after Al-Si infiltration and pre-oxidation treatment, without corrosion damage.

[0057] Comparative example:

[0058] Take the same refractory high-entropy alloy sheet Nb 40 Ta 20 Mo 15 W 10 Ti 15 (at%), circular alloy sheets with a diameter of 30 mm and a thickness of 2 mm were prepared by wire electrical discharge machining (EDM). The EDM residue on the surface was removed with 400-grit sandpaper, and then polished with 800-grit sandpaper. The sheets were then ultrasonically cleaned in alcohol for 5 minutes and dried using a dryer. Finally, they were placed in a molten salt vapor of 45LiCl-55KCl (wt%), sealed in a stainless steel tank to create a micro-oxygen environment, and corroded at 950℃ for 100 hours.

[0059] like Figure 2 As shown, after 100 hours of molten salt steam corrosion at 950℃, the cross-sectional view of the refractory high entropy alloy sheet shows that the surface of the untreated refractory high entropy alloy sheet is severely corroded, the oxides are in the form of plates and cracked and separated from the substrate, and the corrosion depth exceeds 40μm.

[0060] The results show that, after corrosion, cross-sectional observation reveals that the SiO2 / Al2O3 composite oxide layer formed on the surface of the refractory high-entropy alloy is complete and dense, without peeling or corrosion pits; while the refractory high-entropy alloy parts of the same material that were not treated with this invention, after the same corrosion test, had their surface deeply eroded, and the oxides were in a lamellar form and cracked and separated from the substrate, proving that the protective effect of this invention is significant.

Claims

1. A surface treatment method for a refractory high-entropy alloy resistant to molten salt vapor corrosion layer, characterized in that, Includes the following steps: (1) Si and Al atoms are diffused into the surface of refractory high-entropy alloy parts to form X on the metal surface layer. n (Si,Al) m Composite compound layer, where X is a refractory element or its alloy; X n (Si,Al) m In the composite compound layer, n=1, m=1~2; with the sum of Si atoms and Al atoms being 100%, the proportion of Si atoms is 95~98%, and the proportion of Al atoms is 2~5%; Infiltrating Si and Al atoms into the surface of refractory high-entropy alloy components includes the following steps: 1) Preparation of coating powder, the coating powder is composed of the following components by mass percentage: silicon powder 15~18wt%, Al-Si x The powder consists of 15-18 wt% powder, 4-5 wt% CeO2 powder, 14-15 wt% NaF powder, and 45-50 wt% spherical Al2O3 powder. The components are mixed and placed in a ball mill jar. The mixture is ball milled for 24-48 hours to obtain a uniformly mixed coated powder as a penetrant. Among them, Al-Si x The powder is an aluminum-silicon alloy powder, in which the silicon content is 10~30 at%, and the powder diameter is between 1~5 μm; the particle size of silicon powder is 1~3 μm, the particle size of CeO2 powder is 1~30 μm, the particle size of NaF powder is 1~10 μm, and the particle size of spherical Al2O3 powder is 40~50 μm. 2) Embed the refractory high-entropy alloy parts into an alumina crucible containing coated powder, cover the crucible and seal it with ceramic glue, place the crucible in a muffle furnace for heat treatment, raise the temperature from room temperature to the target temperature at a rate of 5℃ / min~10℃ / min, the heat treatment temperature is 1150~1250℃, the treatment time is 2~6h, and then cool the furnace to room temperature; The ceramic adhesive is a bicomponent ceramic adhesive, which consists of a liquid binder phase and a powder filler. The mass ratio of the powder filler to the liquid binder phase is 1:1 to 1.5:

1. The composition and content of each component are as follows: the liquid binder phase consists of 40-60 wt% liquid sodium silicate and 40-60 wt% water, and the modulus of the liquid sodium silicate is 3.22; the powder filler consists of 70-90 wt% MgO powder and 10-30 wt% Al2O3 powder, and the particle size of the MgO powder is 1-5 μm, and the particle size of the Al2O3 powder is 3-10 μm. The ceramic adhesive is applied and sealed in two stages. After the first application is completely cured, the second application is performed. (2) For refractory high-entropy alloy parts with Si and Al atoms infiltrated on the surface, a pre-oxidation treatment is performed to form a SiO2 / Al2O3 composite oxide layer on the surface, including the following steps: 1) Remove the refractory high-entropy alloy parts from the coating powder and ultrasonically clean them in alcohol; 2) Place the refractory high-entropy alloy parts in a muffle furnace at 1150~1250℃ and oxidize them in air for 15~30 minutes.

2. The surface treatment method for the refractory high-entropy alloy resistant to molten salt vapor corrosion layer according to claim 1, characterized in that, The refractory elements are one or more of titanium, vanadium, niobium, molybdenum, tantalum, and tungsten.

3. The surface treatment method for the refractory high-entropy alloy resistant to molten salt vapor corrosion layer according to claim 1, characterized in that, X-shaped formations are sequentially formed from the inside to the outside on the surface of the refractory high-entropy alloy component. n (Si,Al) m Composite compound layer and SiO2 / Al2O3 composite oxide layer.

4. The surface treatment method for the refractory high-entropy alloy resistant to molten salt vapor corrosion layer according to claim 3, characterized in that, X n (Si,Al) m The thickness of the composite compound layer is 20~30μm, and the thickness of the SiO2 / Al2O3 composite oxide layer is 8~12μm.

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