Preparation and evaluation method of coating with high temperature and high flow rate liquid metal corrosion resistance

Abstract

The application discloses a preparation and evaluation method of a high-temperature-resistant and high-flow-rate liquid metal corrosion-resistant coating, and steps are as follows: the surface of a base material is polished to a roughness of 0.8-3.2 microns by using a silicon carbide sandpaper, and then the base material is cleaned and dried; the coating is coated on the surface of the base material by using electroplating or magnetron sputtering; the electroplating method is that the base material is placed in an aluminum-containing or chromium-containing solution, the base material is connected to a negative electrode of a power supply, and electroplating is performed for 0.5-2 hours; the magnetron sputtering method is that an aluminum transition layer or a chromium transition layer is first prepared on the surface of the base material, the preparation condition is a negative bias voltage of 100-400 V and a deposition time of 0.5-2 hours, and then an aluminum dense layer or a chromium dense layer is prepared, the preparation condition is a negative bias voltage of 0-100 V and a deposition time of 0.5-2 hours. The aluminum coating or the chromium coating with a single component is prepared on the surface of the base structural material by using the electroplating method or the magnetron sputtering method, the operation is convenient, the different components in the coating do not need to be proportioned, and the corrosion resistance of the structural material can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of material surface modification technology, and more specifically, to a method for preparing and evaluating coatings resistant to high-temperature, high-flow-rate liquid metal corrosion. Background Technology

[0002] Structural materials immersed in high-temperature, high-flow-rate liquid metal coolants will experience performance degradation due to corrosion, thus affecting their service life. Applying a protective coating to the surface of structural materials is one effective and feasible method to mitigate this corrosion. Currently, the coatings applied to structural material surfaces are relatively complex in composition (such as FeCrAl / FeCrAlYTi coatings), requiring strict control of the component ratios, making the process relatively complex.

[0003] In view of the above, this application is hereby submitted. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for preparing and evaluating coatings resistant to high-temperature, high-flow-rate liquid metal corrosion. A single-component aluminum or chromium coating is prepared on the surface of a substrate structural material via electroplating or magnetron sputtering. Compared to existing coatings with complex compositions such as FeCrAl / FeCrAlYTi, the aluminum or chromium coating has a simpler composition, is easier to operate, and does not require precise proportioning of different components, thus effectively improving the corrosion resistance of the structural material.

[0005] This invention is achieved through the following technical solution: In a first aspect, the present invention provides a method for preparing a coating resistant to corrosion by high-temperature, high-flow-rate liquid metals, comprising the following steps: S1, Select pretreated stainless steel as the base material; S2, A coating is applied to the surface of the substrate material using an electroplating method or a magnetron sputtering method, wherein the coating is an aluminum coating or a chromium coating.

[0006] This invention prepares a single-component aluminum or chromium coating on the surface of a substrate structural material by electroplating or magnetron sputtering. Compared with existing coatings with complex compositions such as FeCrAl / FeCrAlYTi, the aluminum or chromium coating has a simple composition, is easy to operate, does not require the proportioning of different components in the coating, and can effectively improve the corrosion resistance of the structural material.

[0007] In a specific embodiment, step S2, the electroplating method is as follows: The pretreated substrate material is placed in a solution containing aluminum or chromium, and the substrate material is connected to the negative terminal of the power supply for electroplating for 0.5-2 hours.

[0008] In a specific embodiment, step S2, the magnetron sputtering method is as follows: A transition layer of aluminum or chromium is first obtained on the surface of the pretreated substrate material by magnetron sputtering, and then a dense layer of aluminum or chromium is obtained on the transition layer by magnetron sputtering.

[0009] In one specific embodiment, the preparation conditions of the transition layer are: negative bias voltage of 100-400 V and deposition time of 0.5-2 h.

[0010] In one specific embodiment, the preparation conditions of the dense layer are: negative bias voltage of 0-100 V and deposition time of 0.5-2 h.

[0011] In a specific embodiment, the pretreatment method in step S1 is as follows: the surface of the substrate material is polished to a roughness of 0.8-3.2 μm, ultrasonically cleaned in alcohol and deionized water for 5-10 min respectively, and then dried.

[0012] In one specific embodiment, the thickness of the coating is 5-30 μm.

[0013] Secondly, the present invention provides a method for evaluating the corrosion resistance of coatings against high-temperature, high-flow-rate liquid metals, comprising the following steps: The coated substrate material is fixed onto the blades of the rotary autoclave; The rotary autoclave is heated to the target temperature, and the oxygen concentration inside the rotary autoclave is adjusted through the oxygen control system. The flow rate was controlled by adjusting the rotation speed of the rotary autoclave, and the corrosion resistance of the coating was tested. After the experiment, the morphology of the coating cross section was observed to see if there was liquid metal erosion at the interface between the coating and the substrate.

[0014] In one specific implementation, the target temperature is 400-500℃, and the oxygen concentration is 10. -7 -10 -5 wt%, with a flow rate of 0-3 m / s.

[0015] In one specific implementation, the test lasts for 2000 hours.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. The method for preparing and evaluating the high-temperature and high-flow-rate liquid metal corrosion resistant coating provided in the embodiments of the present invention prepares a single-component aluminum or chromium coating on the surface of the substrate structural material by electroplating or magnetron sputtering. Compared with the existing complex-component coatings such as FeCrAl / FeCrAlYTi, the present invention, by coating aluminum or chromium, has a simple composition, does not require the proportioning of different components in the coating, is simple and convenient to operate, and can effectively improve the corrosion resistance of the structural material. 2. The method for preparing and evaluating the high-temperature and high-flow-rate liquid metal corrosion resistant coating provided in this embodiment of the invention can simulate different temperatures, oxygen concentrations, and flow rates by using a rotating autoclave, thereby testing and evaluating the corrosion resistance of the coating under different conditions. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a microstructure diagram of the high-temperature, high-flow-rate liquid metal corrosion resistant coating provided in Embodiment 1 of the present invention after corrosion testing. Figure 2 This is a microstructure diagram of the high-temperature, high-flow-rate liquid metal corrosion resistant coating provided in Embodiment 2 of the present invention after corrosion testing. Figure 3 This is a microstructure diagram of the high-temperature, high-flow-rate liquid metal corrosion resistant coating provided in Comparative Example 1 of the present invention after corrosion testing. Figure 4 This is a microstructure diagram of the high-temperature, high-flow-rate liquid metal corrosion resistant coating provided in Comparative Example 2 of the present invention after corrosion testing. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments. The illustrative embodiments and descriptions of this invention are only used to explain this invention and are not intended to limit this invention.

[0020] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other embodiments, well-known materials or methods have not been specifically described in order to avoid obscuring the invention.

[0021] Throughout this specification, references to “an embodiment,” “an example,” or “an example” mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases “an embodiment,” “an example,” “an example,” or “an example” appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0022] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60–120 and 80–110 are listed for a specific parameter, it is understood that ranges of 60–110 and 80–120 are also expected. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5. In this application, unless otherwise stated, the numerical range "a–b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0023] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), indicating that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0024] Structural materials immersed in high-temperature, high-flow-rate liquid metal coolants will experience performance degradation due to corrosion, thus affecting their service life. Applying a protective coating to the surface of structural materials is one effective and feasible method to mitigate this corrosion. Currently, the coatings applied to structural material surfaces are relatively complex in composition (such as FeCrAl / FeCrAlYTi coatings), requiring strict control of the component ratios, making the process relatively complex.

[0025] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: In a first aspect, the present invention provides a method for preparing a coating resistant to corrosion by high-temperature, high-flow-rate liquid metals, comprising the following steps: S1, Select pretreated stainless steel as the base material; S2, A coating is applied to the surface of the substrate material using an electroplating method or a magnetron sputtering method, wherein the coating is an aluminum coating or a chromium coating.

[0026] The present invention provides a method for preparing a coating resistant to high-temperature, high-flow-rate liquid metal corrosion. This method involves preparing a single-component aluminum or chromium coating on the surface of a substrate structural material via electroplating or magnetron sputtering. Compared to existing coatings with complex compositions such as FeCrAl / FeCrAlYTi, the present invention, through the application of an aluminum or chromium coating, has a simple composition, eliminates the need for precise proportioning of different components, and is easy and convenient to operate. Simultaneously, it effectively improves the corrosion resistance of the structural material.

[0027] The method for preparing a coating resistant to high-temperature and high-flow-rate liquid metal corrosion provided by this invention involves applying the coating by electroplating or magnetron sputtering, which can prevent the coating from peeling off or cracking during corrosion, thereby achieving effective protection of the material surface and improving the material's resistance to corrosion by liquid metal coolants.

[0028] In a specific embodiment, step S2, the electroplating method is as follows: The pretreated substrate material is placed in a solution containing aluminum or chromium, and the substrate material is connected to the negative terminal of the power supply for electroplating for 0.5-2 hours.

[0029] In a specific embodiment, step S2, the magnetron sputtering method is as follows: A transition layer of aluminum or chromium is first obtained on the surface of the pretreated substrate material by magnetron sputtering, and then a dense layer of aluminum or chromium is obtained on the transition layer by magnetron sputtering.

[0030] In one specific embodiment, the preparation conditions of the transition layer are: negative bias voltage of 100-400 V and deposition time of 0.5-2 h.

[0031] In one specific embodiment, the preparation conditions of the dense layer are: negative bias voltage of 0-100 V and deposition time of 0.5-2 h.

[0032] In a specific embodiment, the pretreatment method in step S1 is as follows: the surface of the substrate material is polished to a roughness of 0.8-3.2 μm, ultrasonically cleaned in alcohol and deionized water for 5-10 min respectively, and then dried.

[0033] In one specific embodiment, the thickness of the coating is 5-30 μm.

[0034] Secondly, the present invention provides a method for evaluating the corrosion resistance of coatings against high-temperature, high-flow-rate liquid metals, comprising the following steps: The coated substrate material is fixed onto the blades of the rotary autoclave; The rotary autoclave is heated to the target temperature, and the oxygen concentration inside the rotary autoclave is adjusted through the oxygen control system. The flow rate was controlled by adjusting the rotation speed of the rotary autoclave, and the corrosion resistance of the coating was tested. After the experiment, the morphology of the coating cross section was observed to see if there was liquid metal erosion at the interface between the coating and the substrate.

[0035] In one specific implementation, the target temperature is 400-500℃, and the oxygen concentration is 10. -7 -10 -5 wt%, with a flow rate of 0-3 m / s.

[0036] In one specific implementation, the test lasts for 2000 hours.

[0037] The evaluation method for coatings resistant to high-temperature and high-flow-rate liquid metal corrosion provided by this invention can simulate different temperatures, oxygen concentrations, and flow rates by using a rotating autoclave, thereby testing and evaluating the corrosion resistance of the coating under different conditions.

[0038] Example 1 This invention provides a method for preparing a coating resistant to high-temperature, high-flow-rate liquid metal corrosion, comprising the following steps: Stainless steel was selected as the substrate material, and its surface was polished to 1.6 μm. It was then ultrasonically cleaned for 5 min each in alcohol and deionized water, and dried. A coating was then applied to the substrate surface using electroplating. Specifically, the substrate material was placed in a chromium-containing solution, connected to the negative terminal of a power supply, and electroplated for 1 h to complete the chromium coating preparation. The coating thickness was 23 μm.

[0039] Example 2 This invention provides a method for preparing a coating resistant to high-temperature, high-flow-rate liquid metal corrosion, comprising the following steps: Stainless steel was selected as the substrate material, and its surface was polished to 1.6 μm. It was then ultrasonically cleaned in alcohol and deionized water for 5 min each, and dried. A coating was then applied to the substrate surface using magnetron sputtering. Specifically, an aluminum transition layer was prepared by controlling the negative bias voltage at 250 V and the deposition time at 0.5 h. Next, a dense aluminum layer was prepared on the aluminum transition layer by controlling the negative bias voltage at 40 V and the deposition time at 1 h. The coating thickness was 7 μm.

[0040] Comparative Example 1 This comparative example provides a method for preparing a coating with resistance to liquid metal corrosion, comprising the following steps: FeCrAlTi composite powder was prepared using ferrochrome powder, iron-aluminum powder, and titanium powder as raw materials. Stainless steel was selected as the sample material. The pretreated sample surface (cleaning, drying, and sandblasting) was sprayed with an oxy-acetylene flame using a subsonic spray gun. The spray thickness was about 100 μm. The coating was then laser remelted. After cooling, the oxide scale and slag on the surface were sandblasted and then clad again to complete the preparation of the FeCrAlTi coating.

[0041] Comparative Example 2 This comparative example provides a method for preparing a coating with resistance to liquid metal corrosion, comprising the following steps: 316L stainless steel was selected as the base material. After grinding and cleaning, Ni60 alloy powder was clad onto the stainless steel surface with a thickness of about 0.5 mm using laser cladding technology. Then, an Al coating with a thickness of about 100 μm was sprayed onto the Ni60 coating surface using thermal spraying technology. The sample with the Ni60 coating and Al coating was placed in a heat treatment furnace for high-temperature diffusion treatment to complete the coating preparation.

[0042] Performance testing 1. Corrosion resistance Test Method 1: (1) The coated substrate material prepared in Examples 1-2 is fixed on the blades of a rotary autoclave; (2) The rotary autoclave is heated to 420°C (Example 1) or 500°C (Example 2), and the oxygen concentration inside the rotary autoclave is adjusted to 10 using the oxygen control system. -6 wt% (3) Adjust the rotation speed of the rotary autoclave to control the flow rate to 2 m / s, soak for 2000 h, and test the corrosion resistance of the coating; (4) After the test, observe the morphology of the coating cross section and observe whether there is liquid metal erosion at the interface between the coating and the substrate.

[0043] Test Method 2: (1) The coated substrate materials prepared in Comparative Example 1 and Comparative Example 2 were immersed in liquid metal; (2) High-purity inert gas was introduced, and the coating in Comparative Example 1 was immersed in liquid metal at 550°C for 300 hours, and the coating in Comparative Example 2 was immersed in liquid metal at 400°C for 500 hours to test the corrosion resistance of the coating. (3) After the experiment, the morphology of the coating cross section was observed.

[0044] The results are as follows: Figure 1 The image shows the microstructure of the coating material prepared in Example 1 after corrosion. It can be seen that no liquid metal erosion was observed at the interface between the coating and the substrate material, indicating that the coating can effectively prevent liquid metal erosion.

[0045] Figure 2 The image shows the microstructure of the coating material prepared in Example 2 after corrosion. It can be seen that no liquid metal erosion was observed at the interface between the coating and the substrate material, indicating that the coating can effectively prevent liquid metal erosion.

[0046] Figure 3 The image shows the microstructure of the coating material prepared for Comparative Example 1 after corrosion. It can be seen that no liquid metal erosion was observed at the interface between the coating and the substrate material, indicating that the coating can prevent liquid metal erosion.

[0047] Figure 4 The image shows the microstructure of the coating material prepared for Comparative Example 2 after corrosion. It can be seen that no liquid metal erosion was observed at the interface between the coating and the substrate material, indicating that the coating can prevent liquid metal erosion.

[0048] As can be seen from the above, this application uses electroplating or magnetron sputtering to prepare a single-component aluminum or chromium coating on the surface of a substrate structural material. Compared with existing coatings with complex components such as FeCrAlYTi, it can achieve the same corrosion resistance. At the same time, the composition of this invention is simple, and there is no need to measure the ratio of different components in the coating, making the operation simple and convenient.

[0049] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. 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.

Claims

1. A method for preparing a coating resistant to corrosion by high-temperature, high-flow-rate liquid metal, characterized in that, Includes the following steps: S1, Select pretreated stainless steel as the base material; S2, A coating is applied to the surface of the substrate material using an electroplating method or a magnetron sputtering method, wherein the coating is an aluminum coating or a chromium coating.

2. The method for preparing a coating resistant to high-temperature, high-flow-rate liquid metal corrosion according to claim 1, characterized in that, In step S2, the electroplating method is as follows: The pretreated substrate material is placed in a solution containing aluminum or chromium, and the substrate material is connected to the negative terminal of the power supply for electroplating for 0.5-2 hours.

3. The method for preparing a coating resistant to high-temperature, high-flow-rate liquid metal corrosion according to claim 1, characterized in that, In step S2, the magnetron sputtering method is as follows: A transition layer of aluminum or chromium is first obtained on the surface of the pretreated substrate material by magnetron sputtering, and then a dense layer of aluminum or chromium is obtained on the transition layer by magnetron sputtering.

4. The method for preparing a coating resistant to high-temperature, high-flow-rate liquid metal corrosion according to claim 3, characterized in that, The preparation conditions for the transition layer are: negative bias voltage of 100-400 V and deposition time of 0.5-2 h.

5. The method for preparing a coating resistant to high-temperature, high-flow-rate liquid metal corrosion according to claim 3, characterized in that, The preparation conditions for the dense layer are: negative bias voltage of 0-100 V and deposition time of 0.5-2 h.

6. The method for preparing a coating resistant to high-temperature, high-flow-rate liquid metal corrosion according to claim 1, characterized in that, In step S1, the specific method of pretreatment is to grind the surface of the substrate material to a roughness of 0.8-3.2 μm.

7. The method for preparing a coating resistant to high-temperature, high-flow-rate liquid metal corrosion according to claim 1, characterized in that, The coating thickness is 5-30 μm.

8. A method for evaluating the corrosion resistance of coatings prepared by any one of claims 1-7 against high-temperature, high-flow-rate liquid metals, characterized in that, Includes the following steps: The coated substrate material is fixed onto the blades of the rotary autoclave; The rotary autoclave is heated to the target temperature, and the oxygen concentration inside the rotary autoclave is adjusted through the oxygen control system. The flow rate was controlled by adjusting the rotation speed of the rotary autoclave, and the corrosion resistance of the coating was tested. After the experiment, the morphology of the coating cross section was observed to see if there was liquid metal erosion at the interface between the coating and the substrate.

9. The evaluation method for the corrosion resistance of coatings resistant to high-temperature and high-flow-rate liquid metals according to claim 8, characterized in that, The target temperature is 400-500℃, and the oxygen concentration is 10. -7 -10 -5 wt%, with a flow rate of 0-3 m / s.

10. The evaluation method for the corrosion resistance of coatings resistant to high-temperature and high-flow-rate liquid metals according to claim 8, characterized in that, The test lasted for 2000 hours.

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