Device and method for testing steam oxidation mass transfer mechanism of metal material

Abstract

The invention discloses a device and a method for testing a steam oxidation mass transfer mechanism of a metal material. The device comprises a reaction chamber, and a sample holder is arranged in the reaction chamber; the gas inlet end of the reaction chamber is simultaneously connected with an 18O2 storage piece, an inert gas storage piece, an H216O storage piece and a D218O storage piece; a first heating assembly is arranged outside the reaction chamber, a second heating assembly is arranged outside the H216O storage part, and a third heating assembly is arranged outside the D218O storage part. According to the method disclosed by the invention, an invisible ion diffusion path is converted into a detectable signal gradient through isotope labeling, and experimental verification of an oxygen ion / metal cation diffusion dominant mechanism, visual proving of a hydroxyl participation oxidation process and quantitative analysis of a dissolved oxygen effect are realized for the first time; and a direct experimental criterion is provided for optimization of the oxidation resistance of the metal material.

Description

Technical Field

[0001] This invention belongs to the field of metal material testing technology, and relates to a test device and method for the steam oxidation mass transfer mechanism of metal materials. Background Technology

[0002] Metal components in applications such as coal-fired power plants and nuclear power plants are often exposed to high-temperature, high-pressure steam. The oxidation rate of metallic materials in a steam environment is much higher than in dry air or dry oxygen. This is mainly due to the different oxidation mass transfer mechanisms in these two environments: in steam, oxide film growth is primarily controlled by the inward diffusion of oxygen-containing ions through the oxide film, while in dry air, oxide film growth is dominated by the outward diffusion of metal ions through the oxide film. As for oxygen-containing ions, they are simply oxygen atoms (O₂). 2- Or OH - Whether the oxygen in the oxide film originates from water vapor decomposition, dissolved oxygen in water, or a combination of both remains unknown. Therefore, research on the oxidation mass transfer mechanism of metallic materials in water vapor environments is still limited to theoretical analysis, lacking direct experimental evidence. The fundamental reason for this situation is the difficulty in designing and implementing experiments. Therefore, there is an urgent need for an experimental device that can be used to study the steam oxidation mass transfer mechanism of metallic materials, in order to clarify the oxidation mass transfer mechanism of metallic materials in water vapor environments, and provide a basis for improving and protecting the oxidation performance of metallic materials, as well as for the treatment and control of oxide scale in power plants. Summary of the Invention

[0003] To address the problems existing in the prior art, the present invention provides an experimental apparatus and method for studying the mass transfer mechanism of vapor oxidation of metallic materials, thereby solving the technical problem that the prior art cannot experimentally study the mass transfer mechanism of oxidation of metallic materials in a water vapor environment.

[0004] This invention is achieved through the following technical solution:

[0005] An experimental apparatus for the mass transfer mechanism of vapor oxidation of metallic materials includes a reaction chamber, the interior of which is equipped with a sample rack;

[0006] The air inlet of the reaction chamber is simultaneously connected to... 18 O2 storage unit, inert gas storage unit, H2 16 O storage device and D2 18 O storage device; the 18 O2 storage unit, inert gas storage unit, H2 16 O storage device and D2 18 The O storage device can be switched on and off with the reaction chamber;

[0007] The reaction chamber is equipped with a first heating component on its exterior, and the H2 16The O storage device is externally equipped with a second heating component, namely D2 18 A third heating element is provided on the outside of the O storage unit.

[0008] Preferably, the H2 16 The outlet end of the O storage unit is equipped with a first recovery unit; the D2 18 The outlet end of the O storage device is equipped with a second recovery device; the outlet end of the reaction chamber is equipped with a third recovery device.

[0009] Preferably, the air inlet of the reaction chamber is provided with a first flange, and the first flange is provided with an air inlet hole; 18 O2 storage unit, inert gas storage unit, H2 16 O storage device and D2 18 All O storage components are connected to the reaction chamber via the air inlet;

[0010] The reaction chamber has a second flange with an air outlet, and the reaction chamber is connected to the third recovery unit through the air outlet.

[0011] Preferably, the 18 O2 storage unit, inert gas storage unit, H2 16 O storage device and D2 18 Mass flow meters are installed between the O storage unit and the reaction chamber.

[0012] Preferably, the reaction chamber is a quartz tube, a corundum tube, or a stainless steel tube.

[0013] A test method for the steam oxidation mass transfer mechanism of metallic materials, employing the aforementioned test apparatus for the steam oxidation mass transfer mechanism of metallic materials, includes the following steps:

[0014] The first test sample was placed in the reaction chamber, so that the inert gas storage device was in contact with the reaction chamber and H2. 16 O storage device and D2 18 The O storage device is connected to the reaction chamber and H2. 16 O storage device and D2 18 The O storage device is purged to remove air from the system;

[0015] The reaction chamber is heated using the first heating element, and H2 is heated using the second heating element. 16 The O storage device is heated, and the D2 is heated using a third heating component. 18 O storage components are heated;

[0016] After reaching the set temperature, let H2 16 The O storage device is connected to the reaction chamber, allowing gaseous H2 to be released. 16O reacts with the first test sample. After the reaction is complete, the first test sample that has undergone the oxidation reaction is taken out.

[0017] The second test sample was placed in the reaction chamber, allowing H2 to react. 16 The O storage device is connected to the reaction chamber, allowing gaseous H2 to be released. 16 O reacts with the second test sample, and after the reaction is complete, D2 is made... 18 The O storage device is connected to the reaction chamber, allowing gaseous D2 to be released. 18 O continues to react with the second test sample. After the reaction is complete, the second test sample that has undergone the oxidation reaction is removed.

[0018] The third test sample was placed in the reaction chamber, so that... 18 O2 storage device, H2 16 The O storage device and the reaction chamber are connected, enabling 18 O2, gaseous H2 16 O reacts simultaneously with the third test sample. After the reaction is complete, the third test sample that has undergone the oxidation reaction is removed.

[0019] The oxide film on the surfaces of the first, second, and third test samples after oxidation reaction was peeled off to obtain... 16 O、 18 The depth distribution curves of O, H, and D in the oxide film, through the aforementioned 16 O、 18 The depth distribution curves of O, H and D in the oxide film were used to study the mass transfer mechanism of vapor oxidation in metallic materials.

[0020] Preferred, making 18 O2, gaseous H2 16 When O reacts simultaneously with the third test sample, 18 O2 and gaseous H2 16 The volume ratio of O is 1:(10 8 ~10 9 ).

[0021] Preferably, gaseous H2 16 The reaction time between O and the second test sample is t1, and the gaseous D2... 18 The reaction time between O and the second test sample is t2, where t1 = t2.

[0022] Preferably, the oxidation time of the first test sample is the same as the oxidation time of the second test sample and the oxidation time of the third test sample.

[0023] Preferably, a neutron diffractometer or a secondary ion mass spectrometer is used to peel off the oxide film from the surfaces of the first, second, and third test samples after the oxidation reaction.

[0024] Compared with the prior art, the present invention has the following beneficial technical effects:

[0025] This invention discloses an experimental apparatus for studying the mass transfer mechanism of steam oxidation of metallic materials. The apparatus features four gas pathways, each connected to a reaction chamber via independent pipelines for 18O2, H216O, D218O, and an inert gas. Valves control enable rapid gas switching, allowing for flexible combinations of experimental conditions. Examples include single steam oxidation (introducing only H216O or D218O steam to study oxidation mechanisms in a pure steam environment), mixed gas oxidation (simultaneously introducing H216O and O218O to simulate a high-temperature steam environment containing dissolved oxygen), and staged isotope switching (e.g., introducing H216O first, then switching to D218O), with mass spectrometry analysis distinguishing oxygen ion diffusion paths at different stages. This significantly improves the apparatus's flexibility and versatility. Furthermore, the heating process is designed with a first heating component that precisely controls the reaction chamber temperature, simulating the actual service temperature of the metallic materials. The second heating element 18 and the third heating element 19 independently regulate the temperature of the H216O and D218O storage components, ensuring that the liquid stored material vaporizes as needed without overheating and decomposition. Simultaneously, the inert gas storage component is used to completely eliminate air interference before the experiment, serves as a carrier gas during the experiment, and acts as a protective gas after the experiment to prevent secondary reactions between the high-temperature oxide film and residual water vapor / oxygen during cooling, which could affect the experimental analysis results. This device is simple in design and easy to use, and can be effectively used for the study of the vapor oxidation mass transfer mechanism of metallic materials.

[0026] In addition, the present invention also discloses an experimental method for the steam oxidation mass transfer mechanism of metallic materials, which uses an experimental apparatus for the steam oxidation mass transfer mechanism of metallic materials as described in the present invention.

[0027] First, in the experiment, H₂¹⁶O (light water) and D₂¹⁸O (heavy oxygen heavy water) were used for staged oxidation, through ¹⁶O / 18 O isotope labeling of the oxygen source, combined with the D / H isotope difference, can distinguish the migration direction of oxygen ions in the oxide film (inward or outward) in subsequent analysis. If the gas / oxide interface is enriched with 18O, it indicates that metal cations diffuse outward through the oxide film; if the metal / oxide interface is enriched with 18O, it indicates that inward diffusion of oxygen ions is dominant. Simultaneously, the decomposition of D₂¹⁸O may form D-hydroxyl groups (OD⁻) or 18O₂. 2 - By analyzing the distribution depth of D in the oxide film, it is possible to determine whether hydroxyl groups participate in the mass transfer process (e.g., the gradient distribution of D in the film indicates hydroxyl diffusion), thus enabling the determination of the interaction mechanism between hydroxyl groups and oxygen ions. Therefore, isotope labeling enables the visualization of ion diffusion pathways.

[0028] Secondly, a mixed oxidation experiment of 18O2 and H216O was introduced to simulate the dissolved oxygen environment in water. By comparing the distribution difference of 18O after oxidation with single water vapor and oxidation with dissolved oxygen, the contribution ratio and action stage of dissolved oxygen can be quantitatively analyzed, such as whether it participates in the formation of oxide film or accelerates ion migration, thus realizing the analysis of the role of dissolved oxygen.

[0029] In summary, the method in this invention transforms invisible ion diffusion paths into detectable signal gradients through isotope labeling. Combined with a phased experimental design, it achieves for the first time experimental verification of the oxygen ion / metal cation diffusion-dominated mechanism, visual proof of hydroxyl participation in the oxidation process, and quantitative analysis of the role of dissolved oxygen. This provides direct experimental criteria for optimizing the antioxidant properties of metallic materials. For example, by confirming that the oxidation of a material is dominated by cation diffusion, a surface barrier layer can be designed to inhibit metal ion migration, thereby improving the service life of the material.

[0030] Furthermore, to make 18 O2, gaseous H2 16 When O reacts simultaneously with the third test sample, 18 O2 and gaseous H2 16 The volume ratio of O is 1:(10 8 ~10 9 This method can effectively simulate the dissolved oxygen environment in water, making the test results closer to actual working conditions and increasing the reliability of the test results.

[0031] Furthermore, gaseous H2 16 The reaction time between O and the second test sample is t1, and the gaseous D2... 18 The reaction time between O and the first test sample is t2, where t1 = t2. The initial oxidation (time t1) establishes the basic oxide film, and the secondary oxidation (time t2) achieves diffusion kinetic tracking through isotope switching. By comparing the oxide films on the surfaces of the first and second test samples... 16 O and 18 By analyzing the distribution pattern of O and combining it with the distribution of H and D in the oxide film on the surface of the second test sample, the time sequence analysis of the dynamic mass transfer process can be effectively achieved.

[0032] Furthermore, by analyzing gaseous H2 16 The reaction of O with the first test sample establishes a baseline oxide film, clarifying whether the mass transfer process of the alloy is dominated by outward diffusion of metal cations, inward diffusion of oxygen-containing anions, or both. The oxidation time of the first test sample is the same as that of the second and third test samples. By comparing the thickness of the oxide film on the surfaces of the first and second test samples, 16 O and 18Based on the distribution of O and the analysis of the aforementioned oxidation mass transfer process, we can infer how dissolved oxygen participates in alloy oxidation and whether it involves oxygen exchange between O2 and H2O. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced 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 on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This invention relates to an experimental apparatus for the steam oxidation mass transfer mechanism of metallic materials.

[0035] The components include: 1. Test sample; 2. Sample holder; 3. Reaction chamber; 4. First heating assembly; 5. First flange; 6. Second flange; 7. Air inlet; 8. Air outlet; 9. 18 10. O2 storage unit; 11. Inert gas storage unit; 12. First valve; 13. Second valve; 14. Third valve; 15. Fourth valve; 16. Fifth valve; 17. H2 16 O storage device, 17, D2 18 18. Storage component 19. Second heating component 20. Third heating component 21. Sixth valve 22. First recovery component 23. Seventh valve 24. Second recovery component 25. Eighth valve 26. Ninth valve 27. Third recovery component 28. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0038] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0039] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0040] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0041] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" 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 mechanical connection or an electrical 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 the above terms in the present invention according to the specific circumstances.

[0042] The present invention will now be described in further detail with reference to the accompanying drawings:

[0043] Example 1

[0044] like Figure 1 As shown, this invention discloses an experimental apparatus for the mass transfer mechanism of vapor oxidation in metallic materials, including a reaction chamber 3. A sample rack 2 is provided inside the reaction chamber 3 for placing the test sample 1. The gas inlet of the reaction chamber 3 is simultaneously connected to... 18 O2 storage unit 9, inert gas storage unit 10, H2 16 O storage device 16 and D2 18 O storage device 17; the 18 O2 storage unit 9, inert gas storage unit 10, H2 16 O storage device 16 and D2 18 The O storage device 17 is switched on and off with the reaction chamber 3; the reaction chamber 3 is provided with a first heating component 4 on the outside, and the H2 16 The exterior of the O storage unit 16 is provided with a second heating assembly 18, the D2 18 A third heating element 19 is provided on the outside of the O storage unit 17.

[0045] Further preferably, in order to address the residual H2 leaked after the reaction in the system 16 O and D2 18 O is recycled, and the H2 is recovered. 16 The outlet end of storage unit 16 is provided with a first recovery unit 21; the D2 18 The outlet of the O storage unit 17 is equipped with a second recovery unit 23; the outlet of the reaction chamber 3 is equipped with a third recovery unit 26. The first recovery unit 21 is specifically used to recover unreacted H216O vapor, preventing it from remaining in the pipeline and interfering with the subsequent D218O oxidation stage. If H216O is not completely removed, its 16O may mix into the oxide film after the D218O reaction, resulting in 16O / 18 The O distribution curve is distorted. The second recovery unit 23 is specifically used to recover D218O vapor, preventing heavy water isotope contamination of subsequent experimental stages containing dissolved oxygen, and ensuring the purity of the oxygen source when 18O2 and H216O are mixed for oxidation. The third recovery unit 26 is used to collect residual D218O during the cooling process of reaction chamber 3, preventing condensate from flowing back to the sample surface and causing secondary oxidation, thus ensuring the original composition of the oxide film. By physically isolating the recovery paths of different isotopic reagents, the risk of cross-contamination is eliminated, allowing the depth distribution curve to truly reflect the mass transfer mechanism at each stage.

[0046] The air inlet of the reaction chamber 3 is provided with a first flange 5, and the first flange 5 is provided with an air inlet hole 7; 18 O2 storage unit 9, inert gas storage unit 10, H2 16 O storage device 16 and D2 18 The O storage unit 17 is connected to the reaction chamber 3 via the air inlet 7; the reaction chamber 3 has a second flange 6 with an air outlet 8, and the reaction chamber 3 is connected to the third recovery unit 26 via the air outlet 8. First, the placement and removal of the test sample 1 by the first flange 5 and the second flange 6 are more convenient, and both the first flange 5 and the second flange 6 can be connected to the reaction chamber 3 by a quick-release clamp structure; second, the first flange 5 and the second flange 6 can be fastened with metal gaskets such as copper or nickel and bolts, which are resistant to high temperatures and have better sealing performance than rubber O-rings, preventing steam leakage and pressure fluctuations.

[0047] The 18 O2 storage unit 9, inert gas storage unit 10, H2 16 O storage device 16 and D2 18 Mass flow meters are installed between storage unit 17 and reaction chamber 3, which effectively realizes precise control of system pressure.

[0048] The reaction chamber 3 is made of quartz tube, corundum tube, or stainless steel tube, which effectively ensures the high temperature resistance and chemical stability of the reaction chamber 3, and ensures the safety of the experiment and the accuracy of the test results.

[0049] In this invention, the first heating component 1, the second heating component 18, and the third heating component 19 can be horizontal muffle furnaces. 18 The O2 storage unit 9 and the inert gas storage unit 10 can be gas cylinders.

[0050] Furthermore, to facilitate flexible control of the system's gas path, in 18 The outlet of the O2 storage device 9 is equipped with a first valve 11, and the outlet of the inert gas storage device 10 is equipped with a second valve 12. 18 A third valve 13 is provided on the gas line connecting the O2 storage device 9 and the inert gas storage device 10 to the reaction chamber 3, so that H2 16 O storage device 16 and D2 18 The air inlet of the O storage device 17 is equipped with a fourth valve 14 and a fifth valve 15, respectively, in H2 16 O storage device 16 and D2 18 The outlet of the O storage device 17 is equipped with an eighth valve 24 and a ninth valve 25, and the inlet of the first recovery device 21 and the second recovery device 23 is equipped with a sixth valve 20 and a seventh valve 22, respectively. The above valves enable flexible control of the gas path during the test.

[0051] In addition, to facilitate the suspension and fixation of the samples, the sample holder is equipped with several sample suspension components.

[0052] Example 2

[0053] Based on the experimental apparatus for the steam oxidation mass transfer mechanism of metallic materials according to the present invention, this embodiment provides an experimental method for the steam oxidation mass transfer mechanism of metallic materials, including the following steps:

[0054] The first test sample is placed in reaction chamber 3, so that the inert gas storage device 10 is in contact with reaction chamber 3 and H2. 16 O storage device 16 and D2 18 O storage device 17 is connected to reaction chamber 3 and H2. 16 O storage device 16 and D2 18 The O storage unit 17 is purged to remove air from the system;

[0055] The reaction chamber 3 is heated using the first heating element 4, and the H2 is heated using the second heating element 18. 16 The O storage device 16 is heated, and the D2 is heated by the third heating component 19. 18 O storage component 17 is heated;

[0056] After reaching the set temperature, let H2 16 O storage device 16 is connected to reaction chamber 3, allowing gaseous H2 to be released. 16 O reacts with the first test sample. After the reaction is complete, the first test sample that has undergone the oxidation reaction is taken out.

[0057] The second test sample was placed in reaction chamber 3, so that H2 16 O storage device 16 is connected to reaction chamber 3, allowing gaseous H2 to be released. 16 O reacts with the second test sample, and after the reaction is complete, D2 is made... 18 O storage device 17 is connected to reaction chamber 3, allowing gaseous D2 to be released. 18 O continues to react with the second test sample. After the reaction is complete, the second test sample that has undergone the oxidation reaction is removed.

[0058] The third test sample was placed in reaction chamber 3, so that... 18 O2 storage device 9, H2 16 The O storage device 16 and the reaction chamber 3 are connected, so that 18 O2, gaseous H2 16 O reacts simultaneously with the third test sample. After the reaction is complete, the third test sample that has undergone the oxidation reaction is removed.

[0059] The oxide films on the surfaces of the first, second, and third test samples after the oxidation reaction were peeled off to obtain... 16 O、 18 The depth distribution curves of O, H, and D in the oxide film, through the aforementioned 16 O、 18 The depth distribution curves of O, H and D in the oxide film were used to analyze the mass transfer mechanism of vapor oxidation in metallic materials.

[0060] In a preferred embodiment, make 18 O2, gaseous H2 16 When O reacts simultaneously with the third test sample, 18 O2 and gaseous H2 16 The volume ratio of O is 1:(10 8 ~10 9 ).

[0061] Further preferred is gaseous H2. 16 The reaction time between O and the second test sample is t1, and the gaseous D2... 18 The reaction time between O and the second test sample is t2, where t1 = t2. Furthermore, the oxidation time of the first test sample is the same as the oxidation time of the second and third test samples.

[0062] When performing stripping analysis on the oxide films on the surfaces of the first, second, and third test samples after oxidation, sputtering stripping was performed using a neutron diffractometer or a secondary ion mass spectrometer.

[0063] Example 3

[0064] To further explain the experimental method for the steam oxidation mass transfer mechanism of metallic materials in this invention, combined with... Figure 1 This will be illustrated through this embodiment:

[0065] 1. Prepare test sample 1, i.e., metal sample, with surface roughness meeting the requirements, clean and dry it for later use;

[0066] 2. The first test sample is suspended on the sample holder 2 and placed together in the reaction chamber 3, which can be a sealed quartz tube;

[0067] 3. Open valves 24, 25, 13, 14, 15 and 12 in sequence, and introduce inert gas into the entire circuit at room temperature. The inert gas can be high-purity Ar or N2. The purging time should be no less than 2 hours to remove air from the entire gas path.

[0068] 4. Close the third valve 13, the fourth valve 14, the fifth valve 15, and the ninth valve 25 in sequence to control H2. 16 O storage device 16 and reaction chamber 3 are heated, at which time H2 16 H2 in storage device 16 16 O is liquid H2 16 O, after heating, becomes liquid H2 16 O is converted into gaseous H2 16 O, and make gaseous H2 16 O reacts with the first test sample through oxidation; the second valve 12 remains open to provide carrier gas and protective gas.

[0069] 5. The first test sample and gaseous H2 16 After the reaction at the set temperature for a set time t, the second heating component 18 is removed, followed by closing the eighth valve 24 and opening the sixth valve 20, allowing H2 to react. 16 Gaseous H2 in storage device 16 16 O condenses and flows into the first recovery component 21;

[0070] 6. Turn off heating component 4, open valve 13, and allow reaction chamber 3 to cool to room temperature under the protection of inert gas. Then, close valve 13 and remove the first test sample.

[0071] 7. Prepare a second test sample and repeat steps 1 to 4.

[0072] 8. The second test sample and gaseous H2 16 After the reaction at the set temperature for a set time t1, the second heating component 18 is removed, followed by the closing of the eighth valve 24 and the opening of the sixth valve 20, allowing H2 to react. 16 Gaseous H2 in storage device 16 16 O condenses and flows into the first recovery component 21;

[0073] 9. Open valve 25 (ninth valve) and valve 15 (fifth valve) in sequence to control D2. 18 The O storage device 17 is heated to make the liquid D2O 18 It turns into gaseous D2O 18 And it continues to undergo an oxidation reaction with the second test sample;

[0074] 10. The second test sample and gaseous D2 18 After reaction at a set temperature for a set time t2, where t1 + t2 = t, the third heating component 19 is removed, followed by the closure of the fifth valve 15 and the ninth valve 25, and the opening of the seventh valve 22, allowing D2 to react. 18 Gaseous D2 in storage device 17 18 O condenses and flows into the second recovery unit 23;

[0075] 11. Open the third valve 13 and close the first heating component 4, allowing the second test sample in the reaction chamber 3 to cool with the furnace under the protection of inert gas. The residual gaseous D2 in the reaction chamber... 18 O condenses and flows into the third recycling unit 26;

[0076] 12. Cool the second test sample to room temperature, close the second valve 12 and the third valve 13 in sequence, open the second flange 6, take out the second test sample and dry it at room temperature to obtain the oxidized second test sample;

[0077] 13. Prepare the third test sample, and repeat steps 1 to 3;

[0078] 14. Close valves 15, 20, 22, and 25 in sequence, and open valve 11. Use the second heating element 18 to heat H2. 16 The O storage device 16 is heated, and at the same time, the reaction chamber 3 is heated by the first heating component 4, so that the liquid H2 16 O turns into gaseous H2 16 O;

[0079] 14. Adjust the mass flow meter to make the gaseous state... 18 O2 and gaseous H2 16 The volume ratio of O is 1:(10 8 ~10 9 ), gaseous 18 O2 and gaseous H216 O simultaneously undergoes an oxidation reaction with the second test sample. After a set time t3, where t3 = t, the second heating component 18 and the first heating component 4 are turned off.

[0080] 15. Close the eighth valve 24 and the first valve 11, and open the sixth valve 20 to allow H2 to... 16 Gaseous H2 in storage device 16 16 O condenses and flows into the first recovery unit 21; the third test sample in the reaction chamber 3 is cooled with the furnace under the protection of inert gas;

[0081] 16. After the third test sample is cooled to room temperature, close the second valve 12 and the third valve 13 in sequence, open the second flange 6, take out the oxidized third test sample and dry it at room temperature;

[0082] 17. Using a neutron diffractometer or a secondary ion mass spectrometer, the oxide films on the surfaces of the oxidized first, second, and third test samples obtained in steps 6, 12, and 16 are sputtered and stripped to obtain... 16 O、 18 Depth distribution curves of O, H and D in the oxide film;

[0083] 18. Based on the analysis of the first oxidized test sample obtained in step 17, a baseline oxide film can be established to clarify whether the oxidation process is controlled by the inward diffusion of oxygen-containing anions through the oxide film, the outward diffusion of cations through the oxide film, or both; combined with the analysis of the oxide film on the surface of the second test sample... 16 O、 18 The distribution patterns of O, H, and D can further determine whether the inward diffusion of oxygen-containing anions is controlled by hydroxyl ions or oxygen ions, and whether oxygen exchange exists. Based on the analysis of the third test sample obtained in step 17 after oxidation treatment, the role of dissolved oxygen in the oxidation process can be clarified, and it can be determined how dissolved oxygen participates in the alloy oxidation and whether oxygen exchange between O2 and H2O is involved.

[0084] This invention provides an experimental device for the steam oxidation mass transfer mechanism of metallic materials. Based on isotope tracing technology, the device enables the research and analysis of the steam oxidation mass transfer mechanism of metallic materials, thereby revealing the high-temperature steam oxidation mechanism of metallic materials. It can also clarify the role and mechanism of dissolved oxygen in water in the oxidation process of metallic materials, providing a basis for improving and protecting the oxidation performance of metallic materials, and for the treatment and control of oxide scale in power plants.

[0085] The above are merely preferred embodiments of the present invention and are not intended to limit the present 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.

Claims

1. An experimental apparatus for the mass transfer mechanism of vapor oxidation in metallic materials, characterized in that, It includes a reaction chamber (3), and the interior of the reaction chamber (3) is provided with a sample holder (2); The air inlet of the reaction chamber (3) is simultaneously connected to... 18 O2 storage unit (9), inert gas storage unit (10), H2 16 O storage device (16) and D2 18 O storage device (17); the 18 O2 storage unit (9), inert gas storage unit (10), H2 16 O storage device (16) and D2 18 The O storage device (17) is connected to the reaction chamber (3) in a switchable manner; The reaction chamber (3) is equipped with a first heating component (4) on its exterior, and the H2 16 The O storage unit (16) is provided with a second heating assembly (18) on its exterior, the D2 18 The O storage unit (17) is provided with a third heating component (19) on its exterior.

2. The experimental apparatus for the steam oxidation mass transfer mechanism of metallic materials according to claim 1, characterized in that, The H2 16 The outlet end of the O storage unit (16) is provided with a first recovery unit (21); the D2 18 The outlet end of the O storage unit (17) is provided with a second recovery unit (23); the outlet end of the reaction chamber (3) is provided with a third recovery unit (26).

3. The experimental apparatus for the steam oxidation mass transfer mechanism of metallic materials according to claim 2, characterized in that, The air inlet of the reaction chamber (3) is provided with a first flange (5), and the first flange (5) is provided with an air inlet hole (7); 18 O2 storage unit (9), inert gas storage unit (10), H2 16 O storage device (16) and D2 18 The O storage unit (17) is connected to the reaction chamber (3) in a way that allows it to be switched on or off through the air inlet (7); The reaction chamber (3) has a second flange (6) at its vent, and the second flange (6) has a vent (8). The reaction chamber (3) is connected to the third recovery unit (26) through the vent (8).

4. The experimental apparatus for the steam oxidation mass transfer mechanism of metallic materials according to claim 1, characterized in that, The 18 O2 storage unit (9), inert gas storage unit (10), H2 16 O storage device (16) and D2 18 A mass flow meter is installed between the O storage device (17) and the reaction chamber (3).

5. The experimental apparatus for the steam oxidation mass transfer mechanism of metallic materials according to claim 1, characterized in that, The reaction chamber (3) is a quartz tube, a corundum tube, or a stainless steel tube.

6. A test method for the mass transfer mechanism of vapor oxidation in metallic materials, characterized in that, An experimental apparatus for the vapor oxidation mass transfer mechanism of metallic materials as described in any one of claims 1 to 5, comprising the following steps: The first test sample is placed in the reaction chamber (3), so that the inert gas storage device (10) is in contact with the reaction chamber (3) and H2. 16 O storage device (16) and D2 18 O storage device (17) is connected to the reaction chamber (3) and H2. 16 O storage device (16) and D2 18 The O storage unit (17) is purged to remove air from the system; The reaction chamber (3) is heated using the first heating component (4), and the H2 is heated using the second heating component (18). 16 The O storage device (16) is heated, and the D2 is heated by the third heating component (19). 18 O storage device (17) is heated; After reaching the set temperature, let H2 16 The O storage device (16) is connected to the reaction chamber (3), allowing gaseous H2 to be released. 16 O reacts with the first test sample. After the reaction is complete, the first test sample that has undergone the oxidation reaction is taken out. The second test sample was placed in the reaction chamber (3) to allow H2 to react. 16 The O storage device (16) is connected to the reaction chamber (3), allowing gaseous H2 to be released. 16 O reacts with the second test sample, and after the reaction is complete, D2 is made... 18 The O storage device (17) is connected to the reaction chamber (3), allowing gaseous D2 to be released. 18 O continues to react with the second test sample. After the reaction is complete, the second test sample that has undergone the oxidation reaction is removed. The third test sample was placed in the reaction chamber (3) to allow... 18 O2 storage device (9), H2 16 The O storage device (16) and the reaction chamber (3) are connected, so that 18 O2, gaseous H2 16 O reacts simultaneously with the third test sample. After the reaction is complete, the third test sample that has undergone the oxidation reaction is removed. The oxide films on the surfaces of the first, second, and third test samples after the oxidation reaction were peeled off to obtain... 16 O、 18 The depth distribution curves of O, H, and D in the oxide film, through the aforementioned 16 O、 18 The depth distribution curves of O, H and D in the oxide film were used to study the mass transfer mechanism of vapor oxidation in metallic materials.

7. The experimental apparatus for the steam oxidation mass transfer mechanism of metallic materials according to claim 6, characterized in that, make 18 O2, gaseous H2 16 When O reacts simultaneously with the third test sample, 18 O2 and gaseous H2 16 The volume ratio of O is 1:(10 8 ~10 9 ).

8. The experimental apparatus for the steam oxidation mass transfer mechanism of metallic materials according to claim 6, characterized in that, gaseous H2 16 The reaction time between O and the second test sample is t1, and the gaseous D2... 18 The reaction time between O and the second test sample is t2, where t1 = t2.

9. The experimental apparatus for the steam oxidation mass transfer mechanism of metallic materials according to claim 6, characterized in that, The oxidation time of the first test sample is the same as that of the second test sample and the third test sample.

10. The experimental apparatus for the steam oxidation mass transfer mechanism of metallic materials according to claim 6, characterized in that, The oxide film on the surfaces of the first, second, and third test samples after oxidation reaction was removed using a neutron diffractometer or a secondary ion mass spectrometer.

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