Stress corrosion screening test clamp and device in high-temperature and high-pressure water environment

Abstract

The invention provides a stress corrosion screening test fixture and device in a high-temperature and high-pressure water environment. A plurality of double-shaft connecting assemblies are uniformly arranged in the circumferential direction of a positioning plate. Each clamping unit comprises sample clamps which are connected in sequence, each sample clamp can be used for clamping the two ends of a dumbbell-shaped test sample, the positioning plate is moved in the axial direction, and the same tensile stress can be evenly applied to the multiple test samples which are clamped at the same time; and when one test sample clamped by the same clamping unit is broken under the action of tensile stress, the sample clamp of the clamping unit is still kept in a connected state, the tensile stress test of other non-failure test samples is not influenced, the test efficiency is improved, and the test is more accurate and visual. The screening and testing device can be used for detecting and screening stress corrosion of metal samples in a high-temperature and high-pressure water environment. And a guarantee is provided for simultaneous stress corrosion performance screening detection of a large number of metal material samples in nuclear power plant engineering tests.

Description

Technical Field

[0001] The invention belongs to the field of chemical equipment, and in particular relates to a stress corrosion screening test fixture and a device in a high-temperature and high-pressure water environment. Background Art

[0002] Stress corrosion has always been a typical failure mode of metal materials such as high-strength steel, stainless steel and nickel-based alloys. It is also a common problem that many industries, including the nuclear power field, need to solve urgently. Especially in the complex and harsh service environment of nuclear power plants, metal components face serious threats of stress corrosion failure. Stress corrosion cracking is affected by the coupling of the interaction of materials, environment and stress. When metal materials are in a high temperature and high pressure environment, if they are subjected to certain stress, their performance will change, and the mechanism of stress corrosion will be more complicated. In order to ensure the service safety of nuclear power structural materials and understand the service status of components, it is necessary to accurately screen and test the stress corrosion performance of component materials at different service stages.

[0003] In order to detect changes in stress corrosion performance of metal materials, a clamping assembly is set up to apply stress to the metal sample while clamping the metal sample to cause the sample to deform. The clamping assembly and the metal sample are then placed as a whole in a reactor of a stress corrosion screening test device for a stress corrosion screening test.

[0004] The current stress corrosion screening test equipment has at least the following problems: (1) Due to the many factors that affect stress corrosion cracking of components, it is difficult to quantify the stress corrosion of typical components under specific service conditions (such as the prediction of stress corrosion crack propagation). (2) It is difficult to quantify the stress loading and stress adjustment of metal samples in the reactor. (3) There are very few metal samples that can be placed in the reactor at the same time, and generally a large number of long-term test tasks need to be carried out.

[0005] Therefore, it is necessary to design a stress corrosion screening test fixture and device in a high-temperature and high-pressure water environment, which is suitable for stress corrosion screening tests of metal materials used in nuclear power plants in a high-temperature and high-pressure water environment, and solves the problems of difficult stress corrosion screening tests in a high-temperature and high-pressure water environment and huge volume of repeated long-cycle tests. Summary of the invention

[0006] In view of the above shortcomings of the prior art, the purpose of the present invention is to provide a stress corrosion screening test fixture and device in a high-temperature and high-pressure water environment, which can clamp multiple test samples at the same time for tensile stress testing, solve the problems of difficulty, long cycle and many repeated tests in stress corrosion screening of large quantities of samples, and is extremely valuable in ensuring the safe service of metal materials of key nuclear power equipment.

[0007] To achieve the above-mentioned purpose and other related purposes, the present invention provides a stress corrosion screening test fixture in a high temperature and high pressure water environment, comprising:

[0008] An installation unit, the installation unit comprises a top plate and a bottom plate, and the top plate and the bottom plate are coaxially connected through a connecting column;

[0009] A dual-axis self-balancing unit is located between the top plate and the bottom plate. The dual-axis self-balancing unit includes a positioning plate and dual-axis connecting components evenly arranged along the circumference of the positioning plate. The dual-axis connecting components are rotatably connected to the positioning plate, and the connecting column movably penetrates the positioning plate.

[0010] A plurality of clamping units, one end of which is connected to the biaxial connection assembly, and the other end is fixedly connected to the bottom plate. The clamping unit comprises a plurality of sample clamps connected in sequence, and the sample clamps clamp the two ends of the test sample. When the positioning plate moves toward the top plate, tensile stress is uniformly applied to each test sample.

[0011] In a preferred embodiment of the present invention, each dual-axis connection assembly includes a first connection seat and a second connection seat, the first connection seat and the second connection seat are connected by a first rotating shaft, the second connection seat and the positioning plate are connected by a second rotating shaft, the first rotating shaft and the second rotating shaft are perpendicular to each other, and are horizontally arranged perpendicular to the axis of the positioning plate.

[0012] In a preferred embodiment of the present invention, the stress corrosion screening test fixture also includes a screw and a nut, one end of the screw passes through the positioning plate and the top plate, the nut is threadedly connected to the end of the screw extending out of the top plate, and the screw is coaxially arranged with the positioning plate.

[0013] In a preferred embodiment of the present invention, a first positioning block is disposed at one end of the screw rod, a second positioning block is disposed in the central hole of the positioning plate, and the first positioning block is cooperatively connected with the second positioning block.

[0014] In a preferred embodiment of the present invention, each sample clamp includes a connected sample frame, a first connecting plate and a second connecting plate, and the two ends of the first connecting plate are respectively connected to the first connecting plate and the second connecting plate; wherein, the connection between two adjacent sample clamps is achieved by connecting the second connecting plate of one sample clamp to the sample frame of the other sample clamp.

[0015] In a preferred embodiment of the present invention, test samples are provided between the upper end of the sample frame and its corresponding second connecting plate, and between the lower end of the sample frame and its corresponding first connecting plate, and both ends of each test sample are clamped by clamping rings.

[0016] In a preferred embodiment of the present invention, the clamping ring is a pair of semicircular retaining rings, and mounting holes are provided on both ends of the sample frame, the second connecting plate and the first connecting plate. The outer diameter of the clamping ring is larger than the aperture of the mounting hole, and the inner diameter of the clamping ring is smaller than the end size of the test sample.

[0017] In a preferred embodiment of the present invention, each test sample is dumbbell-shaped, and the test sample, the sample frame, the first connecting plate and the second connecting plate are coaxially arranged.

[0018] To achieve the above-mentioned purpose and other related purposes, the present invention also includes a stress corrosion screening test device, which includes a reactor and the above-mentioned stress corrosion screening test fixture, and the stress corrosion screening test fixture is sealed in the reactor.

[0019] In a preferred embodiment of the present invention, the reaction kettle includes a kettle body, a gas supply device, a pressure control device and a heating furnace. The gas supply device introduces a designed proportion of gas into the kettle body, the pressure control device is used to adjust the pressure of the kettle body, and the heating furnace is used to heat the kettle body.

[0020] The beneficial technical effects of the present invention include at least:

[0021] The present invention proposes a stress corrosion screening test fixture in a high-temperature and high-pressure water environment. A plurality of biaxial connection components are evenly arranged in the circumferential direction of a positioning plate. Each biaxial connection component is connected to one end of a clamping unit, and the other end of each clamping unit is correspondingly connected to a bottom plate. Each clamping unit includes sample clamps connected in sequence. Each sample clamp can be used to clamp both ends of a dumbbell-shaped test sample. By moving the positioning plate in the axial direction, tensile stress can be uniformly applied to the test sample on each sample clamp. Multiple test samples can be clamped at the same time, and the same amount of tensile stress can be applied to the multiple test samples. At the same time, the biaxial connection component has good self-balancing characteristics, which improves the stability and adaptability of the device. It provides a basis for simultaneously screening and testing the stress corrosion performance of a large number of metal material samples in nuclear power plant engineering tests.

[0022] The present invention proposes a stress corrosion screening test fixture in a high-temperature and high-pressure water environment, wherein two adjacent sample clamps are connected by connecting the second connecting plate of one sample clamp with the sample frame of the other sample clamp. The sample clamps of the same clamping unit are connected in sequence, and when one of the test samples clamped by the same clamping unit fails such as fracture under the action of tensile stress, the clamping unit still maintains a connected state, i.e., maintains integrity, does not affect the transmission of force, i.e., does not affect the tensile stress test of other non-failed test samples, and can observe the failure of all test samples at the same time, and compare the failure time and failure degree of different test samples, which not only improves the test efficiency but also makes the test more accurate and intuitive.

[0023] The stress corrosion screening test device in a high-temperature and high-pressure water environment of the present invention can provide a high-temperature and high-pressure water environment for the service of nuclear power metal parts, and accurately control the oxygen content and the internal pressure value of the test sample to carry out stress corrosion detection and screening of metal samples in a simulated environment. In particular, the present invention can realize the detection and screening of the high-temperature and high-pressure stress corrosion performance of 48 samples in a sequential sampling process, and can solve the problems of difficulty, long cycle, and many repeated tests in stress corrosion screening of large quantities of samples in a high-temperature and high-pressure water environment, thereby solving the problem of difficulty in the application of stress corrosion screening and evaluation engineering, and is extremely valuable in ensuring the safe service of metal materials of key nuclear power equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0025] Figure 1 It is a schematic diagram of the structure of a stress corrosion screening test fixture in a high temperature and high pressure water environment in one embodiment of the present invention.

[0026] Figure 2 FIG. 1 is a schematic structural diagram of a dual-axis self-balancing unit in one embodiment of the present invention.

[0027] Figure 3 FIG. 4 is a schematic diagram of the structure of a clamping unit in one embodiment of the present invention.

[0028] Figure 4 The figure is a schematic diagram of the installation of a dual-axis assembly and a positioning plate in one embodiment of the present invention.

[0029] Figure 5 A schematic diagram of the installation of a screw rod and a first positioning block in one embodiment of the present invention.

[0030] Figure 6 This is a schematic diagram of the installation of a positioning plate and a second positioning block in one embodiment of the invention.

[0031] Figure 7 It is a schematic structural diagram of a dual-axis connection assembly in one embodiment of the invention.

[0032] Figure 8 Schematic diagram of the structure of a stress corrosion screening test device in a high temperature and high pressure water environment in one embodiment of the present invention.

[0033] Explanation of reference numerals: dual-axis self-balancing unit 1, positioning plate 11, dual-axis connecting assembly 12, first connecting seat 121, second connecting seat 122, first rotating shaft 123, second rotating shaft 124, threaded connecting rod 125, top plate 21, bottom plate 22, connecting column 23, clamping unit 3, sample clamp 31, sample frame 311, first connecting plate 312, second connecting plate 313, test sample 40, screw rod 51, nut 52, first positioning block 53, second positioning block 54, reactor 10, reactor body 110, thermometer 111, pressure gauge 112, gas supply equipment 120, gas supply pipe 1201, gas cylinder 1202, pressure control equipment 130, gas valve interface 131, safety valve interface 132, heating furnace 14, reactor cover 15. DETAILED DESCRIPTION

[0034] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0035] It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner. Therefore, the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0036] See also Figure 1 and Figure 2 As shown, in order to achieve the above-mentioned purpose and other related purposes, the present invention proposes a stress corrosion screening test fixture in a high-temperature and high-pressure water environment, including a biaxial self-balancing unit 1, a mounting unit and a plurality of clamping units 3. The mounting unit includes a top plate 21 and a bottom plate 22, and the top plate 21 and the bottom plate 22 are coaxially connected by a connecting column 23. The biaxial self-balancing unit 1 is located between the top plate 21 and the bottom plate 22, and includes a positioning plate 11 and biaxial connecting components 12 uniformly arranged on the circumference of the positioning plate 11, each biaxial connecting component 12 is rotatably connected to the positioning plate 11, and the connecting column 23 movably penetrates the positioning plate 11. One end of each clamping unit 3 is connected to the biaxial connecting component 12, and the other end is fixedly connected to the bottom plate 22. The clamping unit 3 includes a plurality of sample clamps 31 connected in sequence, and the sample clamps 31 clamp the two ends of the test sample 40. When the positioning plate 11 moves toward the direction of the top plate 21, tensile stress is uniformly applied to each test sample 40.

[0037] It should be noted that a plurality of biaxial connection components 12 are evenly arranged on the circumference of the positioning plate 11 of the above-mentioned test fixture, each biaxial connection component 12 is connected to one end of the clamping unit 3, and the other end of each clamping unit 3 is correspondingly connected to the bottom plate 22. Each clamping unit 3 includes sample clamps 31 connected in sequence, each sample clamp 31 can be used to clamp the two ends of the dumbbell-shaped test sample 40, and the connecting column 23 movably penetrates the positioning plate 11. The connecting column 23 not only plays the role of fixing and connecting the top plate 21 and the bottom plate 22, but also plays a guiding role for the movement of the positioning plate 11. By moving the positioning plate 11 in the axial direction, tensile stress can be uniformly applied to the test sample 40 on each sample clamp 31, and multiple test samples 40 can be clamped at the same time, and the same amount of tensile stress can be applied to the multiple test samples 40. It provides a basis for simultaneously screening and testing the stress corrosion performance of a large number of metal material samples in nuclear power plant engineering tests.

[0038] See also Figure 2 and Figure 4 As shown, in a preferred embodiment of the present invention, each dual-axis connection assembly 12 includes a first connection seat 121 and a second connection seat 122, the first connection seat 121 and the second connection seat 122 are connected by a first rotating shaft 123, the second connection seat 122 and the positioning plate 11 are connected by a second rotating shaft 124, the first rotating shaft 123 and the second rotating shaft 124 are perpendicular to each other, and are arranged horizontally perpendicular to the axis of the positioning plate 11.

[0039] It should be noted that the positioning plate 11 may be a cross-shaped plate, each extending arm of the cross-shaped plate is provided with an installation cavity, and each installation cavity is provided with a dual-axis connection assembly 12, so that the dual-axis connection assembly 12 is evenly arranged in the circumferential direction of the positioning plate 11.

[0040] See also Figure 7 As shown, specifically, the first connection seat 121 is U-shaped, the second connection seat 122 is located between the openings of the U-shape, and the first rotating shaft 123 passes horizontally through the two side plates of the U-shape to rotatably connect the first connection seat 121 and the second connection seat 122. The second rotating shaft 124 passes horizontally through the second connection seat 122 corresponding to the upper side of the first rotating shaft 123 to rotatably install the second connection seat 122 in the installation cavity of the positioning plate 11, the U-shaped bottom plate of the first connection seat 121 extends out of the installation cavity, and a threaded connecting rod 125 is connected to the U-shaped bottom plate, so that the threaded connecting rod 125 is parallel to the axial direction of the positioning plate 11, and the lower end of the threaded connecting rod 125 is threadedly connected to the upper end of the clamping unit 3.

[0041] It should be noted that the biaxial connection components 12 are evenly distributed in the circumferential direction of the positioning plate 11, and the spacing between each biaxial connection component 12 is the same. Therefore, when the positioning plate 11 moves upward, all the first connection seats 121 will rise synchronously. Since all the first connection seats 121 move upward at the same time, each clamping unit 3 is evenly stressed. The upward movement of the positioning plate 11 causes all the clamping units 3 to be evenly subjected to the same tensile stress. This design achieves uniform distribution of force by ensuring the balance and symmetry of each connection, so that each clamping unit 3 is subjected to the same amount of tensile stress.

[0042] It should be noted that the configuration of the first rotating shaft 123 and the second rotating shaft 124 being perpendicular to each other provides free rotation in two directions, and the first connecting seat 121 and the second connecting seat 122 can also move relatively independently to adapt to different loads and positions. At the same time, when the positioning plate 11 at the upper end moves, any slight imbalance can be compensated by the rotation of the rotating shaft, thereby ensuring that each clamping unit 3 is subjected to uniform tensile stress. Therefore, through the design of the dual-axis connection assembly, combined with the vertical setting of the rotating shaft, it is possible to effectively achieve uniform tensile stress on each clamping unit 3, while having good self-balancing characteristics, and improving the stability and adaptability of the device.

[0043] See also Figure 5 and Figure 6 As shown, in a preferred embodiment of the present invention, it also includes a matching screw rod 51 and a nut 52, one end of the screw rod 51 passes through the positioning plate 11 and the top plate 21, the nut 52 is threadedly connected to the end of the screw rod 51 extending out of the top plate 21, and the screw rod 51 is coaxially arranged with the positioning plate 11. A first positioning block 53 is provided at one end of the screw rod 51, and a second positioning block 54 is provided in the center hole of the positioning plate 11, and the first positioning block 53 is matched and connected with the second positioning block 54.

[0044] It should be noted that the end of the screw rod 51 is fixedly connected to the first positioning block 53, the upper end of the first positioning block 53 is provided with a first positioning groove, the bottom of the first positioning groove protrudes upward, and the lower end of the second positioning block 54 protrudes downward to form a convex block, and the convex block is provided with a second positioning groove. The nut 52 is rotated so that the screw rod 51 drives the first positioning block 53 to move upward, the first positioning groove of the first positioning block 53 and the convex block of the second positioning block 54 cooperate, and the second positioning groove on the convex block cooperates with the convex block of the first positioning groove, which can accurately locate the position of the screw rod 51, so that the screw rod 51 and the center hole of the positioning plate 11 are aligned, and at this time, the nut 52 is continued to be rotated, and the screw rod 51 drives the positioning plate 11 to move in the direction close to the top plate 21, and at this time, tensile stress is evenly applied to each clamping unit 3.

[0045] In a preferred embodiment of the present invention, each sample holder 31 includes a sample frame 311, a first connecting plate 312, and a second connecting plate 313 connected to each other. The two ends of the first connecting plate 312 are respectively connected to the first connecting plate 312 and the second connecting plate 313; wherein, the connection between two adjacent sample holders 31 is achieved by connecting the second connecting plate 312 of one sample holder 31 with the sample frame 311 of the other sample holder 31. Each test sample 40 is dumbbell-shaped, and the two ends of the dumbbell are installation connection parts, and the test sample 40, the sample frame 311, the first connecting plate 312, and the second connecting plate 313 are coaxially arranged.

[0046] It should be noted that the sample frame 311 of each sample holder 31 is a rectangular frame, and the first connecting plate 312 and the second connecting plate 313 can both be H-shaped plates. The lower frame of the first connecting plate 312 is gathered toward the middle and overlapped on the web of the second connecting plate 313, and the lower part of the sample frame 311 is arranged in the upper frame of the first connecting plate 312 and fixedly connected. The upper part of each sample frame 311 is arranged in the lower frame of the second connecting plate 313 of the adjacent sample holder 31 and fixedly connected.

[0047] The lower frame of the first connecting plate 312 and the upper frame gap of the second connecting plate 313 are fitted and connected by a pair of bolts, the lower part of the sample frame 311 and the upper frame gap of the first connecting plate 312 are fitted and connected by a pair of bolts, and the upper part of the sample frame 311 and the lower frame gap of the second connecting plate 313 of the adjacent sample clamp 31 are fitted and connected by a pair of bolts. The upper end of the sample frame 311 and the web of the corresponding second connecting plate 313 are respectively clamped to the two ends of the test sample 40 through a clamp ring, and the lower end of the sample frame 311 and the web of the corresponding first connecting plate 312 are respectively clamped to the two ends of another test sample 40 through a clamp ring. Each sample clamp 31 is an axisymmetric structure, and the symmetry axis is parallel to the axial direction of the positioning plate 11.

[0048] In a preferred embodiment of the present invention, a test sample 40 is provided between the upper end of the sample frame 311 and the corresponding second connecting plate 313, and between the lower end of the sample frame 311 and the corresponding first connecting plate 312, and both ends of each test sample 40 are clamped by a clamp ring. Each clamp ring is a pair of semicircular retaining rings, and mounting holes are provided on both ends of the sample frame 311, the first connecting plate 312, and the second connecting plate 313. The outer diameter of the clamp ring is larger than the aperture of the mounting hole, and the inner diameter of the clamp ring is smaller than the end of the test sample 40.

[0049] It should be noted that the test sample 40 is a dumbbell-shaped structure, and the dimensions of the two ends are larger than the dimensions of the middle section. The two ends are for installation, and the middle section is the test part of the test. The mounting hole can be a stepped hole. When the end of the test sample 40 passes through the stepped hole, a pair of retaining rings are aligned and located in the large hole of the stepped hole to clamp and fix the end of the test sample 40. The retaining ring is a material that is insulated from the metal material, and can be selected from rubber material or fiber reinforced plastic, etc., and its rigidity can meet certain requirements.

[0050] It should be noted that the lower part of the sample frame 311 is fixedly connected to the upper frame of the first connecting plate 312, and the upper part of the sample frame 311 is fixedly connected to the lower frame of the second connecting plate 313 of the adjacent sample clamp 31. Not only the sample clamps 31 of the same clamping unit 3 are connected in sequence, but also when one of the test samples 40 clamped by the same clamping unit 3 fails such as breaking under the action of tensile stress, the clamping unit 3 still maintains the connection state, that is, maintains integrity, does not affect the transmission of force, that is, does not affect the tensile stress test of other non-failed test samples 40, so that the test efficiency is higher.

[0051] It should be noted that each clamping unit 3 includes 6 sample clamps 31, and the upper end of the sample frame 311 close to the top plate 21 and the U-shaped bottom of the second connecting seat 122 of the corresponding biaxial connection assembly 12 are connected by a threaded connecting rod 125. The lower end of the sample clamp 31 close to the bottom plate 22 is also connected to a sample frame 311, and the lower end of the sample frame 311 is connected to the bottom plate 22 by a threaded connecting rod 125. Therefore, in combination with the above-mentioned present invention, it includes 4 biaxial connection assemblies 12, and 4 clamping units 3 are installed respectively. The stress corrosion screening test fixture of the present invention can clamp 48 test specimens at the same time, realizing a large-volume sample test.

[0052] See also Figure 8 As shown, in order to achieve the above-mentioned purpose and other related purposes, the present invention also includes a stress corrosion screening test device, which includes a reactor 10 and the above-mentioned stress corrosion screening test fixture, and the stress corrosion screening test fixture is sealed in the reactor 10. The reactor 10 provides a stress corrosion screening test space environment, and the reactor 10 contains a simulated environmental solution. To ensure that the corrosion test fixture is sealed in the reactor 10, a reactor cover 15 can be set at the upper end of the reactor 10.

[0053] It should be noted that the installation methods of the stress corrosion screening test fixture include but are not limited to the following situations: First, fixed installation is achieved by fixing the bottom plate 22 on the bottom of the reactor 10. Second, it can be fixedly installed on the reactor cover 15 by screws 51. Third, the top plate 21 is fixed to the lower plane of the reactor cover 15 by bolts, the screws 51 pass through the top plate 21 and the center of the reactor cover 15, and the nuts 52 are placed on the upper surface of the reactor cover 15.

[0054] It should be noted that the requirements for nuclear power engineering materials are relatively strict, and generally need to meet the following requirements: Radiation protection requirements, materials must be able to effectively shield and prevent the transmission of radiation (such as neutrons and gamma rays) to ensure the safety of personnel and the environment. Melting point and cracking strength requirements, materials should have a high melting point and cracking resistance to withstand operations under high temperature and high pressure conditions. Long-term stability requirements, materials must maintain the stability of their physical and chemical properties in a long-term radiation environment, and performance degradation must not occur. Fatigue strength requirements, should have good fatigue strength to resist repeated stress and cyclic loading. Chemical stability requirements, materials used in nuclear power plants are often in corrosive media (such as water, acid, alkali, etc.), so the materials must have good corrosion resistance to extend their service life and reduce maintenance costs. Strength and toughness requirements, must have high strength and excellent toughness to withstand mechanical stress and impact under various operating conditions. Thermal expansion coefficient requirements: The thermal expansion coefficient of the material should match that of other components to avoid stress concentration caused by temperature changes. Therefore, a specific test environment needs to be provided to the reactor 10. Only when conducting tests can the required test samples 40 be screened out to meet the performance requirements of nuclear power engineering for materials.

[0055] In a preferred embodiment of the present invention, the reaction kettle 10 includes a kettle body 110, a gas supply device 120, a pressure control device 130 and a heating furnace 14. The gas supply device 120 introduces a designed proportion of gas into the kettle body 110, the pressure control device 130 is used to adjust the pressure of the kettle body 110, and the heating furnace 14 is used to heat the kettle body 110 and the solution therein.

[0056] It should be noted that the gas supply device 120 includes a gas supply pipe 1201 and a gas cylinder 1202. The gas supply pipe 1201 may be provided with a regulating valve. The gas cylinder 1202 contains a mixed gas of oxygen and inert gas in a designed proportion. The gas cylinder 1202 passes the mixed gas into the solution in the reactor 10 through the gas supply pipe 1201. The mixed gas provided can not only maintain the oxygen concentration of the solution, but also promote the progress of the gas-liquid reaction, and enhance the reaction rate and efficiency, especially when it involves redox reactions or other chemical reactions that require the participation of oxygen. The regulating valve can adjust the flow rate of the gas supply and, combined with the proportion of the mixed gas, can achieve detailed control of the reaction environment, thereby optimizing the reaction conditions.

[0057] It should be noted that the pressure control device 130 includes a gas valve interface 131 and a safety valve interface 132, which are used to adjust the gas pressure in the kettle 110. When gas (such as gas products or thermal decomposition gas) is generated during the reaction process and causes the pressure to rise, the vent valve interface 131 can be used to discharge excess gas, thereby maintaining a safe pressure in the kettle 110. The safety valve interface 132 is a safety mechanism. When the internal pressure of the kettle 110 exceeds the set threshold, the safety valve interface 132 can be automatically opened to release excess gas into the external environment to prevent dangerous conditions such as explosion or leakage of the kettle 110. At the same time, when it is necessary to maintain a fixed atmosphere or a specific component ratio, the pressure control device 130 can ensure the proper exchange between the gas in the kettle 110 and the external gas, thereby maintaining the stability of the reaction environment.

[0058] It should be noted that a thermometer 111 and a pressure gauge 112 are disposed on the kettle body 110 to facilitate observation of the temperature and pressure in the kettle body 110 .

[0059] In summary, the stress corrosion screening test fixture and device in a high temperature and high pressure water environment of the present invention at least include the following technical effects:

[0060] (1) The present invention proposes a stress corrosion screening test fixture in a high-temperature and high-pressure water environment, comprising a biaxial self-balancing unit 1, a mounting unit and a plurality of clamping units 3. The biaxial self-balancing unit 1 comprises a positioning plate 11 and biaxial connecting components 12 uniformly arranged on the circumference of the positioning plate 11. The mounting unit comprises a top plate 21 and a bottom plate 22. Each clamping unit 3 is in the shape of an elongated strip and comprises a plurality of sample clamps 31 connected in sequence. A plurality of biaxial connecting components 12 are uniformly arranged on the circumference of the positioning plate 11 of the above-mentioned test fixture, each biaxial connecting component 12 is connected to one end of the clamping unit 3, and the other end of each clamping unit 3 is correspondingly connected to the bottom plate 22. Each clamping unit 3 comprises sample clamps 31 connected in sequence, each sample clamp 31 can be used to clamp the two ends of a dumbbell-shaped test sample 40, and the positioning plate 11 is moved in the axial direction to uniformly apply tensile stress to the test sample 40 on each sample clamp 31, and multiple test samples 40 can be clamped at the same time, and the same amount of tensile stress can be applied to the multiple test samples 40. The biaxial connection assembly 12 has good self-balancing characteristics, which improves the stability and adaptability of the device and provides a basis for simultaneously screening and testing the stress corrosion performance of a large number of metal material samples in nuclear power plant engineering tests.

[0061] (2) The present invention proposes a stress corrosion screening test fixture under high temperature and high pressure water environment, wherein two adjacent sample clamps 31 are connected by connecting the second connecting plate 312 of one sample clamp 31 with the sample frame 311 of the other sample clamp 31. Specifically, the lower part of the sample frame 311 is fixedly connected to the upper frame of the first connecting plate 312, and the upper part of the sample frame 311 is fixedly connected to the lower frame of the second connecting plate 313 of the adjacent sample clamp 31. The sample clamps 31 of the same clamping unit 3 are connected in sequence, and when one of the test samples 40 clamped by the same clamping unit 3 fails such as fracture under the action of tensile stress, the clamping unit 3 still maintains the connection state, i.e., maintains integrity, does not affect the transmission of force, i.e., does not affect the tensile stress test of other non-failed test samples 40. At the same time, the failure of all test samples 40 is observed, and the failure time and failure degree of different test samples 40 are compared, which not only improves the test efficiency but also makes the test more accurate and intuitive.

[0062] (3) The stress corrosion screening test device in a high-temperature and high-pressure water environment of the present invention can provide a high-temperature and high-pressure water environment for the service of nuclear power metal parts, and accurately control the oxygen content and the internal pressure value of the test sample 40 to carry out stress corrosion detection and screening of metal samples in a simulated environment. In particular, the present invention can realize the detection and screening of the high-temperature and high-pressure stress corrosion performance of 48 samples in a sequential sample process, and can solve the problems of difficulty, long cycle, and many repeated tests in stress corrosion screening of large quantities of samples in a high-temperature and high-pressure water environment, thereby solving the problem of difficulty in the application of stress corrosion screening and evaluation engineering, and is extremely valuable in ensuring the safe service of metal materials of key nuclear power equipment.

[0063] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

[0064] In the description herein, many specific details, such as examples of components and / or methods, are provided to provide a complete understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more of the specific details or with other devices, systems, components, methods, components, materials, parts, etc. In other cases, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

[0065] References throughout this specification to "one embodiment," "an embodiment," or "a specific embodiment" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention, and not necessarily in all embodiments. Thus, various appearances of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout this specification do not necessarily refer to the same embodiment. In addition, the particular features, structures, or characteristics of any specific embodiment of the invention may be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the invention described and illustrated herein may be possible in light of the teachings herein and are to be considered part of the spirit and scope of the invention.

[0066] It should also be understood that one or more of the elements shown in the figures may also be implemented in a more separate or more integrated manner, or even removed because they are inoperable in certain circumstances or provided because they may be useful depending on the application.

[0067] In addition, unless otherwise explicitly indicated, any marking arrows in the drawings should be regarded as exemplary only and not limiting. In addition, unless otherwise indicated, the term "or" used herein is generally intended to mean "and / or". In the case where the term is not clear because it is anticipated that the ability to separate or combine is provided, the combination of components or steps will also be regarded as indicated.

[0068] As used in the description herein and throughout the claims that follow, "a," "an," and "the" include plural references unless otherwise indicated. Likewise, as used in the description herein and throughout the claims that follow, the meaning of "in" includes "in" and "on," unless otherwise indicated.

[0069] The above description of the illustrated embodiments of the present invention (including the contents described in the Abstract) is not intended to be an exhaustive list or to limit the present invention to the precise form disclosed herein. Although specific embodiments of the present invention and examples of the present invention are described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the present invention as will be recognized and appreciated by those skilled in the art. As noted, these modifications may be made to the present invention in accordance with the above description of the embodiments described in the present invention, and these modifications will be within the spirit and scope of the present invention.

[0070] Systems and methods have been generally described herein as details that aid in understanding the present invention. In addition, various specific details have been given to provide an overall understanding of embodiments of the present invention. However, those skilled in the relevant art will recognize that embodiments of the present invention may be practiced without one or more of the specific details, or may be practiced using other devices, systems, accessories, methods, components, materials, parts, etc. In other cases, well-known structures, materials, and / or operations are not specifically shown or described in detail to avoid confusion with various aspects of embodiments of the present invention.

[0071] Thus, although the invention has been described herein with reference to specific embodiments thereof, freedom of modification, various changes and substitutions are also within the foregoing disclosure, and it should be understood that in some cases, some features of the invention will be employed without the corresponding use of other features without departing from the scope and spirit of the proposed invention. Thus, many modifications may be made to adapt a particular environment or material to the essential scope and spirit of the invention. The invention is not intended to be limited to the specific terms used in the claims below and / or the specific embodiments disclosed as the best mode contemplated for carrying out the invention, but the invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Thus, the scope of the invention will be determined solely by the appended claims.

Claims

1. A stress corrosion screening test fixture in a high temperature and high pressure water environment, characterized in that: include: An installation unit, the installation unit comprising a top plate and a bottom plate, the top plate and the bottom plate being coaxially connected via a connecting column; A dual-axis self-balancing unit is located between the top plate and the bottom plate, the dual-axis self-balancing unit comprises a positioning plate and dual-axis connecting components evenly arranged along the circumference of the positioning plate, the dual-axis connecting components are rotatably connected to the positioning plate, and the connecting column movably passes through the positioning plate; A plurality of clamping units, one end of each of the clamping units is connected to the biaxial connection assembly, and the other end is fixedly connected to the bottom plate, the clamping unit comprises a plurality of sample clamps connected in sequence, the sample clamps clamp the two ends of the test sample, and when the positioning plate moves toward the direction of the top plate, tensile stress is uniformly applied to each test sample.

2. The stress corrosion screening test fixture according to claim 1, characterized in that: Each of the dual-axis connection components includes a first connection seat and a second connection seat, the first connection seat and the second connection seat are connected by a first rotating shaft, the second connection seat and the positioning plate are connected by a second rotating shaft, the first rotating shaft and the second rotating shaft are perpendicular to each other and are horizontally arranged perpendicular to the axis of the positioning plate.

3. The stress corrosion screening test fixture according to claim 2, characterized in that: The stress corrosion screening test fixture also includes a screw and a nut, one end of the screw passes through the positioning plate and the top plate, the nut is threadedly connected to one end of the screw extending out of the top plate, and the screw is coaxially arranged with the positioning plate.

4. The stress corrosion screening test fixture according to claim 3, characterized in that: A first positioning block is arranged at one end of the screw rod, a second positioning block is arranged in the central hole of the positioning plate, and the first positioning block is matched and connected with the second positioning block.

5. The stress corrosion screening test fixture according to claim 4, characterized in that: The sample clamp comprises a sample frame, a first connecting plate and a second connecting plate connected to each other, wherein two ends of the first connecting plate are respectively connected to the first connecting plate and the second connecting plate; Wherein, the connection between two adjacent sample clamps is achieved by connecting the second connecting plate of one sample clamp with the sample frame of the other sample clamp.

6. The stress corrosion screening test fixture according to claim 5, characterized in that: The test samples are arranged between the upper end of the sample frame and the corresponding second connecting plate, and between the lower end of the sample frame and the corresponding first connecting plate. Both ends of each test sample are clamped by a clamp ring.

7. The stress corrosion screening test fixture according to claim 6, characterized in that: Each of the clamping rings is a pair of semicircular retaining rings, and mounting holes are provided at both ends of the sample frame and the first connecting plate and the second connecting plate. The outer diameter of the clamping ring is larger than the aperture of the mounting hole, and the inner diameter of the clamping ring is smaller than the end size of the test sample.

8. The stress corrosion screening test fixture according to claim 7, characterized in that: Each of the test samples is in a dumbbell shape, and the test sample, the sample frame, the first connecting plate and the second connecting plate are coaxially arranged.

9. A stress corrosion screening test device, characterized in that: It comprises a reaction kettle and the stress corrosion screening test fixture as described in claims 1 to 8, wherein the stress corrosion screening test fixture is sealed in the reaction kettle.

10. The stress corrosion screening test device according to claim 9, characterized in that: The reactor comprises a reactor body, a gas supply device, a pressure control device and a heating furnace. The gas supply device introduces a designed proportion of gas into the reactor body, the pressure control device is used to adjust the pressure of the reactor body, and the heating furnace is used to heat the reactor body.

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