Testing device and method for testing endurance performance of passive self-pressurization small sample

Abstract

The invention relates to the technical field of material performance testing, and discloses a passive self-pressurization small sample endurance performance testing device and a method thereof.The testing device comprises a pre-pressurization part, a pressurization part and a pressure relief part, and the pre-pressurization part is provided with a first end and a second end which are opposite; a pressurizing cavity penetrating through the first end and the second end is formed in the pre-pressurizing part, an operator inputs corresponding gas into the pressurizing cavity in the pre-pressurizing part through an external air pressure source, after the external air pressure source is disconnected, the pressurizing part is sealed, and then the assembled testing device is placed in a heating furnace with the preset temperature to be heated; by means of the design, the pressure source does not need to be maintained in the high-temperature endurance performance testing process, namely, the high-temperature endurance performance testing of the small sample can be achieved without a complex continuous air pressure loading system, a sealing system and a control system. The test cost is saved, and the reliability of the device is improved.

Description

Technical Field

[0001] The invention relates to the technical field of material performance testing, and in particular to a test device and a method for testing the endurance performance of a passive self-pressurizing small sample. Background Art

[0002] There are a large number of pressure-bearing equipment that operate under high temperature and high pressure for a long time in many fields such as nuclear energy, electricity, petrochemicals, and aerospace. During long-term service, these equipment may experience material degradation or even failure. Therefore, it is necessary to conduct real-time evaluation of the mechanical properties of in-service equipment without destroying the structural integrity of the equipment. As a new type of small sample testing technology, air pressure inflation has good application prospects in the field of high-temperature durability performance testing of materials due to its advantages such as few influencing factors in the testing process and simple and reliable geometric models.

[0003] However, the existing patent CN 113340744 A discloses a bulging test device for testing the creep performance of metal sheets. The test device is composed of multiple components such as a pressure loading mechanism, a load-bearing frame, a clamping mechanism, a temperature control furnace, a deformation measuring mechanism and a control system. The device has a complex structure and numerous connecting parts, and has the following problems and defects that need to be solved urgently.

[0004] The pressure loading mechanism is composed of multiple components such as a piston pump, a medium delivery pipe and a pressure sensor. The mechanical structure is complex, and the design, manufacturing, sealing connection, and operation and maintenance costs of the test device are high. The pressure loading mechanism and load-bearing frame and other components and connectors are large in size, and the device is not convenient to move, carry and maintain. The temperature control furnace in the test device needs to be customized for the clamping mechanism, and usually a temperature control furnace can only be used to heat a set of test data. There are many connectors such as valves, and the device needs to consider many sealing factors. The high-temperature endurance test requires a long operating time, and the device needs to add an additional control system to compensate for the gas source pressure in the pipeline to maintain the pressure. The high-temperature endurance test is usually carried out at a temperature above 400°C, and the air pressure is preloaded at high temperature, which places high requirements on the sealing and safety of the device during the pressurization process.

[0005] So far, there is no device that can solve the above problems. Therefore, it is of great significance to propose a test device and method that is simple to operate, low in cost, and easy to carry and can be used for testing the durability performance of small samples of passive pressure expansion. Summary of the invention

[0006] The main purpose of the present invention is to provide a test device and a test method for passive self-pressurizing small sample endurance performance testing, aiming to solve the technical problems in the small sample high-temperature endurance performance test that the test device needs to maintain pressure supply, the acquisition of performance data takes a long time and the operation is complicated.

[0007] To achieve the above object, the present invention provides a test device for testing the endurance performance of a small sample by passive self-pressurization, the test device comprising:

[0008] A pre-pressurizing portion, which has a first end and a second end opposite to each other, wherein a pressurizing cavity penetrating the first end and the second end is disposed inside the pre-pressurizing portion;

[0009] a pressurizing portion, an end of which is detachably connected to the first end, wherein a pre-pressurizing pipe communicating with the pressurizing chamber is provided inside the pressurizing portion, and the pre-pressurizing pipe inputs external gas into the pressurizing chamber so that the interior of the pre-pressurizing pipe has a preset air pressure;

[0010] The pressure relief part has an end portion connected to the second end in a detachable manner, and a pressure relief chamber connected to the pressurizing chamber is arranged inside the pressure relief part, and a small sample to be tested is installed at the connection between the pressure relief chamber and the pressurizing chamber, and the small sample is used to withstand the pressure brought by the preset air pressure in the pressurizing chamber.

[0011] A method for testing the endurance performance of a small sample by passive self-pressurization, the test device comprising the following steps:

[0012] (1) According to formula A converted from the ideal gas law, calculate the preset air pressure value that needs to be input into the test device at normal temperature corresponding to the test pressure value at the preset temperature;

[0013] (2) The external pressure source delivers air pressure of a preset air pressure value to the pressurization chamber connected to the pre-pressurization pipeline through the air inlet hole;

[0014] (3) After the gas pressure delivery is completed, the operator welds and seals all the places where gas leaks between the pre-pressurization pipeline and the outside of the pressurization unit;

[0015] (4) After the entire test device is assembled, place the test device in a heating furnace with a preset temperature for heating;

[0016] (5) The operator records the preset temperature, test pressure and the time required for the small sample to break, thereby obtaining the high temperature endurance performance data of the small sample to be tested;

[0017] (6) After the small specimen is broken, the gas in the pressurized chamber enters the pressure relief chamber. After the test device is taken out of the heating furnace and cooled to room temperature, the operator operates the pressure relief check valve assembly to allow the gas in the pressure relief chamber to flow to the outside;

[0018] (7) Repeat the above operation and heat the test devices with different test pressure values ​​in a heating furnace with the same preset temperature at the same time to obtain the endurance performance of the small gas pressure expansion specimen under different working conditions.

[0019] In the technical solution provided by the present invention, the operator calculates the preset air pressure value according to the test pressure required for the test through the formula A converted from the ideal gas law, and then the external air pressure source inputs the corresponding gas into the pressurization chamber in the pre-pressurization part through the pressurization part. After disconnecting the external air pressure source, the pressurization part is sealed, and then the assembled test device is placed in a heating furnace at a preset temperature for heating, so that the air pressure in the pressurization chamber is self-pressurized in the absence of an external air pressure source to reach the required test air pressure value. The above operation is simple, there is no gas leakage caused by the flange connection, and the setting does not need to be maintained during the high-temperature endurance performance test. The pressure source, that is, the high-temperature endurance performance test of the small sample of gas pressure expansion can be realized without complex continuous air pressure loading, sealing and control systems, which greatly saves the test cost and improves the reliability of the device, and the whole test device is small in size and easy for operators to carry, that is, it has a wide range of application environments. Secondly, the operator can heat multiple test devices with different preset pressure values ​​at the same preset temperature in a heating furnace, and obtain the high-temperature endurance performance of the small sample of gas pressure expansion under different working conditions, which solves the problem that the existing gas pressure expansion test device can only measure the high-temperature endurance performance of small samples under a single working condition, and reduces the time cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] One or more embodiments are exemplarily described by corresponding drawings, which do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and the figures in the drawings do not constitute proportional limitations unless otherwise stated.

[0021] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0022] Figure 2 is a cross-sectional view of the present invention;

[0023] Figure 3 It is a structural schematic diagram of the charging part of the present invention;

[0024] Figure 4 is a cross-sectional view of the charging portion of the present invention;

[0025] Figure 5 It is a cross-sectional view of the pressure relief portion of the present invention (without the pressure relief valve core);

[0026] Figure 6 It is a cross-sectional view of the pressure relief portion of the present invention.

[0027] The reference numerals in the figures are as follows:

[0028] 100. Test equipment;

[0029] 1. Pre-pressurizing part; 11. Pressurizing chamber; 12. Short convex shaft; 13. Pressurizing shaft; 14. Connecting shaft;

[0030] 2. Pressurizing part; 21. Pre-pressurizing pipeline; 211. First pre-pressurizing pipeline; 212. Second pre-pressurizing pipeline; 213. Third pre-pressurizing pipeline; 22. Loading check valve assembly; 221. Annular stop block; 222. Control piston; 223. Valve core; 224. Balance pipeline; 2241. Balance through hole; 2242. Balance channel; 23. Air inlet; 24. Air outlet;

[0031] 3. Pressure relief part; 31. Die shaft; 311. First installation pipeline; 312. Second installation pipeline; 32. Partition block; 321. Second pipeline; 33. Pressure relief valve assembly; 331. First pipeline; 332. Pressure relief valve core; 3321. Balance chamber; 3322. Communication hole; 333. Guide shaft; 3331. Guide pipeline; 34. Gasket; 341. Third pipeline;

[0032] 4. Sealing gasket. DETAILED DESCRIPTION

[0033] In order to facilitate the understanding of the present invention, the present invention is described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on another element, or there can be one or more centered elements therebetween. When an element is described as "connected" to another element, it can be directly connected to another element, or there can be one or more centered elements therebetween. The terms "vertical", "horizontal", "left", "right", "inside", "outside" and similar expressions used in this specification are only for illustrative purposes. In the description of the present invention, the terms "first" and "second" are used only for descriptive purposes and cannot be understood as indicating relative importance or implicitly indicating the number of technical features indicated. Therefore, unless otherwise specified, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features; the meaning of "multiple" is two or more. The term "include" and any variation thereof means non-exclusive inclusion, and one or more other features, integers, steps, operations, units, components and / or combinations thereof may be present or added.

[0034] In addition, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediate medium, or a connection between two components. All technical and scientific terms used in this specification have the same meaning as those generally understood by technicians in the technical field of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in this specification includes any and all combinations of one or more related listed items.

[0035] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] The present invention provides a test device for testing the endurance performance of a small sample by passive self-pressurization, which is mainly used to test the high-temperature endurance performance of a small sample. Figure 1-Figure 6 The test device 100 includes a pre-pressurizing part 1, a charging part 2 and a pressure relief part 3. The pre-pressurizing part 1 has a first end and a second end opposite to each other. A pressure chamber 11 penetrating the first end and the second end is provided inside the pre-pressurizing part 1. The pressure chamber 11 is mainly used to accommodate gas. The end of the charging part 2 is detachably connected to the first end. A pre-pressurizing pipe 21 communicating with the pressure chamber 11 is provided inside the charging part 2. The pre-pressurizing pipe 21 inputs external gas into the pressure chamber 11 so that the pressure chamber 11 has a preset air pressure. As for the pressure relief part 3, its end is detachably connected to the second end, and a pressure relief part 3 is provided inside the pressure relief part 3. A pressure relief chamber is connected to 11, and a small sample to be tested is installed at the connection between the pressure relief chamber and the pressurization chamber 11. The small sample is used to withstand the pressure in the pressurization chamber 11, that is, the air pressure impacts the small sample to make it expand and break. The above design realizes gas self-pressurization in the process from normal temperature to high temperature, and does not need to maintain a pressure source in a high-temperature test environment, that is, no complex air pressure loading, sealing and control system is required to realize the high-temperature endurance performance test of the small sample inflated by air pressure, which greatly saves the test cost and improves the reliability of the device. Moreover, the entire test device 100 is small in size, and different components can be replaced by assembly, so it is convenient for operators to carry and has a wide range of application environments.

[0037] In this embodiment, the charging part 2 also includes a loading check valve assembly 22, which is arranged in the pre-charging pipe 21 to control the connection and blockage between the pre-charging pipe 21 and the pressurization chamber 11, that is, the external pressure source fills the gas into the pressurization chamber 11 through the charging part 2. After reaching the required pressure value, the loading check valve assembly 22 blocks the pressurization chamber 11 to prevent the gas in the pressurization chamber 11 from leaking, thereby affecting the air pressure value required for the small sample to be tested.

[0038] When describing the above structure in detail, it should be noted that in the present invention, please refer to Figure 1 The pressure relief part 3 is defined as the top structure of the test device 100, and the pressure charging part 2 is defined as the bottom structure of the test device 100. Therefore, the positions of other structures in the test device 100 are also understood in accordance with the above positions.

[0039] Please refer to Figure 1 , Figure 3 and Figure 4 As for how the loading one-way valve assembly 22 controls the connection and blocking between the pre-charged pipe 21 and the pressurized chamber 11, the pre-charged pipe 21 includes a first pre-charged pipe 211, a second pre-charged pipe 212 and a third pre-charged pipe 213 that are connected to each other. As for the loading one-way valve assembly 22, it includes an annular limit block 221, a control piston 222 and a valve core 223. The outer periphery of the annular limit block 221 is clamped with the inner wall surface of the first pre-charged pipe 211 near the bottom end. Specifically, the inner wall surface of the first pre-charged pipe 211 near the bottom end is concave with an annular groove, and the outer periphery of the annular limit block 221 is inserted and sealed in the annular groove to limit the position of the control piston 222 and preliminarily seal one end of the first pre-charged pipe 211.

[0040] As for the control piston 222, it is arranged in the first pre-charged pressure pipe 211, the bottom end of the control piston 222 abuts against the top end of the annular limit block 221, and the top end of the control piston 222 is located in the second pre-charged pressure pipe 212, and the valve core 223 is arranged in the third pre-charged pressure pipe 213, the bottom end of the valve core 223 abuts against the top end of the control piston 222, and the top end of the valve core 223 is elastically connected to the top end inside the third pre-charged pressure pipe 213 through a spring. When the pressure source does not input gas to the first pre-charged pressure pipe 211, the valve core 223 is in a balanced state, and the top end of the valve core 223 has a force along the direction of the control piston 222 under the elastic recovery effect, so that the bottom end of the valve core 223 abuts against the top end of the control piston 222, and the bottom end of the valve core 223 externally seals the top end of the second pre-charged pressure pipe 212; when the pressure source does not input gas to the first pre-charged pressure pipe 211, the valve core 223 is in a balanced state, and the top end of the valve core 223 has a force along the direction of the control piston 222 under the elastic recovery effect, so that the bottom end of the valve core 223 abuts against the top end of the control piston 222, and the bottom end of the valve core 223 externally seals the top end of the second pre-charged pressure pipe 212; When the source inputs gas into the first pre-charged pressure pipe 211, since the inner diameter of the top end of the control piston 222 is smaller than the inner diameter of the second pre-charged pressure pipe 212, the bottom end of the valve core 223 will be affected by the positive air pressure, causing the spring to be compressed. At this time, the bottom end of the valve core 223 will be away from the top end of the control piston 222, and the outside of the bottom end of the valve core 223 will no longer seal the top end of the second pre-charged pressure pipe 212, thereby realizing the connection between the first pre-charged pressure pipe 211, the second pre-charged pressure pipe 212 and the third pre-charged pressure pipe 213, thereby realizing the gas input into the pressurized chamber 11. In fact, in order to ensure that the connection between the spring and the top end of the valve core 223 can operate normally, the valve core 223 is provided with a balancing pipe 224 that connects the third pre-charged pressure pipe 213 and the space formed by the connection between the spring and the top end of the valve core 223, so as to ensure that the working process of the valve core 223 is smoother.

[0041] In this embodiment, please refer to Figure 4 The balancing pipeline 224 includes a balancing through hole 2241 and a balancing groove 2242. A groove connected to the top of the third pre-pressurized pipeline 213 is opened inside the valve core 223 along the top direction of the valve core 223. The groove is the balancing groove 2242. As for the balancing through hole 2241, the balancing groove 2242 is connected to the bottom of the third pre-pressurized pipeline 213.

[0042] For further information, please refer to Figure 2-Figure 4 , at least one air inlet hole 23 connected to the first pre-pressurizing pipe 211 is arranged on the outside of the pressurizing part 2 near the bottom end. In the present embodiment, there are four air inlet holes 23, which are arranged in a ring shape around the pressurizing part 2 near the bottom end. The arrangement of multiple air inlet holes 23 can enhance the accuracy of the air pressure value controlled by the pressure source to enter the first pre-pressurizing pipe 211; at least one air outlet hole 24 is arranged on the outside of the pressurizing part 2 near the top end. The air outlet hole 24 is used to connect the third pre-pressurizing pipe 213 and the pressurizing chamber 11. In the present embodiment, there are four air outlet holes 24, which are arranged around the pressurizing part 2 near the top end.

[0043] In this implementation, please refer to Figure 2 The pre-pressurizing part 1 includes a short protruding shaft 12 with various pressurizing cavities 11 inside, a pressurizing shaft 13 and a connecting shaft 14, wherein the inner diameter of the short protruding shaft 12 is smaller than the inner diameter of the pressurizing shaft 13. This design facilitates the top end surface of the short protruding shaft 12 and other structures to clamp the small sample, wherein the inner wall surface of the pressurizing chamber 11 located in the connecting shaft 14 is connected to the external thread of the pressurizing part 2. It should be noted that the air outlet 24 is connected to the pressurizing chamber 11 located in the connecting shaft 14.

[0044] For details, please refer to Figure 4 The gas in the third pre-pressurization pipe 213 enters the pressurization chamber 11 in the connecting shaft 14 through the air outlet 24, and then flows into the pressurization chamber 11 in the pressurization shaft 13 and the short convex shaft 12. Under the influence of the external environment of the test device 100, the air pressure impacts the small sample located on the top end face of the short convex shaft 12.

[0045] In this embodiment, please refer to Figure 1 and Figure 2 as well as Figure 5 and Figure 6 The pressure relief part 3 also includes a die shaft 31, a partition block 32, a gasket 34 and a pressure relief one-way valve assembly. The die shaft 31 is provided with an installation pipe along its bottom end, and the partition block 32 is arranged in the installation pipe to divide the installation pipe into a first installation pipe 311 and a second installation pipe 312. The inner wall surface of the bottom end of the first installation pipe 311 is connected with the external thread of the top end of the pressurizing shaft 13, thereby assembling the pressure relief part 3 and the pre-pressurizing part 1. The gasket 34 is arranged at the bottom end of the partition block 32. The bottom end of the gasket 34 is connected with the top end of the short convex shaft 12 by the gasket 34. The pressure relief one-way valve assembly is arranged in the second installation pipe 312, and the bottom end of the pressure relief one-way valve assembly abuts against the top end of the partition block 32, and the top end of the pressure relief one-way valve assembly abuts against the top surface of the second installation pipe 312, wherein the pressure relief one-way valve assembly has an inner cavity. When the small sample is broken under pressure, the gas in the pressure relief chamber 11 will enter the inner cavity of the pressure relief one-way valve assembly. The volume of the inner cavity is larger than that of the pressure relief chamber 11, so as to buffer the gas in the pressure relief chamber 11.

[0046] As for the structure of the pressure relief one-way valve assembly, in the present embodiment, the bottom end of the pressure relief one-way valve assembly, the partition block 32 and the gasket 34 are provided with a first pipe 331, a second pipe 321 and a third pipe 341 in sequence along the axial direction of the pressurized chamber 11, wherein the inner cavity, the first pipe 331, the second pipe 321 and the third pipe 341 are connected in sequence, and the inner cavity, the first pipe 331, the second pipe 321 and the third pipe 341 constitute a pressure relief chamber, which is used to buffer the gas contained in the pressurized chamber 11 and also circulate the above-mentioned gas to the outside.

[0047] Furthermore, the pressure relief valve assembly 33 includes a pressure relief shaft, which is accommodated in the second installation pipe 312, wherein the first pipe 331 is arranged at the bottom end of the pressure relief shaft, the inner cavity is arranged inside the pressure relief shaft, and a pressure relief valve core 332 is arranged in the inner cavity, and the bottom end of the pressure relief valve core 332 is also elastically connected to the bottom end of the inner cavity through a spring, and as for the top end of the pressure relief valve core 332, a guide shaft 333 is arranged to penetrate the top end of the pressure relief shaft and the top end of the die shaft 31, and the guide shaft 333 is arranged inside to connect the inside of the pressure relief valve core 332 with the outside of the test device 100. A connected guide pipe 3331, wherein a balancing chamber 3321 is arranged inside the valve core 223, that is, the guide pipe 3331 connects the balancing chamber 3321 with the outside of the test device 100, and a plurality of connecting holes 3322 are also arranged outside the valve core 223, and the connecting holes 3322 connect the inner cavity with the balancing chamber 3321, so that the gas in the inner cavity enters the balancing chamber 3321 through the connecting holes 3322, and then flows to the outside of the test device 100 through the guide pipe 3331, thereby completely discharging the gas in the pressurized chamber 11.

[0048] In the present embodiment, the test device 100 includes a plurality of sealing gaskets 4, wherein the sealing gaskets 4 are required to be applied when the various structures inside the sealing test device 100 are sealed with other structures. In the present embodiment, a sealing gasket 4 is arranged between the outside of the control piston 222 and the inner wall surface of the first pre-pressurization pipe 211 to realize secondary sealing of the first pre-pressurization pipe 211. This arrangement prevents the gas in the pre-pressurization pipe 21 after the air inlet hole 23 has been sealed from leaking from the bottom end of the first pre-pressurization pipe 211, thereby affecting the air pressure in the pressurization chamber 11; another sealing gasket 4 is arranged between the outside of the pressurization part 2 and the inner wall surface of the pressurization pipe located inside the connecting shaft 14. This arrangement is to seal the connection between the connecting shaft 14 and the pressurization part 2, to ensure that the gas in the pressurization chamber 11 will not leak from the gap that may be generated at the connection between the connecting shaft 14 and the stamping part, thereby avoiding affecting the existing air pressure in the pressurization chamber 11.

[0049] In this embodiment, please refer to Figure 4 In order to enhance the sealing performance of the external sealing of the bottom end of the valve core 223 and the top end of the second pre-pressurized pipe 212, a sealing gasket 4 is also provided on the periphery of the sealing part to further seal the abutment between the external bottom end of the valve core 223 and the top end of the second pre-pressurized pipe 212, so as to prevent the gas in the pressurized chamber 11 from entering the first pre-pressurized pipe 211 through the second pre-pressurized pipe 212 and affecting the gas pressure in the pressurized chamber 11.

[0050] In fact, in this embodiment, a sealing gasket 4 is also provided between the outside of the pressure relief valve core 332 assembly and the inside of the die shaft 31. The sealing gasket 4 is designed to prevent part of the gas from entering the second installation pipe 312 through the second pipe 321, and then flowing to the outside from the hole gap penetrated by the guide shaft 333 at the top of the die shaft 31. Secondly, a sealing gasket 4 is also provided between the outside of the pressure relief valve core 332 and the inner wall of the inner cavity to ensure that after the small sample is broken, the gas in the inner cavity will not leak to the outside. It should be noted that the outside refers to the environment where the test device 100 is still testing.

[0051] In this embodiment, the bottom end of the third pipe 341 provided in the gasket 34 adopts a chamfer design, so that the small sample clamped on the gasket 34 and the short cam 12 can avoid stress concentration during the air pressure loading process, thereby ensuring that the gasket 34 located between the third pipe 341 and the pressurized chamber 11 can be evenly subjected to pressure shock, so as to obtain an accurate small sample rupture time.

[0052] Please refer to Figure 1-Figure 6 Regarding how to use the above-mentioned test device 100 to test the high temperature endurance performance of a small sample, the test method is as follows:

[0053] (1) According to formula A converted from the ideal gas law, calculate the preset air pressure value that needs to be input by the test device 100 at normal temperature corresponding to the test pressure value at the preset temperature;

[0054] (2) The external pressure source delivers air pressure of a preset air pressure value to the pressurizing chamber 11 connected to the pre-pressurizing pipe 21 through the air inlet 23;

[0055] (3) After the gas pressure delivery is completed, the operator welds and seals all the places where gas leaks between the pre-pressurization pipeline 21 and the outside of the pressurization part 2;

[0056] (4) After the entire test device 100 is assembled, the test device 100 is placed in a heating furnace with a preset temperature for heating;

[0057] (5) The operator records the preset temperature, test pressure and the time required for the small sample to break, thereby obtaining the high temperature endurance performance data of the small sample to be tested;

[0058] (6) After the small sample is broken, the gas in the pressurized chamber 11 enters the pressure relief chamber. After the test device 100 is taken out of the heating furnace and cooled to room temperature, the operator operates the pressure relief check valve assembly to allow the gas in the pressure relief chamber to flow to the outside;

[0059] (7) Repeat the above operation to heat multiple test devices 100 with different preset pressure values ​​in a heating furnace at the same preset temperature to obtain the endurance performance of the small gas pressure expansion sample under different working conditions.

[0060] Regarding the preset air pressure value, first of all, the formula of the ideal gas law is:

[0061] In this embodiment, before and after heating to a preset temperature at room temperature, p1 and p2 respectively represent the gas pressure (MPa) in the pressurized chamber 11 before and after heating, p1 is the preset pressure value, p2 is the test pressure value, V1 and V2 are the gas volumes (L) before and after heating, n1 and n2 are the amount of substance (mol) of the gas before and after heating, T1 and T2 are the absolute temperatures (K) of the gas before and after heating, and R is a constant.

[0062] During the test, argon gas was used as the pressure source. Since the amount of gas substance is the same (n1=n2), we have:

[0063]

[0064] Since the volume change (V1≈V2) caused by the expansion of the small sample can be ignored, we have:

[0065]

[0066] in is formula A;

[0067] In order to prove that formula A is valid, the present invention provides the following calculation example: the radius of the third pipe 341 in the gasket 34 is set to 3.25 mm, the chamfer radius of the third pipe 341 is 1.1 mm, the radius of the pressurized chamber 11 is 4 mm, and the effective length that can accommodate gas is 300 mm (i.e., the length of the connecting shaft 14 is not included); it is assumed that the small sample has undergone obvious bulging deformation, and the height of the dome reaches (3.25+1.1) mm, that is, the loading area of ​​the small sample becomes a hemispherical shell with a radius of 4.35 mm, and its increased volume is ΔV, which is 172.4 mm 3 , compared to its original volume of 15079.6mm 3 , the volume only increased by 1.1%, so the volume change caused by the swelling of the small sample 14 can be ignored, and formula A is valid.

[0068] Therefore, according to formula A, after determining the test pressure of the pressurized chamber 11 after heating, the operator can calculate the preset air pressure value required in the pressurized chamber 11. According to the data, the operator connects the gas through the air inlet 23 of the pressurizing part 2, so that the air pressure in the first pre-pressurizing pipe 211 and the second stamping pipe increases, thereby pushing the valve core 223 to move, so that the gas enters the third pre-pressurizing pipe 213, and then the gas enters the pressurized chamber 11 in the connecting shaft 14 from the air outlet 24. The above-mentioned gas continuously enters the pressurized chamber 11 through an external pressure source. When the pressure source has delivered the corresponding required amount of gas, the external air pressure source is disconnected, and the valve core 223 is under the action of the spring and back pressure, and the bottom end of the valve core 223 is externally sealed. The top of the pre-pressurization pipe 212 is open, so that the gas cannot flow to the air inlet 23 through the air outlet 24. In fact, when the pressure source delivers too much gas, the pressure value of the pressurization chamber 11 is too high. The operator can press the bottom end of the control piston 222 to discharge the gas from the air inlet 23 to reduce the pressure value in the pressurization chamber 11. Then the operator seals the air inlet 23 completely by welding, wherein the gap between the annular limit block 221 and the bottom end of the control piston 222 is also sealed by welding to ensure that the gas in the pressurization chamber 11 will not leak through the pre-pressurization pipe 21 at high temperature. In fact, the connection between the connecting shaft 14 and the pressurization part 2 also needs to be welded and sealed to further enhance the sealing of the pressurization chamber 11.

[0069] Then the operator assembles the entire test device 100, that is, the bottom end of the small sample has been welded to the top edge of the short cam 12, and the pressure relief part 3 has also been assembled accordingly with the pre-pressurization part 1. The assembled test device 100 can be placed in a heating furnace with a preset temperature for heating. Furthermore, the preset temperature range is 500-1200°C, and the normal temperature is 25°C. In this embodiment, the preset temperature is 600°C.

[0070] When the test device 100 is placed in a heating furnace for heating, the gas in the pressurized chamber 11 undergoes a self-pressurization process from room temperature to high temperature, and its pressure will increase rapidly to reach a relatively constant pressure value. This pressure value is the test pressure value of the small sample. Furthermore, a sensor is provided in the heating furnace. The sensor can be voice-controlled or other sensors. It can sense the break of the small sample and transmit the break time data to the external receiving end. This process belongs to the conventional data transmission method in the prior art and will not be elaborated in detail here. After the test is completed, the gas in the pressurized chamber 11 flows from the third pipe 341 to the inner cavity. Due to the increase in volume, the air pressure value decreases significantly. After the test device 100 is cooled from the heating furnace to room temperature, the air pressure value will further decrease. At this time, by pressing the top of the guide shaft 333, the gas will enter the balance chamber 3321 of the pressure relief valve core 332 through the connecting hole 3322, and finally flow to the external environment through the guide pipe 3331.

[0071] During the entire test process, the operator records the test temperature, test pressure and the fracture time required for the small sample to break, so as to determine the high-temperature endurance performance of the small sample under the working condition. Then, the operator can obtain the high-temperature endurance performance of the small sample under different test pressure conditions by setting different test pressure conditions for multiple samples in the same heating furnace at the same time. The above operation method does not require the setting of a complex air pressure loading system, sealing and control system, and avoids the numerous valves and connectors that may exist in the test device 100. Only the above mechanical parts need to be assembled and placed in the heating furnace for testing. There is no need to design a separate fixture, there is no need to customize the heating device for the fixture, and there is no need to continuously apply pressure. Multiple small samples can be tested in the same heating furnace at the same time. Before the test starts, the test device 100 can be immersed in a water tank for air tightness testing. The test efficiency is high and the cost is low. At the same time, since the entire pressurization process is carried out at room temperature, the sealing requirements of the test device 100 are low. After the pressurization is completed, the connection parts of the test device 100 are welded, and the air tightness can be guaranteed.

[0072] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may also be combined, the steps may be implemented in any order, and there are many other changes in different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity. Although the present invention has been described in detail with reference to the above embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the above embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A test device for testing the endurance performance of a small sample by passive self-pressurization, characterized in that: The test device (100) comprises: A pre-pressurizing portion (1) having a first end and a second end opposite to each other, wherein a pressurizing chamber (11) is provided inside the pre-pressurizing portion (1) and passes through the first end and the second end; A pressurizing portion (2), an end of which is detachably connected to the first end, wherein a pre-pressurizing pipe (21) communicating with the pressurizing chamber (11) is provided inside the pressurizing portion (2), and the pre-pressurizing pipe (21) inputs external gas into the pressurizing chamber (11), so that the interior of the pre-pressurizing pipe (21) has a preset gas pressure; The pressure relief portion (3) has an end portion connected to the second end in a detachable manner, and a pressure relief chamber connected to the pressurizing chamber (11) is provided inside the pressure relief portion (3), and a small sample to be tested is installed at the connection between the pressure relief chamber and the pressurizing chamber (11), and the small sample is used to withstand the pressure caused by the preset air pressure in the pressurizing chamber (11).

2. The test device for the passive self-pressurization small sample endurance performance test according to claim 1 is characterized in that: The charging part (2) further comprises a loading check valve assembly (22), wherein the loading check valve assembly (22) is arranged in the pre-charging pipe (21) to control the communication and blocking between the pre-charging pipe (21) and the pressurizing chamber (11).

3. The test device for the passive self-pressurization small sample endurance performance test according to claim 2 is characterized in that: The pre-charge pipeline (21) comprises a first pre-charge pipeline (211), a second pre-charge pipeline (212) and a third pre-charge pipeline (213) which are interconnected; The loading check valve assembly (22) comprises: an annular limiting block (221), the outer periphery of the annular limiting block (221) being snap-fitted to the inner wall surface of the first pre-pressurized pipe (211) near the bottom end; A control piston (222) is arranged in the first pre-pressurized pipe (211), the bottom end of the control piston (222) abuts against the top end of the annular limit block, the top end of the control piston (222) is located in the second pre-pressurized pipe (212), and the inner diameter of the top end of the control piston (222) is smaller than the inner diameter of the second pre-pressurized pipe (212); The valve core (223) is arranged in the third pre-pressurized pipeline (213), the bottom end of the valve core (223) is in contact with the top end of the control piston (222), and the bottom end of the valve core (223) seals the top end of the second pre-pressurized pipeline (212) externally, and the top end of the valve core (223) is elastically connected to the top end inside the third pre-pressurized pipeline (213) through a spring.

4. The test device for the passive self-pressurization small sample endurance performance test according to claim 3 is characterized in that: The charging portion (2) is provided with at least one air inlet hole (23) connected to the first pre-pressurization pipe (211) on the outside near the bottom end; the charging portion (2) is provided with at least one air outlet hole (24) on the outside near the top end, and the air outlet hole (24) is used to connect the third pre-pressurization pipe (213) and the pressurization chamber (11); the valve core (223) is also provided with a balancing pipe for balancing the air pressure of the third pre-pressurization pipe (213).

5. The test device for the passive self-pressurization small sample endurance performance test according to claim 4 is characterized in that: The test device (100) comprises a plurality of sealing gaskets (4), one of the sealing gaskets (4) being arranged between the outside of the control piston (222) and the inner wall surface of the first pre-pressurizing pipe (211); and another sealing gasket (4) being arranged between the outside of the pressurizing part (2) and the inner wall surface of the pressurizing pipe located inside the connecting shaft (14).

6. The test device for the passive self-pressurization small sample endurance performance test according to claim 1 is characterized in that: The pre-pressurizing part (1) comprises a short convex shaft (12) having the pressurizing chamber (11) in each part thereof, a pressurizing shaft (13) and a connecting shaft (14); the inner diameter of the short convex shaft (12) is smaller than the inner diameter of the pressurizing shaft (13); the inner wall surface of the pressurizing chamber (11) in the connecting shaft (14) is connected to the outer thread of the pressurizing part (2).

7. The test device for the passive self-pressurization small sample endurance performance test according to claim 6 is characterized in that: The pressure relief portion (3) further comprises: A die shaft (31) is provided with a mounting pipe inside along the bottom end thereof; a partition block (32) disposed in the installation pipe to divide the installation pipe into a first installation pipe (311) and a second installation pipe (312), wherein the inner wall surface of the bottom end of the first installation pipe (311) is threadedly connected to the outer surface of the top end of the pressure shaft (13); A gasket (34) is arranged at the bottom end of the partition block (32), and the bottom end of the gasket (34) is used to clamp the small sample by cooperating with the top end of the short convex shaft (12); A pressure relief one-way valve assembly is arranged in the second installation pipe (312), and the bottom end of the pressure relief one-way valve assembly abuts against the top end of the partition block (32), and the top end of the one-way valve assembly abuts against the inner top surface of the second installation pipe (312).

8. The test device for the passive self-pressurization small sample endurance performance test according to claim 7 is characterized in that: The pressure relief one-way valve assembly has an inner cavity, and the bottom end of the pressure relief one-way valve assembly, the partition block (32) and the gasket (34) are provided with a first pipe (331), a second pipe (321) and a third pipe (341) in sequence along the axial direction of the pressurizing chamber (11), wherein the inner cavity, the first pipe (331), the second pipe (321) and the third pipe (341) are connected in sequence, and the inner cavity, the first pipe (331), the second pipe (321) and the third pipe (341) constitute the pressure relief chamber.

9. A method for testing the endurance performance of a small sample by passive self-pressurization, characterized in that: The test device is a test device for testing the endurance performance of a small sample by passive self-pressurization as claimed in any one of claims 1 to 8, comprising the following steps: (1) Calculating the preset air pressure value that needs to be input into the test device (100) at normal temperature corresponding to the test pressure value at the preset temperature according to formula A converted from the ideal gas law; (2) an external pressure source delivers air pressure of a preset air pressure value to a pressurizing chamber (11) connected to a pre-pressurizing pipe (21) through an air inlet hole (23); (3) After the gas pressure delivery is completed, the operator welds and seals all the places where gas leakage occurs between the pre-pressurization pipeline (21) and the outside of the pressurization part (2); (4) After the entire test device (100) is assembled, the test device (100) is placed in a heating furnace with a preset temperature for heating; (5) The operator records the preset temperature, test pressure and the time required for the small sample to break, thereby obtaining the high temperature endurance performance data of the small sample to be tested; (6) After the small sample is broken, the gas in the pressurizing chamber (11) enters the pressure relief chamber. After the test device (100) is taken out of the heating furnace and cooled to room temperature, the operator operates the pressure relief check valve assembly so that the gas in the pressure relief chamber can flow to the outside; (7) Repeat the above operation, and heat the test devices (100) with different test pressure values ​​simultaneously in a heating furnace at the same preset temperature to obtain the endurance performance of the small gas pressure expansion sample under different working conditions.

10. A method for testing the endurance performance of a small sample by passive self-pressurization according to claim 9, characterized in that: The ideal gas law includes: p1V1=n1RT1 p2v2=n2RT2 Before and after heating to a preset temperature at room temperature, p1 and p2 are respectively the gas pressures (MPa) in the pressurized chamber (11) before and after heating, p1 is the preset pressure value, p2 is the test pressure value, V1 and V2 are respectively the gas volumes (L) before and after heating, n1 and n2 are respectively the amount of substance (mol) of the gas before and after heating, T1 and T2 are respectively the absolute temperatures (K) of the gas before and after heating, and R is a constant. During the test, argon gas was used as the pressure source, and the amount of gas was the same (n1 = n2), so: Since the volume change (V1≈V2) caused by the expansion of the small sample can be ignored, we have: in is Formula A; and The preset temperature range is 500-1200°C, and the normal temperature is 25°C.

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