A material high-temperature mechanical property testing device based on liquid medium transmission

Abstract

The application discloses a material high-temperature mechanical property testing device based on liquid medium transmission, which comprises a pipeline, a high-temperature box, a measuring mechanism and a pressure control mechanism, one end of the pipeline is connected with the pressure control mechanism, the other end of the pipeline is connected with the measuring mechanism, a check valve is arranged in the pipeline, the check valve is arranged on a box body of the high-temperature box, the check valve is used for dividing the pipeline into a hot section pipeline and a cold section pipeline, the measuring mechanism and the hot section pipeline are arranged in the high-temperature box, a first liquid medium is arranged in the hot section pipeline, and a second liquid medium is arranged in the cold section pipeline, and the first liquid medium is metal. The material high-temperature mechanical property testing device based on liquid medium transmission can realize the hydraulic expansion test of small and micro samples in a temperature range of 350 DEG C to 800 DEG C by arranging the check valve on the pipeline, dividing the pipeline into the hot section and the cold section and then arranging different hydraulic mediums.

Description

Technical Field

[0001] This invention relates to the field of high-temperature mechanical property testing technology for materials, and in particular to a hydraulic bulging testing system for high-temperature mechanical properties of materials using liquid metal as the transmission medium. It is suitable for testing the high-temperature mechanical properties of small samples of pressure-bearing components and welded parts in the primary circuit of metal fast reactors, and can also be used for testing the high-temperature mechanical properties of small samples of non-nuclear high-temperature pressure-bearing components and welded parts in thermal power units and other similar applications. Background Technology

[0002] Accurately obtaining the high-temperature mechanical properties of materials using non-destructive micro-sample testing techniques is of great significance for assessing the structural integrity of pressure-bearing components and welded parts of in-service power units.

[0003] Hydraulic bulging testing technology is developed based on the small punch test technology and incorporates the principle of internal pressure bursting. Compared with conventional small punch testing technology, hydraulic bulging testing technology has fewer influencing factors, simpler structural stress, and is easier to model theoretically. Therefore, compared with small punch testing technology, hydraulic bulging testing technology yields more accurate results and has greater engineering application significance.

[0004] Existing hydraulic bulging test equipment uses hydraulic oil as the transmission medium. Due to the influence of the operating temperature of the hydraulic oil in the test equipment, the upper limit of the current hydraulic bulging equipment is below 300℃, which cannot meet the requirements of high-temperature mechanical property testing of materials above 300℃. Summary of the Invention

[0005] In view of this, in order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a material high-temperature mechanical property testing device based on liquid medium transmission, which can realize relevant tests at high temperatures of 300°C to 800°C.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A high-temperature mechanical property testing device for materials based on liquid medium transmission includes a pipe, a high-temperature chamber, a measuring mechanism, and a pressure control mechanism. One end of the pipe is connected to the pressure control mechanism, and the other end of the pipe is connected to the measuring mechanism. A check valve is installed inside the pipe and is mounted on the body of the high-temperature chamber. The check valve is used to divide the pipe into a hot section and a cold section. The measuring mechanism and the hot section are located inside the high-temperature chamber. A first liquid medium is disposed in the hot section, and a second liquid medium is disposed in the cold section. The first liquid medium is a metal.

[0008] According to some preferred embodiments of the present invention, the measuring mechanism includes a first sealed tube, a second sealed tube, a scale, and a displacement extensometer. The first sealed tube is in communication with the pipeline, and the test sample is disposed between the first and second sealed tubes. The lower end of the scale contacts the upper surface of the test sample. The extensometer is used to measure the relative displacement between the displacement scale and the second sealed tube.

[0009] According to some preferred embodiments of the present invention, a first sealing flange is fixed to the first sealing tube, and a second sealing flange is provided on the second sealing tube; a sealing gasket is provided between the first sealing flange and the second sealing flange, the sealing gasket being annularly arranged, and the test sample being located within the annular sealing gasket. The first sealing tube and the second sealing tube are connected and fixed together by the first sealing flange, the second sealing flange, and bolts.

[0010] According to some preferred embodiments of the invention, the thickness of the sealing gasket is less than the thickness of the test sample. The thickness of the sealing gasket is 98-99.5% of the thickness of the test sample, preferably 99% of the thickness of the test sample.

[0011] According to some preferred embodiments of the present invention, a cavity is provided inside the second sealing tube, and a sphere matching the inner wall of the cavity is provided at the lower end of the scale.

[0012] According to some preferred embodiments of the present invention, the second sealing tube has an upwardly extending limiting portion corresponding to the cavity, the scale extends upward from the cavity through the limiting portion, and the displacement extensometer is disposed between the limiting portion and the scale.

[0013] In some embodiments, a cavity is formed inside the second sealing tube, and an upwardly extending limiting portion is formed on the second sealing tube corresponding to the cavity. A displacement scale is placed on the upper surface of the hydraulically bulging sample to transmit the deformation of the sample in the y-direction, characterizing the distance the sample moves during bulging under high temperature and pressure. Its upper part is a Φ5mm optical axis rod, the middle part is a Φ3mm scale rod, and the bottom is a Φ8mm sphere. The opening in the limiting portion matches the middle scale rod, forming a channel for the scale rod to move. The inner diameter of the cavity inside the second sealing tube matches the size of the sphere at the bottom of the scale, ensuring the accuracy of the displacement characterization and providing a certain sealing effect to protect the sample from high-temperature oxidation.

[0014] According to some preferred embodiments of the invention, the second sealing tube is provided with an inlet tube for introducing inert gas into the cavity. The inert protective gas is introduced through the inert gas inlet tube on the second sealing tube at the bottom of the displacement scale and discharged through the channel through which the displacement scale slides at the top of the second sealing tube.

[0015] According to some preferred embodiments of the present invention, a first measuring point is provided on the first sealing tube, and a second measuring point is provided on the hot section pipe, the measuring point being used to record the changes in loading pressure and test temperature during the test.

[0016] According to some preferred embodiments of the present invention, the check valve is a Tesla valve. That is, a Tesla valve is used to connect the hot section pipe and the cold section pipe, and the internal medium of the Tesla valve is LBE lead-bismuth alloy (hot end side) + high-temperature resistant hydraulic oil (cold end side). The Tesla valve can be used to prevent liquid backflow and prevent sudden hydraulic pulses, making the pressurization process smoother, thereby making the test results more accurate.

[0017] According to some preferred embodiments of the present invention, the first liquid medium is a lead-bismuth eutectic alloy; the second liquid medium is hydraulic oil. The melting point of the first liquid medium is 100–150°C. In some specific embodiments, the LBE lead-bismuth alloy is preferably characterized by a melting point of 123.3°C, a boiling point of 1670°C, and a viscosity coefficient of 0.001 Pa·s.

[0018] According to some preferred embodiments of the present invention, a cooling system is provided on the cold section pipe for cooling the second liquid medium in the cold section pipe.

[0019] According to some preferred embodiments of the invention, the operating temperature of the hot section pipe and the measuring mechanism therein, as well as the hot section pipe, is greater than or equal to 300°C.

[0020] Due to the adoption of the above technical solutions, the advantages of the present invention compared with the prior art are as follows: The material high-temperature mechanical property testing device based on liquid medium transmission of the present invention, by setting a check valve on the pipeline, divides the pipeline into a hot section and a cold section, and then different hydraulic media can be set, so as to realize the hydraulic bulging test of small samples in the temperature range of 350℃~800℃. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a three-dimensional structural diagram of the testing device in a preferred embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the cross-sectional structure of the measuring mechanism in a preferred embodiment of the present invention;

[0024] In the attached diagram, the components are: test device-1, high-temperature chamber-2, measuring mechanism-3, first sealing tube-31, second sealing tube-32, cavity-321, limiting part-322, scale-33, sphere-331, displacement extensometer-34, first sealing flange-35, second sealing flange-36, sealing gasket-37, bolt-38, inlet pipe-39, pressure control mechanism-4, check valve-5, hot section pipe-61, cold section pipe-62, first measuring tube-71, second measuring tube-72, test sample-8, observation port-9, and cooling system-10. Detailed Implementation

[0025] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0026] like Figure 1-2 As shown, the high-temperature mechanical property testing device 1 based on liquid medium transmission in this embodiment includes a pipe, a high-temperature chamber 2, a measuring mechanism 3, a pressure control mechanism 4, and a cooling system 10 for temperature control of the medium in the pipe. One end of the pipe is connected to the pressure control mechanism 4, and the other end is connected to the measuring mechanism 3. A check valve 5 is installed inside the pipe, either on the body of the high-temperature chamber 2 or between the high-temperature chamber 2 and the pressure control mechanism 4. The check valve 5 is a Tesla valve, which divides the pipe into a hot section pipe 61 and a cold section pipe 62. That is, the hot section pipe 61 and the cold section pipe 62 are connected by a Tesla valve. The Tesla valve can prevent liquid backflow and prevent sudden hydraulic pulses, making the pressurization process more stable and thus making the test results more accurate. In this embodiment, an observation port 9 is also provided on the top of the high-temperature chamber 2 corresponding to the measuring mechanism 3 to observe the measurement process.

[0027] A first liquid medium is contained in the hot section pipe 61, and a second liquid medium is contained in the cold section pipe 62. Specifically, the pipe between the Tesla valve and the measuring mechanism 3 contains the first liquid medium, and the pipe between the Tesla valve and the pressure control mechanism 4 contains the second liquid medium. The measuring mechanism 3, the hot section pipe 61, and the first liquid medium are housed within the high-temperature chamber 2. The operating temperature of the hot section pipe 61, the measuring mechanism 3, and the hot section pipe 61 is greater than or equal to 300℃.

[0028] The first liquid medium is a metal with a melting point of 100–150°C. In this embodiment, it is a lead-bismuth eutectic alloy, preferably an LBE lead-bismuth alloy with a melting point of 123.3°C, a boiling point of 1670°C, and a viscosity coefficient of 0.001 Pa·s. The second liquid medium is hydraulic oil. The cooling system 10 is installed on the cold section pipe 62 to cool the hydraulic oil in the cold section pipe 62. The internal medium of the Tesla valve is an LBE lead-bismuth alloy (hot end side) + high-temperature resistant hydraulic oil (cold end side).

[0029] like Figure 2 As shown, the measuring mechanism 3 in this embodiment includes a scale 33, a displacement extensometer 34, a first sealing tube 31, a first sealing flange 35 disposed on the first sealing tube 31, a second sealing tube 32, a second sealing flange 36 disposed on the second sealing tube 32, and a sealing gasket 37 disposed between the first sealing flange 35 and the second sealing flange 36. The first sealing tube 31 is connected to the hot section pipe 61. The test sample 8 is disposed between the first sealing tube 31 and the second sealing tube 32. The lower end of the scale 33 is in contact with the upper surface of the test sample 8. The extensometer is used to measure the relative displacement between the displacement scale 33 and the second sealing tube 32.

[0030] The sealing gasket 37 is annular, and the test sample 8 is located inside the annular sealing gasket 37. The thickness of the sealing gasket 37 is less than the thickness of the test sample 8. The thickness of the sealing gasket 37 is 98-99.5% of the thickness of the test sample 8, preferably 99% of the thickness of the test sample 8. The first sealing tube 31 and the second sealing tube 32 are connected and fixed by the first sealing flange 35, the second sealing flange 36, and bolts 38, thereby sealing the internal space.

[0031] The second sealing tube 32 has a cavity 321 inside, and the lower end of the scale 33 is provided with a ball 331 that matches the inner wall of the cavity 321. The second sealing tube 32 has an upwardly extending limiting part 322 corresponding to the cavity 321. The scale 33 extends upward from the cavity 321 and passes through the limiting part 322. The displacement extensometer 34 is disposed between the limiting part 322 and the scale 33. That is, the second sealing tube 32 has a cavity 321 inside, and the second sealing tube 32 has an upwardly extending limiting part 322 corresponding to the cavity 321. The displacement scale 33 is placed on the upper surface of the hydraulically expanded sample to transmit the deformation of the sample in the y-direction and characterize the distance the sample moves during expansion under high temperature and high pressure. Its upper part is a Φ5mm optical axis rod diameter, the middle part is a Φ3mm scale rod, and the bottom is a Φ8mm ball 331. The opening in the limiting part 322 matches the middle scale rod, forming a channel for the scale rod to move; the inner diameter of the cavity 321 in the second sealing tube 32 matches the size of the ball 331 at the bottom of the scale 33, ensuring the accuracy of displacement characterization, and at the same time having a certain sealing effect to protect the sample from high-temperature oxidation.

[0032] In this embodiment, to further prevent the sample from being oxidized by high temperature, the second sealing tube 32 is provided with an inlet tube 39 for introducing inert gas into the cavity 321. The inert protective gas is introduced through the inert gas inlet tube 39 on the second sealing tube 32 at the bottom of the displacement scale 33 and discharged through the sliding channel (limiting part 322) of the displacement scale 33 at the top of the second sealing tube 32. The first sealing tube 31 is provided with a first measuring tube 71, with a corresponding first measuring point. The hot section pipe 61 is provided with a second measuring tube 72, with a corresponding second measuring point. The measuring points are used to record the changes in loading pressure and test temperature during the test.

[0033] Accurate characterization of the high-temperature mechanical properties of materials is a prerequisite for evaluating the structural integrity of high-temperature pressure-bearing components and their welded parts. Traditional gas-medium bulging tests suffer from unstable pressurization processes and pulse effects that significantly impact measurement results; furthermore, traditional hydraulic bulging tests cannot be performed at temperatures exceeding 300°C. This invention presents a high-temperature mechanical property testing device for materials based on liquid medium transmission. Using liquid metal as the transmission medium, it simulates the real service environment of pressure-bearing components in the primary loop of a metal fast reactor. By installing check valves on the pipeline, it divides the pipeline into hot and cold sections, allowing for the use of different hydraulic media. This enables hydraulic bulging tests on small samples within a temperature range of 350°C to 800°C. The hot section pipeline operates at temperatures ≥300°C and uses LBE lead-bismuth alloy as the transmission medium; the cold section pipeline operates at temperatures <300°C and uses hydraulic oil as the transmission medium.

[0034] This invention realizes the application of hydraulic bulging test technology in the field of high-temperature mechanical property testing of materials, such as high-temperature tensile properties, high-temperature fracture toughness, and high-temperature creep properties testing of pressure-bearing pipeline base materials and weld heat-affected zone materials; it is applicable to the high-temperature mechanical property testing of small samples of pressure-bearing components and welded parts in the primary circuit of metal fast reactors, and can also be used for the high-temperature mechanical property testing of small samples of high-temperature pressure-bearing components and welded parts in other fields such as high-temperature gas-cooled reactors, thermal power units, and petrochemicals, which is of great significance for the accurate assessment of the life of high-temperature pressure-bearing components.

[0035] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A high-temperature mechanical property testing device for materials based on liquid medium transmission, characterized in that, The system includes a pipeline, a high-temperature chamber, a measuring mechanism, and a pressure control mechanism. One end of the pipeline is connected to the pressure control mechanism, and the other end is connected to the measuring mechanism. A check valve is installed inside the pipeline, either on the body of the high-temperature chamber or between the high-temperature chamber and the pressure control mechanism. The check valve divides the pipeline into a hot section and a cold section. The measuring mechanism and the hot section pipeline are located inside the high-temperature chamber. A first liquid medium is contained in the hot section pipeline, and a second liquid medium is contained in the cold section pipeline. The first liquid medium is a metal. The check valve is a Tesla valve; the first liquid medium is a lead-bismuth eutectic alloy; the second liquid medium is hydraulic oil; a cooling system is provided on the cold section pipeline to cool the second liquid medium in the cold section pipeline; the operating temperature of the measuring mechanism and the hot section pipeline is greater than or equal to 300°C. The high-temperature mechanical property test of the material is a hydraulic bulging test; the measuring mechanism includes a first sealing tube, a second sealing tube, a scale and a displacement extensometer, the first sealing tube is connected to the pipeline, the test sample is placed between the first sealing tube and the second sealing tube, and the lower end of the scale is in contact with the upper surface of the test sample.

2. The high-temperature mechanical property testing device for materials according to claim 1, characterized in that, A first sealing flange is fixed on the first sealing tube, and a second sealing flange is provided on the second sealing tube; a sealing gasket is provided between the first sealing flange and the second sealing flange, and the sealing gasket is annular, with the test sample located inside the annular sealing gasket.

3. The high-temperature mechanical property testing device for materials according to claim 2, characterized in that, The thickness of the sealing gasket is less than the thickness of the sample to be tested.

4. The high-temperature mechanical property testing device for materials according to claim 1, characterized in that, The second sealing tube has a cavity, and the lower end of the scale is provided with a sphere that matches the inner wall of the cavity.

5. The high-temperature mechanical property testing device for materials according to claim 4, characterized in that, The second sealing tube has an upwardly extending limiting part corresponding to the cavity, the scale extends upward from the cavity and passes through the limiting part, and the displacement extensometer is disposed between the limiting part and the scale.

6. The high-temperature mechanical property testing device for materials according to claim 4, characterized in that, The second sealing tube is provided with an inlet tube for introducing inert gas into the cavity.

7. The high-temperature mechanical property testing device for materials according to claim 1, characterized in that, A first measuring point is provided on the first sealing tube, and a second measuring point is provided on the hot section pipe. The measuring points are used to measure temperature and pressure.

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