Hydrogen environment fatigue testing machine and control method thereof

Abstract

The invention relates to a hydrogen environment fatigue testing machine and a control method thereof, and relates to the technical field of material performance testing. A driving part, a pressure balancing device and a clamp of the hydrogen environment fatigue testing machine are sequentially arranged from top to bottom, a sample is installed on the clamp, the sample and the clamp are arranged in a test kettle together, an air inlet and an air outlet are formed in the test kettle, the test kettle is filled with hydrogen through the air inlet and the air outlet, and therefore the sample is subjected to a fatigue test in a hydrogen environment. According to the hydrogen environment fatigue testing machine and the control method thereof, the fatigue testing accuracy of the material in the hydrogen environment can be improved, the operation is simple, and the structural safety is high.

Description

Technical Field

[0001] The present application relates to the technical field of material performance testing, and in particular to a hydrogen environment fatigue testing machine and a control method thereof. Background Art

[0002] In various fields of material research, it is necessary to use test equipment to conduct repeated tests, and to draw conclusions based on the test results to judge the performance of the material. Of course, the same is true for fatigue tests of materials in various environments.

[0003] The risk of hydrogen damage to metal materials such as hydrogen-exposed parts is increasing significantly. Especially in high temperature, high pressure and hydrogen-exposed environments, hydrogen atoms can easily penetrate into steel, causing failures such as hydrogen embrittlement and hydrogen blistering. Testing the fatigue performance of materials under high pressure, high temperature and hydrogen-exposed environments is of great significance to the design and manufacture of hydrogen-exposed equipment.

[0004] At present, the main method for testing material fatigue performance is to place the sample in a closed environmental chamber to fill it with hydrogen, and then take it out for fatigue testing. After the sample is taken out of the environmental chamber, hydrogen precipitation will occur, which is different from the service conditions of the material, resulting in inaccurate fatigue test results. Summary of the invention

[0005] The purpose of the present application is to provide a hydrogen environment fatigue testing machine and a control method thereof, which can improve the accuracy of fatigue testing of materials in a hydrogen environment, and has simple operation and high structural safety.

[0006] In order to achieve the above-mentioned object, in a first aspect, the present invention provides a hydrogen environment fatigue testing machine, which includes a bottom plate, a guide column, a crossbeam, a hydraulic push rod, an electric push rod, a slider, a driving member, a pressure balancing device and a test kettle; The test kettle comprises a kettle cover and a kettle body, the kettle body is fixedly mounted on the bottom plate, and the kettle cover is located above the kettle body; The guide column is vertically mounted on the bottom plate, the slider is slidably mounted on the guide column, the slider is fixedly connected to the kettle cover, one end of the electric push rod is detachably connected to the bottom plate, the other end of the electric push rod is connected to the slider, and the electric push rod is used to drive the kettle cover to close onto the kettle body; The crossbeam is slidably arranged on the guide column, one end of the hydraulic push rod is connected to the bottom plate or the bracket, the bracket is fixedly installed at the bottom of the guide column, the other end of the hydraulic push rod is connected to the crossbeam, the driving member is installed on the crossbeam, and the driving member, the pressure balancing device and the clamp are connected in sequence from top to bottom; the driving member is used to drive the pressure balancing device and the clamp, so as to perform fatigue test on the sample installed on the clamp; The test kettle is provided with an air inlet and an air outlet, and hydrogen is filled into the test kettle through the air inlet and the air outlet, so that the sample is subjected to fatigue test in a hydrogen environment.

[0007] In an optional embodiment, two guide pillars are arranged at intervals, and both ends of the crossbeam are respectively arranged on the two guide pillars; the two hydraulic push rods are respectively located at both ends of the crossbeam and on both sides of the crossbeam.

[0008] In an optional embodiment, the kettle cover is fixedly mounted on the bottom of the sliding block.

[0009] In an optional embodiment, the pressure balancing device includes an upper tie rod, an upper balancing cylinder, a middle sealing flange, a lower tie rod and a lower balancing cylinder; The driving member, the upper pull rod, the lower pull rod and the clamp are connected in sequence from top to bottom. The upper balancing cylinder body is connected to the lower balancing cylinder body through the middle sealing flange. The bottom of the lower balancing cylinder body is connected to the kettle cover through bolts. The upper pull rod and the lower pull rod are slidably arranged in the upper balancing cylinder body and the lower balancing cylinder body.

[0010] In an optional embodiment, the test kettle further includes a heat-insulating layer, which is coated on the kettle body, and a water inlet pipe and a water outlet pipe are provided on the heat-insulating layer, and cooling or heating operations are performed through the water inlet pipe and the water outlet pipe.

[0011] In a second aspect, the present invention provides a control method for a hydrogen environment fatigue testing machine, the control method comprising the following steps: S1: Control the electric push rod to drive the kettle cover to descend to the kettle body, and connect the kettle cover and the kettle body with bolts; S2: Perform an air tightness test on the test kettle to check whether the test kettle is leaking; S3: Use a mold temperature controller to adjust the temperature in the test kettle to the test temperature; S4: After the test temperature is reached in the kettle, hydrogen is injected into the test kettle to pressurize it to the test pressure; S5: Perform fatigue test; S6: After the test is completed, stop the machine, turn off the mold temperature controller, and relieve the pressure on the pipeline and kettle body.

[0012] In an optional embodiment, S1 includes: During the process of lowering the kettle cover, the lowering speed of the kettle cover is kept constant at first, then gradually reduced, and finally a gap is reserved with the kettle body, and finally the kettle cover and the kettle body are fastened by bolts.

[0013] In an optional embodiment, between S2 and S3, the control method includes the following steps: After the test kettle is leak-free, vacuum evacuation, nitrogen purge and hydrogen purge are performed on the test kettle in sequence, and finally the pressure of the test kettle is stabilized to the preset pressure.

[0014] In an optional embodiment, after S4, the control method includes the following steps: Depressurize the pipeline.

[0015] In an optional embodiment, S6 includes: After the test is completed, the machine is stopped and the mold temperature controller is turned off; when the temperature in the kettle returns to room temperature, the kettle body is depressurized and after the depressurization is completed, nitrogen is purged in the kettle.

[0016] The beneficial effects of the hydrogen environment fatigue testing machine and the control method thereof provided in this embodiment include: 1. Set up a test kettle and fill it with hydrogen to make the test kettle reach the test pressure and test temperature. At the same time, place the sample in the hydrogen environment of the test kettle for fatigue test. The sample will not produce hydrogen precipitation, which is basically consistent with the service conditions of the sample, thereby improving the accuracy of the fatigue test results of the sample; 2. Use an electric push rod to drive the kettle cover to close on the kettle body to avoid excessive closing force of the kettle cover on the kettle body and avoid collision and damage between the kettle cover and the kettle body; 3. The overall structure of the testing machine is cleverly designed, easy to disassemble and assemble, the fatigue test operation process is simple and highly safe.

[0017] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic structural diagram of a hydrogen environment fatigue testing machine provided in an embodiment of the present application from a first perspective (axial side); Figure 2 A schematic diagram of the structure of the hydrogen environment fatigue testing machine provided in an embodiment of the present application from a second perspective (front view); Figure 3 for Figure 2 Schematic diagram of the section structure along the section line AA; Figure 4 A schematic structural diagram of a hydrogen environment fatigue testing machine provided in an embodiment of the present application from a third viewing angle (side view); Figure 5 for Figure 4 A schematic diagram of the section structure along the section line BB; Figure 6 for Figure 5 An enlarged schematic diagram of the pressure balance device and the test kettle; Figure 7A schematic structural diagram of a hydrogen environment fatigue testing machine provided in an embodiment of the present application from a fourth perspective (top view); Figure 8 A flow chart of a control method for a hydrogen environment fatigue testing machine provided in an embodiment of the present application.

[0020] Icons: 1-base plate; 2-guide column; 3-crossbeam; 4-hydraulic push rod; 5-electric push rod; 6-slider; 7-driving member; 8-pressure balancing device; 81-upper pull rod; 82-housing; 821-water jacket; 83-upper balance cylinder; 84-middle sealing flange; 85-lower pull rod; 86-lower balance cylinder; 9-test kettle; 91-kettle cover; 911-air inlet; 912-air outlet; 92-kettle body; 93-insulation layer; 931-water inlet pipe; 932-water outlet pipe; 94-support frame; 10-bracket; 11-fixture; 12-specimen. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0022] In the description of this application, it should be noted that the terms "inside", "outside", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the application is usually placed when in use, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0023] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "disposed" 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 direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0024] Please refer to Figures 1 to 7 The present embodiment provides a hydrogen environment fatigue testing machine, which includes a base plate 1, a guide column 2, a crossbeam 3, a hydraulic push rod 4, an electric push rod 5, a slider 6, a driving member 7, a pressure balancing device 8 and a test kettle 9.

[0025] Please refer to Figures 2 to 7 The test kettle 9 includes a kettle cover 91, a kettle body 92 and an insulation layer 93. The kettle body 92 is fixedly mounted on the bottom plate 1. A water inlet pipe 931 and a water outlet pipe 932 are provided on the kettle body 92. The insulation layer 93 is coated on the kettle body 92. The kettle cover 91 is located above the kettle body 92.

[0026] The guide column 2 is vertically mounted on the bottom plate 1 , and the slider 6 is slidably mounted on the guide column 2 . The slider 6 is fixedly connected to the kettle cover 91 . Preferably, the kettle cover 91 is fixedly mounted on the bottom of the slider 6 .

[0027] The cross beam 3 is slidably arranged on the guide column 2, one end of the hydraulic push rod 4 is connected to the bottom plate 1 or the bracket 10, the bracket 10 is fixedly installed at the bottom of the guide column 2, and the other end of the hydraulic push rod 4 is connected to the cross beam 3. The hydraulic push rod 4 can drive the cross beam 3 to move along the guide column 2.

[0028] One end of the electric push rod 5 is detachably connected to the bottom plate 1 , and the other end of the electric push rod 5 is connected to the slider 6 . The electric push rod 5 is used to drive the kettle cover 91 to cover the kettle body 92 .

[0029] During the equipment assembly process, the specific working mode of the electric push rod 5 is as follows: 1) When closing the kettle, the electric push rod 5 is controlled to drive the kettle cover 91 to slowly cover the kettle body 92 to avoid excessive closing force of the kettle cover 91 on the kettle body 92; 2) When the kettle is opened to install the fixture 11 , the electric push rod 5 is used to drive the kettle cover 91 to rise, so that the support frame 94 on the kettle cover 91 extends out, which is convenient for installing the fixture 11 on the support frame 94 .

[0030] During the fatigue test, the specific working mode of the electric push rod 5 is as follows: 1) Before the test, the connection between the electric push rod 5 and the kettle cover 91 must be disconnected, that is, the pin connecting the lower end of the electric push rod 5 and the bottom plate 1 must be loosened, and the lower end of the electric push rod 5 must be separated from the bottom plate 1 to prevent the electric push rod 5 from being damaged when the driving member 7 drives the crossbeam 3 to vibrate; 2) After the test is completed, the lower end of the electric push rod 5 is connected to the bottom plate 1, and after the bolts and nuts connecting the kettle body 92 and the kettle cover 91 are removed, the electric push rod 5 is controlled to lift the kettle cover 91 to open the kettle.

[0031] The driving member 7 is installed on the crossbeam 3, and the driving member 7, the pressure balancing device 8 and the top of the clamp 11 are connected in sequence from top to bottom, wherein the bottom of the clamp 11 is fixedly installed on the support frame 94 of the kettle cover 91. The driving member 7 is used to drive the pressure balancing device 8 and the clamp 11, so as to perform fatigue test on the sample 12 installed on the clamp 11. Among them, the driving member 7 can adopt a mechanism in which a motor, a screw rod and a nut cooperate. Specifically, the nut is sleeved on the screw rod, and the screw rod is driven by the motor. The nut is fixedly connected to the pressure balancing device 8, and the rotation of the motor can drive the pressure balancing device 8 to move up and down.

[0032] The test kettle 9 is provided with an air inlet 911 and an air outlet 912 on the kettle cover 91 , and the test kettle 9 is filled with hydrogen through the air inlet 911 and the air outlet 912 , so that the sample 12 is subjected to fatigue test in a hydrogen environment.

[0033] Specifically, the test kettle 9 can be made of A286 material, with a maximum working pressure of 70MPa and a working temperature of -55~+100℃. The installation method of the test kettle 9 is bolt-fastened. The sealing method of the kettle body 92 and the kettle cover 91 of the test kettle 9 is 2 O-ring seals, 1 axial seal, and 1 radial seal; the sealing method of the kettle cover 91 and the pressure balance device 8 is 1 O-ring axial seal. The installation form of the test kettle 9 is that the kettle body 92 is at the bottom and the kettle cover 91 is at the top. The bottom of the kettle body 92 has an opening, and the thermocouple, extensometer cable (high-temperature penetration), etc. are all on the opening of the kettle body 92. When operating in the test kettle 9, the kettle cover 91 is required to be lifted until the support frame 94 in the kettle is completely exposed.

[0034] The insulation layer 93 is provided with a water inlet pipe 931 and a water outlet pipe 932, through which cooling or heating operations can be performed. Specifically, the temperature control method of the kettle body 92 can adopt an oil bath heating method, and a certain temperature of heat transfer oil is injected into the insulation layer 93 through a mold temperature controller, so as to achieve the purpose of heating or cooling the medium in the test kettle 9. The temperature control method adopts the method of controlling the temperature of the heat transfer oil in the mold temperature controller to indirectly control the temperature of the medium in the test kettle 9. If the temperature of the medium in the test kettle 9 is too high or too low, the temperature of the heat transfer oil in the mold temperature controller can be appropriately adjusted.

[0035] Preferably, please refer to Figure 7 , two guide columns 2 are arranged at intervals, and the two ends of the cross beam 3 are respectively arranged on the two guide columns 2; two hydraulic push rods 4 are respectively located at the two ends of the cross beam 3 and on both sides of the cross beam 3. In other words, the two hydraulic push rods 4 are arranged on both sides of the vertical plane where the two guide columns 2 are located. In this way, the two hydraulic push rods 4 synchronously drive the cross beam 3, so that the cross beam 3 can be evenly stressed, and the cross beam 3 will not generate a horizontal shear force on the guide column 2, which is conducive to the smooth sliding of the cross beam 3 on the guide column 2.

[0036] Please refer to Figure 6 The pressure balancing device 8 includes an upper pull rod 81, an outer shell 82, a water jacket 821, an upper balancing cylinder 83, a middle sealing flange 84, a lower pull rod 85 and a lower balancing cylinder 86. The driving member 7, the upper pull rod 81, the lower pull rod 85 and the clamp 11 are connected in sequence from top to bottom. The upper balancing cylinder 83 is connected to the lower balancing cylinder 86 through the middle sealing flange 84, and the bottom of the lower balancing cylinder 86 is connected to the kettle cover 91 by bolts. The outer shell 82 is covered on the upper balancing cylinder 83 and the lower balancing cylinder 86, and the upper pull rod 81 and the lower pull rod 85 are slidably arranged in the upper balancing cylinder 83 and the lower balancing cylinder 86. The outer shell 82 is also provided with a water jacket 821 to facilitate water circulation cooling in the outer shell 82.

[0037] It is worth noting that when conducting fatigue tests, gas with the same pressure as that in the test kettle 9 must be introduced into the lower balance cylinder 86 so that balance can be achieved and the data obtained can be correct.

[0038] The fixture 11 used in this embodiment can be a fracture toughness sample fixture, a fatigue crack extension sample fixture, a low-cycle fatigue sample fixture, etc.

[0039] Please refer to Figure 8 This embodiment also provides a control method for the above hydrogen environment fatigue testing machine. After the hydrogen environment fatigue testing machine is assembled and the sample 12 and the fixture 11 are installed, the control method includes the following steps: S1: Control the electric push rod 5 to drive the kettle cover 91 to descend to the kettle body 92, and connect the kettle cover 91 and the kettle body 92 with bolts.

[0040] Specifically, one hand operates the electric push rod 5 and the other hand holds the kettle cover 91 to slowly lower the kettle cover 91. Since the gap between the inner diameter of the kettle body 92 and the clamp 11 is small, special attention should be paid to avoid the kettle body 92 hitting the clamp 11 during the lowering.

[0041] The bolts on the kettle body 92 pass through the kettle cover 91, and the kettle body 92 is connected to the kettle cover 91. When the kettle cover 91 is lowered, slow down when the two are close to each other, and do not let the kettle cover 91 hit the kettle body 92. A little gap is reserved on the contact surface of the two.

[0042] Apply high-temperature lithium-based grease to the high-pressure sealing nuts and gaskets, and tighten the bolts manually; and tighten the bolts diagonally.

[0043] S2: Perform an airtightness test on the test kettle 9 to check whether the test kettle 9 is leaking.

[0044] Specifically, use the air circuit system to inflate and pressurize the test kettle 9; if the test kettle 9 leaks, tighten the bolts again with a torque wrench; if the leakage cannot be eliminated by tightening the bolts, remove all the nuts of the test kettle 9 after releasing the pressure in the kettle, and tighten the bolts of the test kettle 9 diagonally again; if the leakage still cannot be eliminated, remove the bolts and then remove the kettle cover 91, carefully check whether the sealing surface is damaged, and make sure that the sealing surface is not damaged, then reconnect the kettle cover 91 and the kettle body 92, and continue to inflate and pressurize to check for leakage; repeat the above process until the test kettle 9 is leaking.

[0045] The test kettle 9 is subjected to an airtightness test with nitrogen or oil-free dry air, and the test pressure is 1.05 to 1.1 times the design pressure. The test pressure should be gradually increased step by step. When the pressure rises to half of the test pressure, the pressure should be stopped and the pipeline should be fully inspected. If there is no leakage or other abnormal phenomenon, the pressure can be gradually increased by 10% of the test pressure. The pressure should be stabilized for 5 minutes each time until the specified test pressure is reached, and then the pressure is stabilized for 5 minutes. It is qualified if there is no deformation after inspection. The airtightness test consists of two detection stages, high and low pressure. When the pressure reaches the test pressure, the pressure is maintained for 5 minutes, and the pressure is reduced to the design pressure. The welds and joints are checked first, and all the welds and interfaces of the pipeline are brushed with leak detection liquid. If no bubbles are found, it means there is no leakage; the pressure is maintained again, and the test time should be no less than 30 minutes; after no pressure drop, the pressure is reduced to zero. The second test pressure is 2Mpa±10%, and the test time should be no less than 30 minutes. It is qualified if no leakage and no pressure drop are detected.

[0046] This embodiment uses nitrogen or helium to conduct the leakage test. The leakage rate (A) can be calculated as follows:

[0047] Where A is the average hourly leakage rate, t is the test time, p1 and p2 are the absolute pressures at the beginning and end of the test, respectively, and T1 and T2 are the absolute temperatures at the beginning and end of the test, respectively.

[0048] When using helium for leakage test, the pressure should be maintained for more than 1 hour, and the average hourly leakage rate should be less than 0.5% to be judged as qualified.

[0049] After the test kettle 9 is leak-free, vacuuming, nitrogen purging and hydrogen purging operations may be performed on the test kettle 9 in sequence, and finally the pressure of the test kettle 9 is stabilized to a preset pressure, where the preset pressure is less than the rated maximum pressure of the test kettle 9.

[0050] Among them, after the vacuum operation, the nitrogen purge operation fills the entire pipeline system and the test kettle 9 with nitrogen, and the pressure relief begins after the pressure in the pipeline system and the test kettle 9 reaches a preset value. The purpose of the vacuum operation and the nitrogen purge operation is to purge the system with nitrogen, replace the air in the pipeline, and reduce the oxygen content.

[0051] The pressure of nitrogen purge should be 0.1MPa~0.3Mpa, the gas velocity should not be less than 20m / s, and a white paint plate should be installed at the exhaust port for inspection. It should be qualified if there is no rust or other debris on the plate within 10 minutes. After the test and purge are qualified, nitrogen should be used to replace the oxygen content to less than 1%, and the nitrogen filling should be maintained at 0.2MPa.

[0052] After the nitrogen purge operation, the hydrogen purge operation fills the entire pipeline system and the test kettle 9 with hydrogen. After the pressure in the pipeline system and the test kettle 9 reaches the preset value, the pressure relief begins. The purpose of the hydrogen purge is to purge the system with hydrogen, replace the nitrogen in the pipeline, and increase the hydrogen concentration.

[0053] S3: Using a mold temperature controller, the temperature in the test kettle 9 reaches the test temperature.

[0054] Specifically, the mold temperature controller is turned on to perform oil bath heating or cooling on the kettle body 92. During this period, the pressure in the kettle must be observed. If the pressure in the kettle reaches the maximum pressure required for the test, exhaust and pressure reduction must be performed.

[0055] S4: After the test temperature is reached in the kettle, hydrogen is injected into the test kettle 9 to pressurize it to the test pressure.

[0056] Specifically, after the temperature in the kettle reaches the test temperature, the gas system is used again to inject hydrogen into the test kettle 9 and pressurize it to the test pressure.

[0057] After that, the pipeline can also be depressurized. Among them, the pipeline outside the test kettle 9 is emptied and depressurized first to avoid excessive pressure release affecting system safety. At this time, except for the high-pressure hydrogen left in the test kettle 9, the remaining pipelines have been depressurized separately, reducing the potential explosion energy of the system during the test.

[0058] S5: Perform fatigue test.

[0059] Specifically, after the pressure and temperature meet the test requirements, the test software is started and the fatigue test operation is performed according to the software manual.

[0060] S6: After the test is completed, the machine is stopped, the mold temperature controller is turned off, and the pipeline and the kettle body 92 are depressurized.

[0061] Specifically, after the test is completed, the machine is stopped and the mold temperature controller is turned off; when the temperature in the kettle returns to room temperature, the kettle body 92 is depressurized slowly, and after the depressurization is completed, nitrogen is purged in the kettle.

[0062] The high-pressure hydrogen in the test kettle 9 is vented and depressurized to avoid excessive depressurization that affects system safety. When the pressure of the test kettle 9 returns to normal pressure, the steps of vacuuming and nitrogen purging are repeated until the hydrogen content in the test kettle 9 is reduced to a safe level.

[0063] After that, the hydrogen environment slow fatigue testing machine can be disassembled, and the fixture 11 and the sample 12 can be removed.

[0064] The beneficial effects of the hydrogen environment fatigue testing machine and the control method thereof provided in this embodiment include: 1. Set up a test kettle 9 and fill it with hydrogen to make the test kettle 9 reach the test pressure and test temperature. At the same time, place the sample 12 in the hydrogen environment of the test kettle 9 for fatigue test. The sample 12 will not produce hydrogen precipitation, which is basically consistent with the service conditions of the sample 12, thereby improving the accuracy of the fatigue test results of the sample 12; 2. The electric push rod 5 is used to drive the kettle cover 91 to cover the kettle body 92, so as to avoid excessive closing force of the kettle cover 91 on the kettle body 92, and to avoid collision and damage between the kettle cover 91 and the kettle body 92; 3. The overall structure of the testing machine is cleverly designed, easy to disassemble and assemble, the fatigue test operation process is simple and highly safe.

[0065] It should be noted that, in the absence of conflict, the features in the embodiments of this application may be combined with each other.

[0066] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A hydrogen environment fatigue testing machine, characterized in that: The hydrogen environment fatigue testing machine comprises a base plate (1), a guide column (2), a crossbeam (3), a hydraulic push rod (4), an electric push rod (5), a slide block (6), a driving member (7), a pressure balancing device (8) and a test kettle (9); The test kettle (9) comprises a kettle cover (91) and a kettle body (92), wherein the kettle body (92) is fixedly mounted on the bottom plate (1), and the kettle cover (91) is located above the kettle body (92); The guide column (2) is vertically mounted on the bottom plate (1), the slider (6) is slidably mounted on the guide column (2), the slider (6) is fixedly connected to the kettle cover (91), one end of the electric push rod (5) is detachably connected to the bottom plate (1), the other end of the electric push rod (5) is connected to the slider (6), and the electric push rod (5) is used to drive the kettle cover (91) to cover the kettle body (92); The cross beam (3) is slidably arranged on the guide column (2), one end of the hydraulic push rod (4) is connected to the base plate (1) or the bracket (10), the bracket (10) is fixedly mounted on the bottom of the guide column (2), the other end of the hydraulic push rod (4) is connected to the cross beam (3), the driving member (7) is mounted on the cross beam (3), and the driving member (7), the pressure balancing device (8) and the clamp (11) are connected in sequence from top to bottom; the driving member (7) is used to drive the pressure balancing device (8) and the clamp (11), so as to perform a fatigue test on a sample (12) mounted on the clamp (11); The test kettle (9) is provided with an air inlet (911) and an air outlet (912), and the test kettle (9) is filled with hydrogen through the air inlet (911) and the air outlet (912), so that the sample (12) is subjected to fatigue testing in a hydrogen environment.

2. The hydrogen environment fatigue testing machine according to claim 1, characterized in that: The two guide columns (2) are arranged at intervals, and the two ends of the cross beam (3) are respectively arranged on the two guide columns (2); the two hydraulic push rods (4) are respectively located at the two ends of the cross beam (3) and on both sides of the cross beam (3).

3. The hydrogen environment fatigue testing machine according to claim 1, characterized in that: The kettle cover (91) is fixedly mounted on the bottom of the sliding block (6).

4. The hydrogen environment fatigue testing machine according to claim 1, characterized in that: The pressure balancing device (8) comprises an upper pull rod (81), an upper balancing cylinder (83), a middle sealing flange (84), a lower pull rod (85) and a lower balancing cylinder (86); The driving member (7), the upper pull rod (81), the lower pull rod (85) and the clamp (11) are connected in sequence from top to bottom, the upper balancing cylinder body (83) is connected to the lower balancing cylinder body (86) via the middle sealing flange (84), the bottom of the lower balancing cylinder body (86) is connected to the kettle cover (91) via bolts, and the upper pull rod (81) and the lower pull rod (85) are slidably arranged in the upper balancing cylinder body (83) and the lower balancing cylinder body (86).

5. The hydrogen environment fatigue testing machine according to claim 1, characterized in that: The test kettle (9) further comprises a heat-insulating layer (93), wherein the heat-insulating layer (93) is coated on the kettle body (92), and a water inlet pipe (931) and a water outlet pipe (932) are arranged on the heat-insulating layer (93), and cooling or heating operations are performed through the water inlet pipe (931) and the water outlet pipe (932).

6. A control method for a hydrogen environment fatigue testing machine, characterized in that: The control method comprises the following steps: S1: Controlling the electric push rod (5) to drive the kettle cover (91) to descend to the kettle body (92), and connecting the kettle cover (91) and the kettle body (92) by bolts; S2: Performing an airtightness test on the test kettle (9) to check whether the test kettle (9) is leaking; S3: Using a mold temperature controller to raise the temperature in the test kettle (9) to the test temperature; S4: After the test temperature is reached in the kettle, hydrogen is injected into the test kettle (9) to pressurize it to the test pressure; S5: Perform fatigue test; S6: After the test is completed, the machine is stopped, the mold temperature controller is turned off, and the pipeline and the kettle body (92) are depressurized.

7. The control method of the hydrogen environment fatigue testing machine according to claim 6, characterized in that: S1 includes: During the process of lowering the kettle cover (91), the lowering speed of the kettle cover (91) is first kept constant, then gradually reduced, and finally a gap is reserved between the kettle cover (91) and the kettle body (92), and finally the kettle cover (91) and the kettle body (92) are fastened by bolts.

8. The control method of the hydrogen environment fatigue testing machine according to claim 6, characterized in that: Between S2 and S3, the control method comprises the following steps: After the test kettle (9) is leak-free, a vacuuming operation, a nitrogen purge operation, and a hydrogen purge operation are sequentially performed on the test kettle (9), and finally the pressure of the test kettle (9) is stabilized to a preset pressure.

9. The control method of the hydrogen environment fatigue testing machine according to claim 6, characterized in that: After S4, the control method comprises the following steps: Depressurize the pipeline.

10. The control method of the hydrogen environment fatigue testing machine according to claim 6, characterized in that S6 include: After the test is completed, the machine is stopped and the mold temperature controller is turned off; when the temperature in the kettle returns to room temperature, the kettle body (92) is depressurized, and after the depressurization is completed, nitrogen is purged in the kettle.

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