A multi-field coupled stress corrosion test device and test method for tensioned wire

Abstract

A multi-field coupled stress corrosion test device and test method for tensioned wires, comprising a loading system, a dry-wet cycle system, a freeze-thaw cycle system and a control system; the present invention is applicable to various tensioned wires such as prestressed steel bars, steel strands, anchor cables, etc., and can carry out various tests such as slow strain rate tests and tensile performance tests. It can also simulate the influence of dry-wet cycles, freeze-thaw cycles, monotonic / cyclic loading or coupled salt corrosion environments and other factors on the stress corrosion performance of tensioned wires, explore the corrosion degree and corrosion evolution law of tensioned wires, ensure test safety, and improve test efficiency.

Description

Technical Field

[0001] The invention relates to the field of stress corrosion testing of tensioned wires, and in particular to a multi-field coupled stress corrosion testing device and a testing method for tensioned wires. Background Art

[0002] Stress corrosion refers to the brittle fracture of tensioned wires under the coupling of high-intensity tensile stress and a medium with a corrosive environment. Corrosion cracks occur first, and then the cracks and pits are expanded by tension, resulting in stress loss and wire failure. Prestressed steel bars, steel strands, anchor cables and other tensioned wires have harsh working environments. For example, prestressed anchor cables are often located in rock and soil bodies. Such environments have various mineral compositions, a wide variety of chemical properties, alternating dry and wet conditions, large freeze-thaw cycles, unstable stray currents and other corrosive environmental characteristics. Stress corrosion will inevitably occur, which will directly affect the long-term working performance of the anchor cables. Conducting stress corrosion tests on tensioned wires is the main means to explore their mechanical properties and corrosion mechanisms in a corrosive environment.

[0003] my country's "Test Methods for Prestressed Concrete Steel" (GB / T21839-2019) clearly stipulates the stress corrosion test method, but the test method only uses the wire breakage time in the corrosive solution as the test indicator. The test indicator is single and cannot monitor the stress loss of the tensile wire during the corrosion process. In addition, it is difficult to establish the stress-time relationship by using manual timing, which makes it impossible to quantitatively analyze the corrosion mechanism and corrosion law.

[0004] Existing stress corrosion test equipment mainly focuses on stress corrosion testing of single metal wires in a single corrosion environment. It is unable to couple dry-wet cycle and freeze-thaw cycle environments, and cannot effectively simulate the real working environment of the wire. In addition, the existing equipment has poor sealing, and the exposed lines are easily corroded by corrosive liquids, and pollute the laboratory environment.

[0005] To this end, the present invention provides a tensile wire multi-field coupling stress corrosion test device and test method. Summary of the invention

[0006] In view of the technical defects of the existing wire stress corrosion test device, the purpose of the present invention is to propose a tensile wire multi-field coupling stress corrosion test device and test method, so that the test results are more in line with engineering practice.

[0007] A multi-field coupled stress corrosion test device for a tensioned wire, comprising a loading system, a dry-wet cycle system, a freeze-thaw cycle system and a control system;

[0008] The loading system consists of a fixed end pier head, a fixed end clip anchor, a test box, a loading end pier head, a loading end clip anchor, a hydraulic cylinder, an oil cylinder, and a high-pressure oil pipe. The fixed end pier head is located on the left side of the test box, and the loading end pier head is located on the right side of the test box. The fixed end pier head and the loading end pier head are integrally welded to the test box. Both the fixed end pier head and the loading end pier head are made of high-strength steel to ensure that they will not deform under high pressure. The fixed end pier head is designed with a center penetration to facilitate the passage of wires, and a groove is set at the left end to fix the clip anchor. The hydraulic cylinder and the loading end pier head are designed with a piston sleeve, and the tensioned wire passes through the center , select a suitable loading end clip anchor to clamp the part of the tested wire that is exposed from the center hole. After the oil pressure is transmitted from the oil cylinder to the hydraulic cylinder body through the high-pressure oil pipe, the hydraulic cylinder pushes the clip anchor to move outward. The pressure acts directly on the anchor shell and is then transmitted to the clip. After the clip is stressed, it clamps the tested wire, and finally causes the wire to be subjected to an outward pulling force. At this time, the pressure gauge on the pressure pump displays the corresponding force. By replacing the porous anchor, multiple wires can be tested in parallel. The hydraulic cylinder can be controlled to apply monotonic load and cyclic load according to the experimental design. The inner wall surface of the test box is treated with anti-corrosion.

[0009] The dry-wet circulation system consists of a PU steel wire hose, a circulating water pump, a water stop valve, a detachable solution tank, a round hole nozzle, and a test box cover. The system is located on the left side of the test box, the top of the detachable solution tank is flush with the bottom of the test box, the circulating water pump is placed on the detachable solution tank, the liquid inlet of the circulating water pump is connected to the detachable solution tank through a collecting pipe, and the liquid outlet of the circulating water pump is connected to the test box cover of the central control through a PU steel wire hose; the round hole nozzles are arranged in a plum blossom shape at the bottom of the test box cover; the corrosion solution is injected into the test box and the detachable solution tank, the circulating water pump and the water stop valve are turned on, and the solution can be circulated and pressurized to the test box cover, sprayed through the round hole nozzle, and the circulating water pump pressure is adjusted. The sprayed water is mist water, which can also replace the spray effect of the salt spray box.

[0010] The freeze-thaw cycle system includes a serpentine electric heating tube, a refrigeration system, and a serpentine water circulation tube. The serpentine electric heating tube is located on one side of the inner wall of the test box, the refrigeration system is located below the test box, the serpentine water circulation tube is located at the bottom of the test box, and is connected to the refrigeration system through reserved holes to achieve coolant circulation refrigeration; the refrigeration system includes a condenser, a compressor, a water condenser, etc., and the control terminal controls the alternating operation of heating and refrigeration to simulate the freeze-thaw cycle environment; the surfaces of the electric heating tube and the serpentine water circulation tube are treated with anti-corrosion.

[0011] The control system includes a control panel and a temperature sensor. The control panel is connected to the loading system, the dry-wet circulation system, and the freeze-thaw circulation system. The control panel has functions such as time monitoring, stress monitoring, temperature monitoring, and digital control. The digital control terminal can preset the tension wire loading mode, adjust the pressure and cycle of the circulating water pump, set the freeze-thaw cycle temperature threshold and the number of cycles, and control the loading stress and form of the hydraulic cylinder.

[0012] The device of the present invention can carry out multi-field coupled stress corrosion tests, and different corrosion conditions can be set according to the test plan design, so as to be closer to the actual use environment of the tensioned wire and improve the reliability and accuracy of the test.

[0013] The device of the present invention adopts a sealed design and an anti-corrosion design, which can effectively prevent the corrosion solution from splashing out, ensure a clean working environment, and extend the service life of the device.

[0014] A test method for a tensile wire multi-field coupled stress corrosion test device, the specific test steps comprising:

[0015] Step 1: Prepare the tensile wire specimen, degrease it with soft cloth and acetone, and dry it in air;

[0016] Step 2: Pass the specimen through the fixed end pier head and the loading end pier head, and extend 20 cm on both sides. Use the fixed end clip anchor and the loading end clip anchor to clamp the test wire. Control the hydraulic cylinder through the control panel to apply an initial tensile stress of 1kN to ensure that the test wire is in a holding state. Use silicone anti-corrosion sealant to seal the inside of the tension wire perforation to prevent solution leakage.

[0017] Step 3: If a basic stress corrosion test is to be carried out, the configured SCN - The corrosive solution is poured into the test box until it covers the temperature sensor. The serpentine electric heating tube is turned on through the control panel, and the solution temperature is monitored to maintain at 50±2℃ throughout the test process. The cover of the test box is closed, and the hydraulic cylinder is controlled to load to 80% of the ultimate tensile load of the wire. The timer is used to record the fracture time of the specimen with an accuracy of ±0.1 h using the control panel, and the stress loss is monitored. According to the test design requirements, the cyclic loading mode can also be set through the control panel. This test can simulate different corrosive environments by adjusting the concentration and type of the corrosive solution.

[0018] If the freeze-thaw cycle environment is coupled, after adding the corrosive solution and loading it to the target load, the refrigeration system and the serpentine electric heating tube are turned on through the control panel, and the cycle period and temperature limit are adjusted, the corrosive environment of the tensile wire in the seasonal freezing zone with alternating freeze-thaw can be simulated;

[0019] If the dry-wet cycle environment is coupled, open the water stop valve and add enough corrosive solution to allow it to circulate between the detachable solution box and the test box; set the power and working cycle of the circulating water pump through the control panel, automatically control the running time of the water pump, and pressurize the solution through the test box cover and spray it out from the round hole nozzle to achieve the effect of periodic spraying, thereby simulating the alternating dry and wet corrosion environment of the wire;

[0020] Step 4: Monitor and record stress corrosion time, freeze-thaw cycle number, and dry-wet cycle number through the control panel to obtain the stress loss curve of the corrosion process;

[0021] Step 5: After the test, turn off the circulating water pump, refrigeration system, and serpentine electric heating tube, cool to room temperature, control the hydraulic cylinder to unload, open the water stop valve to drain the solution into the detachable solution tank, and recycle the waste liquid; remove the tensile wire, treat it uniformly or carry out the next fracture microscopic scanning test; clean the detachable solution tank to avoid corrosion of the equipment.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] It can simulate harsh environments such as dry-wet cycles, freeze-thaw cycles coupled with different corrosive solutions, making it more suitable for the working conditions of the tensioned wire; it can achieve monotonic loading or cyclic loading by controlling the hydraulic cylinder, accurately control the stress of the wire and improve the test accuracy; it can accurately record the stress time-course changes and monitor the stress loss of the tensioned wire during the corrosion process; it can carry out multiple groups of parallel tests at the same time to improve the test efficiency; in addition, the device adopts a sealed box-type design with good sealing, which ensures a clean working environment and extends the service life of the device.

[0024] The control is intuitive, the functions are comprehensive, the operation is cheap and the efficiency is outstanding. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a cross-sectional view of the test box of the present invention.

[0026] Figure 2 It is a top view of the test box of the present invention.

[0027] Figure 3 It is a schematic diagram of the test box cover of the present invention.

[0028] Figure 4 It is a schematic diagram of the solution flow direction of the dry-wet circulation system of the present invention.

[0029] Figure 5 It is a schematic diagram of a detachable solution tank of the present invention.

[0030] Figure 6 It is a schematic diagram of the serpentine heating tube and the water circulation tube of the present invention.

[0031] Among them, 1-PU steel wire hose; 2-circulating water pump; 3-water stop valve; 4-detachable solution tank; 5-tension wire; 6-fixed end clip anchor; 7-fixed end pier head; 8-sealing strip; 9-round hole nozzle; 10-test box cover; 11-snake-shaped electric heating tube; 12-temperature sensor; 13-control panel; 14-test box; 15-loading end pier head; 16-loading end clip anchor; 17-hydraulic cylinder; 18-oil cylinder; 19-high-pressure oil pipe; 20-refrigeration system; 21-snake-shaped water circulation pipe. Implementation

[0032] like Figure 1 , Figure 2 , Figure 3 , Figure 5 and Figure 6 As shown, a multi-field coupled stress corrosion test device for a tensile wire includes a loading system, a dry-wet cycle system, a freeze-thaw cycle system and a control system;

[0033] The loading system is composed of a fixed end pier head 7, a fixed end clip anchor 6, a test box 14, a loading end pier head 15, a loading end clip anchor 16, a hydraulic cylinder 17, an oil cylinder 18, and a high-pressure oil pipe 19. The fixed end pier head 7 is located on the left side of the test box 14, and the loading end pier head 15 is located on the right side of the test box 14. The fixed end pier head 7 and the loading end pier head 15 are integrally welded to the test box 14. The fixed end pier head 7 and the loading end pier head 15 are both made of high-strength steel to ensure that they are not deformed under high pressure; the fixed end pier head 7 is designed with a center through-hole to facilitate the passage of wires, and a groove is set at the left end to fix the clip anchor 6; the hydraulic cylinder 17 and the loading end pier head 15 are designed as piston sleeves , the tensile wire 5 passes through the center, and a suitable loading end clip anchor 16 is selected to clamp the part of the tested wire exposed from the center hole. After the oil pressure is transmitted from the oil cylinder 18 to the hydraulic cylinder body 17 through the high-pressure oil pipe 19, the hydraulic cylinder 17 pushes the clip anchor to move outward, and the pressure directly acts on the anchor shell and is then transmitted to the clip. After the clip is stressed, it clamps the tested wire, and finally causes the wire to be subjected to an outward pulling force. At this time, the pressure gauge on the pressure pump displays the corresponding force; by replacing the porous anchor, multiple wires can be tested in parallel; the hydraulic cylinder 17 can be controlled to apply monotonic load and cyclic load according to the experimental design; the inner wall surface of the test box 14 is treated with anti-corrosion.

[0034] The dry-wet circulation system consists of a PU steel wire hose 1, a circulating water pump 2, a water stop valve 3, a detachable solution tank 4, a round hole nozzle 9, and a test box cover 10. The system is located on the left side of the test box 14, the top of the detachable solution tank 4 is flush with the bottom of the test box 14, the circulating water pump 2 is placed on the detachable solution tank 4, the liquid inlet of the circulating water pump 2 is connected to the detachable solution tank 4 through a collecting pipe, and the liquid outlet of the circulating water pump 2 is connected to the test box cover 10 of the central control through the PU steel wire hose 1; the round hole nozzle 9 is arranged in a plum blossom shape at the bottom of the test box cover 10; the corrosive solution is injected into the test box 14 and the detachable solution tank 4, the circulating water pump 2 and the water stop valve 3 are opened, and the solution circulation and pressurization to the test box cover 10 can be realized, and spraying is carried out through the round hole nozzle 9, and the circulating water pump pressure is adjusted. The sprayed water is mist water, which can also replace the spraying effect of the salt spray box.

[0035] The freeze-thaw cycle system includes a serpentine electric heating tube 11, a refrigeration system 20, and a serpentine water circulation tube 21. The serpentine electric heating tube 11 is located on one side of the inner wall of the test box 14, the refrigeration system 20 is located below the test box 14, the serpentine water circulation tube 21 is located at the bottom of the test box 14, and is connected to the refrigeration system 20 through a reserved hole to achieve coolant circulation refrigeration; the refrigeration system 20 includes a condenser, a compressor, a water condenser, etc., and the heating and cooling are controlled alternately by a control terminal to simulate a freeze-thaw cycle environment; the surfaces of the electric heating tube 11 and the serpentine water circulation tube 21 are treated with anti-corrosion.

[0036] The control system includes a control panel 13 and a temperature sensor 12. The control panel 13 is connected to the loading system, the dry-wet circulation system, and the freeze-thaw circulation system. The control panel 13 has functions such as time monitoring, stress monitoring, temperature monitoring, and digital control. The digital control terminal can preset the loading mode of the tensioned wire 5, adjust the pressure and cycle of the circulating water pump 2, set the freeze-thaw cycle temperature threshold and the number of cycles, and control the loading stress and form of the hydraulic cylinder 17.

[0037] The device of the present invention can carry out multi-field coupled stress corrosion tests, and different corrosion conditions can be set according to the test plan design, so as to be closer to the actual use environment of the tensioned wire and improve the reliability and accuracy of the test.

[0038] The device of the present invention adopts a sealed design and an anti-corrosion design, which can effectively prevent the corrosion solution from splashing out, ensure a clean working environment, and extend the service life of the device.

[0039] like Figures 1 to 6 The test method of a tensile wire multi-field coupled stress corrosion test device comprises the following specific test steps:

[0040] Step 1: Prepare the tensile wire 5 specimen, degrease it with soft cloth and acetone, and dry it in air;

[0041] Step 2: Pass the specimen through the fixed end pier 7 and the loading end pier 15, and extend the specimen 20 cm on both sides. Use the fixed end clip anchor 6 and the loading end clip anchor 16 to clamp the test wire. Control the hydraulic cylinder 17 through the control panel 13 to apply an initial tensile stress of 1 kN to ensure that the test wire is in a holding state. Use silicone anti-corrosion sealant to seal the inside of the perforation of the tension wire 5 to prevent the solution from leaking out.

[0042] Step 3: If a basic stress corrosion test is to be carried out, the configured SCN - The corrosive solution is poured into the test box 14, covering the temperature sensor 12, and the serpentine electric heating tube 11 is turned on through the control panel 13, and the solution temperature is monitored to maintain at 50±2°C during the entire test process; the test box cover 10 is closed, and the hydraulic cylinder 17 is controlled to load to 80% of the ultimate tensile load of the wire; the control panel 13 is used to time and record the fracture time of the sample with an accuracy of ±0.1 h, and the stress loss is monitored. According to the test design requirements, the cyclic loading mode can also be set through the control panel 13. This test can simulate different corrosive environments by adjusting the concentration and type of the corrosive solution;

[0043] If the freeze-thaw cycle environment is coupled, after the corrosive solution is added and loaded to the target load, the refrigeration system 20 and the serpentine electric heating tube 11 are turned on through the control panel 13, and the cycle period and temperature limit are adjusted, the corrosive environment of the tensile wire in the seasonal freezing zone with alternating freeze-thaw can be simulated;

[0044] If the dry-wet cycle environment is coupled, open the water stop valve 3, and add a sufficient amount of corrosive solution so that it can circulate between the detachable solution box 4 and the test box 14; set the power and working cycle of the circulating water pump 2 through the control panel 13, automatically control the running time of the water pump, and pressurize the solution through the test box cover 10 and spray it out from the round hole nozzle 9 to achieve the effect of periodic spraying, thereby simulating the alternating dry and wet corrosion environment of the wire;

[0045] Step 4: Monitor and record stress corrosion time, freeze-thaw cycle number, and dry-wet cycle number through the control panel 13 to obtain a stress loss curve of the corrosion process;

[0046] Step 5: After the test is completed, turn off the circulating water pump 2, the refrigeration system 20, the serpentine electric heating tube 11, etc., cool to room temperature, control the hydraulic cylinder 17 to unload, open the water stop valve 3 to discharge the solution to the detachable solution tank 4, and recycle the waste liquid; remove the tensile wire, treat it uniformly or carry out the next step of the fracture microscopic scanning test; clean the detachable solution tank 4 to avoid corrosion of the equipment.

Claims

1. A multi-field coupled stress corrosion test device for tensile wires, Features: Including loading system, wet-dry cycle system, freeze-thaw cycle system and control system; The loading system comprises a fixed end pier head (7), a fixed end clip anchor (6), a test box (14), a loading end pier head (15), a loading end clip anchor (16), a hydraulic cylinder (17), an oil cylinder (18), and a high-pressure oil pipe (19). The fixed end pier head (7) is located on the left side of the test box (14), and the loading end pier head (15) is located on the right side of the test box (14). The fixed end pier head (7) and the loading end pier head (15) are integrally welded to the test box (14). Both the fixed end pier head (7) and the loading end pier head (15) are made of high-strength steel to ensure that they will not deform under high pressure. The fixed end pier head (7) is designed as a central through hole. The wire is passed through, and a groove is provided at the left end to fix the clip anchor (6); the hydraulic cylinder (17) and the loading end pier (15) are designed as a piston sleeve, the tensioned wire (5) passes through the center, and a suitable loading end clip anchor (16) is selected to clamp the portion of the measured wire exposed from the center hole. After the oil pressure is transmitted from the oil cylinder (18) to the hydraulic cylinder (17) through the high-pressure oil pipe (19), the hydraulic cylinder (17) pushes the clip anchor to move outward, and the pressure directly acts on the anchor shell and is then transmitted to the clip. After the clip is stressed, it clamps the measured wire, and finally causes the wire to be subjected to an outward pulling force. At this time, the pressure gauge on the pressure pump displays the corresponding force; By replacing the porous anchor, multiple wires can be tested in parallel; the hydraulic cylinder (17) can be controlled to apply monotonic load and cyclic load according to the experimental design; The dry-wet circulation system comprises a PU steel wire hose (1), a circulating water pump (2), a water stop valve (3), a detachable solution tank (4), a round hole nozzle (9), and a test tank cover (10). The dry-wet circulation system is located on the left side of the test tank (14). The top of the detachable solution tank (4) is flush with the bottom of the test tank (14). The circulating water pump (2) is placed on the detachable solution tank (4). The liquid inlet of the circulating water pump (2) is connected to the detachable solution tank (4) through a liquid collecting pipe. The circulating water pump (2) ) The liquid outlet is connected to the test box cover (10) of the central control through a PU steel wire hose (1); the circular hole nozzles (9) are arranged in a plum blossom shape at the bottom of the test box cover (10); the corrosion solution is injected into the test box (14) and the detachable solution box (4), and the circulating water pump (2) and the water stop valve (3) are turned on to realize the solution circulation and pressurization to the test box cover (10), and sprayed through the circular hole nozzles (9), and the circulating water pump pressure is adjusted. The sprayed water is mist water, which can also replace the spray effect of the salt spray box; The freeze-thaw cycle system comprises a serpentine electric heating tube (11), a refrigeration system (20), and a serpentine water circulation tube (21), wherein the serpentine electric heating tube (11) is located at one side of the inner wall of the test box (14), the refrigeration system (20) is located below the test box (14), and the serpentine water circulation tube (21) is located at the bottom of the test box (14) and is connected to the refrigeration system (20) via a reserved hole to achieve cooling by cooling liquid circulation; The control system comprises a control panel (13) and a temperature sensor (12). The control panel (13) is connected to the loading system, the dry-wet cycle system, and the freeze-thaw cycle system. The control panel (13) has time monitoring, stress monitoring, temperature monitoring, and digital control. The digital control terminal can preset the loading mode of the tensioned wire (5), adjust the pressure and cycle of the circulating water pump (2), set the freeze-thaw cycle temperature threshold and the number of cycles, and control the loading stress and form of the hydraulic cylinder (17).

2. A multi-field coupled stress corrosion test device for tensioned wire according to claim 1, Features: The fixed end pier head (7) and the loading end pier head (15) are integrally welded to the test box (14).

3. A multi-field coupled stress corrosion test device for tensioned wire according to claim 1, Features: The surface of the electric heating tube (11), the surface of the serpentine water circulation tube (21), and the inner wall surface of the test box (14) are subjected to anti-corrosion treatment.

4. A multi-field coupled stress corrosion test device for tensioned wire according to claim 1, Features: The refrigeration system (20) comprises a condenser, a compressor, and a water condenser, and is controlled by a control terminal to alternately operate heating and cooling to simulate a freeze-thaw cycle environment.

5. The test method of the multi-field coupled stress corrosion test device for tensile wires according to claim 1, Features: The test steps include: Step 1: Prepare the tensile wire (5) specimen, degrease it with a soft cloth and acetone, and dry it in air; Step 2: The specimen is passed through the fixed end pier head (7) and the loading end pier head (15), and extended 20 cm on both sides. The test wire is clamped by the fixed end clip anchor (6) and the loading end clip anchor (16). The hydraulic cylinder (17) is controlled by the control panel (13) to apply an initial tensile stress of 1 kN to ensure that the test wire is in a holding state. The inside of the perforation of the tension wire (5) is sealed with silicone anti-corrosion sealant to prevent the solution from leaking out. Step 3: If a basic stress corrosion test is to be carried out, the configured SCN - The corrosive solution is poured into the test box (14) to cover the temperature sensor (12), and the serpentine electric heating tube (11) is turned on through the control panel (13), and the solution temperature is monitored to maintain at 50±2°C during the entire test process; the test box cover (10) is closed, and the hydraulic cylinder (17) is controlled to load to 80% of the ultimate tensile load of the wire; the control panel (13) is used to time and record the fracture time of the sample with an accuracy of ±0.1h, and the stress loss is monitored. According to the test design requirements, a cyclic loading mode can also be set through the control panel (13). The test can simulate different corrosive environments by adjusting the concentration and type of the corrosive solution; If a freeze-thaw cycle environment is coupled, after a corrosive solution is added and loaded to a target load, the refrigeration system (20) and the serpentine electric heating tube (11) are turned on through a control panel (13), and the cycle period and temperature limit are adjusted, the corrosive environment of freeze-thaw alternation of the tensile wire in the seasonal freezing zone can be simulated; If a dry-wet cycle environment is coupled, the water stop valve (3) is opened and a sufficient amount of corrosive solution is added so that it can circulate between the detachable solution box (4) and the test box (14); the power and working cycle of the circulating water pump (2) are set through the control panel (13), and the operation time of the water pump is automatically controlled. The solution is pressurized and sprayed through the test box cover (10) and the circular hole nozzle (9) to achieve a periodic spraying effect, thereby simulating the dry-wet alternating corrosion environment of the wire; Step 4: Monitor and record stress corrosion time, freeze-thaw cycle number, and dry-wet cycle number through the control panel (13) to obtain a stress loss curve of the corrosion process; Step 5: After the test is completed, turn off the circulating water pump (2), the refrigeration system (20), and the serpentine electric heating tube (11), cool to room temperature, control the hydraulic cylinder (17) to unload, open the water stop valve (3) to drain the solution into the detachable solution tank (4), and recycle the waste liquid; remove the tensile wires, treat them uniformly or carry out the next fracture microscopic scanning test; clean the detachable solution tank (4) to avoid corrosion of the equipment.

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