Testing device and method for simulating metal corrosion fatigue in dry-wet alternating atmospheric environment

Abstract

The invention provides a testing device and method for simulating metal corrosion fatigue in a dry-wet alternating atmospheric environment, and belongs to the technical field of testing. The device comprises an environmental box, a salt mist generation device, a drying device, an exhaust and liquid discharge device and a time control device, the environmental box is arranged between chucks of the fatigue testing machine; the salt mist generating device is communicated with the environment box through a salt mist air inlet pipe; the drying device communicates with the environment box through an air inlet pipe. The exhaust and liquid discharge device is communicated with the environmental box through a liquid discharge pipe and an exhaust pipe; electromagnetic control valves are respectively arranged on the air inlet pipe and the exhaust pipe; and the drying device, the salt mist generating device and the electromagnetic control valve are respectively connected with a time control device. According to the invention, through the time control device, the salt mist generation device and the drying device, accurate regulation and control of different dry-wet alternation ratios, humidity and environmental solution concentration are realized, and through the temperature and humidity monitoring device, temperature and humidity changes in a test process are monitored in real time, and adjustability, controllability and real-time monitoring of key environmental factors are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of testing, and particularly relates to a testing device and method for simulating the corrosion fatigue of metals under a dry-wet alternating atmospheric environment. Background Technique

[0002] Disclosing the information of this background technical part is only intended to increase the understanding of the overall background of the present invention, and it is not necessarily regarded as an admission or an implication in any form that this information constitutes the prior art already known to those of ordinary skill in the art.

[0003] Corrosion fatigue is a phenomenon in which metal materials undergo fatigue failure under the coupled action of a corrosive medium environment and an alternating load. In the fields of offshore platform structures, transmission lines, aerospace, oil and gas equipment, bridges, etc., almost all metal materials in contact with the external environment will undergo corrosion fatigue failure under the combined action of environmental and mechanical factors during their service life. Due to the existence of corrosion fatigue, engineering components and equipment often fail without warning far below their designed service life, causing huge economic losses and safety hazards. Therefore, testing and characterizing the corrosion fatigue performance of materials is of great significance for material design, structural design, protection, and maintenance, etc.

[0004] The testing of the corrosion fatigue performance of materials needs to be realized through special corrosion fatigue equipment. For example, the patent with the publication number CN111855552A discloses a corrosion fatigue test device and method in a simulated marine atmospheric environment. By combining a salt spray test and a fatigue test, a humidifying device is set to control the humidity of the test chamber, and a temperature and humidity monitoring device is set to monitor the temperature and humidity of the test chamber in real time, so as to simulate the corrosion fatigue performance of materials in various marine atmospheric environments. However, there are huge differences between the pure salt spray or water bath conditions and the actual atmospheric dry-wet alternating conditions in the actual environment. At the same time, most of the existing corrosion fatigue devices have a single function and cannot provide corrosion fatigue tests under multiple composite environments, and cannot meet the requirements of actual complex and changeable service conditions. Therefore, how to realize the testing of the corrosion fatigue performance of metal materials under the service conditions that conform to the actual atmospheric environment has become an urgent problem to be solved. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a testing device and method for simulating the corrosion fatigue of metals under a dry-wet alternating atmospheric environment, which can realize the adjustable control and real-time monitoring of key environmental factors, be closer to the change law of the actual atmospheric environment, and thus obtain more realistic metal corrosion fatigue test results.

[0006] To achieve the above purpose, the technical solution of the present invention is as follows:

[0007] In a first aspect, a test device for simulating the corrosion fatigue of metals under an alternating wet and dry atmospheric environment includes an environmental chamber, a salt spray generating device, a drying device, an exhaust and drainage device, and a time control device;

[0008] The environmental chamber is arranged between the chucks of a fatigue testing machine; the salt spray generating device is connected to the environmental chamber through a salt spray inlet pipe and is used for conveying salt spray into the environmental chamber; the drying device is connected to the environmental chamber through an air inlet pipe and is used for conveying dry air into the environmental chamber; the exhaust and drainage device is connected to the environmental chamber through a drain pipe and an exhaust pipe and is used for exhausting waste gas and waste liquid in the environmental chamber;

[0009] Electromagnetic control valves are respectively arranged on the air inlet pipe and the exhaust pipe; the drying device, the salt spray generating device, and the electromagnetic control valves are respectively connected to the time control device.

[0010] In a second aspect, a test method based on the above-mentioned test device for simulating the corrosion fatigue of metals under an alternating wet and dry atmospheric environment includes the following processes:

[0011] S1. Install a metal corrosion fatigue test piece in the environmental chamber and clamp the clamping end of the test piece on the chuck of the fatigue testing machine;

[0012] S2. Set the time control device according to the set wet and dry alternation time ratio. When the test enters the wet stage in the wet and dry alternation time, the drying device is closed and the salt spray generating device is opened; when the test enters the dry stage in the wet and dry alternation time, the drying device is opened and the salt spray generating device is closed, realizing an automatic cycle of the wet and dry alternation environment;

[0013] S3. Conduct a metal corrosion fatigue test, monitor the environment in the environmental chamber in real time through a temperature and humidity sensor, and adjust the power of the salt spray generating device and the salt spray generating device through a flow control knob.

[0014] In a third aspect, the application of the above-mentioned test device for simulating the corrosion fatigue of metals under an alternating wet and dry atmospheric environment includes: testing and life assessment of the corrosion fatigue performance of metal structures in the fields of offshore platform structures, transmission lines, aerospace, oil and gas equipment, and bridges under atmospheric environments.

[0015] The beneficial effects of the present invention are as follows:

[0016] 1. The present invention realizes precise control of different wet and dry alternation ratios, humidity, and environmental solution concentrations through the time control device, the salt spray generating device, and the drying device, and realizes real-time monitoring of the temperature and humidity changes during the test through a temperature and humidity monitoring device, achieving adjustable and controllable key environmental factors and real-time monitoring.

[0017] 2. The present invention combines the atmospheric corrosion process with the fatigue test, which can be used to evaluate the corrosion fatigue performance of metal materials under different atmospheric environment service conditions; realizing the true simulation of the key feature of atmospheric corrosion, i.e., the wet-dry alternating environment, and enabling the testing of the corrosion fatigue performance of metal materials that is more in line with the actual service environment.

[0018] 3. The device of the present invention has a simple structure, is easy to install and disassemble, and is convenient to clean. The exhaust and waste liquid collection device can effectively prevent the test solution from polluting the fatigue testing machine and the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings forming a part of this invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0020] Figure 1 It is a schematic structural diagram of the test device for simulating the corrosion fatigue of metals in a wet-dry alternating atmospheric environment in Embodiment 1.

[0021] Figure 2 It is a schematic structural diagram of the environmental chamber in Embodiment 1.

[0022] Among them, 1. Fatigue testing machine; 2. Upper chuck; 3. Wire; 4. Electromagnetic control valve; 5. Air inlet pipe; 6. Drying device; 7. Timing switch; 8. Flow control knob; 9. Salt spray generating device; 10. Exhaust and drainage device; 11. Drain pipe; 12. Lower chuck; 13. Salt spray inlet pipe; 14. Exhaust pipe; 15. Environmental chamber; 16. Specimen; 17. Temperature and humidity sensor; 18. Screw; 19. Upper and lower cover plates; 20. Side plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0024] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0025] A test device for simulating the corrosion fatigue of metals in a wet-dry alternating atmospheric environment, comprising an environmental chamber, a salt spray generating device, a drying device, an exhaust and drainage device, and a timing control device;

[0026] The environmental chamber is arranged between the chucks of the fatigue testing machine; the salt spray generating device is connected to the environmental chamber through a salt spray inlet pipe, and is used for conveying salt spray into the environmental chamber; the drying device is connected to the environmental chamber through an air inlet pipe, and is used for conveying dry air into the environmental chamber; the exhaust and drainage device is connected to the environmental chamber through a drainage pipe and an exhaust pipe, and is used for exhausting waste gas and waste liquid in the environmental chamber;

[0027] Electromagnetic control valves are respectively arranged on the air inlet pipe and the exhaust pipe; the drying device, the salt spray generating device and the electromagnetic control valve are respectively connected to a time control device.

[0028] The function of the time control device is to control the opening / closing time of the devices connected thereto. Through the above settings, the adjustable and controllable key environmental factor of the dry-wet alternating cycle can be realized, so that the test environment in the environmental chamber is closer to the actual service environment, and thus the test results are more in line with the actual state.

[0029] The time control device includes a plurality of timing switches, and the timing switches are respectively arranged on the drying device, the salt spray generating device and the electromagnetic control valve. The electromagnetic control valve can control the on / off state of the air inlet pipe and the exhaust pipe, realize the rapid circulation of air during the drying process, and is used to simulate the atmospheric environment with different dry-wet alternating ratios in the environmental chamber; no electromagnetic control valve is arranged on the drainage pipe. On the one hand, it can ensure the pressure balance between the environmental chamber and the outside world, prevent the salt spray from not being continuously pumped into the cavity of the environmental chamber, and on the other hand, it can prevent the accumulation of solution from affecting the simulation conditions.

[0030] Optionally, a temperature and humidity sensor is arranged in the environmental chamber, and the temperature and humidity sensor is arranged at the upper cover plate of the environmental chamber for real-time monitoring of the temperature and humidity changes of the simulated environment in the environmental chamber.

[0031] Optionally, the environmental chamber includes an upper and lower cover plate and side plates. Openings are respectively arranged on the upper and lower cover plates. The salt spray inlet pipe, the air inlet pipe and the exhaust pipe are respectively provided with openings on the side plates, and the drainage pipe is provided with an opening on the lower cover plate; the openings on the upper and lower cover plates are used for the clamping ends of the test pieces to extend out of the environmental chamber and be connected to the chucks of the fatigue testing machine. The openings on the side plates are used for the set gases, including dry air and salt spray, to enter the environmental chamber, and the drainage pipe is used for discharging the condensed liquid accumulated in the environmental chamber.

[0032] Optionally, the salt spray generating device includes a solution chamber, an ultrasonic vibration sheet and a blowing device. The solution chamber is used for storing the environmental simulation solution, the ultrasonic vibration sheet is used for generating salt spray from the environmental simulation solution, and the blowing device is used for conveying the salt spray into the environmental chamber through the salt spray inlet pipe.

[0033] Optionally, the drying device includes a blast dryer, which is used to introduce dry air into the environmental chamber, capable of quickly replacing the gas in the environmental chamber and enabling a quick switch between wet and dry states.

[0034] Optionally, the testing device includes a controller, which is respectively connected to a time control device, a drying device, a salt spray generating device, and a temperature and humidity sensor. It is used to compare the temperature and humidity detected by the sensor with the set temperature and humidity, and adjust the power of the drying device and the salt spray generating device according to the comparison result, so that the temperature and humidity inside the environmental chamber can quickly change to the set conditions within a specified time.

[0035] The testing method of the testing device for simulating metal corrosion fatigue in a wet-dry alternating atmospheric environment based on the above includes the following processes:

[0036] S1. Install the metal corrosion fatigue specimen in the environmental chamber, and clamp the clamping end of the specimen on the chuck of the fatigue testing machine;

[0037] S2. Set the time control device according to the set wet-dry alternating time ratio. When the test enters the wet stage of the wet-dry alternating time, the drying device is turned off and the salt spray generating device is turned on; when the test enters the dry stage of the wet-dry alternating time, the drying device is turned on and the salt spray generating device is turned off, realizing an automatic cycle of the wet-dry alternating environment;

[0038] S3. Conduct a metal corrosion fatigue test, monitor the environment in the environmental chamber in real time through the temperature and humidity sensor, and adjust the power of the salt spray generating device and the salt spray generating device through the flow control knob.

[0039] Optionally, in S3, the exhaust and drainage device is adjusted through an electromagnetic control valve and a blast dryer to assist in adjusting the environment in the environmental chamber.

[0040] The application of the above testing device for simulating metal corrosion fatigue in a wet-dry alternating atmospheric environment includes: testing and life assessment of the corrosion fatigue performance of metal structures in the fields of offshore platform structures, transmission lines, aerospace, oil and gas equipment, and bridges in the atmospheric environment.

[0041] Compared with conducting a fatigue test after corrosion, this device realizes the synchronous progress of corrosion and fatigue, which is more in line with the actual service conditions of the material. Moreover, through the precise control of wet-dry alternation and the combination of different environmental solutions, the simulation of many atmospheric conditions such as pure salt spray and different wet-dry alternation ratios can be achieved.

[0042] Example 1

[0043] A testing device for simulating metal corrosion fatigue in a wet-dry alternating atmospheric environment, as Figure 1As shown in the figure, it includes an environmental chamber 15, a salt spray generating device 9, a drying device 6, an exhaust and drainage device 10, a time control device, and a temperature and humidity monitoring device 17;

[0044] The environmental chamber 15 is arranged between the upper chuck 2 and the lower chuck 12 of the fatigue testing machine 1; the salt spray generating device 9 is connected to the environmental chamber 15 through a salt spray inlet pipe 13 for conveying salt spray into the environmental chamber 15; the drying device 6 is connected to the environmental chamber 15 through an air inlet pipe 5 for conveying dry air into the environmental chamber 15; the exhaust and drainage device 10 is connected to the environmental chamber 15 through a drain pipe 11 and an exhaust pipe 14 for exhausting waste gas and waste liquid in the environmental chamber 15.

[0045] The time control device includes a plurality of timing switches 7 and electromagnetic control valves 4 connected by a wire 3. The timing switches 7 are respectively connected to the drying device 6, the salt spray generating device 9, and the electromagnetic control valves 4. A plurality of electromagnetic control valves 4 are respectively arranged on the air inlet pipe 5 and the exhaust pipe 14 to simulate an atmospheric environment with different dry-wet alternation ratios in the environmental chamber.

[0046] The temperature and humidity monitoring device includes a temperature and humidity sensor 17 arranged at the upper cover plate 19 of the environmental chamber 15 for real-time monitoring of the temperature and humidity changes in the simulated environment inside the environmental chamber.

[0047] Through the above settings, precise control of different dry-wet alternation ratios, humidity, and environmental solution concentrations can be achieved, and the temperature and humidity changes during the test can be monitored in real time through the temperature and humidity monitoring device, realizing adjustable, controllable, and real-time monitoring of key environmental factors.

[0048] The environmental chamber is as Figure 2 shown, including upper and lower cover plates 19 and side plates 20. The area of the upper and lower cover plates 19 is larger than the cross-sectional area of the cavity of the side plates 20, which can play a sealing role at the upper and lower ends of the cavity of the side plates 20; bolt holes are respectively arranged on the upper and lower cover plates 19, and the upper and lower cover plates 19 are connected by a screw rod 18, thereby squeezing the middle side plates 20 to obtain the environmental chamber 15; the material of the environmental chamber 15 is a transparent acrylic plate, which is easy to observe the internal situation of the environmental chamber 15 during the test; openings are respectively arranged on the upper and lower cover plates 19 for the clamping ends of the metal corrosion fatigue specimen 16 to extend out of the environmental chamber 15 and be connected to the fatigue testing machine 1. To ensure that the gas in the environmental chamber 15 does not leak, the gap between the opening and the clamping end of the specimen 16 is sealed by silicone rubber. The selected silicone rubber has a small elastic modulus to avoid causing resistance to the deformation of the specimen; the salt spray inlet pipe 13, the air inlet pipe 5, and the exhaust pipe 14 are respectively provided with openings on the side plates 20 to enable the supplemented gas in the environmental chamber 15 to fully contact the specimen 16; the drain pipe 11 is provided with an opening on the lower cover plate for discharging the condensed liquid in the environmental chamber 15.

[0049] The salt spray generating device 9 includes an ultrasonic humidifier. The ultrasonic humidifier includes a flow control knob 8, a solution chamber, an ultrasonic vibrating sheet, and a blower device. The solution chamber is used to store the environmental simulation solution. The ultrasonic vibrating sheet is used to generate salt spray from the environmental simulation solution. The blower device is used to deliver the salt spray into the environmental chamber 15 through the salt spray inlet pipe 13. The power of the blower device is regulated by the controller to ensure the accuracy of the humidity in the chamber and environmental simulation.

[0050] The drying device 6 includes a blast dryer, which is connected to the controller and can deliver dry air into the environmental chamber 15. The power of the blast dryer is regulated by the controller, and the accuracy of the humidity in the chamber and environmental simulation is achieved by adjusting the ratio of the dry air and salt spray entering the environmental chamber 15.

[0051] The time control device includes a plurality of timing switches 7 and electromagnetic control valves 4 for realizing the regulation of different wet-dry alternating states.

[0052] The temperature and humidity monitoring device includes a temperature and humidity sensor 17 for real-time monitoring of the temperature and humidity changes in the environment simulated in the environmental chamber.

[0053] The test method of the test device for simulating metal corrosion fatigue in a wet-dry alternating atmospheric environment based on this embodiment includes the following processes:

[0054] S1. Install the metal corrosion fatigue specimen 16 in the cavity of the side plate 20 of the environmental chamber 15. After blocking the upper and lower ends of the cavity of the side plate 20 with the upper and lower cover plates 19, fix the upper and lower cover plates 19 and the side plate 20 with screws 18 to make it the environmental chamber 15. Make the clamping end of the specimen 16 extend out through the opening of the upper and lower cover plates 19 of the environmental chamber 15, and fill the gap between the specimen 16 and the opening with silicone rubber, and clamp the clamping end of the specimen 16 on the chuck of the fatigue testing machine 1.

[0055] S2. Set the time control device according to the set wet-dry alternating time ratio. When the test enters the wet stage in the wet-dry alternating time, the drying device 6 is closed and the salt spray generating device 9 is turned on. When the test enters the dry stage in the wet-dry alternating time, the drying device 6 is turned on and the salt spray generating device 9 is closed to realize the automatic cycle of the wet-dry alternating environment.

[0056] S3. Conduct the metal corrosion fatigue test, monitor the environment in the environmental chamber 15 in real time through the temperature and humidity sensor 17, and adjust the power of the salt spray generating device 9 through the controller. Record the fatigue life when the specimen 16 fractures.

[0057] Embodiment 2

[0058] The metal fatigue corrosion test method using the test device for simulating metal corrosion fatigue in a wet-dry alternating atmospheric environment of Embodiment 1 includes the following steps:

[0059] S1. Gradually grind the Q420B steel specimen 16 along the length direction, clean it with alcohol and dry it; place the specimen into the specimen position reserved by the upper and lower covers of the environmental chamber 15, and seal it with silicone rubber, leaving the clamping parts of the upper chuck 2 and the lower chuck 12 at both ends.

[0060] S2. After the preparation work is completed, place the sealed environmental chamber 15 in the middle of the fatigue testing machine 1, and clamp both ends of the specimen to the upper chuck 2 and the lower chuck 12 respectively; connect the drying device 6 and the salt spray generating device 9 to the environmental chamber 15 in sequence; the solution in the solution chamber of the salt spray generating device 9 is 3.5wt% NaCl aqueous solution; set the relevant test parameters of the fatigue testing machine.

[0061] S2. Set the relevant parameters of the timing switch 7 in the controller, set the wet-dry alternation ratio to 1:1, the drying duration of the drying device is 1h, and the salt spray generating duration of the salt spray generating device 9 is also 1h; turn on the time control device, the salt spray generating device 9 and the drying device 6; when entering the wetting stage, the blast dryer is turned off, and when the salt spray enters the environmental chamber 15 through the salt spray inlet pipe 13, the electromagnetic control valve 4 connecting the exhaust pipe 14 and the air inlet pipe 5 is closed; when entering the drying stage, the salt spray generator 9 is turned off, the electromagnetic control valve 4 connecting the exhaust pipe 14 and the air inlet pipe 5 is opened, and the drying device works; through the time control device, an automatic cycle of the wet-dry alternating environment is realized.

[0062] S3. Start the corrosion fatigue test, and realize the corrosion fatigue test under various composite environmental factors through the time control device, the drying device 6 and the salt spray generating device 9. Real-time monitor the temperature and humidity changes in the environmental chamber 15 through the temperature and humidity sensor 17, and record the fatigue life when the specimen 16 fractures.

[0063] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A test device for simulating the corrosion fatigue of metals in a wet-dry alternating atmospheric environment, characterized in that It includes an environmental chamber, a salt spray generating device, a drying device, an exhaust and drainage device, and a time control device; The environmental chamber is arranged between the chucks of the fatigue testing machine; the salt spray generating device is connected to the environmental chamber through a salt spray inlet pipe and is used to transport salt spray into the environmental chamber; the drying device is connected to the environmental chamber through an air inlet pipe and is used to transport dry air into the environmental chamber; the exhaust and drainage device is connected to the environmental chamber through a drainage pipe and an exhaust pipe and is used to discharge the waste gas and waste liquid in the environmental chamber; Electromagnetic control valves are respectively arranged on the air inlet pipe and the exhaust pipe; the drying device, the salt spray generating device, and the electromagnetic control valves are respectively connected to the time control device.

2. The test device for simulating the corrosion fatigue of metals in an alternating wet and dry atmospheric environment according to claim 1, wherein The environmental chamber includes upper and lower covers and side plates. Openings are respectively arranged on the upper and lower covers. The salt spray inlet pipe, the air inlet pipe, and the exhaust pipe respectively have openings on the side plates, and the drainage pipe has an opening on the lower cover.

3. The test device for simulating metal corrosion fatigue in an alternating wet and dry atmospheric environment according to claim 1, characterized in that, The salt spray generating device includes a solution chamber, an ultrasonic vibration sheet, and a blowing device. The solution chamber is used to store the environmental simulation solution. The ultrasonic vibration sheet is used to generate salt spray from the environmental simulation solution. The blowing device is used to transport the salt spray into the environmental chamber through the salt spray inlet pipe.

4. The test device for simulating metal corrosion fatigue in a wet-dry alternate atmospheric environment according to claim 1, characterized in that, The drying device includes a blast dryer, and the blast dryer is connected to the controller.

5. The test device for simulating metal corrosion fatigue in an alternating wet and dry atmospheric environment according to claim 1, wherein, The exhaust and drainage device includes an exhaust fan.

6. The test device for simulating metal corrosion fatigue in an alternating wet and dry atmospheric environment according to claim 1, wherein, The time control device includes a plurality of timing switches; Or, the temperature and humidity sensor is arranged at the upper cover of the environmental chamber; Or, the test device includes a controller, and the controller is respectively connected to the time control device and the temperature and humidity sensor.

7. The test device for simulating metal corrosion fatigue in an alternating wet and dry atmospheric environment according to claim 1, characterized in that The environmental chamber includes upper and lower covers and side plates. The areas of the upper and lower covers are larger than the cross-sectional area of the cavity of the side plates and can play a sealing role at the upper and lower ends of the cavity of the side plates; bolt holes are respectively arranged on the upper and lower covers, and the upper and lower covers are connected by screw rods.

8. A testing method based on the testing device for simulating metal corrosion fatigue in an alternating wet and dry atmospheric environment as described in any one of claims 1 - 7, characterized in that, It includes the following processes: S1. Install the metal corrosion fatigue test piece in the environmental chamber and clamp the clamping end of the test piece on the chuck of the fatigue testing machine; S2. Set the time control device according to the set dry-wet alternation time ratio. When the test enters the wet stage of the dry-wet alternation time, the drying device is closed and the salt spray generating device is opened; when the test enters the dry stage of the dry-wet alternation time, the drying device is opened and the salt spray generating device is closed, realizing the automatic cycle of the dry-wet alternation environment; S3. Conduct a metal corrosion fatigue test, monitor the environment in the environmental chamber in real time through the temperature and humidity sensor, and adjust the power of the salt spray generating device and the salt spray generating device.

9. The test method according to claim 8, wherein In S3, the exhaust and drainage device is adjusted through the electromagnetic control valve and the blast dryer to assist in adjusting the environment in the environmental chamber.

10. An application of a test device for simulating metal corrosion fatigue in an alternating wet and dry atmospheric environment as described in claims 1-7, characterized in that, It includes the test and life assessment of the corrosion fatigue performance of metal structures in the fields of offshore platform structures, transmission lines, aerospace, oil and gas equipment, and bridges under atmospheric environment.

Images