Testing device for simulating accelerated corrosion of metal material in plateau complex environment

Abstract

The invention discloses a test device for simulating accelerated corrosion of a metal material in a plateau complex environment, which comprises a box body (1) provided with an electric control system (12); the water collecting tank (2) is arranged at the lower part of the box body (1); the sample carrying table (9) is arranged above the water collecting tank (2); the electrolyte water tank (6) is arranged above the sample carrying table (9); a throttling valve (16) and a liquid outlet device (22) are arranged on the liquid outlet pipeline; the circulating water pump (3) is arranged between the water collecting tank (2) and the electrolyte water tank (6); and the electrode loop comprises an anode wire (19), a cathode wire (20), a graphite electrode (21) and a direct-current power supply. By means of temperature control, oxygen enrichment, anodic polarization and the like, acceleration is carried out under the condition of low conductivity, ultraviolet rays and temperature and humidity control are integrated, a simulated accelerated corrosion test is carried out on the plateau environment, and therefore a basis is provided for material selection and evaluation.

Description

Technical Field

[0001] The present invention relates to the field of corrosion resistance testing and evaluation of metal materials, and in particular to a device for testing accelerated corrosion of metal materials in a simulated complex plateau environment. Background Art

[0002] The design, construction and construction of high-altitude bridges face a series of harsh environmental challenges unique to high-altitude areas, such as extreme high and low temperature cycles, dry-wet cycles, freeze-thaw cycles, ultraviolet radiation, and high maintenance costs. In order to evaluate the corrosion resistance of high-performance steel, it is necessary to conduct natural corrosion tests on hanging pieces in the complex environment of the plateau. Due to the long time period of actual corrosion tests, it is also necessary to simulate corrosion in different plateau environments through laboratory accelerated corrosion methods to conduct a comprehensive assessment of the corrosion resistance of steel. When conducting simulated accelerated corrosion tests, it is necessary to combine the actual service conditions, focus on the aforementioned complex factors, and design accelerated corrosion test methods and equipment in the laboratory to simulate the complex environment of the plateau.

[0003] Typical characteristics of the complex plateau environment are large diurnal temperature swings, complex dry-humidity and freeze-thaw cycles, and ultraviolet radiation. However, industrial pollution in the plateau is far lower than in developed inland areas, and there is no high chloride ion concentration environment like on the coast, which leads to lower conductivity of droplets on metal surfaces and different corrosion mechanisms. Currently, there is a lack of systematic work on evaluating the corrosion resistance of steel in complex plateau environments. Most existing patents and standards related to accelerated corrosion simulation use salt solutions as electrolytes for acceleration, and do not consider or provide solutions for the complex characteristics of the plateau environment. Summary of the Invention

[0004] The purpose of the present invention is to provide a device for accelerating corrosion testing of metal materials in a simulated plateau environment, so as to realize the testing of the corrosion performance of metal materials in a laboratory simulated plateau environment.

[0005] According to the present invention, a device for accelerating corrosion testing of metal materials in a simulated complex plateau environment comprises:

[0006] A box body, on which an electric control system is provided;

[0007] A water collecting tank is arranged at the lower part of the box;

[0008] A sample carrier is arranged above the water collecting tank;

[0009] The electrolyte water tank is arranged above the sample carrier; it has a liquid outlet pipeline, and a throttle valve and a liquid outlet are arranged on the liquid outlet pipeline;

[0010] A circulating water pump is provided between the water collecting tank and the electrolyte tank;

[0011] The electrode circuit includes an anode wire, a cathode wire, a graphite electrode and a DC power supply; wherein the graphite electrode is arranged on the sample carrier, the anode wire is connected to the test sample, the cathode wire is connected to the graphite electrode, and the DC power supply is connected between the anode wire and the cathode wire.

[0012] Specifically, the test device of the present invention further comprises an oxygen blowing pipe for quantitatively supplying oxygen to the electrolyte in the electrolyte tank.

[0013] The test device of the present invention further comprises an ultraviolet lamp, which is arranged above the sample carrier. Preferably, the ultraviolet lamp has a power greater than or equal to 150W and a wavelength range of 200-400nm.

[0014] The test device of the present invention further comprises a refrigeration device, including a refrigeration compressor and a cold air pipe, wherein the outlet of the cold air pipe faces the test sample on the sample carrier.

[0015] The test device of the present invention further comprises a heating device for controlling the ambient temperature in the box.

[0016] The test device of the present invention also includes a ventilation system arranged on the top of the box; the ventilation system has four working modes: sealing, natural connection to the atmosphere, forced exhaust and forced blowing.

[0017] The test device of the present invention further comprises a temperature and humidity monitor arranged in the box.

[0018] Preferably, the liquid outlet includes a drip nozzle and a spray nozzle, and the two can be switched.

[0019] The present invention accelerates the corrosion process under low conductivity conditions through temperature control, oxygen enrichment, anodic polarization, and other means, and integrates ultraviolet light and temperature and humidity control to achieve simulated accelerated corrosion tests in plateau environments, thereby providing a basis for material selection and evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the accelerated corrosion test device for metal materials in a simulated complex plateau environment according to the present invention.

[0021] Figure 2 This is a schematic diagram of the main structure of the test device in the present invention.

[0022] Figure 3 It is an axonometric view of the main structure of the test device in the present invention.

[0023] Figure 4 This is the rear elevation axonometric drawing of the main structure of the test device in the present invention. DETAILED DESCRIPTION

[0024] The following describes in detail the specific embodiments of the accelerated corrosion test device for metal materials in a simulated plateau complex environment of the present invention with reference to the accompanying drawings. It should be understood by those skilled in the art that the embodiments described below are merely illustrative of the present invention and are not intended to limit the present invention in any way.

[0025] See also Figure 1 and Figure 2 The accelerated corrosion test device for metal materials according to the present invention mainly includes a box 1, a water collection tank 2, a circulating water pump 3, an oxygen blowing pipe 5, an electrolyte water tank 6, an ultraviolet lamp 8, a sample carrier 9, a heating device 11, an electronic control system 12, a main control panel 23, a refrigeration device, an electrode circuit and a temperature and humidity monitor.

[0026] The box 1 is the main structure of the device, with a basic strength support structure and certain sealing requirements. It isolates the external atmosphere and maintains a special physical and chemical environment inside. The box 1 is generally manufactured by welding multi-layer structural steel sheets or profiles, and the interior can be coated with corrosion-resistant materials such as ceramics, engineering plastics or stainless steel. Line or pipeline channels are reserved on the inner wall of the box 1 to integrate other equipment and functions. The front of the box 1 is a sliding door structure with a slide rail. The sample 17 is placed and other equipment is configured through the front. The sliding door and the box are sealed, and a glass observation window is installed on the sliding door to monitor the test progress and equipment working conditions in the test chamber. Temperature and humidity sensors that meet the test accuracy requirements are installed in the test chamber to control the environment inside the test chamber.

[0027] The water collecting tank 2 is arranged at the lower part of the box body 1. The sample carrier 9 is arranged above the water collecting tank 2. The electrolyte water tank 6 is arranged above the sample carrier 9. The circulating water pump 3 is arranged between the water collecting tank 2 and the electrolyte water tank 6. The water inlet of the circulating water pump 3 is connected to the bottom water outlet of the water collecting tank 2 through the circulating water pipe 18, and a filter 4 is provided on the circulating water pipe 18. The water outlet of the circulating water pump 3 is connected to the water supply pipe 7, and the water outlet of the water supply pipe 7 faces the electrolyte water tank 6. The electrolyte water tank 6 has a liquid outlet pipeline, and a throttle valve 16 and a liquid outlet 22 are provided on the liquid outlet pipeline. The water collecting tank 2, the circulating water pipe 18, the circulating water pump 3, the electrolyte water tank 6, the water supply pipe 7, the throttle valve 16, and the liquid outlet 20 constitute a complete electrolyte circulation loop.

[0028] The electrode circuit includes an anode wire 19, a cathode wire 20, a graphite electrode 21, and a DC power supply. The graphite electrode 21 is mounted on the sample carrier 9, the anode wire 19 is connected to the sample 17, the cathode wire 20 is connected to the graphite electrode 21, and the DC power supply in the electronic control system 12 is connected between the anode wire 19 and the cathode wire 20.

[0029] The electrolyte (which can be deionized water, chloride ion solution, sulfate ion solution, etc., depending on the test requirements) flows from the electrolyte tank 6 through the liquid outlet 22, drips or sprays onto the sample 17 and the sample carrier 9, soaking the sample 17 and the graphite electrode 21 to form a current loop, and flows from the edge of the sample carrier 9 into the water collection tank 2 below, and returns to the electrolyte tank 6 through the circulating water pump 3 and the water supply pipe 7. The oxide debris appearing in the solution is filtered and cleaned by the filter 4. The water supply pipe 7 can be a plastic or composite pipe with a diameter of 10mm-5mm. The circulating water pump 3 can be a micro water pump, and a power of 16W can meet the water circulation requirements. The electrolyte tank 6 can be made of engineering plastic, and the water collection tank 2 can be made of stainless steel or other corrosion-resistant metal materials. Both are equipped with liquid level sensors. The working mode of the circulating water pump 3 can be set to start when a specific liquid level is reached. When the total water volume is lower than a specific value, the system will prompt to replenish the electrolyte. The liquid outlet 22 includes a drip nozzle and a spray nozzle, which can be switched freely. The operating mode is determined by the test plan: the drip nozzle is used in the immersion mode, and the spray nozzle is used in the salt spray mode. The drip nozzle does not form a continuous vertical liquid flow during operation, preventing leakage caused by the current loop between the sample 17 and the graphite electrode 21 through the liquid flow. The electrolyte flow rate of the liquid outlet 22 is controlled by the throttle valve 16. The throttle valve 16 is an electronically controlled device, and the flow rate is regulated by the main control panel 23. The upper limit of the flow rate is 0.5L / min. The specific value is freely selected according to the test plan and requirements.

[0030] The oxygen blowpipe 5 is connected to an external air pump via a pipe, or it can be connected to a cylinder of oxygen or other gas. For routine testing, the air pump can be used to blow air into the electrolyte in the electrolyte tank 6 to increase the oxygen content. For high-rate accelerated testing simulating plateau environments, pure oxygen can be blown in via an oxygen cylinder. To simulate certain industrial atmospheres, corrosive gases such as SO2 can be blown in. The upper limit of the gas flow rate is 10 L / min and is controlled and adjusted by the main control panel 23.

[0031] The UV lamp 8 is designed to simulate the strong UV radiation of the plateau environment. The distance from the sample 17 can be adjusted within a certain range through the side hinge structure. The power of the UV lamp 8 should be greater than or equal to 150W, and the UV wavelength range is 200-400nm. It can simulate strong radiation with a meteorological UV index of more than level 15, and achieve a UV radiation intensity of more than 10mW / cm on the surface of the sample 17. 2 The specific intensity is set according to the test plan and requirements. The intensity of the ultraviolet lamp 8 is controlled by the main control panel 23.

[0032] Heating device 11 preferably utilizes an infrared heating lamp, comprising one or a group of infrared lamps, with a total heating power of approximately 500W. This provides for rapid heating and heat preservation within chamber 1, maintaining an air temperature of 60°C within the chamber or a surface temperature of sample 17 of 70°C. The heating mode, power, and temperature control of heating device 11 are controlled by a main control panel 23.

[0033] The ventilation system 10 is mounted on a removable cover 13 at the top of the chamber 1. The removable cover 13 is hinged and can be flipped up to facilitate equipment configuration. The ventilation system 10 offers four operating modes: sealed, naturally open to the atmosphere, forced exhaust, and forced blowing. Forced exhaust and blowing are achieved via fans in the vents, with a single fan power of 50W sufficient. The ventilation system 10's primary function is to control the humidity within the chamber 1. In the sealed operating mode, the electrolyte spray and heating device 11 operate to achieve an internal humidity of over 95%. In the forced exhaust and forced blowing modes, the humidity within the chamber is rapidly reduced. The ventilation system 10 can include two vents, each with its own independently controlled fan, enabling different functional combinations, such as left-hand blowing and right-hand exhaust for rapid ventilation. The fan power is adjustable, and the blades are made of engineering plastic or other corrosion-resistant materials. The motor, rotor, and joints are sealed or otherwise specially treated to protect them from corrosive environments. Independent operation is controlled by the main control panel 23.

[0034] The refrigeration system, consisting of cold air pipes 14 and a refrigeration compressor 15, can maintain the surface temperature of sample 17 below -20°C, simulating the low-temperature environment of the plateau. The compressor has a power of 2kW, and the refrigerant and refrigeration components must meet low-temperature refrigeration requirements. Cooling is achieved by directly spraying air onto sample 17 through cold air pipes 14. The power and temperature of the refrigeration system are controlled by a main control panel 23. During operation, the cabinet 1 is sealed and is not activated simultaneously with the heating device 11.

[0035] The material of the sample carrier 9 can be corrosion-resistant insulating materials such as engineering plastics or ceramics. The size of sample 17 is limited to less than 100mm×100mm×10mm. It is recommended to use thin sheet samples of less than 50mm×50mm×5mm. Sample 17 needs to be pre-treated and connected to the wire using brazing or conductive glue, and epoxy resin encapsulation is performed at the connection to prevent the wire metal from being exposed to the electrolyte environment. Sample 17 is connected to the anode wire 19, and the graphite electrode 21 is connected to the cathode wire 20. A DC circuit is formed through the ion conductor of the intermediate electrolyte and the DC power supply to accelerate the corrosion of sample 17. The upper limit of the voltage between the anode and the cathode is 1V, and the adjustment control accuracy is 2mV. It can also be controlled by current. The current range is 0-1mA, which is adjusted according to the test plan and requirements and controlled by the main control panel 23.

[0036] The electric control system 12 provides power interfaces and control elements for various components in the device. The main control panel 23 is electrically connected to the electric control system 12 to control the opening and closing and operation of various components.

[0037] The following describes the accelerated corrosion test method for simulating a complex plateau environment. The test plan and purpose determine the specific configuration and process of the test. The following describes the specific test process using two test designs.

[0038] A. Conventional accelerated corrosion testing can be performed according to the following steps:

[0039] 1. Install the sample according to the design requirements, mechanically polish the sample surface, and fix it on the sample carrier without using current acceleration.

[0040] 2. Pour deionized water or 3% NaCl solution into the electrolyte tank and sump. The specific electrolyte to be used depends on the test sample and test purpose. The main control panel sets the circulating water pump to operate to maintain a constant electrolyte tank level.

[0041] 3. Set up the oxygen blowing device, select air as the gas source, set the gas flow rate to 1L / min, synchronize the electrolyte drip nozzle, and set the oxygen blowing device to work in the dripping state.

[0042] 4. Set the test cycle: heat to 45°C, seal with humidity above 95%, drip electrolyte onto the sample surface with the nozzle, turn on the UV lamp, and continue for 1 hour; cool naturally to room temperature, ventilate naturally, stop the nozzle, turn off the UV lamp, and continue for 1 hour; repeat this cycle.

[0043] 5. Set the test time, such as 72 hours, and monitor the total amount of electrolyte during the test. If it falls below a certain amount, replenish the electrolyte.

[0044] B. High-speed accelerated corrosion testing can be performed according to the following steps:

[0045] 1. Install the sample according to the design requirements, mechanically polish the sample surface, and secure it to the sample stage. Connect the sample to the wire via brazing, then seal the joint and wire metal with epoxy resin. Connect the anode wire. Connect the graphite electrode to the cathode wire.

[0046] 2. Fill the electrolyte tank and sump with deionized water, 3% NaCl solution, 0.01 mol / L NaHSO3 solution, etc. The specific electrolyte to use depends on the test sample and the target simulation environment. The main control panel sets the circulating water pump to operate to maintain a constant electrolyte tank level.

[0047] 3. Set up the oxygen blowing device, select pure oxygen as the gas source, set the gas flow rate to 1L / min, synchronize the electrolyte drip nozzle, and set the oxygen blowing device to work in the dripping state.

[0048] 4. Set the test cycle, heat to 45 ° C, seal with humidity above 95%, drip electrolyte onto the sample surface with a nozzle, turn on the UV lamp, and apply a constant voltage of 0.5V to the cathode and anode with a DC power supply for 1 hour; turn off the heating, cool naturally to room temperature, ventilate naturally, stop the nozzle, turn off the UV lamp, turn off the DC power supply, and continue for 0.5 hours; turn off the ventilation and seal, start the refrigeration compressor, spray cold air onto the sample, and reduce the sample temperature to -20 ° C; repeat this cycle.

[0049] 5. Set the test time, such as 24 hours, monitor the total amount of electrolyte during the test, and replenish the electrolyte when it falls below a certain amount.

[0050] The above description is only a specific embodiment of the invention and is not intended to limit the invention in any way. Any equivalent changes and modifications made thereto in accordance with the spirit of the invention are within the scope of the technical protection scheme of the invention.

Claims

1. A device for testing accelerated corrosion of metal materials in a simulated complex plateau environment, characterized in that: include: A box body (1) is provided with an electric control system (12); A water collecting tank (2) is arranged at the lower part of the box body (1); A sample carrier (9) is arranged above the water collecting tank (2); An electrolyte water tank (6) is arranged above the sample carrier (9); and has a liquid outlet pipeline, on which a throttle valve (16) and a liquid outlet (22) are arranged; A circulating water pump (3) is arranged between the water collecting tank (2) and the electrolyte water tank (6); The electrode circuit comprises an anode wire (19), a cathode wire (20), a graphite electrode (21) and a DC power supply; wherein the graphite electrode (21) is arranged on a sample carrier (9), the anode wire (19) is connected to a test sample, the cathode wire (20) is connected to the graphite electrode (21), and the DC power supply is connected between the anode wire (19) and the cathode wire (20).

2. The accelerated corrosion test device for metal materials under a simulated plateau complex environment according to claim 1 is characterized in that: The invention also comprises an oxygen blowing pipe (5) for quantitatively supplying oxygen to the electrolyte in the electrolyte water tank (6).

3. The accelerated corrosion test device for metal materials under a simulated plateau complex environment according to claim 1 is characterized in that: It also includes an ultraviolet lamp (8) which is arranged above the sample carrier (9).

4. The accelerated corrosion test device for metal materials under a simulated plateau complex environment according to claim 1 is characterized in that: It also includes a refrigeration device, including a refrigeration compressor (15) and a cold air pipe (14), and the outlet of the cold air pipe (14) is directed toward the test sample on the sample carrier (9).

5. The accelerated corrosion test device for metal materials under a simulated plateau complex environment according to claim 1 is characterized in that: It also includes a heating device (11) for controlling the ambient temperature in the box.

6. The accelerated corrosion test device for metal materials under a simulated plateau complex environment according to claim 1 is characterized in that: It also includes a ventilation system (10) arranged on the top of the box body (1); the ventilation system (10) has four working modes: sealing, natural connection to the atmosphere, forced exhaust and forced blowing.

7. The accelerated corrosion test device for metal materials under a simulated plateau complex environment according to claim 1 is characterized in that: It also includes a temperature and humidity monitor arranged in the box body (1).

8. The accelerated corrosion test device for metal materials under a simulated plateau complex environment according to claim 1 is characterized in that: The liquid outlet (22) comprises a drip nozzle and a spray nozzle, and the two can be switched.

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