An accelerated corrosion simulation test apparatus and method in a marine environment

Abstract

This invention discloses an accelerated corrosion simulation test device and method in a marine environment, relating to the field of environmental corrosion technology. It was invented to comprehensively and objectively simulate corrosive environments under different protective conditions. The device includes a test chamber and a potentiostat; inside the test chamber are multiple sample racks, auxiliary anodes, and reference electrodes; the auxiliary anodes and reference electrodes are connected to the potentiostat, and the samples on the multiple sample racks are connected to a sliding rheostat and the potentiostat via cathode current-carrying cables; the device also includes a constant-temperature water bath, an oxygen cylinder, and a corrosion environment parameter testing tube; the test chamber is located inside the constant-temperature water bath; the test chamber has an air inlet duct and an air outlet; wherein the air inlet duct is connected to the oxygen cylinder; the corrosion environment parameter testing tube communicates with the interior of the test chamber.

Description

Technical Field

[0001] This invention relates to the field of environmental corrosion technology, and in particular to an accelerated corrosion simulation test apparatus and method in a marine environment. Background Technology

[0002] Marine environments are highly corrosive, and metal structures operating in these environments face severe corrosion problems. Major infrastructure projects operating in marine environments, such as immersed tunnels, cross-sea bridge steel pipe piles, and offshore wind power steel pipe piles, all have long service life requirements. For example, the Shenzhen-Zhongshan Bridge is designed for a 100-year lifespan, the Hong Kong-Zhuhai-Macau Bridge for 120 years, and the Hangzhou Bay Bridge for 100 years. The highly corrosive environment and high durability requirements make corrosion protection design and prediction work significant and challenging. Currently, corrosion protection of metal structures in marine environments mainly employs a combination of protective coatings, cathodic protection, and reserved corrosion margins. Protective coatings cannot achieve absolute insulation between the metal surface and the environment, and some damage to the coating is inevitable during construction. Furthermore, the protective performance of the coating further declines with the extension of service time. The effectiveness of cathodic protection is affected by many factors, and in actual operation, it often fails to achieve the results expected in the design phase. At the same time, the service life of cathodic protection systems is limited, making it difficult to meet the same lifespan requirements as the main structure. Therefore, conducting corrosion evaluation and prediction of metal structures under different coating failure rates and cathodic protection levels is particularly important.

[0003] Currently, there are two main methods for testing material corrosion in marine environments: one is field exposure testing of materials in actual marine environments, and the other is corrosion testing of materials in simulated marine environments. Although the latter method offers controllable conditions, a short testing cycle, high efficiency, and good reproducibility of test results, the simulation testing equipment currently used mostly simulates the corrosive environment and lacks simulation of different states of protective methods such as coatings and cathodic protection. This makes it difficult to comprehensively and objectively simulate the corrosive environment under different protective conditions. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide an accelerated corrosion simulation test device and method in a marine environment, which facilitates a comprehensive and objective simulation of corrosion environments under different protective conditions.

[0005] In a first aspect, the accelerated corrosion simulation test apparatus in a marine environment provided by embodiments of the present invention includes: a test chamber and a potentiostat; a multi-layer sample rack, an auxiliary anode, and a reference electrode are provided inside the test chamber; wherein, the auxiliary anode and the reference electrode are connected to the potentiostat via wires, and the samples on the multi-layer sample rack are connected to a sliding rheostat and the potentiostat via cathode current-carrying cables; the samples are used to simulate the damage rates of different coatings on a metal substrate and its surface; the sliding rheostat is used to adjust the circuit resistance of the circuit containing the samples of different layers, thereby adjusting the cathodic protection current of different circuits to simulate different cathodic protection levels; the auxiliary anode is used to introduce the cathodic protection current into a simulated seawater solution; the reference electrode is used to test the energizing potential of the samples of different layers; and the potentiostat is used to display... The device includes an output parameter adjustment mechanism; the output parameter includes the electrical potential of the sample; the device further includes: a constant temperature water bath, an oxygen cylinder, and a corrosion environment parameter testing tube; the test chamber is located inside the constant temperature water bath; the test chamber is equipped with an air inlet pipe and an air outlet; wherein, the air inlet pipe is connected to the oxygen cylinder; the corrosion environment parameter testing tube is connected to the interior of the test chamber; the oxygen cylinder is used to maintain the dissolved oxygen content required for the accelerated corrosion test through the air inlet pipe; the air outlet is used to slowly add a preset solution to the simulated seawater solution to adjust the pH value required for the accelerated corrosion test; the constant temperature water bath is used to provide the test chamber with a constant temperature required for the accelerated corrosion test; the corrosion environment parameter testing tube is used to test the dissolved oxygen content, pH value, and temperature.

[0006] Optionally, each layer of the multi-layer sample holder includes multiple sample slots, and each sample slot contains a voltage-conducting sheet. The voltage-conducting sheet is used to connect the samples in the same layer in series and serve as a cathode protection cathode circuit.

[0007] Optionally, the potentiostat includes a positive terminal, a negative terminal, a reference electrode terminal, a zero-position cathode terminal, and a control panel; the auxiliary anode and the reference electrode are connected to the potentiostat via wires; the samples on the multi-layer sample holder are connected to the sliding rheostat and the potentiostat via cathode current-carrying cables, including: the auxiliary anode is connected to the positive terminal via a wire; the reference electrode is connected to the reference electrode terminal via a reference electrode wire; samples on different layers of the multi-layer sample holder are connected to the sliding rheostat, the negative terminal, and the zero-position cathode terminal via cathode current-carrying cables; the display and adjustment of output parameters includes: displaying and adjusting output parameters via the control panel.

[0008] Optionally, the samples on different layers of the multi-layer sample holder are connected to the sliding rheostat, the negative terminal, and the zero-position cathode terminal via cathode current-carrying cables. This includes: each layer of the multi-layer sample holder has a cathode current-carrying cable led out, each cathode current-carrying cable is connected in series with a sliding gearbox and then combined into one cable and connected to the negative terminal to return the cathodic protection current to the negative terminal of the potentiostat.

[0009] Optionally, the constant temperature water bath includes a heating element and a first temperature sensor; providing the test chamber with the constant temperature required for the test includes: providing the test chamber with the constant temperature required for the test through the heating element and the first temperature sensor.

[0010] Optionally, the corrosion environment parameter testing tube includes a first test port, a second test port, and a third test port; the testing of dissolved oxygen content, pH value, and temperature includes: a dissolved oxygen sensor corresponding to the first test port for testing dissolved oxygen content; a pH sensor corresponding to the second test port for testing pH value; and a second temperature sensor corresponding to the third test port for testing temperature.

[0011] Optionally, maintaining the dissolved oxygen content required for the accelerated corrosion test through the air inlet duct includes: introducing the oxygen cylinder into the simulated seawater solution through the air inlet duct and the pressure reducing valve to maintain the dissolved oxygen content required for the accelerated corrosion test, wherein the pressure reducing valve is disposed between the air inlet duct and the oxygen cylinder.

[0012] Secondly, the accelerated corrosion simulation test method in a marine environment provided by the embodiments of the present invention includes the following steps: applying different coatings to the exposed surface of the sample and creating defects to simulate different coating protection states; placing the sample on a multi-layer sample holder and placing the multi-layer sample holder inside the test chamber; pouring the prepared seawater simulation solution into the test chamber; controlling and monitoring preset parameters of the seawater simulation solution; wherein the preset parameters include temperature, dissolved oxygen content, and pH value; adjusting a sliding rheostat according to a preset energized potential value to simulate different cathodic protection levels; wherein the sliding rheostat is a sliding rheostat in the circuit where the sample is located in different layers; and observing the surface state of the sample.

[0013] Optionally, placing the sample on the multi-layer sample holder and placing the multi-layer sample holder in the test chamber includes: placing the sample one by one into the sample slot of the multi-layer sample holder, so that the sample is in good contact with the conductive sheet in the sample slot, and placing the multi-layer sample holder layer by layer into the test chamber.

[0014] Optionally, before adjusting the sliding rheostat according to the preset energizing potential value to simulate different cathodic protection levels, the method further includes: testing the self-corrosion potential value of the samples with different layers, and determining the preset energizing potential value of the samples with different layers based on the cathodic polarization value of the samples with different layers and the self-corrosion potential value.

[0015] Optionally, adjusting the sliding rheostat according to the obtained required energized potential value to simulate different cathodic protection levels includes: starting the potentiostat, sequentially bringing the tip of the reference electrode close to the surface of the sample of different layers, and obtaining the energized potential values ​​of the sample of different layers displayed on the control panel of the potentiostat; adjusting the sliding rheostat according to the obtained energized potential values ​​of the sample of different layers until the energized potential value displayed on the control panel is close to the preset energized potential value, so as to simulate different cathodic protection levels of the sample of different layers.

[0016] Optionally, controlling and monitoring the preset parameters of the seawater simulation solution includes: monitoring the first temperature of the constant temperature water bath through a first temperature sensor in the constant temperature water bath; monitoring the second temperature of the seawater simulation solution through a second temperature sensor in the corrosion environment parameter test tube; and adjusting the value of the first temperature according to the second temperature to control the temperature of the seawater simulation solution.

[0017] Optionally, the control and monitoring of the preset parameters of the seawater simulation solution further includes: after the second temperature stabilizes, monitoring the pH value of the seawater simulation solution using a pH sensor installed in the corrosion environment parameter test tube; if the measured pH value is higher than the preset requirement value, slowly adding a first preset solution to the seawater simulation solution through the air outlet inside the test chamber until the measured pH value matches the preset requirement value; if the measured pH value is lower than the preset requirement value, slowly adding a second preset solution to the seawater simulation solution through the air outlet inside the test chamber until the measured pH value matches the preset requirement value.

[0018] Optionally, the preset parameters for controlling and monitoring the seawater simulation solution further include: after the second temperature stabilizes, monitoring the dissolved oxygen content of the seawater simulation solution using a dissolved oxygen sensor installed in the corrosion environment parameter test tube; opening the air outlet and pressure reducing valve inside the test chamber to continuously introduce oxygen into the seawater simulation solution, and controlling the dissolved oxygen content by adjusting the pressure reducing valve.

[0019] Optionally, after observing the surface state of the sample, the method further includes: adjusting the position of the reference electrode inside the test chamber during the observation of the sample surface state, and testing the energized potential values ​​of different layers of the sample; if the measured energized potential value deviates from the preset energized potential value, then the sliding rheostat of the circuit containing the sample in different layers is adjusted until the energized potential values ​​of the sample in different layers are stable.

[0020] The accelerated corrosion simulation test apparatus and method in a marine environment provided by this invention includes: a test chamber and a potentiostat; the test chamber is equipped with a multi-layer sample rack, an auxiliary anode, and a reference electrode; wherein, the auxiliary anode and the reference electrode are connected to the potentiostat via wires, and the samples on the multi-layer sample rack are connected to a sliding rheostat and the potentiostat via cathode current-carrying cables; the samples are used to simulate the damage rate of different coatings on a metal substrate; the sliding rheostat is used to adjust the circuit resistance of the circuit containing the samples of different layers, thereby adjusting the cathodic protection current of different circuits to simulate different cathodic protection levels; the auxiliary anode is used to introduce the cathodic protection current into the simulated seawater solution; the reference electrode is used to test the energizing potential of the samples of different layers; the potentiostat is used to display and adjust... The device includes a constant-temperature water bath, an oxygen cylinder, and a corrosion environment parameter testing tube. The test chamber is located inside the constant-temperature water bath. The test chamber has an inlet duct and an outlet. The inlet duct is connected to the oxygen cylinder. The corrosion environment parameter testing tube communicates with the interior of the test chamber. The oxygen cylinder maintains the dissolved oxygen content required for the accelerated corrosion test through the inlet duct. The outlet is used to slowly add a preset solution to the simulated seawater solution to adjust the pH value required for the accelerated corrosion test. The constant-temperature water bath provides a constant temperature for the test chamber. The corrosion environment parameter testing tube measures dissolved oxygen content, pH value, and temperature. Therefore, it can comprehensively and objectively simulate the corrosion environment under different protective conditions. Attached Figure Description

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

[0022] Figure 1 This is a cross-sectional schematic diagram of an accelerated corrosion simulation test device in a marine environment according to an embodiment of the present invention;

[0023] Figure 2 This is a C-C top view of the test chamber in an accelerated corrosion simulation test device in a marine environment according to an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the sample holder in an accelerated corrosion simulation test apparatus in a marine environment according to an embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of a method for simulating accelerated corrosion in a marine environment according to an embodiment of the present invention. Detailed Implementation

[0026] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0027] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0028] Example 1

[0029] The accelerated corrosion simulation test device in the marine environment provided in this embodiment of the invention is mainly applicable to the corrosion simulation test scenario of metal structures in the marine environment, and can comprehensively and objectively simulate the corrosion environment under different protection conditions.

[0030] Figure 1 This is a cross-sectional schematic diagram of an accelerated corrosion simulation test device in a marine environment according to an embodiment of the present invention. Figure 2 This is a C-C top view of the test chamber in an accelerated corrosion simulation test apparatus for a marine environment according to an embodiment of the present invention. (See attached diagram.) Figure 1 and Figure 2As shown, in some embodiments, the device includes: a test chamber 1 and a potentiostat 2; inside the test chamber 1 are a multi-layer sample holder 3, an auxiliary anode 4, and a reference electrode 5; wherein, the auxiliary anode 4 and the reference electrode 5 are connected to the potentiostat 2 via wires, and the sample 6 on the multi-layer sample holder 3 is connected to the sliding rheostat 7 and the potentiostat 2 via a cathode current-carrying cable; the sample 6 is used to simulate the different damage rates of the metal substrate and its surface coatings; the sliding rheostat 7 is used to adjust the circuit resistance of the circuit containing the sample 6 in different layers, thereby adjusting the cathodic protection current of different circuits to simulate different cathodic protection levels; the auxiliary anode 4 is used to introduce the cathodic protection current into the simulated seawater solution; the reference electrode 5 is used to test the energizing potential of the sample 6 in different layers; the potentiostat 2 is used to display and adjust the output parameters; the output... The output parameters include the electrical potential of the sample; the device further includes: a constant temperature water bath 8, an oxygen cylinder 9, and a corrosion environment parameter testing tube 10; the test chamber is located inside the constant temperature water bath 8; the test chamber 1 is provided with an air inlet duct 11 and an air outlet 12; wherein, the air inlet duct 11 is connected to the oxygen cylinder 9; the corrosion environment parameter testing tube 10 is connected to the interior of the test chamber 1; the oxygen cylinder 9 is used to maintain the dissolved oxygen content required for the accelerated corrosion test through the air inlet duct 11; the air outlet 12 is used to slowly add a preset solution to the seawater simulation solution to adjust the pH value required for the accelerated corrosion test; the constant temperature water bath 8 is used to provide the test chamber 1 with a constant temperature required for the accelerated corrosion test; the corrosion environment parameter testing tube 10 is used to test the dissolved oxygen content, pH value, and temperature.

[0031] Specifically, the auxiliary anode 4 can be an MMO anode, connected to the positive terminal 21 of the potentiostat via a wire, used to introduce cathodic protection current into the simulated seawater solution. The reference electrode 5 can be a silver / silver chloride reference electrode, the position of its end being adjustable vertically, connected to the reference electrode terminal 23 of the potentiostat via a reference electrode wire, used to test the protection potential of different layers of samples. Different layers of samples serve as cathodes and are subjected to cathodic protection. By adjusting the sliding rheostat in the circuit containing different layers of samples, the circuit resistance is changed, thereby achieving different levels of cathodic protection. The protection potential of different layers of samples is tested through the reference electrode, achieving quantitative control. Through different experimental treatment methods and process control, synchronous or batch corrosion simulation tests can be conducted on different samples in the laboratory, such as different materials, different exposed areas, different coating processes, and different cathodic protection levels. This provides a scientific and reasonable laboratory experimental device for studying the corrosion behavior of various metal materials and coatings in the marine environment and for developing new materials.

[0032] See Figure 3As shown, Figure 3 This is a schematic diagram of the sample holder in an accelerated corrosion simulation test device in a marine environment according to an embodiment of the present invention. In some embodiments, each layer of the multi-layer sample holder 3 includes multiple sample slots 31, and each sample slot 31 contains a voltage-conducting sheet 32. The voltage-conducting sheet 32 ​​is used to connect the sample 6 in the same layer in series and serve as a cathode protection cathode circuit.

[0033] Understandably, the multi-layered sample holder design allows for the simultaneous installation of a large number of samples, ensuring the accuracy and reproducibility of test results. Simultaneously, it enables the phased removal and evaluation of samples after different cycles, facilitating long-term studies of corrosion behavior and its development. The sample holder 3 has several sample slots 31 evenly distributed around its circumference. The conductive plates 32 at the bottom of different sample slots 31 can be connected as a single unit using copper sheets, leading out to the second conductor 221 and the fourth conductor 241. The conductive plates can be made of copper and are used to connect samples in the same layer in series, serving as a cathodic protection cathode circuit.

[0034] In some embodiments, the potentiostat 2 includes a positive terminal 21, a negative terminal 22, a reference electrode terminal 23, a zero-position cathode terminal 24, and a control panel 25; the auxiliary anode 4 and the reference electrode 5 are connected to the potentiostat 2 via wires, and the sample 6 on the multi-layer sample holder 3 is connected to the sliding rheostat 7 and the potentiostat 2 via a cathode current-carrying cable, including: the auxiliary anode 4 is connected to the positive terminal 21 via a wire, the reference electrode 5 is connected to the reference electrode terminal 23 via a reference electrode wire, and the samples 6 on different layers of the multi-layer sample holder 3 are connected to the sliding rheostat 7, the negative terminal 22, and the zero-position cathode terminal 24 via cathode current-carrying cables; the display and adjustment of output parameters includes: displaying and adjusting output parameters via the control panel 25.

[0035] For details, please refer to Figure 1 The auxiliary anode 4 is suspended at the center of the test chamber 1 by a first wire 211, which passes through the top cover of the test chamber and is connected to the positive terminal 21 of the potentiostat 2. A second wire 221 passes through the top cover of the test chamber 1 and is connected in series with a sliding rheostat to the negative terminal 22, used to return the cathodic protection current to the negative terminal of the potentiostat. The reference electrode 5 passes through the top cover of the test chamber 1 and can be adjusted vertically; it is connected to the reference electrode terminal 23 of the potentiostat 2 by a third wire 231. A fourth wire 241 passes through the top cover of the test chamber 1 and is connected to the zero-position cathode terminal 24 of the potentiostat 6. The potentiostat 2 is accessed via a control panel 25.

[0036] In some embodiments, the samples 6 on different layers of the multi-layer sample holder 3 are connected to the sliding rheostat 7, the negative terminal 22, and the zero-position cathode terminal 24 via cathode current-carrying cables. This includes: a cathode current-carrying cable is led out from each layer of the multi-layer sample holder 3, and each cathode current-carrying cable is connected in series with a sliding gearbox 7 and then combined into a wire and connected to the negative terminal 22 to return the cathodic protection current to the negative terminal of the potentiostat.

[0037] Specifically, the multi-layer sample holder can have three layers. The second conductor 221 includes a first sub-conductor, a second sub-conductor, and a third sub-conductor. The first sub-conductor of the sample from the first layer of the sample holder is connected in series with a first sliding rheostat. The second sub-conductor of the sample from the second layer of the sample holder is connected in series with a second sliding rheostat. The third sub-conductor of the sample from the third layer of the sample holder is connected in series with a third sliding rheostat. The first, second, and third sliding rheostats are connected in parallel and then combined into a single conductor, which is connected to the negative terminal 22.

[0038] To achieve accelerated corrosion simulation, a constant-temperature water bath, oxygen cylinder, and corrosion environment parameter testing tubes are set up to monitor and control key corrosion parameters such as dissolved oxygen content, pH value, and temperature. This accelerates the corrosion simulation and allows for the acquisition of a large amount of scientifically valid experimental data in a short time, providing an effective evaluation of the long-term corrosion behavior of marine structures with extended service lives. Furthermore, by setting and controlling different cathodic protection levels for samples from different layers, this invention can realistically simulate the actual operating conditions of large structures in real-world environments, including varying cathodic protection levels at different locations and changes in cathodic protection levels over time. This allows for a more realistic and comprehensive simulation of the corrosion environment under different cathodic protection levels.

[0039] Specifically, the corrosion parameter testing tube 10 can be a connecting pipe extending from the bottom right side of the test chamber 1. The outlet of the oxygen cylinder 9 is connected to the air inlet pipe 11 of the test chamber 1 via a pressure reducing valve 13. The outlet of the air inlet pipe 11 is below the surface of the test solution, i.e., the simulated seawater solution. The top cover of the test chamber 1 can be equipped with an air outlet 12, and the bottom left side of the test chamber 1 can be equipped with a drain outlet 22, which is controlled by a needle valve 22.

[0040] In some embodiments, the constant temperature water bath 8 includes a heating element 81 and a first temperature sensor 82; providing the test chamber 1 with the constant temperature required for the test includes: providing the test chamber with the constant temperature required for the test through the heating element 81 and the first temperature sensor 82.

[0041] In some embodiments, the corrosion environment parameter testing tube 10 includes a first test port, a second test port, and a third test port; the testing of dissolved oxygen content, pH value, and temperature includes: a dissolved oxygen sensor 101 corresponding to the first test port for testing dissolved oxygen content; a pH sensor 102 corresponding to the second test port for testing pH value; and a second temperature sensor 103 corresponding to the third test port for testing temperature.

[0042] In some embodiments, maintaining the dissolved oxygen content required for the accelerated corrosion test through the air inlet duct 11 includes: introducing the oxygen cylinder 9 into the simulated seawater solution through the air inlet duct 11 and the pressure reducing valve 13 to maintain the dissolved oxygen content required for the accelerated corrosion test, wherein the pressure reducing valve 13 is disposed between the air inlet duct 11 and the oxygen cylinder 9.

[0043] The embodiments of this invention can simulate different levels of corrosion protection, and have better simulation of the actual marine corrosion environment with corrosion protection system. At the same time, by monitoring and controlling corrosion parameters, the corrosion behavior of metal structures with ultra-long service life can be studied through short-cycle indoor accelerated corrosion tests, which saves costs, has good acceleration, simulation and reproducibility, is simple to operate and easy to observe, and is suitable for carrying out accelerated corrosion simulation tests of marine environment under different protection conditions in the laboratory.

[0044] Based on the same or corresponding technical concept as the accelerated corrosion simulation test device in the marine environment provided in the foregoing embodiments, this embodiment of the invention also provides an accelerated corrosion simulation test method in the marine environment, see below. Figure 4 As shown, Figure 4 This is a schematic diagram of a method for simulating accelerated corrosion in a marine environment according to an embodiment of the present invention, including the following steps:

[0045] S1. Apply different coatings to the exposed surface of the sample and create defects to simulate different coating protection conditions.

[0046] Specifically, different coatings can be applied to the exposed surfaces of samples with different layers and / or different samples with the same layer, and corresponding defects can be artificially created to simulate different coating protection states.

[0047] S2. Place the sample on the multi-layer sample holder and place the multi-layer sample holder inside the test chamber.

[0048] Specifically, the test chamber can be a can-shaped container, and its main structure can be plexiglass, i.e., a transparent and sealed container, facilitating observation of the test process. The multi-layer sample rack can have three layers, and the number of layers can be increased or decreased according to test requirements. The multi-layer sample rack is used to support the samples, which can be coated samples, used to simulate different damage rates of the metal substrate and its surface coating.

[0049] In some embodiments, placing the sample on the multi-layer sample holder and placing the multi-layer sample holder in the test chamber includes: placing the sample one by one into the sample slot of the multi-layer sample holder, so that the sample is in good contact with the conductive sheet in the sample slot, and placing the multi-layer sample holder layer by layer into the test chamber.

[0050] For details, please refer to Figures 1 to 3 The sample holder 3 has several sample slots 31 evenly distributed on its circumference. The conductive plates 32 at the bottom of different sample slots 31 can be connected together by copper plates and lead out wires 221 and 241. The wire 221 passes through the top cover of the test chamber 1 and is connected in series with a sliding rheostat. The wire 241 passes through the top cover of the test chamber 1 and is connected to the zero-position cathode terminal 24 of the potentiostat 6. The auxiliary anode 4 is suspended at the center of the test chamber 1 by the first wire 211, which passes through the top cover of the test chamber and is connected to the positive terminal 21 of the potentiostat 2. The reference electrode 5 passes through the top cover of the test chamber 1 and can be adjusted up and down. It is connected to the reference electrode terminal 23 of the potentiostat 2 by the second wire 231.

[0051] S3. Pour the prepared seawater simulation solution into the test chamber.

[0052] S4. Control and monitor the preset parameters of the seawater simulation solution; wherein the preset parameters include temperature, dissolved oxygen content and pH value.

[0053] In some embodiments, controlling and monitoring preset parameters of the seawater simulation solution includes:

[0054] The first temperature of the constant temperature water bath is monitored by a first temperature sensor in the constant temperature water bath; the second temperature of the seawater simulation solution is monitored by a second temperature sensor in the corrosion environment parameter test tube; the value of the first temperature is adjusted according to the second temperature to control the temperature of the seawater simulation solution.

[0055] For details, please refer to Figure 1 After pouring the prepared seawater solution or seawater simulation solution into the test chamber 1, the constant temperature water bath 8 can be turned on and the temperature set to the first temperature. The first temperature is monitored and controlled by the first temperature sensor 82. The temperature measured by the second temperature sensor 103 is the actual temperature of the seawater simulation solution, which is recorded as the second temperature. The set value of the first temperature is adjusted according to the second temperature so that the second temperature is the same as the test requirement temperature and remains unchanged.

[0056] In some embodiments, controlling and monitoring the preset parameters of the seawater simulation solution further includes: after the second temperature stabilizes, monitoring the pH value of the seawater simulation solution using a pH sensor installed in the corrosion environment parameter test tube; if the measured pH value is higher than a preset requirement value, slowly adding a first preset solution to the seawater simulation solution through the air outlet inside the test chamber until the measured pH value matches the preset requirement value; if the measured pH value is lower than the preset requirement value, slowly adding a second preset solution to the seawater simulation solution through the air outlet inside the test chamber until the measured pH value matches the preset requirement value.

[0057] Specifically, after the second temperature stabilizes, the pH value of the seawater solution or seawater simulation solution measured by the pH sensor 102 is first read. If the measured pH value is higher than the required value, hydrochloric acid solution is slowly added to the seawater solution or seawater simulation solution through the air outlet 12 using a dropper. If the measured pH value is lower than the required value, NaOH solution is slowly added to the seawater solution or seawater simulation solution through the air outlet 12 using a dropper until the measured pH value matches the required value.

[0058] In some embodiments, controlling and monitoring the preset parameters of the seawater simulation solution further includes: after the second temperature stabilizes, monitoring the dissolved oxygen content of the seawater simulation solution using a dissolved oxygen sensor installed in the corrosion environment parameter test tube; opening the air outlet and pressure reducing valve inside the test chamber to continuously introduce oxygen into the seawater simulation solution, and controlling the dissolved oxygen content by adjusting the pressure reducing valve.

[0059] Specifically, after the second temperature stabilizes, the dissolved oxygen content of the seawater solution or simulated seawater solution measured by the dissolved oxygen sensor 101 is read first, then the air outlet 12 is opened, and finally the pressure reducing valve 13 is slowly opened to continuously introduce oxygen into the seawater solution. The dissolved oxygen content is controlled by adjusting the pressure reducing valve 13.

[0060] S5. Adjust the sliding rheostat according to the preset energized potential value to simulate different cathodic protection levels; wherein, the sliding rheostat is the sliding rheostat of the circuit where the sample is located in different layers.

[0061] To achieve quantitative control, in some embodiments, before adjusting the sliding rheostat according to a preset energizing potential value to simulate different cathodic protection levels, the method further includes: testing the self-corrosion potential value of different layers of the sample, and determining the preset energizing potential value of the different layers of the sample based on the cathodic polarization value of the different layers of the sample and the self-corrosion potential value.

[0062] Specifically, the self-corrosion potential of different layers of samples is first tested, and then the required energizing potential value is calculated based on the cathodic polarization value of different samples. The calculation formula is: energizing potential = self-corrosion potential - cathodic polarization value.

[0063] In order to test the protection potential of the sample by a reference electrode, in some embodiments, adjusting the sliding rheostat according to the obtained desired energized potential value to simulate different cathodic protection levels includes: starting a potentiostat, sequentially bringing the tip of the reference electrode close to the surface of different layers of the sample, and obtaining the energized potential values ​​of the different layers of the sample displayed on the control panel of the potentiostat; adjusting the sliding rheostat according to the obtained energized potential values ​​of the different layers of the sample until the energized potential value displayed on the control panel is close to the preset energized potential value, so as to simulate different cathodic protection levels of the different layers of the sample.

[0064] Specifically, after calculating the required energizing potential value using the cathodic polarization values ​​of different samples, the potentiostat is activated via the control panel. The tip of the reference electrode is brought close to, but not in contact with, the surface of the first sample layer. The energizing potential value displayed on the control panel is read, and then the sliding rheostat connected to the first sample layer is adjusted until the energizing potential value displayed on the control panel is close to the required value. The test is then performed by bringing the tip of the reference electrode close to the surface of the second sample layer. The energizing potential value displayed on the control panel at this point is the energizing potential of the second sample layer. Similarly, the sliding rheostat connected to the second sample layer is adjusted until the energizing potential value displayed on the control panel is close to the required value. The same method is used to adjust the energizing potential of other sample layers. The energizing potential of each layer is then fine-tuned again using the above operating procedure until the energizing potential of each layer matches the required value.

[0065] S6. Observe the surface condition of the sample.

[0066] In some embodiments, after observing the surface state of the sample, the method includes: adjusting the position of the reference electrode inside the test chamber during the observation of the surface state of the sample, and testing the energized potential values ​​of different layers of the sample; if the measured energized potential value deviates from the preset energized potential value, then the sliding rheostat of the circuit containing the sample in different layers is adjusted until the energized potential values ​​of the sample in different layers are stable.

[0067] Specifically, after the test begins, the surface condition of the sample can be observed. During the process, the protection potential of different sample layers is tested by adjusting the position of the reference electrode. If the protection potential values ​​of different sample layers deviate from the design value, they are adjusted in step S4 until the protection potential stabilizes. The protection potential can be the energized potential value of each sample layer, and the design value can be a preset energized potential value. It is understood that after the test, the needle valve at the bottom of the test chamber can be opened to drain the seawater through the drain port, and the sample can be removed.

[0068] In summary, the accelerated corrosion simulation test device and method in marine environments provided by the embodiments of the present invention have a simple structure, strong operability, and can simulate complex and diverse environments. Through this device and method, long-term corrosion behavior under different coating protection levels and different cathodic protection levels in complex marine environments can be experimentally evaluated using low-cost, short-cycle, and multi-factor laboratory simulation technology. It can comprehensively and objectively simulate corrosion environments under different protection conditions, thereby evaluating and predicting the corrosion of metal structures under different protection conditions.

[0069] It is understood that the description in the specification is kept as concise and clear as possible while maintaining clarity and transparency. Different embodiments of the present invention are consistent with the spirit of the invention, but differ in their focus. The solutions and their effects can be referred to each other, and some related content will not be repeated here.

[0070] It should be noted that in this document, the terms "upper," "lower," etc., indicating orientation or positional relationship, are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly, for example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising a..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. This will be understood by those skilled in the art through the specific circumstances.

[0071] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An accelerated corrosion simulation test device in a marine environment, characterized in that, include: The test chamber and the potentiostat are provided; inside the test chamber, there are multiple sample racks, auxiliary anodes and reference electrodes; wherein, the auxiliary anodes and the reference electrodes are connected to the potentiostat via wires, and the samples on the multiple sample racks are connected to the sliding rheostat and the potentiostat via cathode current-carrying cables; The sample was used to simulate different damage rates of the metal substrate and its surface coatings. The sliding rheostat is used to adjust the circuit resistance of the circuit in which the sample is located in different layers, thereby adjusting the cathodic protection current of different circuits and simulating different cathodic protection levels. The auxiliary anode is used to introduce cathodic protection current into the simulated seawater solution; The reference electrode is used to test the energizing potential of the sample in different layers; The potentiostat is used to display and adjust output parameters; the output parameters include the energized potential of the sample. The device further includes: a constant temperature water bath, an oxygen cylinder, and a corrosion environment parameter testing tube; the test chamber is located inside the constant temperature water bath; the test chamber is equipped with an air inlet pipe and an air outlet; wherein, the air inlet pipe is connected to the oxygen cylinder; and the corrosion environment parameter testing tube communicates with the interior of the test chamber. The oxygen cylinder is used to maintain the dissolved oxygen content required for the accelerated corrosion test through the air inlet duct. The air outlet is used to slowly add a preset solution to the simulated seawater solution to adjust the pH value required for the corrosion acceleration test. The constant temperature water bath is used to provide the test chamber with the constant temperature required for the accelerated corrosion test. The corrosion environment parameter test tube is used to test dissolved oxygen content, pH value and temperature.

2. The accelerated corrosion simulation test device in a marine environment according to claim 1, characterized in that, Each layer of the multi-layer sample holder includes multiple sample slots, and each sample slot contains a voltage-conducting sheet. The voltage-conducting sheet is used to connect the samples in the same layer in series and serve as a cathode protection cathode circuit.

3. The accelerated corrosion simulation test device in a marine environment according to claim 1, characterized in that, The potentiostat includes a positive terminal, a negative terminal, a reference electrode terminal, a zero-position negative terminal, and a control panel. The auxiliary anode and the reference electrode are connected to the potentiostat via wires, and the samples on the multilayer sample holder are connected to the sliding rheostat and the potentiostat via cathode current-carrying cables, including: The auxiliary anode is connected to the positive terminal via a wire, the reference electrode is connected to the reference electrode terminal via a reference electrode wire, and the samples of different layers on the multi-layer sample holder are connected to the sliding rheostat, the negative terminal, and the zero-position cathode terminal via cathode current-carrying cables. The display and adjustment of output parameters include: The output parameters can be displayed and adjusted through the control panel.

4. The accelerated corrosion simulation test device in a marine environment according to claim 3, characterized in that, The samples on different layers of the multi-layer sample holder are connected to the sliding rheostat, the negative terminal, and the zero-position cathode terminal via cathode current-carrying cables, including: Each layer of the multi-layer sample holder has a cathode current-carrying cable led out. Each cathode current-carrying cable is connected in series with a sliding rheostat and then combined into one cable and connected to the negative terminal to return the cathode protection current to the negative terminal of the potentiostat.

5. The accelerated corrosion simulation test apparatus in a marine environment according to claim 1, characterized in that, The constant temperature water bath includes a heating element and a first temperature sensor; Providing the test chamber with the constant temperature required for the test includes: The heating element and the first temperature sensor provide the test chamber with the constant temperature required for the test.

6. The accelerated corrosion simulation test apparatus in a marine environment according to claim 1, characterized in that, The corrosion environment parameter testing tube includes a first test port, a second test port, and a third test port; the tests for dissolved oxygen content, pH value, and temperature include: The first test port is equipped with a dissolved oxygen sensor to test the dissolved oxygen content; the second test port is equipped with a pH sensor to test the pH value; and the third test port is equipped with a second temperature sensor to test the temperature.

7. The accelerated corrosion simulation test apparatus in a marine environment according to claim 1, characterized in that, The dissolved oxygen content required for the accelerated corrosion test maintained through the air inlet duct includes: The oxygen cylinder is introduced into the simulated seawater solution through the air inlet duct and the pressure reducing valve to maintain the dissolved oxygen content required for the accelerated corrosion test. The pressure reducing valve is located between the air inlet duct and the oxygen cylinder.

8. A method for simulating accelerated corrosion in a marine environment, applied to the accelerated corrosion simulation test apparatus in a marine environment as described in any one of claims 1 to 7, characterized in that, Including the following steps: Different coatings were applied to the exposed surface of the sample, and defects were created to simulate different coating protection conditions; The sample is placed on a multi-layer sample holder, and the multi-layer sample holder is placed inside the test chamber; Pour the prepared seawater simulation solution into the test chamber; The preset parameters of the simulated seawater solution are controlled and monitored; wherein the preset parameters include temperature, dissolved oxygen content, and pH value. The sliding rheostat is adjusted according to the preset energizing potential value to simulate different cathodic protection levels; wherein, the sliding rheostat is the sliding rheostat of the circuit in which the sample is located in different layers; Observe the surface condition of the sample.

9. The accelerated corrosion simulation test method in a marine environment according to claim 8, characterized in that, The step of placing the sample on the multi-layer sample holder and placing the multi-layer sample holder inside the test chamber includes: The samples are placed one by one into the sample slots of the multi-layer sample holder, so that the samples are in good contact with the conductive plates in the sample slots, and the multi-layer sample holder is placed layer by layer into the test chamber.

10. The accelerated corrosion simulation test method in a marine environment according to claim 8, characterized in that, Before adjusting the sliding rheostat according to a preset energized potential value to simulate different cathodic protection levels, the method further includes: The self-corrosion potential values ​​of the samples with different layers are tested, and the preset energizing potential values ​​of the samples with different layers are determined based on the cathodic polarization values ​​and the self-corrosion potential values ​​of the samples with different layers.

11. The accelerated corrosion simulation test method in a marine environment according to claim 8, characterized in that, The step of adjusting the sliding rheostat according to a preset energized potential value to simulate different cathodic protection levels includes: Start the potentiostat and bring the tip of the reference electrode close to the surface of the sample of different layers in turn to obtain the energized potential values ​​of the sample of different layers displayed on the control panel of the potentiostat. Adjust the sliding rheostat according to the obtained energizing potential values ​​of the samples with different layers until the energizing potential value displayed on the control panel is consistent with the preset energizing potential value, so as to simulate the different cathodic protection levels of the samples with different layers.

12. The accelerated corrosion simulation test method in a marine environment according to claim 8, characterized in that, The preset parameters for controlling and monitoring the simulated seawater solution include: The first temperature of the constant temperature water bath is monitored by the first temperature sensor in the constant temperature water bath. The second temperature of the simulated seawater solution is monitored by a second temperature sensor in the corrosion environment parameter test tube. Adjust the value of the first temperature according to the second temperature to control the temperature of the seawater simulation solution.

13. The accelerated corrosion simulation test method in a marine environment according to claim 12, characterized in that, The preset parameters for controlling and monitoring the simulated seawater solution also include: After the second temperature stabilizes, the pH value of the simulated seawater solution is monitored by a pH sensor installed in the corrosion environment parameter test tube. If the measured pH value is higher than the preset requirement value, the first preset solution is slowly added dropwise to the seawater simulation solution through the air outlet inside the test chamber until the measured pH value is consistent with the preset requirement value. If the measured pH value is lower than the preset requirement value, a second preset solution is slowly added dropwise to the seawater simulation solution through the air outlet inside the test chamber until the measured pH value matches the preset requirement value.

14. The accelerated corrosion simulation test method in a marine environment according to claim 12, characterized in that, The preset parameters for controlling and monitoring the simulated seawater solution also include: After the second temperature stabilizes, the dissolved oxygen content of the simulated seawater solution is monitored by a dissolved oxygen sensor installed in the corrosion environment parameter test tube. Open the air outlet and pressure reducing valve inside the test chamber to continuously introduce oxygen into the simulated seawater solution, and control the dissolved oxygen content by adjusting the pressure reducing valve.

15. The accelerated corrosion simulation test method in a marine environment according to claim 8, characterized in that, After observing the surface condition of the sample, the method includes: During the observation of the surface condition of the sample, the position of the reference electrode inside the test chamber is adjusted, and the energizing potential values ​​of different layers of the sample are tested. If the measured energized potential value deviates from the preset energized potential value, the sliding rheostats of the circuits containing the samples in different layers are adjusted until the energized potential values ​​of the samples in different layers stabilize.

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