Galvanic corrosion test system for simulating high-temperature steam-water environment

Abstract

The invention discloses a galvanic corrosion test system for simulating a high-temperature steam-water environment. The galvanic corrosion test system comprises an experiment barrel, a dissolved oxygen monitoring unit and a temperature, pH and conductivity monitoring unit, a barrel cover is mounted at the top of the experiment barrel, a working electrode clamp is mounted in the experiment barrel, a working electrode groove is formed in the working electrode clamp, a working electrode is mounted in the working electrode groove, and a galvanic corrosion reaction is carried out in the experiment barrel; the dissolved oxygen monitoring unit comprises an oxygen conveying pipe connected to the experiment barrel, and oxygen is input into the experiment barrel through the oxygen conveying pipe, so that the dissolved oxygen amount of the electrolyte is increased; the device further comprises a dissolved oxygen monitor, the electrolyte in the experiment barrel is input into the dissolved oxygen monitor to monitor the dissolved oxygen amount in real time, and the electrolyte in the dissolved oxygen monitor is monitored and then flows back into the experiment barrel. The temperature, pH and conductivity monitoring unit comprises a temperature sensing electrode, a pH sensing electrode and a conductivity sensing electrode which are connected to the experiment barrel and are respectively used for monitoring the temperature value, the pH value and the conductivity value of the electrolyte.

Description

Technical Field

[0001] The invention belongs to the technical field of friction equipment, and in particular relates to a galvanic corrosion test system simulating a high-temperature steam-water environment. Background Art

[0002] In high-temperature environments such as the petroleum, chemical, and aerospace industries, different metal materials are often used in the same equipment and exposed to the same corrosive media. Galvanic corrosion occurs when a potential difference exists between the two metals. This causes the metal with the more negative potential (the anode) to corrode faster in the corrosive medium, while the metal with the more positive potential (the cathode) corrodes more slowly. This difference in corrosion rates can accelerate equipment damage. In high-temperature environments, the corrosion process accelerates, especially in complex corrosive media, where the effects of galvanic corrosion are more pronounced. To mitigate the effects of galvanic corrosion, it is necessary to study its principles and effects.

[0003] Currently, there are some high-temperature and high-pressure galvanic corrosion testing systems, but these systems generally suffer from insufficient design flexibility, limited functionality, and difficulty meeting the growing demand for corrosion testing. Existing systems are generally only capable of temperature regulation and are unable to effectively monitor and quantitatively control other factors in the corrosive medium. For example, most systems are unable to monitor or adjust important corrosion environment parameters such as the solution's pH value, conductivity, and dissolved oxygen concentration in real time, resulting in an inability to fully assess the impact of galvanic corrosion on materials. At the same time, existing equipment generally lacks precise control and monitoring of the dissolved oxygen environment, making it difficult to provide galvanic corrosion test data under different dissolved oxygen conditions, thereby affecting the accuracy and repeatability of the test. Summary of the Invention

[0004] In response to the shortcomings of existing high-temperature galvanic corrosion testing equipment, in order to effectively evaluate the galvanic corrosion performance between two metal materials in a high-temperature environment, the present invention provides a galvanic corrosion test system that simulates a high-temperature steam-water environment. The system can perform more comprehensive measurement and evaluation of the galvanic corrosion behavior of different metal material combinations under simulated real corrosive media and high-temperature conditions.

[0005] To this end, the present invention adopts the following technical solutions: A galvanic corrosion test system simulating a high-temperature steam-water environment includes a test barrel, a dissolved oxygen monitoring unit, and a temperature, pH, and conductivity monitoring unit; A barrel cover is installed on the top of the experimental barrel, a working electrode fixture is installed in the experimental barrel, the working electrode fixture contains a working electrode slot, the working electrode slot is installed in the working electrode, and the galvanic corrosion reaction is carried out in the experimental barrel; The dissolved oxygen monitoring unit includes an oxygen delivery pipe connected to the experimental bucket, through which oxygen is input into the experimental bucket to increase the dissolved oxygen content of the electrolyte; it also includes a dissolved oxygen monitor. The electrolyte in the experimental bucket is input into the dissolved oxygen monitor to monitor the dissolved oxygen content in real time, and the electrolyte in the dissolved oxygen monitor flows back into the experimental bucket after monitoring; The temperature pH conductivity monitoring unit includes a temperature sensing electrode, a pH sensing electrode, and a conductivity sensing electrode connected to the experimental bucket, which are respectively used to monitor the temperature value, pH value, and conductivity value of the electrolyte.

[0006] Further, a pair of working electrode fixtures made of PEEK are provided in the experimental bucket. Each working electrode fixture contains a working electrode groove. The sample spacing is adjusted by placing a partition between the two working electrodes, and the working electrode fixture is tightened by screws.

[0007] Further, the inner surface of the working electrode is in contact with and electrically connected to a copper conductive column embedded at the bottom of the working electrode groove. A spring is sleeved on the outer periphery of the copper conductive column to keep the copper conductive column in close contact with the inner surface of the working electrode. The bottom of the copper conductive column is connected to the working electrode lead wire to the outside of the experimental bucket through a set screw.

[0008] Further, the working electrode fixture is fixed to the lid of the experimental bucket through studs. A working electrode lead wire fixing frame is provided at the top of the lid. The working electrode lead wire is connected to the external traction wire of the working electrode in a spot welding form at the fixing frame.

[0009] Further, the experimental bucket is made of high borosilicate glass, and a heating unit and a heat preservation sleeve are arranged outside the barrel body of the experimental bucket.

[0010] Further, the temperature pH conductivity monitoring unit also includes a temperature display, a pH display, and a conductivity display, which are respectively used to display the monitored values.

[0011] Further, an oxygen removal unit is also included. An air inlet and an air outlet are provided at the top of the lid. The oxygen removal unit is connected to the air inlet and the air outlet, and the oxygen removal unit passes gas into the experimental bucket to discharge the oxygen in the experimental bucket. (Not only removing the oxygen in the bucket, but also greatly reducing the oxygen content in the solution, thereby creating an anaerobic or hypoxic environment)<The beneficial effects of the present invention are as follows: 1. This system is equipped with a pH value and conductivity detection unit, which can monitor and control the state of the corrosion environment in real time, ensuring accurate galvanic corrosion tests under different corrosion conditions. By real-time monitoring of these key parameters, the system can more accurately evaluate the influence of the corrosion medium on the galvanic corrosion process between metals, improving the reliability and accuracy of the test.

[0012] 2. The system is equipped with an external deoxygenation unit and a dissolved oxygen monitoring unit, which can achieve high-precision detection of dissolved oxygen concentration (±1 ppb) and conduct galvanic corrosion tests under different dissolved oxygen environments. This function enables the system to simulate variable corrosion environments, accurately analyze the influence of dissolved oxygen concentration changes on the galvanic corrosion rate, and provide more detailed and comprehensive data support for corrosion research in high-temperature and high-pressure environments.

[0013] 3. The system has a flexible galvanic corrosion test sample fixture that supports simultaneous testing of two samples and can ensure the electrochemical corrosion test of a single sample. This design improves the flexibility of the test, can meet diverse experimental requirements, and ensures efficient experiments under different samples and different corrosion environments.

[0014] 4. The system overcomes many deficiencies of existing high-temperature galvanic corrosion test equipment in design, has a variety of real-time monitoring and control functions, can comprehensively and accurately evaluate galvanic corrosion behavior under high temperature and complex corrosion environments, meets the diverse needs of modern corrosion tests, and provides a scientific basis for the selection of metal materials and the design of equipment in high-temperature corrosion media. Brief Description of the Drawings

[0015] Figure 1 is a schematic structural diagram of the test system of the present invention; Figure 2 is a front view of the structure of the test system of the present invention; Figure 3 is a top view of the structure of the test system of the present invention; Figure 4 is a schematic diagram of the transmission of the experimental system of the present invention; Figure 5 is a galvanic current test curve at 50 °C, 75 °C, and 100 °C in the specific embodiment of the present invention; In the figure: 1 - experimental bucket, 2 - bucket cover, 3 - temperature pH conductivity monitoring unit, 4 - ventilation unit, 5 - dissolved oxygen monitoring unit, 6 - experimental bucket wall, 7 - strip heating unit, 8 - galvanic test unit, 9 - working electrode fixture, 10 - working electrode groove, 11 - partition board, 12 - hexagon socket set screw, 13 - copper conductive column, 14 - spring, 15 - set screw, 16 - working electrode lead, 17 - wire fixing bracket, 18 - temperature sensor, 19 - pH electrode, 20 - conductivity electrode, 21 - air inlet, 22 - air outlet, 23 - water return port, 24 - water outlet, 25 - reference electrode, 26 - auxiliary electrode, 27 - temperature value display, 28 - pH value display, 29 - conductivity value display, 30 - dissolved oxygen detection unit display. Specific Embodiment

[0016] The present invention will be further described below in conjunction with the drawings and specific embodiments: As Figure 1 and 2 shown, a galvanic corrosion test system includes an experimental bucket 1, a bucket cover 2, a temperature pH conductivity monitoring unit 3 and a dissolved oxygen monitoring unit 5.

[0017] The experimental bucket 1 is made of high borosilicate glass, and is provided with a strip-shaped heating unit 7 and a heat preservation sleeve on the outer wall, which can not only ensure the uniform heating of the bucket body but also provide safety guarantee. Inside the bucket, there is a pair of working electrode jigs 9 made of PEEK material. Each working electrode jig 9 contains a working electrode groove 10. The distance between the two working electrodes is adjusted by placing a partition 11, and the working electrode jig is tightened by a hexagon socket set screw 12.

[0018] As Figure 3 shown, the inner surface of the working electrode contacts and is electrically connected to the copper conductive column 13 embedded at the bottom of the working electrode groove. A spring 14 is sleeved on the outer periphery of the copper conductive column 13, and the copper conductive column 13 is kept in close contact with the inner surface of the working electrode through the spring 14. The bottom of the copper conductive column is connected to the working electrode lead 16 through a set screw 15 to the outside of the bucket cover 2. The working electrode jig 9 is fixed to the bucket cover 2 through a stud. A wire fixing bracket 17 for the working electrode lead 16 is provided at the top of the bucket cover 2. The working electrode lead 16 is connected to the external traction wire of the working electrode in a spot welding form at the wire fixing bracket 17, and can be freely connected to the electrochemical workstation.

[0019] As Figure 4 shown, the top of the bucket cover 2 is provided with interfaces for a temperature sensing electrode 18, a pH electrode 19, and a conductivity electrode 20, and is connected to the monitoring unit 3 through wires. The front of the monitoring unit is respectively equipped with a temperature display 27, a pH value display 28, and a conductivity value display 29, which can realize the real-time monitoring of the corrosion environment status. The top of the bucket cover 2 is provided with an air inlet 21 and an air outlet 22, and through-hole switch valves are tightly connected at the interfaces. The lower part of the switch valve of the air inlet 21 extends into the bucket, and the upper part is connected to the ventilation unit 4, which can realize the required deaeration operation; the switch valve of the air outlet 22 is tightly connected to the interface to ensure the smooth progress of gas circulation and deaeration operation. The top of the bucket cover 2 is provided with a water return port 23 and a water outlet 24; the interface of the water return port 23 is equipped with a through-hole rotary switch valve that is tightly connected. The lower part extends into the bucket, and the upper part is connected to the water outlet 24 of the dissolved oxygen monitoring unit 5; the joint of the water outlet 24 is equipped with a through-hole rotary switch valve that is tightly connected. The upper part is connected to the water inlet of the dissolved oxygen monitoring unit 5, and the two together realize the circulation of the solution in the bucket; the front of the dissolved oxygen monitoring unit 5 is equipped with a dissolved oxygen value display 30, which can realize the accurate real-time monitoring of the dissolved oxygen content in the solution. The reference electrode 25, the auxiliary electrode 26 and the working electrode form a complete three-electrode system, and are correspondingly connected to the electrochemical workstation to meet the corresponding test requirements.

[0020] This device is used in conjunction with an external deoxygenation unit, which consists of a pure nitrogen gas tank and its supporting equipment. By introducing nitrogen gas into the experimental bucket for one hour, an anaerobic environment for the test solution can be achieved. The specific experimental operation process is as follows: 1. Specimen and electrode installation Place two different test specimens in two working electrode slots respectively, and separate the two working electrode specimens with partition 11. By using partitions of different thicknesses, the influence law of the galvanic couple distance on galvanic corrosion can be studied. Subsequently, insert the reference electrode 25 and the auxiliary electrode 26 into the corresponding positions of the bucket lid 2 respectively. After pouring the solution into the bucket body, quickly cover the bucket lid 2 and tighten the screw connecting the bucket lid 2 and the bucket body to ensure the tightness inside the bucket.

[0021] The test specimen acts as the working electrode and is placed in the working electrode slot 10 of the working electrode fixture 9. It is externally connected to the working electrode port of the electrochemical workstation through the copper conductive column 13 and the working electrode lead 16.

[0022] 2. Deoxygenation operation Connect the ventilation unit 4 to the air inlet 21, and at the same time open the valve switches of the air inlet 21 and the air outlet 22, and introduce pure nitrogen gas for a duration of one hour to complete the deoxygenation operation and ensure that the experimental environment reaches an anaerobic state.

[0023] 3. Test preparation and start After the deoxygenation operation is completed, immediately close the switch valves of the air inlet 21 and the air outlet 22. Connect the electrochemical electrode wires to the auxiliary electrode 26, the reference electrode 25, and the working electrode Ⅰ correspondingly, and connect the GND wire to the working electrode Ⅱ. Then, turn on the temperature control unit and set the target temperature. When the temperature inside the bucket body is stable at the target temperature ±0.1°C, start the VersaStudio software to carry out the galvanic corrosion test work.

[0024] The test data of the galvanic current at 50°C, 75°C, and 100°C are as Figure 5 shown.

Claims

1. An electric couple corrosion test system for simulating a high-temperature steam-water environment, characterized in that, It includes an experimental bucket, a dissolved oxygen monitoring unit, and a temperature pH conductivity monitoring unit; A bucket cover is installed on the top of the experimental bucket. A working electrode fixture is installed inside the experimental bucket. The working electrode fixture contains a working electrode groove, and a working electrode is installed in the working electrode groove. The galvanic corrosion reaction is carried out inside the experimental bucket; The dissolved oxygen monitoring unit includes an oxygen inlet pipe connected to the experimental bucket. Oxygen is input into the experimental bucket through the oxygen inlet pipe to increase the dissolved oxygen content of the electrolyte. It also includes a dissolved oxygen monitor. The electrolyte inside the experimental bucket is input into the dissolved oxygen monitor to monitor the dissolved oxygen content in real time. The electrolyte in the dissolved oxygen monitor flows back into the experimental bucket after monitoring; The temperature pH conductivity monitoring unit includes a temperature sensing electrode, a pH sensing electrode, and a conductivity sensing electrode connected to the experimental bucket, which are used to monitor the temperature value, pH value, and conductivity value of the electrolyte respectively.

2. The galvanic corrosion test system for simulating a high-temperature steam-water environment according to claim 1, wherein A pair of working electrode fixtures made of PEEK are provided inside the experimental bucket. Each working electrode fixture contains a working electrode groove. The sample spacing is adjusted by placing a partition between the two working electrodes, and the working electrode fixture is tightened with screws.

3. The galvanic corrosion test system for simulating a high-temperature steam water environment according to claim 2, wherein The inner surface of the working electrode is in contact with and electrically connected to a copper conductive post embedded at the bottom of the working electrode groove. A spring is sleeved on the outer periphery of the copper conductive post to keep the copper conductive post in close contact with the inner surface of the working electrode. The bottom of the copper conductive post is connected to the working electrode lead to the outside of the experimental bucket through a set screw.

4. The galvanic corrosion test system for simulating a high-temperature steam water environment according to claim 3, wherein The working electrode fixture is fixed to the bucket cover of the experimental bucket through studs. A working electrode lead fixing bracket is provided on the top of the bucket cover. The working electrode lead is connected to the external traction wire of the working electrode in a spot welding form at the fixing bracket.

5. The galvanic corrosion test system for simulating a high-temperature steam water environment according to claim 1, wherein, The experimental bucket is made of high borosilicate glass, and a heating unit and a heat preservation sleeve are arranged outside the barrel body of the experimental bucket.

6. The galvanic corrosion test system for simulating a high-temperature steam water environment according to claim 1, wherein, The temperature pH conductivity monitoring unit also includes a temperature display, a pH display, and a conductivity display, which are used to display the monitored values respectively.

7. The galvanic corrosion test system for simulating a high-temperature steam water environment according to claim 1, characterized in that It also includes a deoxygenation unit. An air inlet and an air outlet are provided on the top of the bucket cover. The deoxygenation unit is connected to the air inlet and the air outlet. The deoxygenation unit introduces gas into the experimental bucket to discharge the oxygen in the experimental bucket.

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