A buried pipeline stray current anode transient interference corrosion monitoring device and testing method

Abstract

The present invention discloses a buried pipeline stray current anode transient interference corrosion monitoring device and a testing method, relating to the technical field of stray current interference corrosion monitoring. The device comprises an experimental box, an experimental medium, a transient interference system and an interference testing system. The transient interference system comprises a constant potential instrument, a switching controller, a metal electrode bundle, an auxiliary electrode group and a reference electrode. The output value and output cycle of the constant potential instrument are adjusted to simulate the interference intensity and interference frequency of cathodic protection and stray current. The buried pipeline stray current anode transient interference corrosion monitoring device and the testing method of the present invention utilize a metal electrode bundle to realize the monitoring and evaluation function of the transient corrosion effect of the anode transient interference on the pipeline. The current distribution on the surface of each metal electrode is scanned by program control to characterize the local corrosion characteristics of the pipeline. The method is more comprehensive and systematic than traditional testing methods, and the data obtained is more valuable for reference.

Description

Technical Field

[0001] The invention relates to the technical field of stray current interference corrosion monitoring, in particular to a buried pipeline stray current anode transient interference corrosion monitoring device and a testing method. Background Art

[0002] Stray current transient interference refers to transient interference signals such as surge voltage, ringing voltage, and spark discharges that occur on power transmission and transformation lines. These signals are characterized by extremely short durations but high voltage amplitudes and transient energy. This type of anodic transient interference immediately creates a localized area of ​​high anodic current on the pipeline surface, causing localized anodic dissolution of the pipeline substrate. This localized anodic current exacerbates localized metal corrosion on the pipeline surface. This high-current anodic transient interference poses significant risks to pipeline operational safety.

[0003] The most direct way to evaluate the corrosion impact of stray current is to measure the magnitude and duration of the current flowing into the pipeline. However, direct measurement of stray current is more complicated. Generally, the indirect parameter method of stray current is used to reflect the magnitude of stray current, thereby evaluating the degree of corrosion impact on metal pipelines.

[0004] Traditional test strip methods or electrochemical methods can only obtain the average corrosion rate of the pipeline, but cannot monitor and evaluate the instantaneous corrosion effect of anodic transient interference on the pipeline. In view of the limitations of existing stray current monitoring methods and the lack of monitoring methods for buried pipeline stray current anodic transient interference corrosion, a systematic evaluation of the anodic transient interference corrosion of buried pipeline stray current is urgently needed to invent a buried pipeline stray current anodic transient interference corrosion monitoring device and testing method. Summary of the Invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a buried pipeline stray current anode transient interference corrosion monitoring device and testing method.

[0006] To achieve the above-mentioned purpose, the present invention is implemented through the following technical solutions:

[0007] A buried pipeline stray current anode transient interference corrosion monitoring device, consisting of an experimental box, an experimental medium, a transient interference system and an interference test system;

[0008] The experimental box is a rectangular box with an opening on the upper cover, and the experimental medium is soil or a soil simulation solution; the upper cover of the experimental box prevents the evaporation of water in the experimental medium and affects the medium resistivity;

[0009] The transient interference system consists of a potentiostat, a switching controller, a metal electrode bundle, an auxiliary electrode group, and a reference electrode. The interference intensity and frequency of cathodic protection and stray current are simulated by adjusting the output value and output cycle of the potentiostat. The metal electrode bundle uses 100 metal electrodes arranged in a 10×10 pattern, and the metal electrodes are made of the same material as the buried pipeline under study. The metal electrodes are sealed with insulating sealing material, and the gap between adjacent electrodes is 0.1 to 0.2 mm. One end of the metal electrode bundle is connected to the metal electrode bundle wire, and the other end is exposed in the experimental medium as a working surface. The 100 metal electrodes have the same shape and size.

[0010] The metal electrodes are divided into two groups. Any one of (5, 5), (5, 6), (6, 5), and (6, 6) in the 10×10 arrangement (i.e., any one close to the center of the metal electrode bundle) is an independent group, and the remaining 99 electrodes are a working electrode group. The metal electrodes of the independent group are connected to the WE1 port of the switching controller, and the electrodes of the working electrode group are connected to the WE end of the potentiostat via the WE2 port of the switching controller. The switching frequency of the 99 electrodes is controlled by a built-in program of the switching controller to be switched once every 1 to 2 seconds. The reference electrode is connected to the RE end of the potentiostat, and the auxiliary electrode group is connected to the CE end of the potentiostat.

[0011] The reference electrode is a saturated calomel electrode or a saturated copper sulfate electrode; the auxiliary electrode group is a titanium mesh;

[0012] The experimental medium is added with appropriate ions according to the test requirements to simulate the actual corrosion environment.

[0013] The interference test system consists of a metal electrode bundle, a metal electrode bundle wire, a switching controller and a zero-resistance ammeter. The two ends of the zero-resistance ammeter are respectively connected to the WE1 and WE2 ends of the switching controller, and are used to measure the current feedback signal of each electrode in the electrode bundle under anode transient interference.

[0014] Preferably, the experimental medium is selectively added with appropriate salt ions such as Cl-, HCO3-, CO3 2- etc. to simulate the actual soil corrosion environment.

[0015] Preferably, the local corrosion rate of the electrode under anode transient interference is calculated by using Faraday's law through current density;

[0016] The corrosion rate indicates the extent of metal corrosion per unit time. The mass of metal lost per unit area at any time and the current density passing through the corrosion cell at that time follow Faraday's law. If the corrosion rate is expressed as the number of moles of metal dissolved per unit area per unit time, then according to Faraday's law:

[0017]

[0018] Where: v—corrosion rate, mol / m 2 s; ΔW—weight loss, g; i—current density, A / m 2 ; n—number of electrons gained or lost (valence); F—Faraday constant, 96500C / mol; M—metal atomic weight, g / mol; S—corrosion area, m 2 ; t—power-on time, s.

[0019] Preferably, the metal electrode is in the shape of a cuboid with dimensions of 1-2 mm×1-2 mm×40-60 mm, preferably 2 mm×2 mm×50 mm.

[0020] The present invention also includes using the above-mentioned buried pipeline stray current anode transient interference corrosion monitoring device for buried pipeline stray current anode transient interference corrosion monitoring, including the following steps:

[0021] ① After welding the test wires at one end of 100 metal electrodes, arrange them in a 10×10 pattern and fix them in the mold. Seal them with epoxy insulation material to form a metal electrode bundle. After sealing, polish the working surface of the metal electrode bundle and set aside.

[0022] ② Lay about 4 to 6 cm of experimental medium in the experimental box, place the metal electrode bundle horizontally on the experimental medium on one side of the experimental box, with the working surface facing the inside of the experimental box, and then place the auxiliary electrode group parallel to the working surface of the metal electrode bundle at the other end of the experimental box. Insert the titanium mesh into the soil, making sure the bottom of the titanium mesh does not touch the bottom of the experimental box; then bury the reference electrode, with the tip of the reference electrode as close as possible to the center of the metal electrode bundle, but not touching it; the above operations ensure that the center of the metal electrode bundle, the center of the auxiliary electrode group, and the tip of the reference electrode are at the same height;

[0023] ③ Continue to add experimental medium until the metal electrode bundle is completely covered. During the addition of the experimental medium, compact it as much as possible to avoid the formation of voids.

[0024] ④ Wiring: Connect the CE end of the potentiostat to the auxiliary electrode group, the RE end to the reference electrode, and the WE end to the WE2 port of the switching controller; connect the WE1 end of the switching controller to the metal electrode in the center of the metal electrode bundle, and connect the WE2 end to the other 99 metal electrodes in the metal electrode bundle; connect the two ends of the zero-resistance ammeter to the WE1 and WE2 ends of the switching controller respectively;

[0025] ⑤ Turn on the potentiostat to provide -1.05V cathodic protection for the metal electrode bundle, which should be stable for at least 24 hours. At this time, turn on the zero resistance potentiometer and only detect the cathodic current, indicating that the metal electrode bundle is in the cathodic protection state. If no cathodic protection current is detected, end the experiment and check the connection for any abnormalities.

[0026] ⑥After 24 hours, the output of the potentiostat can be adjusted according to the test requirements to apply an anode transient interference signal to the metal electrode bundle. Each time the interference signal is adjusted, the zero-resistance ammeter can observe the initial anode current peak accompanying this potential change, that is, the anode transient feedback current of each metal electrode can be accurately measured.

[0027] ⑦ The cathode or anode current is determined by the positive or negative feedback current, and the corrosion conditions of different parts of the pipeline are further determined. Origin drawing software is used to display the current distribution on the electrode surface in three dimensions to identify the corrosion characteristics of the pipeline under the transient interference of stray current anode.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] The present invention discloses a buried pipeline stray current anodic transient interference corrosion monitoring device and testing method, which are used for buried pipeline stray current anodic transient interference corrosion testing. The device utilizes a metal electrode bundle to monitor and evaluate the transient corrosion effects of anodic transient interference on the pipeline. By program-controlled scanning of the current distribution on the surface of each metal electrode, the local corrosion characteristics of the pipeline can be characterized. This method is more comprehensive and systematic than traditional testing methods, and the data obtained is more valuable for reference.

[0030] The buried pipeline stray current anodic transient interference corrosion monitoring device and testing method of the present invention, targeting the dynamic characteristics of stray current interference, adopts a metal electrode bundle to measure the current feedback signal of each metal electrode under stray current anodic transient interference, characterizes the local corrosion characteristics of the electrode surface, and further, can use Faraday's law to calculate the local corrosion rate of the electrode under anodic transient interference through current density, and quantify the dynamic stray current anodic transient interference corrosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a structural diagram of a buried pipeline stray current anode transient interference corrosion monitoring device;

[0032] Figure 2 A top view of the structure of a buried pipeline stray current anode transient interference corrosion monitoring device;

[0033] Figure 3 Schematic diagram of the working surface of the metal electrode bundle;

[0034] Figure 4 Schematic diagram of the auxiliary electrode group structure;

[0035] Figure 5Schematic diagram of the electrode surface current under different anode transient interferences, where the horizontal axis represents the interference duration and the vertical axis represents the metal electrode test current; A is the electrode surface current diagram under 1000mV anode transient interference, B is the electrode surface current diagram under 800mV anode transient interference, and C is the electrode surface current diagram under 500mV anode transient interference;

[0036] Figure numerals: 1. Experimental box; 2. Experimental medium; 3. Metal electrode bundle; 4. Metal electrode bundle wire; 5. Switching controller; 6. Zero resistance ammeter; 7. Constant potential instrument; 8. Auxiliary electrode group; 9. Reference electrode; 10. Metal electrode; 11. Insulating sealing material. DETAILED DESCRIPTION

[0037] The purpose of the present invention is to provide a buried pipeline stray current anode transient interference corrosion monitoring device and testing method. The present invention is further described below in conjunction with specific embodiments.

[0038] Example 1

[0039] A buried pipeline stray current anode transient interference corrosion monitoring device, such as Figure 1 and Figure 2 As shown, it consists of an experimental box 1, an experimental medium 2, a transient interference system and an interference test system;

[0040] The experimental box 1 is a rectangular box with an opening on the upper cover, and the experimental medium 2 is soil or a soil simulation solution; the upper cover of the experimental box 1 prevents the evaporation of water in the experimental medium and affects the medium resistivity;

[0041] The transient interference system is composed of a constant potential instrument 7, a switching controller 5, a metal electrode bundle 3, an auxiliary electrode group 8 and a reference electrode 9; by adjusting the output value and output cycle of the constant potential instrument 7, the interference intensity and interference frequency of the cathodic protection and stray current are simulated; Figure 3 As shown, the metal electrode bundle 3 uses 100 metal electrodes 10 arranged in a 10×10 pattern. The metal electrodes are made of the same material as the buried pipeline under investigation. The metal electrodes 10 are sealed with an insulating sealant 11, and the gap between adjacent electrodes is 0.1 to 0.2 mm. One end of the metal electrode bundle 3 is connected to the metal electrode bundle wire 4, and the other end is exposed in the experimental medium as a working surface. The 100 metal electrodes 10 have the same shape and size.

[0042] like Figure 3 As shown, the metal electrodes 10 are divided into two groups. Any one of (5, 5), (5, 6), (6, 5), (6, 6) in the 10×10 arrangement (i.e., any one close to the center of the metal electrode bundle) is an independent group ( Figure 3The remaining 99 electrodes are working electrode groups. The metal electrodes of the independent groups are connected to the WE1 port of the switching controller 5. The electrodes of the working electrode group are connected to the WE end of the constant potential instrument 7 through the WE2 port of the switching controller 5. The switching controller 5 has a built-in program to control the switching frequency of the 99 electrodes to be switched once every 1 to 2 seconds. The reference electrode 9 is connected to the RE end of the constant potential instrument 7, and the auxiliary electrode group 8 is connected to the CE end of the constant potential instrument 7.

[0043] The reference electrode 9 is a saturated calomel electrode or a saturated copper sulfate electrode; the auxiliary electrode group 8 is a titanium mesh, such as four titanium meshes connected together, such as Figure 4 As shown;

[0044] The total area of ​​the titanium mesh of the auxiliary electrode group must be no less than the working area of ​​the metal electrode bundle. The distance between the two titanium meshes is 1-1.5 times the width of a single titanium mesh. The number of titanium meshes can be calculated based on the required area and width. This shape design can make the auxiliary electrode working area relatively more dispersed, and a more uniform and stable current can be obtained between the metal electrode bundle and the auxiliary electrode group in the experimental box.

[0045] The experimental medium is added with appropriate ions according to the test requirements, such as Cl - 、HCO3 - 、CO3 2- etc., to simulate the actual corrosion environment;

[0046] The interference test system consists of a metal electrode bundle 3, a metal electrode bundle wire 4, a switching controller 5 and a zero-resistance ammeter 6. The two ends of the zero-resistance ammeter 6 are respectively connected to the WE1 end and the WE2 end of the switching controller 5, and are used to measure the current feedback signal of each electrode in the electrode bundle under anode transient interference;

[0047] Furthermore, Faraday's law was used to calculate the local corrosion rate of the electrode under anode transient interference through current density.

[0048] The corrosion rate indicates the extent of metal corrosion per unit time. The mass of metal lost per unit area at any time and the current density passing through the corrosion cell at that time follow Faraday's law. If the corrosion rate is expressed as the number of moles of metal dissolved per unit area per unit time, then according to Faraday's law:

[0049]

[0050] Where: v—corrosion rate, mol / m 2 s; ΔW—weight loss, g; i—current density, A / m 2 ; n—number of electrons gained or lost (valence); F—Faraday constant, 96500C / mol; M—metal atomic weight, g / mol; S—corrosion area, m2 ; t—power-on time, s.

[0051] Example 2

[0052] A buried pipeline stray current anode transient interference corrosion monitoring device according to Example 1 is used for buried pipeline stray current anode transient interference corrosion monitoring. Experimental medium 2 uses field soil. The test process includes:

[0053] ① After welding the test wires at one end of 100 metal electrodes 10, arrange them in a 10×10 pattern and fix them in a mold. Seal them with epoxy insulation material to form a metal electrode bundle 3. After sealing, polish the working surface of the metal electrode bundle 3 and set aside.

[0054] ② Lay about 4 to 6 cm of experimental medium 2 in the experimental box 1, place the metal electrode bundle 3 horizontally on the experimental medium 2 on one side of the experimental box 1, with the working surface facing the inside of the experimental box 1, and then place the auxiliary electrode group 8 at the other end of the experimental box 1 parallel to the working surface of the metal electrode bundle 3. Insert the titanium mesh into the soil, with the bottom of the titanium mesh 1-2 cm away from the bottom of the experimental box; then bury the reference electrode 9, with the tip of the reference electrode 9 as close as possible to the center of the metal electrode bundle 3, but not touching it; the above operations ensure that the center of the metal electrode bundle 3, the center of the auxiliary electrode group 8, and the tip of the reference electrode 9 are at the same height;

[0055] ③ Then continue to add experimental medium 2 until the metal electrode bundle 3 is completely covered. During the addition process, the experimental medium 2 should be compacted as much as possible to avoid the formation of voids;

[0056] ④ Wiring: The CE end of the potentiostat 7 is connected to the auxiliary electrode group 8, the RE end is connected to the reference electrode 9, and the WE end is connected to the WE2 port of the switching controller 5; the WE1 end of the switching controller 5 is connected to the metal electrode in the center of the metal electrode bundle 3, and the WE2 end is connected to the other 99 metal electrodes of the metal electrode bundle 3; the two ends of the zero-resistance ammeter 6 are connected to the WE1 and WE2 ends of the switching controller 5 respectively;

[0057] ⑤ Turn on the potentiostat 7 to provide -1.05V cathodic protection for the metal electrode bundle 3, which remains stable for at least 24 hours. At this time, turn on the zero resistance potentiometer 6. If only cathodic current is detected, it means that the metal electrode bundle 3 is in the cathodic protection state. If no cathodic protection current is detected, end the experiment and check whether there is any abnormality in the connection.

[0058] ⑥ After 24 hours, the output of the constant potentiostat 7 can be adjusted according to the test requirements to apply the anode transient interference signal to the metal electrode bundle 3; each time the interference signal is adjusted, the zero resistance ammeter 6 can observe the initial anode current peak accompanying this potential change, that is, the anode transient feedback current of each metal electrode can be accurately measured;

[0059] ⑦ The cathode or anode current can be judged by the positive or negative feedback current, and the corrosion conditions of different parts of the pipeline can be further judged. Origin drawing software can be used to display the current distribution on the electrode surface in three dimensions to identify the corrosion characteristics of the pipeline under the transient interference of stray current anode.

[0060] Furthermore, the corrosion rate of the pipeline is calculated using the current density using Faraday's law.

[0061] The corrosion rate indicates the extent of metal corrosion per unit time. The mass of metal lost per unit area at any time and the current density passing through the corrosion cell at that time follow Faraday's law. If the corrosion rate is expressed as the number of moles of metal dissolved per unit area per unit time, then according to Faraday's law:

[0062]

[0063] Where: v—corrosion rate, mol / m 2 s; ΔW—weight loss, g; i—current density, A / m 2 ; n—number of electrons gained or lost (valence); F—Faraday constant, 96500C / mol; M—metal atomic weight, g / mol; S—corrosion area, m 2 ; t—power-on time, s.

[0064] The size of the metal electrode ranges from 1 to 2 mm × 1 to 2 mm × 40 to 60 mm, with the preferred size being 2 mm × 2 mm × 50 mm; the material is 20#, Q345, X65, X80, etc., and the working area is 1 to 4 mm 2 .

[0065] Figure 5 This is the electrode surface current under different anode transient interferences obtained using the above-mentioned device and test process, where the horizontal axis represents the interference duration and the vertical axis represents the metal electrode test current. It can be seen that with the increase of the anode transient interference, the current density measured by the metal electrode increases accordingly, and the greater the interference, the earlier the peak current on the electrode surface appears.

Claims

1. A buried pipeline stray current anode transient interference corrosion monitoring device, comprising an experimental box (1), an experimental medium (2), a transient interference system and an interference test system; characterized in that: The experimental box (1) is a rectangular box with an opening on the upper cover, and the experimental medium (2) is soil or a soil simulation solution; the upper cover of the experimental box (1) prevents the evaporation of water in the experimental medium and affects the medium resistivity; The transient interference system is composed of a constant potential instrument (7), a switching controller (5), a metal electrode bundle (3), an auxiliary electrode group (8) and a reference electrode (9); the interference intensity and interference frequency of cathodic protection and stray current are simulated by adjusting the output value and output cycle of the constant potential instrument (7); the metal electrode bundle (3) uses 100 metal electrodes (10) arranged in a 10×10 pattern, and the metal electrodes are made of the same material as the buried pipeline under study; the metal electrodes (10) are sealed with an insulating sealing material (11), and the gap between adjacent electrodes is 0.1 to 0.2 mm. One end of the metal electrode bundle (3) is connected to the metal electrode bundle wire (4), and the other end is exposed in the experimental medium as a working surface. The 100 metal electrodes (10) are all of the same shape and size; The metal electrodes (10) are divided into two groups. Any one of (5, 5), (5, 6), (6, 5), and (6, 6) in the 10×10 arrangement is an independent group, and the remaining 99 electrodes are working electrode groups. The metal electrodes of the independent group are connected to the WE1 port of the switching controller (5), and the electrodes of the working electrode group are connected to the WE end of the constant potential instrument (7) through the WE2 port of the switching controller (5). The switching controller (5) has a built-in program that controls the switching frequency of the 99 electrodes to be switched once every 1 to 2 seconds. The reference electrode (9) is connected to the RE end of the constant potential instrument (7), and the auxiliary electrode group (8) is connected to the CE end of the constant potential instrument (7). The reference electrode (9) is a saturated calomel electrode or a saturated copper sulfate electrode; the auxiliary electrode group (8) is a titanium mesh; The interference test system comprises a metal electrode bundle (3), a metal electrode bundle wire (4), a switching controller (5) and a zero-resistance ammeter (6), wherein two ends of the zero-resistance ammeter (6) are respectively connected to the WE1 end and the WE2 end of the switching controller (5), and is used to measure the current feedback signal of each electrode in the electrode bundle under anode transient interference.

2. The buried pipeline stray current anode transient interference corrosion monitoring device according to claim 1 is characterized by: Appropriate ions are added to the experimental medium according to test requirements to simulate the actual corrosion environment.

3. The buried pipeline stray current anode transient interference corrosion monitoring device according to claim 1 is characterized by: The local corrosion rate of the electrode under anode transient interference is calculated by using Faraday's law and current density; The corrosion rate indicates the extent of metal corrosion per unit time. The mass of metal lost per unit area at any time and the current density passing through the corrosion cell at that time obey Faraday's law. If the corrosion rate is expressed as the number of moles of metal dissolved per unit area per unit time, then according to Faraday's law: Where: v—corrosion rate, mol / m 2 s; ΔW—weight loss, g; i—current density, A / m 2 ; n—number of electrons gained or lost; F—Faraday constant, 96500C / mol; M—metal atomic weight, g / mol; S—corrosion area, m 2 ; t—power-on time, s.

4. The buried pipeline stray current anode transient interference corrosion monitoring device according to claim 1 is characterized by: The metal electrode (10) is in the shape of a rectangular parallelepiped, with a size of 1-2 mm×1-2 mm×40-60 mm.

5. A method for monitoring buried pipeline anode transient interference corrosion using the buried pipeline stray current anode transient interference corrosion monitoring device according to claim 1, characterized in that: The following steps are involved: ① After welding the test wires at one end of 100 metal electrodes (10), they are arranged in a 10×10 pattern and fixed in a mold, and sealed with epoxy insulating sealant to form a metal electrode bundle (3). After the sealing is completed, the working surface of the metal electrode bundle (3) is polished and set aside; ② Lay an experimental medium (2) of about 4 to 6 cm in thickness in the experimental box (1), place the metal electrode bundle (3) horizontally on the experimental medium (2) on one side of the experimental box (1), with the working surface facing the inside of the experimental box (1), and then place the auxiliary electrode group (8) parallel to the working surface of the metal electrode bundle (3) at the other end of the experimental box (1), and insert the titanium mesh into the soil; then bury the reference electrode (9), with the tip of the reference electrode (9) as close as possible to the center point of the metal electrode bundle (3), but not touching it; the above operations make the center point of the metal electrode bundle (3), the center point of the auxiliary electrode group (8) and the tip of the reference electrode (9) at the same height; ③ Then continue to add the experimental medium (2) until the metal electrode bundle (3) is completely covered. The experimental medium (2) should be compacted as much as possible during the addition process to avoid the formation of voids; ④ Wiring: The CE end of the potentiostat (7) is connected to the auxiliary electrode group (8), the RE end is connected to the reference electrode (9), and the WE end is connected to the WE2 port of the switching controller (5); the WE1 end of the switching controller (5) is connected to a metal electrode in the center of the metal electrode bundle (3), and the WE2 end is connected to the other 99 metal electrodes of the metal electrode bundle (3); The two ends of the zero resistance ammeter (6) are respectively connected to the WE1 end and the WE2 end of the switching controller (5); ⑤ Turn on the constant potential instrument (7) to provide -1.05V cathodic protection for the metal electrode bundle (3) and keep it stable for at least 24 hours; at this time, turn on the zero resistance potentiometer (6) and only detect the cathode current, indicating that the metal electrode bundle (3) is in the cathodic protection state; if no cathodic protection current is detected, end the experiment and check whether there is any abnormality in the connection; ⑥ After 24 hours, the output of the constant potential instrument (7) is adjusted according to the test requirements to apply an anode transient interference signal to the metal electrode bundle (3); each time the interference signal is adjusted, the zero resistance ammeter (6) can observe the initial anode current peak value accompanying this potential change, that is, the anode transient feedback current of each metal electrode can be accurately measured; ⑦ The cathode or anode current is judged by the positive or negative feedback current, and the corrosion conditions of different parts of the pipeline are further judged; the current distribution on the electrode surface is displayed in three dimensions using mapping software to identify the corrosion characteristics of the pipeline under the transient interference of stray current anode.

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