A detachable array electrode electrochemical experimental system and its testing method

Abstract

The invention relates to the technical field of electrochemical behavior testing of under-scale corrosion, and in particular to a detachable array electrode electrochemical experimental system and a testing method thereof. The system comprises an array electrode corrosion monitoring system, one end of which is connected to an array electrode system for under-scale corrosion, and the other end is connected to an electrochemical workstation; the detachable array electrode system for under-scale corrosion comprises: an electrode fixing bushing, an array electrode, an under-scale corrosion packaging mold, an electrode base and a metal baffle installed at the bottom of the electrode base; the invention realizes the detachability of the array electrode by setting a metal spring inside a motor base, and limits the array electrode in combination with the under-scale corrosion packaging mold, thereby realizing the replacement of a single electrode and the characterization of the morphology after corrosion, which greatly improves the work efficiency while ensuring the microscopic morphology characterization of the metal under the scale layer, and is helpful for in-depth analysis of the under-scale corrosion mechanism under the action of different external environmental factors.

Description

Technical Field

[0001] The invention belongs to the research field of electrochemical behavior testing of metal wellbore pipe column under-scale corrosion, and specifically relates to a detachable array electrode electrochemical experimental system and a testing method thereof. Background Art

[0002] With the increase in my country's oil and gas production, safety problems caused by metal pipeline corrosion failure are becoming more frequent. Among them, local corrosion failure of wellbore pipes caused by under-scaling corrosion is the most serious. During the water injection development of oil fields, the fluid produced by oil wells has a complex composition and will carry solid particles such as mud and sand in the geological reservoir to the low-flow area of ​​the gathering and transportation pipeline. On the other hand, CO 2 Carbonic acid dissolved in water will dissolve a large amount of Ca 2+ Mg 2+ Mineral ions such as metal mineral cations commonly found in formation water and CO 2 The carbonate ions produced by dissolving in water react to form CaCO 3 MgCO 3 etc., and form deposited scale layers on the inner wall of the pipeline. These irregular scale layers will cover the inner wall of the pipeline, causing serious scaling in the oilfield production and gathering and transportation systems. These sediments become a diffusion barrier between the produced fluid and the inner pipe wall, thereby changing the local pH value, the distribution of ferrous ions and the concentration of corrosive substances in the scale layer area, making the electrochemical behavior of the carbon steel under the scale and the exposed carbon steel form a large difference, ultimately leading to the heterogeneity of the water chemical environment. In severe cases, it will cause corrosion perforation of the carbon steel pipeline under the sediment, resulting in huge economic losses and energy waste.

[0003] Existing laboratory studies on under-scale corrosion behavior are mostly conducted by combining macroscopic electrochemical testing technology with submicroscopic microelectrode array testing technology. The microelectrode array can not only reflect the changes in corrosion current density and potential distribution of independent array electrodes, but also be coupled to present the electrochemical corrosion behavior of the entire area when the external environment changes. Microelectrode array testing technology can better characterize the corrosion electrochemical information of the scale layer and its surrounding areas based on changes in the external environment in real time. However, the existing under-scale corrosion experimental equipment cannot realize the morphological analysis test of the substrate surface after corrosion, the thickness of the scale layer is difficult to adjust, and the preparation of the under-scale corrosion array electrode is cumbersome, and a single electrode cannot be replaced if it is damaged. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned under-deposition corrosion experimental device and provide a detachable array electrode electrochemical experimental system and a testing method thereof.

[0005] The technical solution of the present invention is as follows:

[0006] A detachable array electrode electrochemical experimental system can be used for under-scale corrosion experiments under different environmental parameters. The array electrode metal sheet electrochemical experimental system includes an array electrode metal sheet system for under-scale corrosion, an array electrode metal sheet corrosion monitoring system, and an electrochemical workstation. One end of the array electrode metal sheet corrosion monitoring system is connected to the array electrode metal sheet system for under-scale corrosion, and the other end is connected to the electrochemical workstation. The array electrode metal sheet system for under-scale corrosion consists of a number of detachable array electrode metal sheets, a reference electrode, and a counter electrode.

[0007] The detachable array electrode metal sheet system for under-deposit corrosion comprises: an electrode fixing bushing, an array electrode metal sheet, an under-deposit corrosion packaging mold, an electrode base and a metal baffle installed at the bottom of the electrode base.

[0008] Preferably, the under-scale corrosion encapsulation mold is connected to the electrode fixing bushing by threads. The under-scale corrosion encapsulation mold is used to encapsulate the deposited scale on the one hand, and to limit the movement of the array electrode metal sheet on the other hand. At the same time, the thickness of the deposited scale is adjusted based on the change in the number of threads. A threaded installation port is reserved above the electrode base, which is also connected to the electrode fixing bushing by threads.

[0009] Preferably, the electrode base contains a spring, one end of the spring is in close contact with the array electrode metal sheet, and the other end is connected to the metal baffle, and a rubber ring is provided between the metal baffle and the electrode base. The under-scale corrosion encapsulation mold is used to limit the array electrode metal sheet, and the array electrode metal sheet is used to bear the applied deposited scale. Silicone rubber is encapsulated on the outside of the spring, and epoxy resin is filled between the silicone rubber and the electrode base to ensure the wear resistance of the spring during the expansion and contraction process while achieving insulation. A wire groove is provided at the bottom of the metal baffle and the electrode base, and a copper wire is provided inside the spring. The outside of the wire is coated with a fluororubber tube to prevent the electrode from short-circuiting.

[0010] Preferably, after the experiment of the detachable array electrode metal sheet system for under-deposit corrosion is completed, the under-deposit corrosion packaging mold is removed, and the array electrode metal sheet can be ejected by the built-in spring for easy disassembly, so as to facilitate the microscopic corrosion morphology characterization of the metal under-deposit corrosion in the later stage.

[0011] Preferably, according to the order set by the electrode sheet installation plug-in board, the array electrode metal sheets are arranged in the horizontal direction in sequence, the reference electrode metal sheets are located on the left and right sides of the array electrode metal sheets, and the counter electrode metal sheets are distributed on the upper and lower sides of the array electrode metal sheets; the copper wires are welded to the electrode sheets at the bottom of each electrode by a welding gun to ensure connectivity, and epoxy resin is poured to ensure insulation from each other. According to specific experimental requirements, the reference electrode metal sheet can be selected from solid silver / silver chloride electrodes, pure zinc sheets, etc., and the counter electrode metal sheet can be selected from platinum sheets, silver sheets, etc.

[0012] A test method for a detachable array electrode electrochemical experimental system is specifically applied to the above-mentioned detachable array electrode electrochemical experimental system. The specific test method is as follows:

[0013] Step 1: Use wire cutting technology to cut the metal to be studied into several 10 mm × 3 mm × 3 mm rectangular working electrode sheets, cut the reference electrode metal material into 10 mm × 5 mm × 5 mm reference electrode metal sheets, and cut the counter electrode metal material into 30 mm × 2 mm × 3 mm counter electrode metal sheets. Use acetone to remove the surface oil film and ultrasonically clean it in ethanol.

[0014] Step 2: Use a welding gun to spot-weld the copper wire to the array electrode metal sheet, the reference electrode metal sheet, and the counter electrode metal sheet for electrical signal export; and use a multimeter to test whether they are conductive.

[0015] Step 3: Place the welded array electrode metal sheets into the electrode sheet installation plug-in board in a predetermined order, and lead one end of the wire out of the mold to facilitate the collection of electrical signals. The working electrode sheet is embedded in the electrode fixing bushing, which is fixed to the electrode base through a thread, so that the spring is in a compressed state; the array electrode metal sheet is limited by the under-scaling corrosion packaging mold above.

[0016] Step 4: Prepare the scale layer type based on the experimental needs and deposit it in the under-scale corrosion encapsulation mold, adjust the depth of the under-scale corrosion encapsulation mold screwed into the electrode fixing bushing, and immerse it in the test solution for testing.

[0017] Step 5: The corrosion electrochemical behavior of the array electrode metal sheet system for under-deposition corrosion was characterized using the NI-PXI microelectrode array corrosion electrochemical test system developed based on Labview. The test system contains a fast matrix conversion switch and a digital multimeter with potential and current protection functions to obtain the distribution information of the coupled corrosion current density and corrosion potential. Before the coupled corrosion current density and potential test, the copper wires at the lower ends of all metal sheets were coupled to the aviation plug connector until a stable open circuit potential (OCP) was obtained. For current measurement, a fast matrix conversion switch was used to separate each electrode to be measured from the other electrode arrays, and all other electrode arrays were short-circuited together. Then, the corrosion current between each electrode and the array electrode metal sheet was obtained in turn. During the corrosion potential measurement, the coupled array electrode metal sheets were temporarily disconnected from each other, and the corrosion potential of each array electrode metal sheet based on the reference electrode was obtained based on the fast matrix conversion switch.

[0018] Step 6: After the experiment, clean the deposited scale on the surface of the array electrode metal sheet and remove the packaging mold corroded under the scale, separate the aviation plug connector, pop out the array electrode metal sheet through the spring, use manual pliers to remove the solder joints between the copper wire and the metal sheet, and then take out the array electrode metal sheet.

[0019] Step 7: Rinse the removed array electrode metal sheet with deionized water and anhydrous ethanol, and dry it for subsequent characterization of the corrosion morphology and pitting depth of the metal sheet surface.

[0020] The beneficial effects of the present invention are:

[0021] (1) The array electrode is detachable. The array electrode is detachable by setting a metal spring inside the motor base. The array electrode is limited by the under-scale corrosion packaging mold, so that the replacement of a single working electrode and the characterization of the morphology after corrosion can be realized. This greatly improves the work efficiency while ensuring the microscopic morphology of the metal under the scale layer, which helps to deeply analyze the under-scale corrosion mechanism under different external environmental factors.

[0022] (2) The thickness of the scale layer can be adjusted. The existence of the under-scale corrosion encapsulation mold can, on the one hand, limit the ejection of the working electrode, and on the other hand, the thickness of the scale layer can be adjusted based on the design of the under-scale corrosion encapsulation mold and the threaded connection between it and the motor fixed bushing.

[0023] (3) Modular characterization of array electrodes. Due to the difference in sediment scale type and coverage area, there will be large differences in electrochemical corrosion between the metal under the scale layer and the metal at the edge of the scale layer. By setting the working electrode modularly in the electrode mounting plug, it is possible to perform independent electrochemical tests on the metal under the scale layer or the metal at the edge of the scale layer, and at the same time, the metal under the scale layer / the metal at the edge of the scale layer can be coupled as an independent whole, and the macroscopic electrochemical testing technology (EIS, potentiodynamic polarization, etc.) can be used to study the kinetics and mechanism of corrosion electrochemical reactions.

[0024] The present invention can effectively combine external variables such as scale layer type and scale layer thickness with electrochemical testing.

[0025] Based on the experimental conditions, a detachable array electrode electrochemical experimental system and test method for metal under-scale corrosion monitoring can realize under-scale corrosion experiments under different environmental parameters (dissolved oxygen content, temperature, flow rate, pH, etc.). At the same time, external variables such as scale layer type and scale layer thickness can be effectively combined with microelectrode array corrosion electrochemical testing, which is helpful to accurately and real-time characterize the electrochemical information of the scale layer area and provide technical support for the study of under-scale corrosion behavior of metal pipelines. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a schematic diagram of the connection of the detachable array electrode electrochemical experimental system;

[0028] Figure 2 It is a schematic diagram of the cross-sectional structure of a detachable array electrode for under-scale corrosion;

[0029] Figure 3 A top view of a detachable array electrode system for under-scale corrosion;

[0030] Figure 4 It is a three-dimensional effect diagram and a cross-sectional schematic diagram of the electrode fixing bushing and the under-scale corrosion packaging mold;

[0031] Figure 5 It is a three-dimensional rendering and a cross-sectional schematic diagram of the electrode base.

[0032] The reference numerals in the figure are as follows: 1. electrode fixing bushing; 2. array electrode metal sheet; 3. epoxy resin; 4. electrode base; 5. deposited scale; 6. silicone rubber; 7. spring; 8. rubber ring; 9. threaded mounting port; 10. copper wire; 11. wire groove; 12. metal baffle; 13. fluororubber hose; 14. under-scale corrosion packaging mold; 15. counter electrode metal sheet; 16. reference electrode metal sheet; 17. electrode sheet mounting plug-in board; 18. aviation plug connector; 19. fast matrix conversion switch; 20. digital multimeter. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0034] See attached Figure 1 The present invention mentions a detachable array electrode electrochemical experimental system, and its technical solution is: the detachable array electrode electrochemical experimental system includes an array electrode system for under-scale corrosion, an array electrode corrosion monitoring system and an electrochemical workstation.

[0035] Among them, one end of the array electrode corrosion monitoring system is connected to the array electrode system for under-scale corrosion, and the other end is connected to the electrochemical workstation; the array electrode system for under-scale corrosion is composed of several detachable array electrodes, reference electrodes and counter electrodes.

[0036] See attached Figure 2The detachable array electrode system for under-scale corrosion comprises: an electrode fixing bushing 1, an array electrode metal sheet 2, an under-scale corrosion encapsulation mold 14, an electrode base 4 and a metal baffle 12. The under-scale corrosion encapsulation mold 14 is used to encapsulate the deposited scale 5 on the one hand, and to limit the movement of the array electrode metal sheet 2 on the other hand. At the same time, the thickness of the deposited scale 5 is adjusted based on the change in the number of threads. A threaded mounting port 9 is reserved above the electrode base 4, and is also connected to the electrode fixing bushing 1 by a thread. A spring 7 is provided inside the electrode base 4, one end of the spring 7 is tightly attached to the array electrode metal sheet 2, and the other end is connected to the metal baffle 12, and a rubber ring 8 is provided between the metal baffle 12 and the electrode base 4. Silicone rubber 6 is encapsulated on the outside of the spring 7, and epoxy resin 3 is filled between the silicone rubber 6 and the electrode base 4 to ensure the wear resistance of the spring 7 during the expansion and contraction process while ensuring insulation. A wire groove 11 is provided at the bottom of the metal baffle 12 and the electrode base 4, and a copper wire 10 is provided inside the spring 7, and the copper wire 10 is coated with a fluorine rubber tube 13 on the outside to prevent the electrode from short-circuiting.

[0037] After the experiment of the detachable array electrode system for under-deposition corrosion is completed, the under-deposition corrosion encapsulation mold 14 is rotated counterclockwise in the top view direction to achieve dismantling, thereby removing the position restriction of the array electrode metal sheet 2. The specific effect is as follows Figure 4 and Figure 5 shown.

[0038] The array electrode metal sheet 2 can be ejected by the internal spring 7 for easy disassembly, so as to facilitate the microscopic corrosion morphology characterization and composition analysis of the array electrode metal sheet 2 by means of SEM, EDS and XRD.

[0039] See attached Figure 3 , according to the order set by the electrode sheet installation plug-in board 17, the array electrode metal sheets 2 are arranged in the horizontal direction in sequence, the reference electrode metal sheets 16 are respectively located on the left and right sides of the array electrode metal sheets 2, and the counter electrode metal sheets 15 are distributed on the front and back sides of the array electrode metal sheets 2; the copper wire 10 is welded to the array electrode metal sheet 2, the counter electrode metal sheet 15, and the reference electrode metal sheet 16 at the bottom of each electrode by a welding gun to ensure connectivity, and is insulated from each other by pouring epoxy resin 3. According to specific experimental requirements, the reference electrode metal sheet 16 can be selected from solid silver / silver chloride electrodes, pure zinc sheets, etc., and the counter electrode metal sheet 15 can be selected from platinum sheets, silver sheets, etc.

[0040] The present invention provides a detachable array electrode electrochemical experimental system, and its experimental operation steps include the following steps based on different research variables:

[0041] Specific test example 1:

[0042] Different scale types (CaCO 3 、FeCO 3, sand, sulfate-reducing bacteria (SRB), CaCO 3 + FeCO 3 、CaCO 3 +FeCO 3 +SRB and CaCO 3 + FeCO 3 +SRB +Grit) was used as an example of research variable.

[0043] The testing method of the detachable array electrode electrochemical experimental system for monitoring metal corrosion under scale described in the present invention is as follows:

[0044] Step 1: Use wire-cutting electrospark technology to cut the metal to be studied into several 10 mm × 3 mm × 3 mm rectangular array electrode metal sheets 2, cut the reference electrode metal material into 10 mm × 5 mm × 5 mm reference electrode metal sheets 16, and cut the counter electrode metal material into 30 mm × 2 mm × 3 mm counter electrode metal sheets 15, remove the surface oil film with acetone, and perform ultrasonic cleaning in ethanol.

[0045] Step 2: Use a welding gun to connect the copper wire 10 with the array electrode metal sheet 2, the reference electrode metal sheet 16, and the counter electrode metal sheet 15 for deriving electrical signals; and use a multimeter to test whether they are conductive.

[0046] Step 3: Place the welded array electrodes into the electrode sheet installation plug-in board 17 in a predetermined order, and lead one end of the wire out of the mold to facilitate the collection of electrical signals. The array electrode metal sheet 2 is embedded in the electrode fixing bushing 1, and the electrode fixing bushing 1 is connected to the electrode base through a thread, so that the spring 7 is in a compressed state; the array electrode metal sheet 2 is limited by the under-scaling corrosion packaging mold 14 above.

[0047] Step 4: Based on experimental needs, purchase CaCO from Sinopharm Group 3 、FeCO 3 SRB can be cultivated by itself, and the diameter of the gravel can be selected between 250μm and 425μm; the mixed scale layer can be configured according to the established proportion of the experiment, and CaCO 3 、FeCO 3 and gravel are dissolved in the test solution and stirred into a slurry state, and the prepared different types of deposited scale 5 are covered in the under-scale corrosion encapsulation mold 14, and the depth of the under-scale corrosion encapsulation mold 14 screwed into the electrode fixing bushing 1 is adjusted and immersed in the test solution for testing.

[0048] Step 5: The corrosion electrochemical behavior of the array electrode system for under-deposition corrosion is characterized using the NI-PXI microelectrode array corrosion electrochemical test system developed based on Labview. The test system includes a fast matrix conversion switch 19 and a digital multimeter 20 with potential and current protection functions to obtain submicroscopic distribution information of coupled corrosion current density and corrosion potential. Before conducting coupled corrosion current density and potential tests, all copper wires 10 at the lower end of the metal sheet are coupled to the aviation plug connector 18 until a stable open circuit potential (OCP) is obtained.

[0049] For current measurement, a fast matrix switch 19 is used to separate each electrode to be measured from other array electrodes, and other electrode arrays are short-circuited and coupled together.

[0050] Then, the corrosion current between each electrode and the array electrode is obtained in turn using a digital multimeter 20. During the corrosion potential measurement process, the coupled array electrodes are temporarily disconnected from each other, and the corrosion potential of each array electrode metal sheet 2 based on the reference electrode is obtained based on the fast matrix switching switch 19.

[0051] Step 6: After the experiment, clean the deposited scale 5 on the surface of the array electrode metal sheet and remove the packaging mold 14 corroded under the scale, separate the aviation plug connector 18, pop out the array electrode metal sheet 2 through the spring 7, use manual pliers to remove the solder joints between the copper wire 10 and the array electrode metal sheet 2, and then take out the array electrode metal sheet 2.

[0052] Step 7: Rinse the removed array electrode metal sheet 2 with deionized water and anhydrous ethanol, and dry it to prepare for subsequent morphological characterization and component analysis of the metal sheet surface corrosion morphology, pitting depth, etc.

[0053] Specific test example 2:

[0054] Take temperature, pH and dissolved oxygen content as research variables for example.

[0055] The present application also provides a test method for a detachable array electrode electrochemical experimental system, and the specific test method is as follows:

[0056] Step 1: Use wire-cutting electrospark technology to cut the metal to be studied into several 10 mm × 3 mm × 3 mm rectangular array electrode metal sheets 2, cut the reference electrode metal material into 10 mm × 5 mm × 5 mm reference electrode metal sheets 16, and cut the counter electrode metal material into 30 mm × 2 mm × 3 mm counter electrode metal sheets 15, remove the surface oil film with acetone, and perform ultrasonic cleaning in ethanol.

[0057] Step 2: Use a welding gun to spot-weld the copper wire 10 to the array electrode metal sheet 2, the reference electrode metal sheet 16, and the counter electrode metal sheet 15 for electrical signal extraction; and use a multimeter to test whether they are conductive.

[0058] Step 3: Place the welded array electrodes into the electrode sheet installation plug-in board 17 in a predetermined order, and lead one end of the wire out of the mold to facilitate the collection of electrical signals. The array electrode metal sheet 2 is embedded in the electrode fixing bushing 1, and the electrode fixing bushing 1 is connected to the electrode base through a thread, so that the spring 7 is in a compressed state; the array electrode metal sheet 2 is limited by the under-scaling corrosion packaging mold 14 above.

[0059] Step 4: Based on the experimental needs, the scale layer can be configured according to the established proportion of the experiment; by adding CaCO 3 / FeCO 3 / and gravel are dissolved in the test solution and stirred into a slurry state, and the prepared different types of deposited scale 5 are covered in the under-scale corrosion packaging mold 14, and the depth of the under-scale corrosion packaging mold 14 screwed into the electrode fixing bushing 1 is adjusted to perform the under-scale corrosion test.

[0060] Step 5: Based on the setting of experimental variables, the temperature of the solution to be tested is controlled by adjusting the temperature of the water bath. The test temperature range of the detachable array electrode electrochemical experimental system for monitoring corrosion under metal scale described in the present invention is 10~80℃. By setting a closed system for the array electrode system to be tested, based on N 2 :O 2 / CO 2 :O 2 Different volume ratios can be used to adjust the dissolved oxygen content. Different medium components of the solution to be tested can be used to adjust the pH of the solution.

[0061] Step 6: The corrosion electrochemical behavior of the array electrode system for under-deposition corrosion is characterized using the NI-PXI microelectrode array corrosion electrochemical test system developed based on Labview. The test system includes a fast matrix conversion switch 19 and a digital multimeter 20 with potential and current protection functions to obtain submicroscopic distribution information of coupled corrosion current density and corrosion potential. Before conducting coupled corrosion current density and potential tests, all copper wires 10 at the lower end of the metal sheet are coupled to the aviation plug connector 18 until a stable open circuit potential (OCP) is obtained.

[0062] For current measurement, a fast matrix switch 19 is used to separate each electrode to be measured from other array electrodes, and other electrode arrays are short-circuited and coupled together.

[0063] Then, the corrosion current between each electrode and the array electrode is obtained in sequence using the digital multimeter 20 .

[0064] During the corrosion potential measurement process, the coupled array electrodes are temporarily disconnected from each other, and the corrosion potential of each array electrode metal sheet 2 based on the reference electrode is obtained based on the fast matrix conversion switch 19.

[0065] Step 7: After the experiment, clean the deposited scale 5 on the surface of the array electrode metal sheet and remove the packaging mold 14 corroded under the scale, separate the aviation plug connector 18, pop out the array electrode metal sheet 2 through the spring 7, use manual pliers to remove the solder joints between the copper wire 10 and the array electrode metal sheet 2, and then take out the array electrode metal sheet 2.

[0066] Step 8: Rinse the taken-out array electrode metal sheet 2 with deionized water and anhydrous ethanol, and dry it for subsequent morphological characterization and component analysis of the metal sheet surface corrosion morphology, pitting depth, etc.

[0067] The present invention can effectively combine external variables such as scale layer type and scale layer thickness with electrochemical testing;

[0068] Based on the experimental conditions, a detachable array electrode electrochemical experimental system and its testing method in the present application can realize under-scale corrosion experiments under different environmental parameters (dissolved oxygen content, temperature, flow rate, pH, etc.), and can effectively combine external variables such as scale layer type and scale layer thickness with microelectrode array corrosion electrochemical testing, which helps to accurately and real-time characterize the electrochemical information of the scale layer area and provide technical support for the study of under-scale corrosion behavior of metal pipelines.

[0069] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention (including the claims) is limited to these examples. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0070] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A test method for a detachable array electrode electrochemical experimental system, comprising a detachable array electrode electrochemical experimental system, wherein the test method is applied in the experimental system, and is characterized in that: The detachable array electrode electrochemical experimental system comprises a detachable array electrode system for under-scale corrosion, an array electrode corrosion monitoring system and an electrochemical workstation; one end of the array electrode corrosion monitoring system is connected to the array electrode system for under-scale corrosion, and the other end is connected to the electrochemical workstation; The detachable array electrode system for under-scale corrosion comprises: an electrode fixing bushing (1), an array electrode metal sheet (2), an under-scale corrosion packaging mold (14), an electrode base (4), and a metal baffle (12) installed at the bottom of the electrode base (4); The under-scale corrosion encapsulation mold (14) is connected to the electrode fixing bushing (1) by means of threads; a threaded mounting opening (9) is reserved above the electrode base (4), and the electrode base (4) is also connected to the electrode fixing bushing (1) by means of threads; a spring (7) is arranged inside the electrode base (4), the upper end of the spring (7) is in close contact with the array electrode metal sheet (2), and the lower end is connected to the metal baffle (12); the array electrode metal sheet (2) is pressed against the lower side of the under-scale corrosion encapsulation mold (14) by means of the spring (7); The under-scale corrosion encapsulation mold (14) is used, on the one hand, to limit the movement of the array electrode metal sheet (2), and on the other hand, to encapsulate the deposited scale (5) applied on the array electrode metal sheet (2), and can adjust the movement of the array electrode metal sheet (2) relative to the under-scale corrosion encapsulation mold (14) based on the threaded connection between the under-scale corrosion encapsulation mold (14) and the electrode fixing bushing (1), so as to adjust the applied thickness of the deposited scale (5) on the array electrode metal sheet (2); The test method comprises the following steps: Step 1: Using wire cutting technology, the metal to be studied is cut into a number of 10 mm × 3 mm × 3 mm rectangular array electrode metal sheets (2), the reference electrode metal material is cut into a 10 mm × 5 mm × 5 mm reference electrode metal sheet (16), and the counter electrode metal material is cut into a 30 mm × 2 mm × 3 mm counter electrode metal sheet (15), the surface oil film is removed using acetone, and ultrasonic cleaning is performed in ethanol; Step 2: using a welding gun to spot-weld the copper wire (10) to the array electrode metal sheet (2), the reference electrode metal sheet (16), and the counter electrode metal sheet (15) respectively for electrical signal extraction; and using a multimeter to test whether they are conductive; Step 3: The welded array electrodes are placed into the electrode sheet mounting plug board (17) in a predetermined order, and one end of the wire is led out of the electrode sheet mounting plug board (17) to facilitate the collection of electrical signals; wherein the array electrode metal sheet (2) is embedded in the electrode fixing bushing (1), and the electrode fixing bushing (1) is connected to the electrode base (4) via a thread; the array electrode metal sheet (2) is limited by an under-scaling corrosion packaging mold (14) above, so that the spring (7) is in a compressed state; Step 4: based on the experimental requirements, the type of deposited scale (5) is prepared and deposited in the under-scale corrosion encapsulation mold (14), the depth of the under-scale corrosion encapsulation mold (14) screwed into the electrode fixing bushing (1) is adjusted, and the mold is immersed in the solution to be tested for testing; Step 5: Use a microelectrode array corrosion electrochemical test system to characterize the corrosion electrochemical behavior of the array electrode system for under-deposition corrosion, the test system comprising a fast matrix conversion switch (19) and a digital multimeter (20) with potential and current protection functions to obtain the distribution information of coupled corrosion current density and corrosion potential; before conducting coupled corrosion current density and potential tests, all copper wires (10) at the lower ends of all metal sheets are coupled to the aviation plug connector (18) until a stable open circuit potential is obtained; for current measurement, use a fast matrix conversion switch (19) to separate each electrode to be measured from other electrode arrays, and all other electrode arrays are short-circuited together; then, use to obtain the corrosion current between each electrode and the array electrode in turn; during the corrosion potential measurement process, the coupled array electrodes are temporarily disconnected from each other, and the corrosion potential of each array electrode metal sheet (2) based on the reference electrode is obtained based on the fast matrix conversion switch (19); Step 6: After the experiment is over, the deposited scale (5) on the surface of the array electrode metal sheet (2) is removed and the encapsulation mold (14) for corrosion under the scale is removed, the aviation plug connector (18) is separated, the array electrode metal sheet (2) is ejected by the spring (7), and the solder joint between the copper wire (10) and the array electrode metal sheet (2) is removed with a manual pliers, and then the array electrode metal sheet (2) is taken out; Step 7: The removed array electrode metal sheet (2) is rinsed with deionized water and anhydrous ethanol, and dried to prepare for subsequent characterization of the surface corrosion morphology and pitting depth of the array electrode metal sheet (2).

2. The testing method of a detachable array electrode electrochemical experimental system according to claim 1, characterized in that: A rubber ring (8) is provided between the metal baffle (12) and the electrode base (4); the outer side of the spring (7) is encapsulated with silicone rubber (6), and the space between the silicone rubber (6) and the electrode base (4) is filled with epoxy resin (3); the bottom of the metal baffle (12) and the electrode base (4) is provided with a wire groove (11); a copper wire (10) is provided inside the spring (7), and the outside of the copper wire (10) is covered with a fluorine rubber tube (13).

3. The testing method of a detachable array electrode electrochemical experimental system according to claim 2, characterized in that: The array electrode metal sheets (2) are arranged in sequence in a horizontal direction, and reference electrode metal sheets (16) are distributed on the left and right sides of the array electrode metal sheets (2), and counter electrode metal sheets (15) are distributed on the front and rear sides of the array electrode metal sheets (2); the bottom of each electrode is welded to a copper wire (10); and each electrode is located in an electrode sheet mounting plug board (17).

4. The testing method of a detachable array electrode electrochemical experimental system according to claim 3, characterized in that: It can be used for under-deposit corrosion experiments under different environmental parameters.

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