A corrosion monitoring probe and a method of manufacturing the same

Abstract

The present application relates to the technical field of corrosion monitoring, and particularly relates to a corrosion monitoring probe and a preparation method thereof, which comprises, from outside to inside, an insulating ring support, a cylindrical cathode, a filler and a reference electrode, a plurality of anodes are arranged on the insulating ring support, the cylindrical cathode and the reference electrode serve as fixed electrodes, the anodes serve as corrosion electrodes, the corrosion thickness and time of a plating layer are monitored through current or point position conversion of the corrosion electrodes in a corrosion environment; the preparation method is that the anodes are prepared by surface treatment, welding of current leads, anticorrosive paint coating and plating of a plating layer, and then the anodes are embedded into the insulating ring support, the reference electrode and the cylindrical cathode are sequentially assembled. The corrosion monitoring probe has the advantages of simple processing and low design cost, a plurality of groups of anodes obtain a plurality of groups of data for mutual verification, and the metal corrosion condition can be objectively and accurately evaluated through current and potential changes in a short time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of corrosion monitoring, in particular to a corrosion monitoring probe and a preparation method thereof. BACKGROUND

[0002] With the continuous construction of various energy facilities, the problem of metal component corrosion is increasingly prominent. In particular, buried metals such as pipelines, support frames, grounding bodies, etc. are affected by soil, underground water, bacteria, etc. for a long time, which may cause corrosion, and the corrosion may be so serious that it may even cause leakage, explosion and other serious safety problems. Therefore, the task of corrosion monitoring during the construction of buried metals is becoming more and more important.

[0003] Corrosion monitoring points are designed at positions where the corrosion environment in the production site is the most severe and serious corrosion may occur. Corrosion monitoring points are designed in the entire production process to meet the system monitoring requirements, reflect the corrosion condition of the production system and the serious corrosion area, play a warning role, and can evaluate the corrosion prevention measures such as adding corrosion inhibitors.

[0004] The corrosion monitoring process is composed of three parts: corrosion data acquisition, result analysis and determination, and effect evaluation and corrosion prevention measure suggestion. Among them, the acquisition of corrosion data is the core of the entire work, and the corrosion probe is the core of the core.

[0005] The current technical methods and principles of corrosion monitoring mainly include the following: coupon weight loss method, resistance probe, inductance probe, linear polarization resistance method, hydrogen permeation method, electrochemical noise method, FSM method, etc. The coupon weight loss method is to place the coupon in the corrosion medium and measure the weight loss periodically, which requires a long time and complicated operation. The resistance probe method measures the corrosion rate according to the change of the resistance probe caused by corrosion, which is relatively fast and flexible in application. The inductance probe method measures the decrease of the thickness of the sensitive element by measuring the change of the inductance, which has a fast response time. The linear polarization resistance method measures the corrosion rate according to the change of the polarization resistance on the surface of the polarization probe during the corrosion process, which is relatively easy to be disturbed. The hydrogen permeation method calculates the hydrogen permeation rate by measuring the amount of hydrogen molecules permeating into the hydrogen probe, which requires a long time. The electrochemical noise method detects the severity of corrosion by using the weak signals generated during the corrosion process, which is affected by many interference factors. The FSM method measures the corrosion rate according to the potential change of multiple points on the specially designed test pipe segment, which is expensive.

[0006] Corrosion monitoring with an electrochemical corrosion monitoring probe has the advantages of fast response time and flexible application. The prior art discloses a metal corrosion monitoring probe, which comprises a probe base, a working electrode ring, an auxiliary electrode ring and a reference electrode column; the working electrode ring and the auxiliary electrode ring are peripherally sleeved on the probe base with a spacing, and the reference electrode column is fixed inside the probe base; the metal corrosion monitoring probe can realize real-time monitoring of the corroded pipeline of the metal pipeline through an external monitoring instrument, but since there is only one working electrode ring, the data source is single, and the monitoring result is easily affected. SUMMARY

[0007] In view of the technical problems existing in the prior art corrosion monitoring technology, the purpose of the present application is to provide a corrosion monitoring probe and a preparation method thereof, which comprises, from the outside to the inside, an insulating ring support, a cylindrical cathode, a filler and a reference electrode, a plurality of anodes are arranged on the insulating ring support, the cylindrical cathode and the reference electrode serve as fixed electrodes, and the anodes serve as corrosion electrodes; the corrosion monitoring probe uses a certain number of metal strips with fixed length and width and different thickness of plating as anodes, uses stable metal or reference electrodes as cathodes, uses heterogeneous metal potential and current as indexes, a plurality of anodes obtain a plurality of groups of data for mutual verification, is convenient to use, has accurate and reliable results, has low preparation cost, and can carry remote transmission equipment and serve for a long time.

[0008] In order to achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0009] In the first aspect of the present application, a corrosion monitoring probe is provided, which comprises, from the outside to the inside, an insulating ring support, a cylindrical cathode, a filler and a reference electrode, a plurality of anodes are arranged on the insulating ring support, the cylindrical cathode and the reference electrode serve as fixed electrodes, and the anodes serve as corrosion electrodes, the current or point position of the corrosion electrodes in the corrosion environment is changed to monitor the plating corrosion thickness and time.

[0010] As a further technical scheme, the anode is a metal strip with a plating layer, the plating layer has a fixed length and width, the part outside the plating layer is coated with anticorrosive paint, and the surface where the plating layer is located faces the outside; or, the base material and plating material of the anode are consistent with the monitored metal and its plating layer, preferably, the anode is one of a zinc-plated steel strip, a copper-plated steel strip or an iron-copper-plated strip; or, the length of the metal strip is 50-70mm, the width is 4-6mm, and the thickness is 1-3mm.

[0011] When the anode plating layer is corroded, its potential and current will change; according to the current value and time during this period, the corrosion amount of the plating metal can be calculated by using the Faraday's law of electrolysis; the corrosion rate can also be calculated according to the previous plating thickness; setting multiple anode plating layers after corrosion will obtain multiple corrosion data, which is convenient for regular summary and long-term monitoring.

[0012] As a further technical solution, the insulating ring support is a pair of concentric rings, the inner diameter is consistent with the outer diameter of the copper cylinder, square holes are opened at equal intervals in the circumferential direction, and the number of square holes is 4-40; or, the material of the insulating ring support is one of epoxy resin, silicone rubber, silicon dioxide, ceramic, plastic and polytetraethylene.

[0013] As a further technical solution, the cylindrical cathode is a cylindrical stable metal material with a hole in the center of the cylinder bottom; preferably, the cylindrical cathode is a copper cylinder; or, the height of the cylindrical cathode is 50-70 mm, the wall thickness is 3-5 mm, and the hole in the cylinder bottom is 3-5 mm.

[0014] The material of the cylindrical cathode is arranged as a counter electrode during monitoring, and considering cost and effect, a copper cylinder is usually selected; the diameter of the cylindrical cathode is set according to the number and width of the anodes.

[0015] As a further technical solution, the reference electrode is arranged in the center of the cylindrical cathode, and the bottom is flush with or slightly higher than the cylinder opening of the cylindrical cathode; preferably, the reference electrode is a copper / saturated copper sulfate reference electrode.

[0016] The corrosion monitoring probe is equipped with a reference electrode, which facilitates the detection of the potential of the cathode and anode, and further ensures the accuracy of the detection result.

[0017] As a further technical solution, the filler is one of kaolin, bentonite and diatomite; the use of the filler can fix the reference electrode inside the cylindrical cathode, and can also reinforce the overall structure of the corrosion probe.

[0018] In a second aspect of the present application, a preparation method of a corrosion monitoring probe is provided, which specifically includes the following steps:

[0019] (1) A plurality of anode plating layers face the outer side and are embedded in a pair of insulating ring supports in parallel at equal intervals;

[0020] (2) The insulating ring support is sleeved on the outer side of the cylindrical cathode, and the reference electrode is placed in the center of the cylindrical cathode, so that the bottom of the reference electrode is flush with or slightly higher than the cylinder opening;

[0021] (3) The inside of the cylindrical cathode is filled with a filler, which is temporarily sealed with a plastic bag or filled during installation.

[0022] Further, the metal strip is polished before electroplating to make the roughness between Ra1.6-0.8 μm, then the fixed length and width of the electroplating surface are reserved, the remaining part of the metal strip is coated with an insulating anticorrosive paint, and finally the metal strip is electroplated; the thickness of the plating layer can be controlled by setting the electroplating parameters, and the plating is polished, corroded and thinned after plating; when batch preparation is performed, a plurality of large plates can be electroplated as a whole, and then cut and thinned, which greatly saves the preparation time of the anodes.

[0023] Further, the plating layer thickness of the detection surface is obtained or verified by cross-section metallographic method, and the number and its thickness accurate to 0.1 μm are recorded, and the metal, its lead number and plating layer thickness are one-to-one corresponding; after the plating layer thickness is detected, the non-plating layer surface is again subjected to insulation corrosion prevention treatment.

[0024] In the third aspect of the present application, a corrosion monitoring device is provided, comprising a plurality of corrosion monitoring probes, a plurality of current leads and a data acquisition instrument, the plurality of current leads are insulated from each other, one end is connected with the data acquisition instrument, and the other end is connected with the bottom of the cylindrical cathode, the plurality of anodes and the reference electrode respectively.

[0025] The current leads insulated from each other ensure that the plurality of anodes will not be connected in series to form a circuit, ensuring the accuracy of the detection results; the entire sensor is divided into three types of channels, namely a plurality of cathode leads, anode leads and reference electrode leads, which are insulated from each other and connected to the data acquisition instrument to obtain current, potential and other data, which are mutually verified to reduce the failure rate and error.

[0026] The beneficial effects of the present application are:

[0027] (1) Compared with other corrosion sensors, the corrosion monitoring probe of the present application has the advantages of simple processing and low design cost. The metal corrosion condition can be objectively and accurately evaluated in a short time, that is, the corrosion charge amount in a period of time is obtained by integrating the current, and then the metal corrosion weight loss in this period of time is calculated; the corrosion thickness and time of the plating layer can also be determined according to the potential change after the anode plating layer is lost one by one, so as to evaluate the corrosion condition of the environment and study the development process of corrosion.

[0028] (2) Compared with the existing metal corrosion probe, the corrosion monitoring probe of the present application is provided with a plurality of anodes with different thickness plating layers, and a plurality of groups of current and potential data between different anodes and the cylindrical cathode, different anodes and the reference electrode can be obtained, which are mutually verified to make the monitoring result accurate and reliable.

[0029] (3) The corrosion monitoring probe of the present application can also be used for metal corrosion monitoring in liquid and gas environmental media after being appropriately modified. BRIEF DESCRIPTION OF DRAWINGS

[0030] The drawings accompanying the specification of the present application form a part thereof, serve to provide further understanding of the present application, and together with the description of the exemplary embodiments of the present application and their description serve to explain the present application, and do not constitute an improper limitation of the present application.

[0031] Figure 1 It is a structure schematic view of the galvanized steel strip of embodiment 1 of the present application;

[0032] Figure 2 It is a structure schematic view of the insulating ring support of embodiment 1 of the present application;

[0033] Figure 3 Figure 2 is a schematic diagram of a radial cross-section of a corrosion monitoring probe according to an embodiment of the present application;

[0034] Figure 4 Figure 3 is a schematic diagram of a structure of a corrosion monitoring probe according to an embodiment of the present application;

[0035] Figure 5 Figure 4 is a schematic diagram of selection of an end point of plating according to an embodiment of the present application;

[0036] In the figure, 1 is an epoxy insulating ring support, 1-1 is a square hole, 2 is a copper cylinder, 3 is a filler, 4 is a copper / saturated copper sulfate reference electrode, 5 is a galvanized steel strip, 5-1 is a zinc plating layer, and 6 is a current lead. DETAILED DESCRIPTION

[0037] It should be noted that the following detailed description is illustrative only, and is intended to provide further description in connection with the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0038] It is also important to note that the use of the term "example" herein, along with the use of the term "exemplary" in the following detailed description, is intended to further illustrate example embodiments of the present application, and is not intended to foreclose other embodiments that can fall within the scope of the present application. Unless otherwise specified, the use of the ordinal adjectives "first", "second", "third", etc., are merely to distinguish between different features to which reference is made in the context in which the terms are used, and are not intended to imply that any or all of the features so distinguished are necessarily related or similar to each other in any way.

[0039] Example 1

[0040] A method for preparing a corrosion monitoring probe for monitoring galvanized steel:

[0041] 1. Anode preparation

[0042] The metal strip is selected to be a Q235 steel strip with a length of 60 mm, a width of 5 mm, and a thickness of 2 mm, and the material parameters are consistent with the steel substrate of the monitored galvanized steel.

[0043] First, the steel strip is polished to have a roughness of Ra 1.6-0.8 μm; then, a fixed size detection surface is reserved on the side surface for plating, and the remaining parts are coated with an insulating anticorrosive paint; the zinc plating layer is plated on the reserved detection surface, and the thickness of the zinc plating layer of each galvanized steel strip is set to present a gradient by setting the plating parameters and polishing, etching after plating; the thickness of the plating layer of the detection surface is obtained or verified by a cross-section metallographic method, and the number and its thickness are recorded to an accuracy of 0.1 μm, and the metal, its lead number, and the plating layer thickness are one-to-one corresponding; after detecting the plating layer thickness, the non-plating layer surface is again coated with an insulating anticorrosive paint.Figure 1 As shown, the prepared galvanized steel strip 5 has a zinc plating layer 5-1 with the same length and width but different thickness.

[0044] 2. Corrosion monitoring probe assembly

[0045] The cylindrical cathode is a T2 pure copper cylinder with a wall thickness of 2 mm, a height of 60 mm, and a φ4 mm hole in the center of the bottom. Figure 2 As shown, the epoxy resin insulating ring support 1 has 8 equidistantly designed square holes 1-1; the reference electrode is a copper / saturated copper sulfate reference electrode; and the filler is kaolin.

[0046] First, the prepared galvanized steel strip plating layer is outwardly embedded into a pair of epoxy resin insulating ring supports in parallel and equidistantly; the insulating ring support is sleeved on the outside of the copper cylinder; the copper / saturated copper sulfate reference electrode is placed in the center of the cylindrical cathode, so that the bottom of the reference electrode is flush with or slightly higher than the cylinder mouth; the connection between the insulating ring support and the cylindrical cathode is filled with kaolin, which is temporarily sealed with a plastic bag.

[0047] Example 2

[0048] As shown in the accompanying drawings Figure 3 A corrosion monitoring probe for monitoring galvanized steel, arranged from the outside to the inside in turn with an epoxy resin insulating ring support 1, a copper cylinder 2, kaolin 3, and a copper / saturated copper sulfate reference electrode 4; the epoxy resin insulating ring support 1 is provided with a plurality of galvanized steel strips 5, each of which has a zinc plating layer 5-1 with the same length and width but different thickness, and the epoxy resin insulating ring support 1 has 8 equidistantly arranged square holes 1-1.

[0049] The epoxy resin insulating ring support 1 is a pair of concentric rings, and 8 square holes 1-1 consistent with the size of the end face of the galvanized steel strip 5 are equidistantly arranged on the epoxy resin insulating ring support 1 to fix the galvanized steel strip 5. The inner diameter of the epoxy resin insulating ring support 1 is consistent with the outer diameter of the copper cylinder 2, which is sleeved on the outside of the copper cylinder 2, meeting the installation requirements of the corrosion monitoring probe and preventing the galvanized steel strip 5 from directly contacting the copper cylinder 2 to cause inaccurate monitoring results.

[0050] The copper cylinder 2 is a T2 pure copper cylinder with a wall thickness of 2 mm, a height of 60 mm, and a φ4 mm hole in the center of the bottom. The small hole in the center of the bottom of the copper cylinder 2 meets the installation needs of the copper / saturated copper sulfate reference electrode 4; the material of the cylindrical cathode is set as a counter electrode during the monitoring process, and T2 pure copper cylinder is selected considering the cost and effect.

[0051] The copper / saturated copper sulfate reference electrode 4 is arranged in the center of the copper cylinder 2, flush with or slightly higher than the cylinder opening of the copper cylinder 2, facilitating detection of the potentials of the cathode and the anode, and further ensuring the accuracy of the detection results; the kaolin 3 is used as the filler to fill the inside of the copper cylinder, which can not only fix the copper / saturated copper sulfate, but also support the copper cylinder.

[0052] The galvanized steel strip 5 is a Q235 steel strip plated with a zinc plating layer 5-1, with a length of 60 mm, a width of 5 mm, and a thickness of 2 mm; the zinc plating layers 5-1 of different galvanized steel strips 5 have the same length and width but different thicknesses; when the zinc plating layer 5-1 is corroded away, the potential and current will change; according to the current value and time during this period, the corrosion amount of the zinc plating layer can be calculated by using the Faraday's law of electrolysis; the corrosion rate can also be calculated according to the previous zinc plating layer thickness; multiple groups of galvanized steel strips are arranged, and after the zinc plating layer is corroded, multiple sets of corrosion data are obtained, which is convenient for regular summary and long-term monitoring.

[0053] Example 3

[0054] As shown in the accompanying drawings Figure 4 A corrosion monitoring device for monitoring galvanized steel includes a plurality of corrosion monitoring probes, a plurality of current leads, and a data acquisition instrument; the corrosion monitoring probe is sequentially arranged from the outside to the inside with an epoxy resin insulating ring support 1, a copper cylinder 2, kaolin 3, and a copper / saturated copper sulfate reference electrode 4; the epoxy resin insulating ring support 1 is provided with a plurality of galvanized steel strips 5, each galvanized steel strip 5 has a zinc plating layer 5-1 with the same length and width but different thicknesses, and the epoxy resin insulating ring support 1 has eight equidistantly arranged square holes 1-1; the plurality of current leads 6 are insulated from each other, one end is connected with the data acquisition instrument, and the other end is welded with the bottom of the copper cylinder 2, the plurality of galvanized steel strips 5, and the copper / saturated copper sulfate reference electrode 4, respectively.

[0055] The corrosion monitoring probe is placed in the corrosion monitoring point to monitor the corrosion of the galvanized steel. The current leads connected with the galvanized steel strips 5, the copper cylinder 2, and the copper / saturated copper sulfate reference electrode 4 are connected to the data acquisition instrument, and the changes of the potential and current between each galvanized steel strip 5 and the copper cylinder 2 and the copper / saturated copper sulfate reference electrode 4 caused by the change of the plating layer are observed.

[0056] As shown in the accompanying drawings Figure 5 Since zinc is more active than iron, the current decreases and the potential moves positively after the zinc plating layer 5-1 is corroded away. During the monitoring process, the potential-time relationship of the zinc plating layer 5-1 from complete to corrosion to complete corrosion is approximately a straight line-curved straight line shape. The time corresponding to the inflection point of the corrosion process curve and the straight line after the corrosion is completed is the time required for the zinc plating layer 5-1 to be completely corroded.

[0057] The corrosion time of the zinc coating 5-1 of all the galvanized steel strips 5 is calculated with the thickness of the zinc coating 5-1, so as to obtain the corrosion speed of the zinc coating 5-1, the arrangement of the plurality of galvanized steel strips 5 ensures the accuracy of the corrosion speed calculation result, and the corrosion time of the zinc coating of the galvanized steel can be inferred; in addition, the potential and current between the galvanized steel strip 5 and the copper cylinder 2, and the potential and current between the galvanized steel strip 5 and the copper / saturated copper sulfate reference electrode 4 can be monitored respectively, so as to obtain the corresponding corrosion time, calculate the corrosion rate, and verify each other to reduce the result error.

[0058] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. The present application can be variously changed and modified by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An erosion monitoring probe, characterized by, The corrosion monitoring probe comprises, from outside to inside, an insulating ring support, a cylindrical cathode, a filler and a reference electrode, a plurality of anodes are arranged on the insulating ring support, the cylindrical cathode and the reference electrode serve as fixed electrodes, the anodes serve as corrosion electrodes, and the corrosion thickness and time of a coating are monitored by current or potential conversion of the corrosion electrodes in a corrosion environment. The anodes are metal strips with fixed length and width and different thickness of the coating. The plurality of anode coating surfaces face outward and are embedded in a pair of insulating ring supports in parallel and at equal intervals. The insulating ring support is a pair of concentric rings with an inner diameter consistent with the outer diameter of the copper cylinder and square holes opened at equal intervals in the ring direction, and the number of the square holes is 4-40. The anodes are metal strips with a coating, the coating has fixed length and width, the part outside the coating is coated with anticorrosive paint, and the surface where the coating is located faces outward; the base material and the coating material of the anode are consistent with the metal to be monitored and its coating; the length of the metal strip is 50-70 mm, the width is 4-6 mm, and the thickness is 1-3 mm. The anodes are one of zinc-plated steel strips, copper-plated steel strips or iron-copper-plated strips. The reference electrode is arranged at the center of the cylindrical cathode and is flush with the cylinder opening of the cylindrical cathode at the bottom. The reference electrode is a copper / saturated copper sulfate reference electrode.

2. The corrosion monitoring probe of claim 1, wherein, The cylindrical cathode is a cylindrical stable metal material with a hole opened at the center of the cylinder bottom. The height of the cylindrical cathode is 50-70 mm, the wall thickness is 3-5 mm, and the diameter of the hole opened at the cylinder bottom is 3-5 mm.

3. The corrosion monitoring probe of claim 2, wherein, The cylindrical cathode is a copper cylinder.

4. The corrosion monitoring probe of claim 1, wherein The insulating ring support is a pair of concentric rings with an inner diameter consistent with the outer diameter of the copper cylinder and square holes opened at equal intervals in the ring direction, and the number of the square holes is 4-40. The material of the insulating ring support is one of epoxy resin, silicone rubber, silicon dioxide, ceramic, plastic and polytetraethylene.

5. The corrosion monitoring probe of claim 1, wherein The filler is one of kaolin, bentonite and diatomite.

6. A method of manufacturing the corrosion monitoring probe according to any one of claims 1 to 5, characterized in that, The method comprises the following steps: (1) The plurality of anode coating surfaces face outward and are embedded in a pair of insulating ring supports in parallel and at equal intervals. (2) The insulating ring support is sleeved on the outside of the cylindrical cathode, and the reference electrode is placed at the center of the cylindrical cathode, so that the bottom of the reference electrode is flush with the cylinder opening. (3) The inside of the cylindrical cathode is filled with the filler, which is temporarily sealed with a plastic bag or filled during installation.

7. A method of making a corrosion monitoring probe as claimed in claim 6, characterised by, The method also comprises a preparation method of the anode: the metal strip is polished before electroplating the coating, so that the roughness is between Ra1.6-0.8 μm, then a fixed size of the surface to be electroplated is reserved, the remaining part of the metal strip is coated with insulating anticorrosive paint, and finally the metal strip is electroplated, the thickness of the coating is controlled by electroplating parameters, and the coating is polished, etched and thinned after electroplating.

8. A method of manufacturing a corrosion monitoring probe as claimed in claim 7, characterised by, The coating thickness of the detection surface is obtained or verified by the cross-section metallographic method, and the number and the thickness accurate to 0.1 μm are recorded, the metal, its lead number and the coating thickness are one-to-one corresponding; after detecting the coating thickness, the non-coating surface is coated with insulating anticorrosive paint again.

9. An apparatus for monitoring corrosion, characterized by The method comprises a plurality of corrosion monitoring probes as claimed in any one of claims 1-5, a plurality of current leads and data acquisition instruments, the plurality of current leads are insulated from each other, one end is connected with the data acquisition instrument, and the other end is connected with the bottom of the cylindrical cathode, the plurality of anodes and the reference electrode respectively.

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