CN-121977993-A - System and method for detecting corrosion resistance of metal outer anti-corrosion coating

CN121977993ACN 121977993 ACN121977993 ACN 121977993ACN-121977993-A

Abstract

The invention provides a detection system and a detection method for corrosion resistance of a metal external anti-corrosion coating, and relates to the technical field of coating corrosion detection, wherein the system comprises a measurement host device, a detection device and a detection device, wherein the measurement host device comprises a measurement pool and an electrode system; the hinge mechanism comprises a hinge base and a hinge connecting rod, wherein the hinge base can be fixed on the surface of the tested equipment, the hinge connecting rod is used for connecting the hinge base with the measuring host device, and the control device is used for supplying power and controlling the detection flow, and the measuring host device and the hinge mechanism are both connected with the control device. The method adopts the average value of the phase angle attenuation rate under 3-5 characteristic frequencies in the 5mHz-30mHz interval to evaluate the performance or aging condition of the coating. The evaluation method overcomes the limitations of the existing coating performance detection method, and has important popularization value.

Inventors

WANG YONGCAI
CHEN XUCHAO
YU LIUJIE
WANG HAI
LIU CHENG
WANG HAO
WANG WEIJIE
DI ZHIGANG
ZHANG ZHU

Assignees

中海油常州涂料化工研究院有限公司
中海油能源发展股份有限公司
中海油常州涂料化工研究院有限公司上海海铠防腐工程技术分公司

Dates

Publication Date: 20260505
Application Date: 20251014

Claims (10)

1. A system for detecting corrosion resistance of a metal outer corrosion-resistant coating, comprising: the measuring host device comprises a measuring pool and an electrode system, wherein the measuring pool is used for forming a closed test environment, and the electrode system can collect electrochemical signals of a coating of the tested equipment and form an electrochemical test loop; The hinge mechanism comprises a hinge base and a hinge connecting rod, wherein the hinge base can be fixed on the surface of the tested equipment, and the hinge connecting rod is used for connecting the hinge base and the measuring host device; And the control device is used for supplying power and controlling the detection flow, and the measurement host device and the hinge mechanism are connected with the control device.
2. The system for detecting corrosion resistance of a metallic outer corrosion resistant coating according to claim 1, wherein said electrode system comprises a working electrode for metallic connection with a coated substrate of said device under test.
3. The system for detecting corrosion resistance of a metallic outer corrosion resistant coating according to claim 2, wherein the electrode system further comprises an auxiliary platinum electrode pad and a reference platinum electrode pad, wherein: the auxiliary platinum electrode plate and the reference platinum electrode plate are both fixed on the inner wall of the measuring cell; The working electrode, the auxiliary platinum electrode sheet and the reference platinum electrode sheet are matched to form an electrochemical test loop.
4. A system for detecting corrosion resistance of a metallic outer corrosion resistant coating according to any of claims 1-3, wherein said measurement host device further comprises: The first test electrolyte buffer tank is used for conveying electrolyte into the measuring tank, and is connected with the measuring tank through a first pipeline, and a first pump body is arranged on the first pipeline; the second test electrolyte buffer tank is used for receiving the electrolyte output in the measuring tank, and is connected with the measuring tank through a second pipeline, and a second pump body is arranged on the second pipeline; The first test electrolyte buffer tank is connected with the second test electrolyte buffer tank through a third pipeline, the third pipeline is used for refluxing electrolyte in the second test electrolyte buffer tank to the first test electrolyte buffer tank, an adjusting valve is arranged on the third pipeline, and the first pump body, the second pump body and the adjusting valve are electrically connected with the control device.
5. The system for detecting corrosion resistance of a metallic outer corrosion resistant coating according to claim 4, wherein the measuring cell comprises: a measuring cell capable of containing the electrolyte, the measuring cell being provided with an inlet for connecting the first pipeline and an outlet for connecting a second pipeline; and a sealing rubber gasket arranged on the bottom circumference side of the measuring electrolytic cell.
6. A system for detecting corrosion resistance of a metallic outer corrosion resistant coating according to any of claims 1-3, wherein the control means comprises a master control and power module, a hinge control module, an electrochemical measurement control module, and a data storage and remote transmission module, wherein: the hinge control module is connected with the hinge mechanism; The electrochemical measurement control module is connected with the measurement host device; The hinge control module, the electrochemical measurement control module and the data storage and remote transmission module are all connected with the total control and power supply module, and the total control and power supply module is used for supplying power and controlling a detection flow; The data storage and remote transmission module is used for storing test data and remotely transmitting the test data to a remote receiver.
7. The system for detecting corrosion resistance of a metal outer corrosion resistant coating according to claim 6, wherein the master control comprises a microcomputer system for presetting and executing a detection period, a timing on-off and a detection operation program; The power source comprises a lithium battery or a dry battery.
8. A method for detecting corrosion resistance of a metal outer corrosion-resistant coating, characterized in that a system for detecting corrosion resistance of a metal outer corrosion-resistant coating according to any one of claims 1 to 7 is adopted, comprising the following steps: s1, installing and debugging detection system hardware on coating equipment, and filling electrolyte into a first test electrolyte buffer tank, wherein the electrolyte consists of 3.5% sodium chloride and 0.1% sodium benzoate; S2, setting detection parameters by a control device, wherein the detection parameters comprise a detection period and electrochemical impedance measurement parameters; S3, measuring initial impedance parameters, starting a detection system, driving a measuring host device to displace by a hinge mechanism, and fastening the measuring host device to the surface of the coating; S4, pumping the electrolyte in the first test electrolyte buffer tank into the measuring tank by the first pump body, and implementing electrochemical test by the measuring tank; S5, the hinge mechanism drives the measuring host device to displace and keep away from the surface of the coating; s6, the data storage and remote transmission system stores test data and remotely transmits the data to the remote receiver; and S7, detecting shutdown and dormancy of the system, automatically starting the system when the next measurement time point is needed, and repeating the steps S1-S6.
9. The method for detecting corrosion resistance of a metal outer corrosion protection coating according to claim 8, wherein in step S2, the electrochemical impedance measurement parameters include an impedance amplitude and a characteristic frequency value, and the impedance amplitude is selected according to the coating thickness d, and specifically includes: When d is less than or equal to 50 mu m, the impedance amplitude is +/-15 mV; When 50 μm < d is less than or equal to 150 μm, the impedance amplitude is +/-20 mV; When d >150 μm, the impedance amplitude is + -30 mV.
10. The method for detecting corrosion resistance of metal outer anticorrosive coating according to claim 8, wherein in the long-term electrochemical impedance spectrum test of the same coating, average value of phase angle attenuation rate at 3-5 characteristic frequencies in the interval of 5mHz-30mHz is adopted The method for evaluating the performance or aging condition of the coating comprises the following steps of: wherein, θ 0 is the initial phase angle under a certain characteristic frequency, and θ i is the phase angle at the moment i under a certain characteristic frequency; average value of phase angle attenuation rate The calculation formula of (2) is as follows: wherein eta 1 -η n is the phase angle attenuation rate under 3-5 selected characteristic frequencies, and n is the number of the characteristic frequencies.

Description

System and method for detecting corrosion resistance of metal outer anti-corrosion coating Technical Field The invention relates to the technical field of corrosion detection of coatings, in particular to a system and a method for detecting corrosion resistance of a metal outer anti-corrosion coating. Background Various industrial and residential metal equipment facilities, such as carbon steel, stainless steel, aluminum alloys, and the like, often require corrosion protection coatings to slow down the damage of corrosion to the substrate. The coating protection is widely applied due to the characteristics of convenient construction, lower cost, excellent protection effect and the like. However, during the service of the coating, the metal matrix is often damaged due to penetration of corrosive media, and the protection of the coating is disabled. The coating is very slow in the actual service process. The handling of coatings is often confusing during the periodic maintenance of some metal equipment, facilities, and devices. Because the condition of the in-service coating, including performance parameters and residual life, is not available, the extreme mode of recoating the visually ineffective coating or recoating all of the coating is often employed, resulting in either inadequate protection or unnecessary waste. The key point of the problem is that the key performance of the coating in the service process of the coating cannot be obtained effectively, and especially the key performance parameters and the residual life of the coating failure cannot be obtained through nondestructive monitoring and detection means. Some traditional coating performance detection means, such as adhesion, drawing method, direct current electric spark and other technologies, limit the application range of the coating due to the destructiveness of the coating. In recent years, some nondestructive electrochemical monitoring and detection methods are applied to online service performance assessment of the coating. The patent invention is named as a method and a system for rapidly evaluating corrosion resistance of an in-service coating, and the Chinese patent invention with the patent number of CN101634623A can effectively reflect the change rule of impedance in the service process of the coating based on the change of the phase angle of the coating/metal system with the service time under specific frequency. The electrochemical method for rapidly evaluating the performance of the in-service coating is further established, and an in-service coating performance rapid evaluating and managing software system suitable for industrial sites is designed and developed on the basis of the electrochemical method for rapidly evaluating the performance of the in-service coating and predicting the service life of the in-service coating, and the electrochemical method has the advantages of rapid and convenient measurement, reliable data, simple instrument and no need of analyzing impedance data. However, the phase angle change at the characteristic frequency of the single electrochemical impedance is used as a standard for evaluating the corrosion resistance of the coating, and the error is large. Although a phase angle with a characteristic frequency of 10mHz is representative, there are significant differences in different types of coatings, different service environments. The patent name is a coating failure monitoring probe and a field coating failure rapid monitoring method, and Chinese patent invention patent No. CN108827868A proposes to evaluate the aging condition of the coating by four indexes of impedance value, phase angle, characteristic frequency and specific capacitance and aging coefficient. And develop special probe device, apply to the coating monitoring on the scene. However, the method is complex in detection, and data analysis requires a relatively professional person to perform fitting. Therefore, a system and a method for detecting corrosion resistance of a metal outer anti-corrosion coating are needed to solve the above technical problems. Disclosure of Invention The invention aims to provide a system and a method for detecting the corrosion resistance of a metal outer anti-corrosion coating, which can be used for accurately, rapidly and nondestructively testing the coating performance. The preferred technical solutions of the technical solutions provided by the present invention can produce a plurality of technical effects described below. In order to achieve the above purpose, the present invention provides the following technical solutions: The invention provides a detection system for corrosion resistance of a metal external anti-corrosion coating, which comprises the following components: the measuring host device comprises a measuring pool and an electrode system, wherein the measuring pool is used for forming a closed test environment, and the electrode system can collect electrochemical signals of a coating of