CN116625924A - Test method for corrosion resistance performance of anti-corrosion coating - Google Patents

Abstract

The invention relates to a method for testing the corrosion resistance performance of an anticorrosion coating. In the above test method of corrosion resistance performance of anti-corrosion coating, the test piece coated with anti-corrosion coating is placed in a corrosive medium. The chemical noise data is used to judge the corrosion condition of the anti-corrosion coating. The above test method realizes simultaneous monitoring and tracking of various performance changes of the anti-corrosion coating during the whole process of aging of the anti-corrosion coating. By collecting electrochemical noise data, the damage of the corrosion coating can be identified from the current and time signal analysis. The time and degree of the situation, etc., to realize the quantitative evaluation of the performance of the anti-corrosion coating. The above test method can convert the weak change signal that is difficult to identify by visual inspection or other detection means into an easily measurable electrical parameter for measurement and recording, and can also avoid signals such as applied voltage from electrochemical testing from interfering with the normal aging of the coating.

Description

Test method for corrosion resistance performance of anti-corrosion coating

technical field

The invention relates to the technical field of anticorrosion, in particular to a method for testing the anticorrosion performance of an anticorrosion coating.

Background technique

The anti-corrosion coating has good electrical insulation and water resistance, and is convenient for on-site construction and good economy. It is widely used in the protection of metal materials. For example, for power transmission equipment exposed to the outdoors for a long time, it can resist the erosion of high temperature, high humidity, salt spray and other environmental factors by applying anti-corrosion coating.

At present, in the corrosion resistance analysis of anti-corrosion coatings, the corrosion test is often carried out first, and then the relevant performance test is carried out. For example, firstly, according to the characteristics of the research environment, the corrosion test conditions are designed in a targeted manner, such as ultraviolet radiation, high and low temperature cycles, damp heat, salt spray, seawater medium immersion, etc., and the corrosion test is carried out on the anti-corrosion coating samples, and then the samples are taken out for hardness testing. , coating water absorption, surface morphology evaluation and other related performance tests. However, the above-mentioned traditional methods lack long-term continuous tracking and monitoring data on coating performance, coating protection status and coating damage in the process of testing and evaluating the performance of anti-corrosion coatings.

Contents of the invention

Based on this, it is necessary to provide a method for testing the corrosion resistance of anti-corrosion coatings, because traditional methods cannot continuously track and monitor data.

A method for testing the corrosion resistance of an anti-corrosion coating, comprising the following steps:

Coating the anti-corrosion coating on the substrate to obtain the test piece;

placing the detection piece in a corrosive medium for corrosion treatment;

The detection piece placed in the corrosive medium is used as a working electrode and connected to an electrochemical workstation;

The corrosive medium is electrically connected to an electrolytic cell soaked with a counter electrode and a reference electrode;

performing an electrochemical noise test during said corrosion treatment;

The corrosion condition of the anti-corrosion coating is judged according to the measured electrochemical noise data.

In one of the embodiments, the corrosive medium is salt solution, acid solution or alkali solution. Salt solutions are, for example, but not limited to solutions of sodium chloride, potassium chloride, calcium chloride, magnesium chloride, zinc chloride, ferric chloride, ferrous chloride, cupric chloride, and silver chloride. The acid solution is, for example, but not limited to sulfuric acid, hydrochloric acid, nitric acid, acetic acid, carbonic acid, hydrofluoric acid and the like. The lye is, for example, but not limited to sodium hydroxide, potassium hydroxide and the like.

In one of the embodiments, the base body includes metal material. The metal material may be, but not limited to, gold, silver, copper, iron, tin, platinum, aluminum, zinc, titanium, tungsten, lead, nickel, etc. and alloys of the above metals.

In one of the embodiments, the counter electrode is a platinum electrode.

In one of the embodiments, the reference electrode is a saturated calomel electrode or a saturated silver chloride electrode.

In one of the embodiments, the electrochemical noise test includes:

By applying a constant open circuit potential and measuring the current between the working electrode and the counter electrode, data on the change in current over time were obtained.

In one of the embodiments, the judging the corrosion condition of the anti-corrosion coating according to the measured electrochemical noise data includes:

According to the fluctuation amplitude of the electrochemical noise, the severity of corrosion of the anti-corrosion coating is judged.

In one of the embodiments, the fluctuation amplitude of the electrochemical noise is evaluated by the standard deviation, and the standard deviation is calculated by the following formula:

In the formula, S is the standard deviation, _xi is the instantaneous value of the measured current or potential in the electrochemical noise test, and n is the number of sampling points set in the experiment.

In one of the embodiments, the judging the corrosion condition of the anti-corrosion coating according to the measured electrochemical noise data includes:

According to the fluctuation shape of the electrochemical noise, the corrosion type of the anti-corrosion coating is judged.

In one of the embodiments, the anti-corrosion coating includes a primer, an intermediate paint and a top coat arranged in layers;

A first sample obtained by coating only a primer on a substrate, a second sample obtained by coating only a primer and a midcoat on a substrate, and a sample obtained by coating a substrate with a primer, midcoat, and topcoat were provided. The obtained third samples were subjected to the corrosion treatment respectively, and were respectively used as working electrodes to carry out the electrochemical noise test;

According to the electrochemical noise data of the third sample and referring to the electrochemical noise data of the first sample and the second sample, the degree of corrosion of the third sample is judged.

Compared with existing schemes, the above-mentioned anti-corrosion coating corrosion resistance test method has the following beneficial effects:

In the above test method of corrosion resistance performance of anti-corrosion coating, the test piece coated with anti-corrosion coating is placed in a corrosive medium. The chemical noise data is used to judge the corrosion condition of the anti-corrosion coating. The above test method realizes simultaneous monitoring and tracking of various performance changes of the anti-corrosion coating during the whole process of aging of the anti-corrosion coating. By collecting electrochemical noise data, the damage of the corrosion coating can be identified from the current and time signal analysis. The time and degree of the situation, etc., to realize the quantitative evaluation of the performance of the anti-corrosion coating. The above test method can convert the weak change signal that is difficult to identify by visual inspection or other detection means into an easily measurable electrical parameter for measurement and recording, and can also avoid signals such as applied voltage from electrochemical testing from interfering with the normal aging of the coating.

Description of drawings

Figure 1 is a schematic diagram of measuring electrochemical noise by the potentiostatic method, where WE represents the working electrode, CE represents the counter electrode, and RE represents the reference electrode.

Detailed ways

In order to make the above-mentioned purpose, features and advantages of the present application more obvious and understandable, the specific implementation manners of the present application will be described in detail below in conjunction with the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the application. However, the present application can be implemented in many other ways different from those described here, and those skilled in the art can make similar improvements without departing from the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of the application are only for the purpose of describing specific embodiments, and are not intended to limit the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial" , "radial", "circumferential" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the application and simplifying the description, rather than indicating or implying the referred device or Elements must have certain orientations, be constructed and operate in certain orientations, and thus should not be construed as limiting the application.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be understood as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

The anticorrosion coating corrosion resistance testing method of an embodiment of the present invention, comprises the following steps:

Step S1, coating the anti-corrosion coating on the substrate to obtain the inspection piece.

In step S2, the detection piece is placed in a corrosive medium for corrosion treatment.

In step S3, the detection piece placed in the corrosive medium is used as the working electrode and connected to the electrochemical workstation.

Step S4, electrically connecting the corrosive medium to the electrolytic cell immersed in the counter electrode and the reference electrode. Figure 1 is a schematic diagram of measuring electrochemical noise by the potentiostatic method, where WE represents the working electrode, CE represents the counter electrode, and RE represents the reference electrode.

In step S5, an electrochemical noise test is performed during the corrosion treatment.

Step S6, judging the corrosion condition of the anti-corrosion coating according to the measured electrochemical noise data.

In the above test method of corrosion resistance performance of anti-corrosion coating, the test piece coated with anti-corrosion coating is placed in a corrosive medium. The chemical noise data is used to judge the corrosion condition of the anti-corrosion coating. The above test method realizes simultaneous monitoring and tracking of various performance changes of the anti-corrosion coating during the whole process of aging of the anti-corrosion coating. By collecting electrochemical noise data, the damage of the corrosion coating can be identified from the current and time signal analysis. The time and degree of the situation, etc., to realize the quantitative evaluation of the performance of the anti-corrosion coating.

The above test method can convert the weak change signal that is difficult to identify by visual inspection or other detection means into an easily measurable electrical parameter for measurement and recording, and can also avoid signals such as applied voltage from electrochemical testing from interfering with the normal aging of the coating.

Wherein, in step S1, the substrate is used as the carrier of the anti-corrosion coating in the corrosion resistance test. Preferably, the base body comprises metallic material. The metal material may be, but not limited to, gold, silver, copper, iron, tin, platinum, aluminum, zinc, titanium, tungsten, lead, nickel, etc. and alloys of the above metals. It can be understood that the matrix can also be a composite material of metal material and non-metal material.

Optionally, in step S2, the corrosive medium may be but not limited to salt solution, acid solution or alkali solution. Salt solutions are, for example, but not limited to solutions of sodium chloride, potassium chloride, calcium chloride, magnesium chloride, zinc chloride, ferric chloride, ferrous chloride, cupric chloride, and silver chloride. The acid solution is, for example, but not limited to sulfuric acid, hydrochloric acid, nitric acid, acetic acid, carbonic acid, hydrofluoric acid and the like. The lye is, for example, but not limited to sodium hydroxide, potassium hydroxide and the like. At the same time, the above-mentioned salt solution, acid solution or alkali solution has high ion content and strong activity, and can be directly used as the electrolyte in the electrolytic cell to transport ions at the cathode and anode to realize electron exchange.

Optionally, in step S4, the counter electrode may be, but not limited to, a platinum electrode or the like. The reference electrode can be, but is not limited to, a saturated calomel electrode, a saturated silver chloride electrode, and the like.

It can be understood that in step S4, the corrosive medium soaked with the detection piece may be connected to the electrolytic cell soaked with the counter electrode and the reference electrode through a salt bridge.

In step S5, the electrochemical noise test may adopt a potentiostatic method, that is, by applying a constant open circuit potential, measuring the current between the working electrode and the counter electrode, and obtaining the data of the change of the current with time.

For step S6, judging the corrosion condition of the anti-corrosion coating according to the measured electrochemical noise data, including judging the severity of corrosion of the anti-corrosion coating according to the fluctuation range of the electrochemical noise.

In the time-domain analysis of electrochemical noise, the fluctuation range of electrochemical noise (EN) corresponds to the strength of the corrosion resistance of the anti-corrosion coating, and the larger the fluctuation range, the more severe the corrosion of the anti-corrosion coating.

The fluctuation range of EN is generally evaluated by the standard deviation S. The standard deviation S is proportional to the deviation formed by the instantaneous value and the average value of the current or potential during the test. The formula for calculating the standard deviation S is as follows:

In the formula, _xi is the instantaneous value of the measured current or potential in the electrochemical noise test, which can be directly derived from the test computer; n is the number of sampling points set in the test.

The greater the standard deviation S of the current noise, the greater the corrosion rate, the worse the protection of the anti-corrosion coating or the more serious the damage of the anti-corrosion coating.

For step S6, judging the corrosion condition of the anti-corrosion coating according to the measured electrochemical noise data, including judging the corrosion type of the anti-corrosion coating according to the fluctuation shape of the electrochemical noise.

In the electrochemical noise time-domain analysis, the fluctuation shape of EN corresponds to the corrosion type. Uniform corrosion shows that the EN data points are approximately symmetrically distributed on both sides of the mean value. Pitting appears as a continuous abrupt change in the EN data points, in other words, a continuous spike in the data plot.

The type of corrosion is assessed by the pitting index PI. The pitting index PI is calculated by the following formula:

PI = S _I /I _RMS

In the formula, S _I is the current standard deviation calculated from the measured data, and I _RMS is the root mean square value of the sample test surface current. When PI is close to 1.0, it means that surface pitting occurs. When PI is between 0.1 and 1.0, it means that localized corrosion occurs. When PI is close to 0, it means that the electrode surface is in the type of uniform corrosion or better protection.

When the electrochemical noise data does not have obvious magnitude changes, it indicates that the integrity of the anti-corrosion coating is good. At this time, focus on the standard deviation S, noise resistance Rn and pitting corrosion index PI, etc., which are the key to evaluating the corrosion rate and corrosion type. data.

When the electrochemical noise data has a significant magnitude mutation, it indicates that the type of material on the sample surface or its integrity has changed at this time.

When obvious bubbles appear on the surface of the working electrode, the electrochemical noise data is significantly larger at this time, indicating that the anti-corrosion coating has been corroded and has defects.

Optionally, the anti-corrosion coating is not limited to a single coating, but may also include multiple sub-coatings arranged in layers. For example, common anti-corrosion coatings include primers, intermediate paints and top coats. Wherein, the primer is directly arranged on the substrate, that is, it is in direct contact with the substrate. The primer has certain conductivity, such as inorganic zinc-rich paint or various organic zinc-rich paints. The intermediate paint plays the role of connecting the primer and the topcoat, which can improve the adhesion and connection strength between the primer and the topcoat, and can increase the thickness of the paint film. The intermediate paint can be epoxy intermediate paint, epoxy mica iron intermediate paint, alkyd mica iron intermediate paint, etc. Topcoat, also known as finish paint, is the last layer of paint applied in multi-layer painting. The topcoat is made of coatings with excellent weather resistance, such as epoxy topcoat, fluorocarbon topcoat, acrylic topcoat, polyurethane topcoat, etc.

It can be understood that when the anti-corrosion coating includes primer, intermediate paint and top paint, when the anti-corrosion coating is corroded, the top paint is corroded first, and then the intermediate paint, primer and substrate in sequence.

In order to study the corrosion degree of the above-mentioned anti-corrosion coating, the difference in conductivity of the substrate and multiple sub-coatings can be used to conduct electrochemical noise tests on the samples with the help of a three-electrode system and an electrochemical workstation.

More specifically, for an anti-corrosion coating that includes multiple sub-coats, when making a test piece, in addition to coating all the sub-coats on the substrate as a test piece, it is also possible to make additional coatings with only a few sub-coats on the substrate. The detection piece obtained by coating, as the working electrode, is connected to the electrochemical workstation, and connected to the electrolytic cell soaked with the counter electrode and the reference electrode through the salt bridge. Electrochemical noise tests were performed on various test pieces.

For example, when the anti-corrosion coating includes a primer, an intermediate paint and a top coat, the difference in electrical conductivity of the substrate, primer, intermediate paint, and top coat can be used to perform electrochemical noise on the sample with the help of a three-electrode system and an electrochemical workstation. test.

More specifically, the first sample is obtained by coating a primer on the substrate, the second sample is obtained by coating a primer and an intermediate paint on a substrate, and the second sample is obtained by coating a primer, an intermediate paint and a top coat on a substrate For the third sample, the above-mentioned first sample, second sample and third sample were respectively immersed in corrosive medium, used as the working electrode, connected to the electrochemical workstation, and connected to the electrode soaked with the counter electrode and the reference electrode through the salt bridge. than the electrode in the electrolytic cell. In addition, the substrate without anti-corrosion coating can also be used as a control experiment, that is, the substrate without anti-corrosion coating is used as the working electrode for corrosion resistance test experiments.

It can be understood that the corrosive medium immersed in the first sample, the second sample, the third sample and the substrate not coated with anti-corrosion coating remains consistent, and their respective corresponding counter electrodes and reference electrodes remain consistent.

When the current noise data has an obvious magnitude mutation, it indicates that the type or integrity of the sample surface substance has changed at this time. For the third sample obtained by coating the primer, intermediate paint and topcoat on the substrate, when the current noise data has a significant magnitude change, refer to the first sample, the second sample and the uncoated anti-corrosion The current noise data of the substrate of the coating can be used to determine which layer of the primer, intermediate paint, topcoat or substrate the anti-corrosion coating of the third sample is corroded at this time. When obvious bubbles appear on the surface of the working electrode, the electrochemical noise data is significantly larger by several orders of magnitude at this time, indicating that the anti-corrosion coating has been corroded and has defects, exposing the primer or substrate, and the experiment can be ended at this time.

Compared with the traditional method of successively carrying out corrosion resistance experiment and performance test, the anticorrosion coating corrosion resistance performance test method of the present invention has the following advantages:

The invention proposes an in-situ monitoring method in the corrosion resistance analysis of anti-corrosion coatings, which realizes the combination of corrosion resistance experiment and real-time monitoring, and realizes the simultaneous monitoring and tracking of anti-corrosion coatings in the whole process of aging of anti-corrosion coatings Changes in various aspects of performance, and transform the weak change signals that are difficult to identify by visual inspection or other detection methods into electrical parameters that are easy to measure for measurement and recording.

In the traditional method, only some qualitative descriptions can be made, and there are shortcomings such as long experimental period, inaccurate experimental results, and poor reproducibility. Furthermore, the set time interval can only be set artificially through experience, etc., and it is easy to miss the initial stage of anti-corrosion coating failure, which has a great impact on the analysis of the initial cause, manifestation and development process of anti-corrosion coating failure. Compared with the conventional coating detection method, the electrochemical test is fast and convenient, and there is no need to establish the electrode process model of the technical test system in advance; it does not need to meet the three basic conditions of resistance. The detection equipment is simple and the amount of information provided is rich. Long-distance monitoring can be realized. From the subsequent current and time signal analysis, the time and degree of coating damage, pitting, and cracks that lead to the exposure of the primer or even the metal substrate can be identified, and the quantitative evaluation of the performance of the anti-corrosion coating can be realized.

In the traditional method, only surface observation and non-destructive testing are carried out after the sample is taken out, which cannot fully characterize the state of the sample. If you want to fully understand the performance changes in various aspects and carry out relevant performance testing experiments, it will inevitably cause damage to the surface of the sample, resulting in that it cannot be put back into the corrosion-resistant box for further aging experiments after the test, and the sample can only be replaced. The electrochemical noise technology adopted in the present invention is an in-situ non-destructive monitoring technology. During the measurement process, there is no need to apply external disturbances to the measured electrode that may change the corrosion process of the corrosion electrode, that is, the detection means itself will not cause damage to the sample. .

Specific examples are provided below to illustrate the present invention, but the present invention is not limited to the following examples.

Example 1

The anti-corrosion coating in this embodiment is a single coating. The anticorrosion coating corrosion resistance test method that the present embodiment provides, comprises the following steps:

Step 1, prepare test samples. The anti-corrosion coating is coated on the substrate to obtain the test piece.

Step 2, conduct corrosion test. Immerse the above test piece in corrosive medium.

Step 3, connect the electrochemical noise measurement system. Connect the detection piece to the electrochemical workstation as the working electrode, and connect it to the electrolytic cell immersed in the counter electrode and reference electrode through the salt bridge. Electrochemical noise was monitored by potentiostatic method, by applying a constant open circuit potential and measuring the current between the working electrode and the counter electrode.

Step 4, record and save the fluctuation shape and magnitude range of the electrochemical noise data.

When the electrochemical noise data does not have obvious magnitude changes, it indicates that the integrity of the anti-corrosion coating is good. At this time, focus on the standard deviation S, noise resistance Rn and pitting corrosion index PI, etc., which are the key to evaluating the corrosion rate and corrosion type. data.

When the electrochemical noise data has a significant magnitude mutation, it indicates that the type of material on the sample surface or its integrity has changed at this time. When obvious bubbles appear on the surface of the working electrode, the electrochemical noise data is significantly larger by several orders of magnitude at this time, indicating that the anti-corrosion coating has been corroded and has defects, exposing the substrate, and the experiment can be ended at this time.

Step 5, the test results are analyzed and exported by EC-Lab software, and the results are re-drawn and presented by Origin software.

Example 2

The anti-corrosion coating in this embodiment includes a primer, an intermediate paint and a finish paint. The anticorrosion coating corrosion resistance test method that the present embodiment provides, comprises the following steps:

Step 1, prepare test samples. The samples include: the substrate without anti-corrosion coating; the first sample obtained by coating the primer only on the substrate; the second sample obtained by coating the primer and intermediate paint only on the substrate; A third sample obtained by applying a primer, an intermediate coat, and a top coat. Multiple pieces of the above samples were prepared for repeated verification and control tests.

Step 2, conduct corrosion test. Group the above four samples into groups and immerse them in corrosive media respectively.

Step 3, connect the electrochemical noise measurement system. Connect the sample to the electrochemical workstation as the working electrode, and connect it to the electrolytic cell immersed in the counter electrode and reference electrode through the salt bridge. Electrochemical noise was monitored by potentiostatic method, by applying a constant open circuit potential and measuring the current between the working electrode and the counter electrode.

Step 4, respectively record and save the fluctuation shape and magnitude range of the electrochemical noise data of the four samples at the beginning stage, and focus on the data of the third sample that is completely coated.

When the electrochemical noise data does not have obvious magnitude changes, it indicates that the integrity of the anti-corrosion coating is good. At this time, focus on the standard deviation S, noise resistance Rn and pitting corrosion index PI, etc., which are the key to evaluating the corrosion rate and corrosion type. data.

When the electrochemical noise data has a significant magnitude mutation, it indicates that the type of material on the sample surface or its integrity has changed at this time. At this time, referring to the current noise data of the first sample, the second sample, and the substrate not coated with anti-corrosion coating, it can be judged that the anti-corrosion coating of the third sample is corroded to the primer, intermediate paint, and top coat. Or which layer of the substrate.

When obvious bubbles appear on the surface of the working electrode, the electrochemical noise data is significantly larger by several orders of magnitude at this time, indicating that the anti-corrosion coating has been corroded and has defects, exposing the primer or substrate, and the experiment can be ended at this time.

Step 5, the test results are analyzed and exported by EC-Lab software, and the results are re-drawn and presented by Origin software.

The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be determined by the appended claims, and the description can be used to interpret the contents of the claims.

Claims (10)

1. The corrosion resistance test method of the anti-corrosion coating is characterized by comprising the following steps of:

coating the anticorrosive coating on the substrate to obtain a detection piece;

placing the detection piece in a corrosive medium for corrosion treatment;

connecting the detection member placed in the corrosive medium to an electrochemical workstation as a working electrode;

electrically connecting the corrosive medium to an electrolytic cell soaked with a counter electrode and a reference electrode;

electrochemical noise testing is carried out in the corrosion treatment process;

and judging the corrosion condition of the anti-corrosion coating according to the measured electrochemical noise data.

2. The method for testing the corrosion resistance of the anti-corrosion coating according to claim 1, wherein the corrosive medium is a salt solution, an acid solution or an alkali solution.

3. The method for testing the corrosion resistance of an anti-corrosive coating according to claim 1, wherein the substrate comprises a metallic material.

4. The method for testing the corrosion resistance of an anti-corrosive coating according to claim 1, wherein the counter electrode is a platinum electrode.

5. The method for testing the corrosion resistance of the anti-corrosion coating according to claim 1, wherein the reference electrode is a saturated calomel electrode or a saturated silver chloride electrode.

6. The method for testing the corrosion resistance of an anti-corrosive coating according to claim 1, wherein the electrochemical noise test comprises:

by applying a constant open circuit potential, the current between the working electrode and the counter electrode is measured, and data of the current change with time is obtained.

7. The method for testing the corrosion resistance of the corrosion-resistant coating according to any one of claims 1 to 6, wherein the determining the corrosion condition of the corrosion-resistant coating according to the measured electrochemical noise data comprises:

and judging the corrosion intensity of the anti-corrosion coating according to the fluctuation amplitude of the electrochemical noise.

8. The method for testing the corrosion resistance of an anti-corrosive coating according to claim 7, wherein the fluctuation range of the electrochemical noise is evaluated by a standard deviation calculated by the following formula:

wherein S is standard deviation, x _i And n is the sampling point number set in the test, and is the transient value of the actual measured current or potential in the electrochemical noise test.

9. The method for testing the corrosion resistance of the corrosion-resistant coating according to any one of claims 1 to 6, wherein the determining the corrosion condition of the corrosion-resistant coating according to the measured electrochemical noise data comprises:

and judging the corrosion type of the corrosion-resistant coating according to the fluctuation shape of the electrochemical noise.

10. The method for testing the corrosion resistance of the anti-corrosion coating according to any one of claims 1 to 6, wherein the anti-corrosion coating comprises a primer, a middle paint and a top paint which are laminated;

providing a first sample obtained by coating a primer on a substrate, a second sample obtained by coating a primer and an intermediate paint on a substrate, and a third sample obtained by coating a primer, an intermediate paint, and a top coat on a substrate, respectively performing the corrosion treatment, and respectively performing an electrochemical noise test as a working electrode;

and judging the corrosion degree of the third sample according to the electrochemical noise data of the third sample and referring to the electrochemical noise data of the first sample and the second sample.