A method for continuous performance testing of metal-based protective coatings

Abstract

The present invention provides a method for continuous performance testing of a metal-based protective coating, wherein the method is to perform performance testing on the metal-based protective coating so as to more accurately assess and evaluate the protective performance of the metal-based coating. The main process of the performance test is: the first step is to perform a four-point bending test, the second step is to perform a 1000h neutral salt spray accelerated corrosion test, the third step is to perform a high-temperature jet ablation test, the fourth step is to perform an electrochemical corrosion test, an impact resistance test and an adhesion test respectively, and the fifth step is to collate and analyze the test results. The method provided by the present invention is used to continuously test the protective performance of the metal-based coating, which can more accurately evaluate the service life of the metal-based coating, is conducive to the development of materials with better performance, and has broad application prospects.

Description

Technical Field

[0001] The invention belongs to the field of metal-based protective coatings, and more specifically, relates to a method for testing the protective performance of metal-based coatings. Background Art

[0002] With the advancement of science and technology and the improvement of economic level, land resources are becoming increasingly depleted, and the development of marine business has become an indispensable part of the development of all countries. my country is rich in marine resources, and marine engineering equipment such as offshore oil drilling platforms, offshore wind power / nuclear power, ships and port machinery are increasing. However, the marine environment is very complex and harsh. The marine engineering equipment used is directly exposed to the marine environment and is very susceptible to corrosion under the conditions of the marine atmosphere, which rapidly accelerates the damage and failure of the marine engineering equipment, reduces its service life, and increases maintenance costs. How to improve the performance of marine engineering equipment and extend its service life is an urgent problem to be solved.

[0003] Metal-based protective coatings have broad application prospects due to their excellent corrosion resistance, high wear resistance and outstanding mechanical strength. In order to ensure the long-term stability and reliability of these coatings in extreme or changing environments, it is particularly important to develop an efficient continuous performance test method. First, the design of the continuous performance test method should take into account the need to simulate the actual working environment. This includes the control and adjustment of factors such as temperature, humidity, and chemical media so that the test conditions can truly reflect the challenges that the coating may encounter in actual use. For example, by testing the coating in an environment with high temperature, high humidity or corrosive chemicals, its performance under extreme conditions can be evaluated. The continuity of the test is key. Compared with traditional short-term tests, long-term performance tests can provide more information about the changes in material properties over time. This includes long-term monitoring of the coating's mechanical properties (such as hardness and toughness), chemical stability (such as corrosion resistance), and physical properties (such as adhesion). By continuously recording data, the gradual changes in the coating's performance can be observed, allowing for a more accurate prediction of its life. To achieve this goal, high-precision testing equipment and advanced data collection techniques must be used. For example, the corrosion protection of a coating can be evaluated using an electrochemical polarization curve test, while its mechanical properties can be measured using a tensile test. Therefore, the performance test method should be flexible and adaptable to different testing needs. This means that the test procedure should be able to be adjusted to different application scenarios and specific coating characteristics. For example, in the automotive industry, the coating may need to show excellent wear resistance, while in the chemical industry, its corrosion resistance may be more important.

[0004] In summary, the methods for performance testing of metal-based protective coatings involve multiple aspects: environmental simulation, long-term monitoring, the use of high-precision test equipment, advanced data analysis techniques, and the flexibility and adaptability of the test methods. Through these comprehensive methods, the long-term performance of the coating can be evaluated more comprehensively and accurately, providing a reliable scientific basis for its use in various industrial applications. Therefore, the use of a method for testing the performance of metal-based protective coatings has important academic significance and practical value. Summary of the invention

[0005] In order to solve the above problems, the object of the present invention is to provide a method for continuous performance testing of metal-based protective coatings, so as to observe the gradual changes in the coating properties and more accurately predict its lifespan.

[0006] In order to achieve the above object, the present invention provides a method for continuous performance testing of a metal-based protective coating, comprising the following steps:

[0007] 1) Four-point bending test: Prepare a sample with a size of 300mm×150mm×6mm, use a universal testing machine to perform a reverse four-point bending test on the coating sample on the sample, set the loading rate to 1mm / min, and perform three sets of parallel tests;

[0008] 2) Neutral salt spray accelerated corrosion test: Place the coating on the sample that has completed step 1) in a neutral salt spray accelerated corrosion test chamber for testing, and conduct three sets of parallel tests;

[0009] 3) High temperature jet ablation test: Fix the sample that has completed step 2) directly opposite the emitter of the high temperature jet ablation equipment, so that the coating of the sample faces the high temperature jet emitter. The high temperature jet ablation angle is 90°, the test lasts for 120 seconds, and three sets of parallel tests are performed;

[0010] 4) Electrochemical corrosion test: The sample completed in step 3) was immersed in the corrosion solution on the electrochemical workstation of the three-electrode system for 1 h. After the open circuit potential was stabilized, it was scanned at a scan rate of 0.5 mV / s to obtain the polarization curve. Three sets of parallel tests were performed;

[0011] 5) Impact resistance test: The samples completed in step 3) were subjected to impact resistance test: a hemisphere with a weight of 1.8 kg and a diameter of 15.875 mm was used, the impact height was 1200 mm, and a single group was impacted 25 times according to a 5×5 dot matrix, with the center distance between two adjacent impact points being 20±1.5 mm; three groups of parallel tests were conducted;

[0012] 6) Adhesion test: Cut the sample completed in step 3) into 10mm×10mm×6mm, use adhesive to bond the sample and the counterpart, and then cure according to the curing pressure, temperature and time specified by the adhesive; install the bonded sample on the tensile fixture, center it on the tensile testing machine, and stretch it at a stretching speed of 2mm / min, and record the sample's failure load; conduct three sets of parallel tests;

[0013] 7) Test result collation and analysis: collate and analyze the results of step 4) electrochemical corrosion test, step 5) impact resistance test, and step 6) adhesion test.

[0014] Furthermore, the metal-based protective coating is an iron-based amorphous coating.

[0015] Furthermore, the conditions of the neutral salt spray accelerated corrosion test in step 2) are: a sodium chloride solution with a concentration of 50 g / L, a pH value of 6.5-7.2, a temperature of 35±2°C, a humidity greater than 95%, and continuous spraying for 24 hours for 1000 hours.

[0016] Furthermore, the high temperature jet ablation in step 3) is flame ablation, plasma ablation or laser ablation.

[0017] Furthermore, in step 3), the working electrode in the three-electrode system is the epoxy-sealed coating sample, the reference electrode is a saturated calomel electrode, and the auxiliary electrode is a platinum sheet electrode.

[0018] Furthermore, in step 4), the corrosion solution is a 3.5wt.% NaCl solution.

[0019] The beneficial effects of the present invention are:

[0020] The present invention provides a method for continuously testing the performance of a metal-based protective coating. The method sequentially performs a four-point bending test, a neutral salt spray test, a wake scour test, an electrochemical corrosion test, an impact resistance test, an adhesion test, and a coating appearance test on the coating to obtain continuous observation data of the coating, observe the gradual change of the coating performance, and thus more accurately predict the coating life, realize damage monitoring of the protective coating on the surface of marine engineering equipment, ensure the performance of the marine engineering equipment, extend the service life of the marine engineering equipment, and reduce maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A flow chart of a method for continuous performance testing of a metal-based protective coating provided by the present invention.

[0022] Figure 2 A photograph of the four-point bending test results of the coating according to the method for continuous performance testing of the metal-based protective coating provided by the present invention.

[0023] Figure 3 A photograph of the neutral salt spray accelerated corrosion test results of the coating using the method for continuous performance testing of the metal-based protective coating provided by the present invention.

[0024] Figure 4 A photograph of the high-temperature jet ablation test results of the coating using the method for continuous performance testing of the metal-based protective coating provided by the present invention.

[0025] Figure 5 A photograph of the electrochemical test results of the coating according to the method for continuous performance testing of the metal-based protective coating provided by the present invention.

[0026] Figure 6 A schematic diagram of the distribution of impact points and impact sequences for an impact resistance test of a metal-based protective coating in a method for continuous performance testing of a metal-based protective coating provided by the present invention.

[0027] Figure 7 A photograph of the impact resistance test results of the metal-based protective coating according to the method for continuous performance testing of the metal-based protective coating provided by the present invention.

[0028] Figure 8 A photograph of the adhesion test results of the coating according to the method for continuous performance testing of the metal-based protective coating provided by the present invention. DETAILED DESCRIPTION

[0029] The embodiments of the present invention will be described in detail and comprehensively below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0030] The present invention provides a method for continuous performance testing of metal-based protective coatings, such as Figure 1 As shown, the following steps are included:

[0031] 1) Four-point bending test: Prepare a sample with a size of 300mm×150mm×6mm, use a universal testing machine to perform a reverse four-point bending test on the coating sample on the sample, and set the loading rate to 1mm / min; to avoid the contingency of the experimental results, perform three sets of parallel tests.

[0032] The four-point bending test method under laboratory universal testing machine conditions was used to verify the reverse bending resistance of metal-based coating materials and study their failure behavior.

[0033] 2) Neutral salt spray accelerated corrosion test: Place the coating on the sample that has completed step 1) in a neutral salt spray accelerated corrosion test chamber for testing; the test solution is a 50g / L sodium chloride solution with a pH value of 6.5-7.2, the test temperature is (35±2)℃, the spray is continuously sprayed for 24 hours, and the test time is 1000 hours. To avoid the contingency of the experimental results, three sets of parallel tests are conducted.

[0034] The neutral salt spray accelerated corrosion test method was adopted in the laboratory to simulate the marine atmosphere environment. The neutral salt spray accelerated corrosion test was carried out on the coating samples after the four-point bending test, and their corrosion failure behavior was studied.

[0035] 3) High temperature jet ablation test: Fix the sample that has completed step 2) directly opposite the high temperature jet so that the coating of the sample faces the high temperature jet. The high temperature jet ablation angle is 90° and the test is performed for 120 seconds. To avoid the randomness of the experimental results, three sets of parallel tests are performed.

[0036] The flame ablation test method was used in a laboratory environment to verify the high-temperature jet ablation test of the coating samples after the neutral salt spray accelerated corrosion test, and its ablation failure behavior was studied.

[0037] 4) Electrochemical corrosion test: The sample completed in step 3) was immersed in the corrosion solution on the electrochemical workstation of the three-electrode system for 1 hour. After the open circuit potential was stabilized, it was scanned at a scan rate of 0.5mV / s to obtain the polarization curve; the electrolyte solution used was 3.5wt.% NaCl solution. To avoid the accidental nature of the experimental results, three sets of parallel tests were performed.

[0038] The electrochemical corrosion test method was adopted in the laboratory to simulate the seawater corrosion environment. The coating samples after the high-temperature jet ablation test were subjected to electrochemical corrosion test to obtain the polarization curves and key fitting parameters, and the electrochemical corrosion failure behavior was studied.

[0039] 5) Impact resistance test: The samples completed in step 3) were subjected to impact resistance test: a hemisphere with a weight of 1.8 kg and a diameter of 15.875 mm was used, the impact height was 1200 mm, and a single group was impacted 25 times according to a 5×5 dot matrix, with the center distance between two adjacent impact points being 20±1.5 mm; three groups of parallel tests were conducted;

[0040] The impact resistance test method was adopted in laboratory environment to carry out impact resistance test on the coating samples after high temperature jet ablation test. The percentage of area of ​​the coating samples that remained intact after the impact resistance test was calculated, and its impact resistance failure behavior was studied.

[0041] 6) Adhesion test: Cut the sample completed in step 3) into 10mm×10mm×6mm, use adhesive to bond the sample and the counterpart, and then cure according to the curing pressure, temperature and time specified by the adhesive; install the bonded sample on the tensile fixture, center it on the tensile testing machine, and stretch it at a speed of 2mm / min, and record the sample's failure load; in order to avoid the randomness of the experimental results, three sets of parallel tests were carried out.

[0042] The adhesion test method under laboratory tensile testing machine conditions was used to test the adhesion of the coating samples after high-temperature jet ablation test, and the bonding performance between the coating and the substrate was evaluated.

[0043] 7) Sorting and analyzing test results: Sorting and analyzing the results of step 4) electrochemical corrosion test, step 5) impact resistance test, and step 6) adhesion test.

[0044] Example 1

[0045] Two spare parts of 316L stainless steel coating equipment were prepared on the surface of 45 steel using supersonic flame spraying technology and different spraying processes as specimens. They were cut according to the test requirements using an electric spark wire cutting machine, and two coating specimens that can be used for testing were prepared; they are called coating 1 and coating 2 respectively.

[0046] 1. Four-point bending test

[0047] The size of the coating sample is 300mm×150mm×6mm. A microcomputer-controlled electronic universal testing machine is used to conduct a reverse four-point bending test on the sample (the coating surface is the inner side of the bend), and the loading rate is set to 1mm / min; 5 parallel samples are selected. Figure 2 This is the macroscopic morphology of the coating surface after reverse four-point bending. Figure 2 It can be seen that there is no delamination, peeling or cracking in the two coating samples.

[0048] 2. Neutral salt spray accelerated corrosion test

[0049] The coating samples were selected from the coatings that had been subjected to the four-point bending test, and the sample size was 300mm×150mm×6mm. The neutral salt spray accelerated corrosion test was carried out in a salt spray test chamber. The salt spray chamber conditions were set, the chamber temperature was (35±2)℃, the horizontal spray collection rate was 1mL / h~2.5mL / h, the sodium chloride concentration was (50±10) / L, and the pH value was 6.5~7.2; the test panels were placed in the salt spray chamber for continuous testing; the surface of the test panels was regularly checked for blistering, rust, and rust spread. The surface morphology of the coating after the four-point bending test is as follows: Figure 3 As shown. Figure 3It can be seen that no obvious corrosion was found on the surfaces of the two coatings, which indicates that the coating samples after the four-point bending test have good resistance to neutral salt spray accelerated corrosion.

[0050] 3. High temperature jet ablation test

[0051] The high temperature jet ablation test can be performed using flame ablation equipment, plasma ablation equipment or laser ablation equipment. In this example, flame ablation equipment is selected.

[0052] The coating that has been subjected to the neutral salt spray accelerated corrosion test is subjected to the high temperature jet ablation test, and the sample size is 300mm×150mm×6mm. During the test, a hole is drilled in one section of the coating sample so that it is fixed directly opposite the high temperature jet, and the high temperature jet ablation angle is 90°. Figure 4 The surface morphology of the coating after high-temperature jet ablation. Figure 4 It can be seen that no obvious failure phenomenon was found on the surfaces of the two coatings, which indicates that the coating samples after the neutral salt spray accelerated corrosion test can withstand the high-temperature jet ablation test.

[0053] 4. Electrochemical corrosion test, impact resistance test and adhesion test

[0054] 1) Electrochemical corrosion test

[0055] The coating samples that have undergone high-temperature jet ablation test were taken and cut into 10mm×10mm×6mm. The corrosion resistance of the samples that have undergone high-temperature jet ablation test was analyzed. The electrochemical test was carried out on an electrochemical workstation using a conventional three-electrode system. The working electrode is the epoxy-sealed coating sample, the reference electrode is a saturated calomel electrode, and the auxiliary electrode is a platinum sheet electrode. The electrolyte solution uses a 3.5wt.% NaCl solution. During the test, the coating sample was immersed in the corrosion solution for 1h, and after the open circuit potential was stabilized, the polarization curve test was carried out at a scanning rate of 0.5mV / s. The test results are as follows Figure 5 As shown. Figure 5 It can be seen that after high-temperature jet ablation, the corrosion resistance of coating 1 is worse than that of the original coating, and the corrosion resistance of coating 2 is not much different from that of the original coating.

[0056] 2) Impact resistance test

[0057] When testing the impact resistance of coating samples, the coating samples that have been ablated by high-temperature jets are cut into sizes of 150 mm × 150 mm × 6 mm. The sample is impacted 25 times in sequence using an impact tester, with an impact height of 1.2 meters. The continuous impact points form a 5 × 5 matrix, such as Figure 6 shown. Figure 6 The numbers in the middle are in order of impact from small to large, and the center distance between two adjacent impact points is 20±1.5mm. Figure 7 The surface morphology of the coating after the impact resistance test. Figure 7 It can be seen that the surfaces of the two coatings are intact.

[0058] 3) Adhesion test

[0059] The coating sample after the high-temperature jet ablation test was cut into a disc-shaped test sample with a diameter of 25 mm, and the sample was bonded to the mating piece with a high-viscosity glue. A universal testing machine was used to perform a tensile test at a tensile speed of 2 mm / min, and the measured value was recorded. Figure 8 The following are the test results of adhesion. Figure 8 It can be seen that after high-temperature jet ablation, the bonding strength of coating 1 decreases, while the bonding strength of coating 2 does not change much.

[0060] 5. Organize and analyze test results

[0061] It can be seen from the above tests that the performance of the tested coating 1 sample in the electrochemical corrosion test was not as expected, but it performed well in the impact resistance test, and it did not perform as expected in the adhesion test, indicating that the coating sample prepared by the spraying process is prone to corrosion and fall off in the marine environment; the tested coating 2 sample performed well in all the above tests, indicating that the coating sample prepared by the spraying process can meet the requirements of long-term use in extreme marine environments. The coating use effect of the sampling equipment in actual use is indeed consistent with this embodiment, indicating that the method provided by the present invention can indeed reflect the use of the equipment coating.

[0062] The continuous performance test method of the metal-based protective coating provided by the present invention can be determined based on the simulation of the actual working environment. In the continuous performance test, when all the test results of the coating sample are passed, it indicates that the coating sample can meet the use requirements under the simulated working environment; when the coating sample fails a certain performance test, it indicates that the coating sample does not meet the use conditions in this specific environment (especially the extremely complex marine environment), and the sample can be adjusted by adjusting the coating composition, spraying process, etc. to improve its corresponding performance as needed. If a spare sample is taken for the engineering equipment that has been put into use, it can be warned that maintenance or replacement is required after a specific time limit. The continuous performance test method can evaluate the performance of metal-based protective coatings, estimate the service life of the coating, and provide a reliable scientific basis for the development, use, maintenance and maintenance of new coating materials.

[0063] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A method for continuous performance testing of a metal-based protective coating, characterized in that: The steps include: 1) Four-point bending test: Prepare a sample with a size of 300mm×150mm×6mm, use a universal testing machine to perform a reverse four-point bending test on the coating sample on the sample, set the loading rate to 1mm / min, and perform three sets of parallel tests; 2) Neutral salt spray accelerated corrosion test: Place the coating on the sample that has completed step 1) in a neutral salt spray accelerated corrosion test chamber for testing, and conduct three sets of parallel tests; 3) High temperature jet ablation test: Fix the sample that has completed step 2) directly opposite the emitter of the high temperature jet ablation equipment, so that the coating of the sample faces the high temperature jet emitter. The high temperature jet ablation angle is 90°, the test lasts for 120 seconds, and three sets of parallel tests are performed; 4) Electrochemical corrosion test: The sample completed in step 3) was immersed in the corrosion solution on the electrochemical workstation of the three-electrode system for 1 h. After the open circuit potential was stabilized, it was scanned at a scan rate of 0.5 mV / s to obtain the polarization curve. Three sets of parallel tests were performed; 5) Impact resistance test: The samples completed in step 3) were subjected to impact resistance test: a hemisphere with a weight of 1.8 kg and a diameter of 15.875 mm was used, the impact height was 1200 mm, and a single group was impacted 25 times according to a 5×5 dot matrix, with the center distance between two adjacent impact points being 20±1.5 mm; three groups of parallel tests were conducted; 6) Adhesion test: Cut the sample completed in step 3) into 10mm×10mm×6mm, use adhesive to bond the sample and the mating piece, and then cure according to the curing pressure, temperature and time specified by the adhesive; install the bonded sample on the tensile fixture, center it on the tensile testing machine, and stretch it at a stretching speed of 2mm / min, and record the sample's failure load; Three parallel experiments were conducted; 7) Test result collation and analysis: collate and analyze the results of step 4) electrochemical corrosion test, step 5) impact resistance test, and step 6) adhesion test respectively; The method is applied to marine engineering equipment; The metal-based protective coating is an iron-based amorphous coating.

2. The method for continuous performance testing of a metal-based protective coating according to claim 1, characterized in that: Step 2) The conditions of the neutral salt spray accelerated corrosion test are: a sodium chloride solution with a concentration of 50 g / L, a pH value of 6.5-7.2, a temperature of 35±2°C, a humidity greater than 95%, continuous spraying for 24 hours, and a duration of 1000 hours.

3. The method for continuous performance testing of a metal-based protective coating according to claim 1, characterized in that: Step 3) The high temperature jet ablation is flame ablation, plasma ablation or laser ablation.

4. The method for continuous performance testing of a metal-based protective coating according to claim 1, characterized in that: Step 3) In the three-electrode system, the working electrode is the epoxy-sealed coating sample, the reference electrode is a saturated calomel electrode, and the auxiliary electrode is a platinum sheet electrode.

5. The method for continuous performance testing of a metal-based protective coating according to claim 1, characterized in that: Step 4) The corrosion solution is a 3.5wt.% NaCl solution.

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