An in-situ metallographic coating method

Abstract

The application discloses a kind of field metallographic film coating methods, at least comprising the following steps: providing a metal component, the surface of the metal component is provided to be measured area;Polish the area to be measured until the roughness of the area to be measured reaches preset value;Wipe the area to be measured;Once wash the area to be measured, and in the process of once washing and after once washing, the area to be measured is continuously dried until the temperature of the area to be measured rises to preset temperature;The area to be measured is immersed and etched until the metal luster of the surface of the area to be measured is dim;After the area to be measured is washed for the second time, dry the area to be measured;And film coating on the area to be measured.By the field metallographic film coating method provided by the application, the interference of high humidity field environment on the film coating process can be avoided, the film coating quality is improved, and the accuracy of the field metallographic inspection result is improved.

Description

Technical Field

[0001] This invention relates to the field of metallographic testing technology for metallic materials, and in particular to an on-site metallographic coating method. Background Technology

[0002] On-site metallographic testing technology is convenient, fast, and efficient, playing an indispensable role in the failure analysis of metal components. Therefore, it is widely used in the testing of industrial equipment in power, chemical, aerospace, and shipbuilding industries. However, the humidity of the on-site environment cannot be regulated. Excessive humidity can lead to moisture between the metallographic coating and the metal component, affecting the quality of the coating and preventing the successful acquisition of microstructural information, thus causing deviations in the inspection results. Therefore, there is an urgent need for an on-site metallographic coating method to avoid the negative impact of high humidity on coating quality. Summary of the Invention

[0003] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide an on-site metallographic coating method that can avoid the interference of high humidity on-site environment on the coating process, improve coating quality, and thus improve the accuracy of on-site metallographic inspection results.

[0004] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution.

[0005] This invention provides a method for on-site metallographic coating, comprising at least the following steps:

[0006] A metal component is provided, and a test area is formed on the surface of the metal component;

[0007] Polish the area to be tested until the roughness of the area to be tested reaches a preset value;

[0008] Wipe the area to be tested;

[0009] The area to be tested is cleaned once, and during and after the cleaning process, the area to be tested is continuously dried until the temperature of the area to be tested rises to a preset temperature.

[0010] The test area is etched until the metallic luster of the surface of the test area becomes dull;

[0011] After a second cleaning of the test area, the test area is dried; and

[0012] A film is applied to the area to be tested.

[0013] In one embodiment of the present invention, the preset temperature is 35℃~45℃.

[0014] In one embodiment of the present invention, after a preset time has elapsed during the first cleaning process, drying begins and the area to be tested is cleaned again until the first cleaning process is completed, at which point the area to be tested is dried again.

[0015] In one embodiment of the present invention, the temperature of the heat source used to dry the area to be tested is 70°C to 90°C.

[0016] In one embodiment of the present invention, the heat source is a hot air gun or a hot air blower.

[0017] In one embodiment of the present invention, the method for drying the area to be tested is thermal drying.

[0018] In one embodiment of the present invention, the temperature of the heat source for heat drying is 20°C to 30°C.

[0019] In one embodiment of the present invention, the preset value is 0.2Ra to 10Ra.

[0020] In one embodiment of the present invention, the amount of cleaning agent used in the single cleaning process is (80mL~10mL) / mm. 2 The area to be tested.

[0021] In one embodiment of the present invention, the method of etching the area to be tested is chemical etching or electrolytic etching.

[0022] In summary, this invention provides an on-site metallographic coating method that avoids the influence of high humidity on the coating process, improves coating quality, and thus enhances the accuracy of on-site metallographic inspection results. Furthermore, the on-site metallographic coating method provided by this invention can still rapidly and efficiently analyze the properties of metal components even in complex on-site environments, facilitating direct assessment of defects in on-site metal components. This improves the ability to manage component failures online and provides timely technical support for on-site production.

[0023] Of course, implementing any of the methods of this invention does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a flowchart of an on-site metallographic coating method in one embodiment of the present invention. Detailed Implementation

[0026] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0027] It should be understood that the invention can be embodied in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0028] The technical solution of the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] On-site metallographic inspection utilizes portable metallographic microscopes or coated metallographic methods to perform microstructural description, inclusion detection, grain size analysis, ferrite content detection, and harmful phase detection on metal equipment. Among these, on-site coated metallographic inspection, as a type of on-site metallographic inspection, uses modern technology and equipment to inspect and test metal equipment without damaging or affecting its performance or material properties. Specifically, in coated metallographic inspection, the microstructure information of the on-site metal equipment is transferred to coated paper through metallographic replication methods. The coated paper is then observed and analyzed to obtain information such as the material damage state, aging state, carbide coefficient, degree of creep porosity, cracking trend, and service life of the on-site metal equipment. This method is widely used in petrochemical refineries, nuclear power plants, and coal-fired power plants.

[0030] In on-site metallographic inspection with coating, the environment is far from ideal compared to a laboratory setting. Complex and unfavorable environmental factors exist, including high humidity, excessively hot or cold temperatures, noise, dust, and insufficient lighting. These factors can affect coating quality, leading to unsuccessful acquisition of microstructural information and increasing the likelihood of false defects during on-site metallographic inspection of crack morphology, resulting in misjudgments of defect nature. While common environmental factors such as dust and insufficient lighting can be addressed by using headlamps, wiping with lint-free cloths, or repeated washing and drying, there is currently no convenient and effective method to avoid the impact of humidity on coating quality in high-humidity environments. This invention provides an improved on-site metallographic coating method that effectively avoids the influence of high humidity on the coating process, ensures a bubble-free and tight adhesion between the coating and the metal parts, improves coating quality, and thus enhances the accuracy of on-site metallographic inspection results, providing timely technical support for on-site production.

[0031] Please see Figure 1 As shown, the present invention provides a method for on-site metallographic coating, which includes at least the following steps S11 to S17.

[0032] S11. A metal component is provided, and a test area is set on the surface of the metal component.

[0033] S12. Grind the area to be tested until the roughness of the area to be tested reaches the preset value.

[0034] S13. Wipe the area to be tested.

[0035] S14. Clean the test area once, and continue to dry the test area during and after the cleaning process until the temperature of the test area rises to the preset temperature.

[0036] S15. Etch the area to be tested until the metallic luster of the surface of the area to be tested becomes dull.

[0037] S16. After cleaning the test area a second time, dry the test area.

[0038] S17. Apply a film to the area to be tested.

[0039] Please see Figure 1 As shown, in one embodiment of the present invention, in step S11, the metal component is in the field environment. The material of the metal component includes at least one of carbon steel, low alloy steel, martensitic stainless steel, and austenitic stainless steel. The area to be tested is, for example, an area on the surface of the metal component with defects such as cracks. Since there is a defective area to be tested on the surface of the metal component, it is necessary to perform on-site metallographic coating on the area to be tested to determine the material properties of the area, thereby assessing the service life of the entire metal component and providing technical support for on-site production.

[0040] Please see Figure 1 As shown, in one embodiment of the present invention, in step S12, the area to be tested is polished until the roughness of the area reaches a preset value. The preset value is, for example, 0.2 Ra to 10 Ra. Specifically, a straight grinder or angle grinder is used to polish the area to be tested. By polishing the area to be tested, impurities such as rust, oxides, and oil stains on the surface of the area are removed, exposing the metal substrate of the area to be tested. This allows for accurate acquisition of the microstructure information of the area to be tested during subsequent film coating, thereby improving the accuracy of the metallographic inspection results.

[0041] Please see Figure 1 As shown, in one embodiment of the present invention, after grinding the area to be tested, in step S13, the area to be tested is wiped to remove particles generated during the grinding process or dust present in the environment. Specifically, for example, a lint-free cloth is used to wipe the area to be tested. The lint-free cloth is, for example, a soft surface, dust-free, anti-static, with good liquid absorption, and suitable for wiping sensitive surfaces, to avoid the material of the lint-free cloth adhering to the area to be tested. The present invention does not limit the shape and size of the lint-free cloth, and it can be selected according to actual needs. In this embodiment, the lint-free cloth is, for example, square, and the side length of the lint-free cloth is, for example, 100mm to 300mm.

[0042] Please see Figure 1 As shown, in one embodiment of the present invention, after wiping the area to be tested, in step S14, after cleaning the area to be tested with a cleaning agent for a preset time, the area to be tested is dried using a heat source, while simultaneously cleaning the area to be tested again until the amount of cleaning agent is used up. Then, the area to be tested is dried again until the temperature of the area to be tested rises to a preset temperature. The cleaning agent includes, for example, at least one of anhydrous ethanol and deionized water, etc. The purity of the anhydrous ethanol is, for example, analytical grade, etc., and the amount of cleaning agent used is, for example, (80mL~110mL) / mm. 2 When cleaning the test area, for example, by rinsing the test area with a spray bottle, the area of ​​the nozzle outlet in the spray bottle is, for example, 3 mm². 2 ~5mm 2The preset time is, for example, 3s to 10s. The temperature of the heat source drying the area to be tested is, for example, 70℃ to 90℃. The heat source is, for example, a hot air gun or hot air blower. The preset temperature is, for example, 35℃ to 45℃. The temperature of the area to be tested is measured, for example, using an infrared thermometer. The temperature range of the infrared thermometer is, for example, -18℃ to 275℃. In this embodiment, the heat source is, for example, a hot air gun. The power of the hot air gun is, for example, 2000W to 3000W. The hot air gun is selected for its rapid heating, precise temperature control, and stepless temperature adjustment for ease of use. Cleaning the area to be tested removes residual polishing materials, grease, dust, and other impurities to avoid affecting the uniform etching of the area to be tested by the etchant during the subsequent etching process. By drying the area to be tested, not only can the cleaning agent remaining on the area be removed during the cleaning process, but the temperature of the area to be tested can also be maintained within a preset temperature range. During the subsequent etching, secondary cleaning, drying and coating processes, the heat of the area to be tested can evaporate the moisture in the high humidity environment to prevent moisture from adhering to the area to be tested, thereby improving the coating quality.

[0043] Please see Figure 1 As shown, in one embodiment of the present invention, after drying the area to be tested, in step S15, the area to be tested is etched until the metallic luster of the surface of the area to be tested is dull, revealing a microstructure. The etching method may be, for example, chemical etching or electrolytic etching. In this embodiment, the etching method is, for example, chemical etching. Specifically, for example, a degreased cotton ball soaked in an etchant is used to evenly wipe the area to be tested, allowing the etchant to etch the area. The composition of the etchant can be selected according to the metal material of the area to be tested. When the material of the area to be tested is, for example, carbon steel or low alloy steel, the etchant is, for example, a nitric acid alcohol solution with a volume fraction of, for example, 3% to 6%, and the etching time of the etchant on the area to be tested is, for example, 5 to 15 seconds. When the metal material of the area to be tested is, for example, martensitic stainless steel, the etchant is, for example, a mixed solution of ferric chloride, hydrochloric acid and water with a volume ratio of, for example, 1:(2 to 5):(10 to 15), and the mass fraction of hydrochloric acid used in preparing the etchant is, for example, 36 wt% to 38 wt%, and the etching time of the etchant on the area to be tested is, for example, 1 min to 10 min. When the metal material of the area to be tested is, for example, austenitic stainless steel, the etchant is, for example, aqua regia with a volume ratio of, for example, nitric acid and hydrochloric acid in the aqua regia of 1:3, and the etching time of the etchant on the area to be tested is, for example, 1 min to 25 min. By etching the area to be tested, the microstructure of the area can be exposed, which facilitates the accurate acquisition and analysis of the microstructure in subsequent coating.

[0044] Please see Figure 1As shown, in one embodiment of the present invention, after etching the test area, in step S16, the test area is cleaned a second time to remove the etchant. Specifically, a cleaning agent is used to clean the test area a second time until the cleaning agent is used up. The cleaning agent may include, for example, a low-boiling-point solvent such as anhydrous ethanol, and the purity of the anhydrous ethanol may be, for example, analytical grade. The amount of cleaning agent used may be, for example, (50 mL to 110 mL) per mm. 2 When cleaning the test area, for example, by rinsing the test area with a spray bottle, the area of ​​the nozzle outlet in the spray bottle is, for example, 3 mm². 2 ~5mm 2 .

[0045] Please see Figure 1 As shown, in one embodiment of the present invention, after the secondary cleaning of the test area, in step S16, the test area is dried, and drying is stopped when the temperature of the test area begins to rise. The drying of the test area may be achieved using methods such as heat drying, with the temperature of the heat source being, for example, 20°C to 30°C, and the heat source being, for example, a hair dryer or a hot air blower. In this embodiment, the heat source is, for example, a hair dryer, with a power of at least 200W, and the hair dryer is, for example, a hair dryer capable of blowing hot air and stepless temperature adjustment to improve its convenience. By drying the test area until its temperature shows a rising trend, the cleaning agent on the test area is completely removed, ensuring that the test area remains completely dry.

[0046] Please see Figure 1As shown, in one embodiment of the present invention, after drying the test area, a film is coated onto the test area in step S17. Specifically, an appropriate amount of solvent is first uniformly dropped onto the test area, and then metallographic coating paper is quickly and smoothly placed over the test area. A clean component is used to gently press the metallographic coating paper to ensure close adhesion between the metallographic coating paper and the test area, while simultaneously squeezing out air bubbles and excess solvent between the metallographic coating paper and the test area, ensuring that there are no air bubbles or gaps between the metallographic coating paper and the test area, and that they are tightly adhered. The solvent is, for example, acetone, and the size of the metallographic coating paper is, for example, greater than or equal to the size of the test area. By coating the test area, the metallographic coating paper can imprint the microstructure of the test area, thereby allowing analysis of the microstructure of the test area from the metallographic coating paper. Furthermore, since the temperature of the area to be tested remains within the preset temperature after step S14, the surface of the area to be tested always has relatively high heat during the etching, secondary cleaning, and coating processes. The residual heat of the area to be tested can evaporate the moisture in the high-humidity environment, thereby preventing water vapor from remaining on the surface of the area to be tested, ensuring no air bubbles between the coating and the area to be tested, improving the quality of the coating, and thus improving the accuracy of the on-site metallographic testing results. Therefore, the on-site metallographic coating method provided by this invention can still quickly and efficiently analyze the properties of the area to be tested in a high-humidity environment, facilitating direct assessment of defects in on-site metal components, thereby improving the ability to manage component failures online and providing timely technical support for on-site production.

[0047] Please see Figure 1 As shown, in one embodiment of the present invention, after the metallographic film is applied to the area to be tested, it is left to stand until the metallographic film paper dries. Then, the metallographic film paper is peeled off, separating it from the area to be tested. The metallographic film paper is then pasted onto a glass slide and observed, for example, under a metallographic microscope for on-site metallographic examination and analysis. The standing time can be selected based on the ambient temperature. In this embodiment, when the ambient temperature is 25°C, the standing time is, for example, 5-20 minutes.

[0048] In summary, this invention provides an on-site metallographic coating method. By raising the temperature of the test area before etching, secondary cleaning, and coating, and utilizing the residual heat of the test area, it avoids the presence of moisture between the test area and the coating during the coating process. This mitigates the impact of high humidity on the coating process, improves coating quality, and thus enhances the accuracy of on-site metallographic inspection results. Furthermore, the on-site metallographic coating method provided by this invention can still rapidly and efficiently analyze the properties of metal components even in complex on-site environments. It facilitates direct assessment of defects in on-site metal components, thereby improving the ability to manage component failures online and providing timely technical support for on-site production.

[0049] The embodiments of the present invention disclosed above are merely illustrative of the invention. The embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for on-site metallographic coating, characterized in that, At least the following steps are included: A metal component is provided, and a test area is formed on the surface of the metal component; Polish the area to be tested until the roughness of the area to be tested reaches a preset value; Wipe the area to be tested; The area to be tested is cleaned once, and during and after the cleaning process, the area to be tested is continuously dried until the temperature of the area to be tested rises to a preset temperature. The test area is etched until the metallic luster of the surface of the test area becomes dull; After cleaning the test area a second time, dry the test area. as well as A film is applied to the area to be tested.

2. The on-site metallographic coating method according to claim 1, characterized in that, The preset temperature is 35℃~45℃.

3. The on-site metallographic coating method according to claim 1, characterized in that, After a preset time has elapsed during the first cleaning process, drying begins and the area to be tested is cleaned again until the first cleaning process is completed, at which point the area to be tested is dried again.

4. The on-site metallographic coating method according to claim 1, characterized in that, The temperature of the heat source used to dry the area to be tested is 70℃~90℃.

5. The on-site metallographic coating method according to claim 4, characterized in that, The heat source is a hot air gun or a hot air blower.

6. The on-site metallographic coating method according to claim 1, characterized in that, The method for drying the area to be tested is thermal drying.

7. The on-site metallographic coating method according to claim 6, characterized in that, The temperature of the heat source for the heat drying is 20℃~30℃.

8. The on-site metallographic coating method according to claim 1, characterized in that, The preset value is 0.2Ra to 10Ra.

9. The on-site metallographic coating method according to claim 1, characterized in that, The amount of cleaning agent used in the single cleaning process is (80mL~10mL) / mm. 2 The area to be tested.

10. The on-site metallographic coating method according to claim 1, characterized in that, The method for etching the area to be tested is chemical etching or electrolytic etching.

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