Preparation method for extracting carbon replica of steel for high-carbon wire rod

Abstract

The invention relates to the technical field of metal material sample preparation, in particular to a preparation method for extracting carbon replica of steel for a high-carbon wire rod. The method specifically comprises the following steps: S1, preparing a sample; s2, immersing the sample into a nitric acid alcohol solution; s3, placing the sample in a sample chamber of a high-vacuum coating instrument, evaporating a carbon film with the thickness of 10-20 nm on the surface of the sample, and taking out the sample after vacuum is relieved; s4, performing electrolytic film removal by adopting an electrolytic polishing corrosion instrument; s5, after the carbon film falls off, the nitric acid alcohol on the carbon film is cleaned until the absolute ethyl alcohol in the weighing bottle is colorless; s6, the carbon film is transferred into deionized water, after the carbon film is fully unfolded, the carbon film is fished up through a transmission electron microscope and a copper net and placed on filter paper, and the carbon film is tightly attached to the copper net; and S7, baking the carbon film sample adhered to the copper mesh for 30-60 seconds, and placing the dried sample under an electron microscope for observation to complete the preparation of the steel extraction carbon replica sample for the high-carbon wire rod. The method has the advantages of high demolding speed, complete and firm carbon film form, simple configuration and low cost.

Description

Technical Field

[0001] The present invention relates to the technical field of metal material sample preparation, and particularly to a preparation method for extracting carbon replicas of high-carbon wire rod steel. Background Art

[0002] High-carbon wire rod steel is a type of steel with a relatively high carbon content, generally referring to steel with a carbon content greater than 0.5%. It has high hardness and strength, which makes it widely used in fields such as mechanical manufacturing, construction, and metallurgy. However, at the same time, the ductility and toughness of high-carbon wire rod steel are relatively low, which may cause cracks and fractures during use. Therefore, attention needs to be paid to the matching of mechanical properties and process conditions during use. The main components of high-carbon wire rod steel are carbon and iron, and may also contain a small amount of other elements. To enhance its strengthening effect, some specific alloying elements are usually added. These elements mainly include micro-alloying elements such as manganese (Mn), silicon (Si), chromium (Cr), and vanadium (V). The Mn element can increase the strength and hardness of the wire rod, and at the same time, it will not reduce the reduction of area and impact toughness of the wire rod, which helps to improve the comprehensive performance of the material. The Si element dissolves in ferrite and can significantly increase the yield strength and tensile strength of hot-rolled wire rods, and also helps to improve the thermal stability of the wire. The addition of the Cr element can refine the pearlite lamellar spacing, increase the rate of sorbitization, significantly increase the tensile strength of the material, and improve its reduction of area. The V element can also play an important strengthening role in steel. By forming stable carbides with carbon, it effectively prevents grain growth, thereby strengthening the matrix of the steel. The addition and coordination of these alloying elements can enable the wire rod steel to maintain high strength and hardness while improving its plasticity, toughness, hardenability, and other properties, achieving better comprehensive performance.

[0003] Micro-alloying elements such as manganese, silicon, and chromium mostly increase the strengthening effect in a solid solution form, while for the alloying element vanadium, it is more desirable to form stable carbonitrides to effectively prevent grain growth and thereby increase the strength of the matrix. The matrix structure of wire rod steel is basically pearlite, and a large amount of cementite in pearlite will seriously affect the observation of vanadium-containing precipitation phases. Therefore, extracting the vanadium-containing precipitation phases can greatly enhance the research effect of the precipitation strengthening mechanism of vanadium in wire rod steel.

[0004] Extraction carbon replica can not only reveal the surface relief of the sample, but also extract some fine constituent phases, such as second-phase particles, with the carbon film and maintain their original distribution in the sample. Its greatest advantage is that in addition to observing the size, morphology and distribution of these small particles under a transmission electron microscope, their phases can also be determined by electron diffraction. The extraction carbon replica technique is applicable to a variety of materials and specimen types, without being restricted by the type and shape of the materials. Therefore, it has broad application prospects in the fields of materials science, metallurgy, machinery, etc. The preparation process of extraction carbon replica is relatively simple, easy to master and operate. Although some specific equipment and reagents are required, overall, the implementation difficulty of this technique is not high and it is suitable for application in laboratories or industrial sites. Although the extraction carbon replica technique requires the use of some specific chemical reagents and equipment, its cost is relatively low compared to other high-end analysis techniques (such as transmission electron microscopes, etc.). At the same time, since this technique can prepare high-quality samples, it has a high cost performance. To sum up, the preparation of extraction carbon replica samples has the advantages of simple operation and good cost-effectiveness, and it is a sample preparation technique with important application value in the field of materials science research.

[0005] The existing method for preparing extraction carbon replica of steel samples is to cut the sample with a carbon film deposited on it into small squares about 2mm×2mm in size, and soak them in a nitric acid alcohol solution of about 10% for several minutes or more than ten minutes until the carbon film naturally peels off. The existing method for preparing extraction carbon replica of steel samples has at least the following defects and deficiencies: For high-carbon wire rod steel, since its matrix structure is pearlite and there are a large number of very large cementite in the pearlite, due to the strong corrosion resistance of cementite, when the sample is soaked in the nitric acid alcohol solution, a large amount of cementite firmly pins the carbon film to the sample, resulting in the sample being unable to be demembraned even after a long time of soaking. Even if the carbon film peels off after soaking for two or three hours, the sample will rust due to long-term soaking in acid, and a thick rust layer will adhere to the surface of the carbon film, resulting in the inability to observe such samples normally under a transmission electron microscope even if the carbon film naturally peels off. Summary of the Invention

[0006] In order to overcome the deficiencies of the prior art, the present invention provides a method for preparing extraction carbon replica of high-carbon wire rod steel, with a fast demembraning speed, a complete and strong carbon film morphology, simple configuration and low cost.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A method for preparing extraction carbon replica of high-carbon wire rod steel specifically includes the following steps:

[0009] S1: Cut the cylindrical wire rod sample into a cylinder with a height of 13 - 16mm, polish it until there are no scratches on the surface, and repeatedly polish with water until there is no residue of the polishing paste;

[0010] S2: Immerse the polished surface of the sample into a nitric acid alcohol solution with a volume percentage concentration of 3 - 6%, and corrode until the surface of the specimen changes color, i.e., the metallographic structure can be faintly seen. Clean and dry the corrosion solution on the specimen surface, and place it in a sample box.

[0011] S3: Place the sample in the sample chamber of a high - vacuum coating instrument, evacuate to above 8×10 -5 mbar, and evaporate a carbon film with a thickness of 10 - 20 nm on the sample surface. Take out the sample after releasing the vacuum.

[0012] S4: Scratch small squares with a length and width of 2 - 3 mm on the coated surface of the sample. Prepare a nitric acid alcohol solution with a volume percentage concentration of 3 - 6% as the electrolyte, and use an electrolytic polishing and etching instrument to electrolytically remove the film. The electrolysis time is 5 - 15 min, until the carbon film falls off.

[0013] S5: After the carbon film falls off, fish out the carbon film and put it into a weighing bottle filled with anhydrous ethanol, wash the nitric acid alcohol on the carbon film until the anhydrous ethanol in the weighing bottle shows colorless, and cover the bottle cap for storage.

[0014] S6: Transfer the carbon film to deionized water. After the carbon film is fully unfolded, use a copper mesh for transmission electron microscopy to fish up the carbon film and place it on filter paper. The carbon film will adhere tightly to the copper mesh.

[0015] S7: Bake the carbon film sample adhered to the copper mesh for 30 - 60 s. After the sample is dried, it can be placed under the electron microscope for observation. The preparation of the carbon extraction replica sample of the high - carbon wire rod is completed.

[0016] Furthermore, in S1, mechanically grind the cylindrical surface of the sample successively with 150 - 240#, 400 - 600#, and 800 - 1200# sandpapers, and mechanically polish until the surface has no scratches.

[0017] Furthermore, in S2, immerse the polished surface of the sample into a nitric acid alcohol solution with a volume percentage concentration of 4%.

[0018] Furthermore, in S2, clean the corrosion solution on the specimen surface with anhydrous ethanol.

[0019] Furthermore, in S3, use a Leica ACE600 high - vacuum coating instrument for the high - vacuum coating instrument.

[0020] Furthermore, in S4, prepare 100 - 200 ml of a nitric acid alcohol solution with a volume percentage concentration of 3 - 6% as the electrolyte.

[0021] Furthermore, in S4, use a NaiBo EP - 06 type electrolytic polishing and etching instrument for the electrolytic polishing and etching instrument.

[0022] Further, in S5, the carbon film is cleaned with absolute ethanol for more than two times until the absolute ethanol in the weighing bottle shows colorless.

[0023] Further, in S6, the copper mesh is a Φ3mm copper mesh.

[0024] Further, in S7, the carbon film sample adhered to the copper mesh is baked under an infrared baking lamp.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] 1. In the prior art, the electrolytic corrosion method is adopted in the sample metallographic corrosion link, and the corrosion reagent is a mixed solution of acetylacetone + tetramethylammonium chloride + methanol. All three solutions have certain toxicity, pungent smell and are flammable and explosive, which will cause certain harm to the physical and mental health of experimental personnel. In addition, an electrolytic corrosion instrument needs to be started, and the corrosion time is about more than ten minutes. The present invention only needs to configure a nitric acid alcohol solution with a volume percentage concentration of about 4%, and immerse the sample in the corrosion solution for dozens of seconds until the surface of the sample changes color. In contrast, the metallographic corrosion solution of this method has low cost and fast metallographic corrosion speed, greatly improving the work efficiency.

[0027] 2. In the prior art, a carbon film with a thickness of more than 20 nm or even micron level is evaporated by a vacuum coating instrument. The carbon film evaporated by an ordinary vacuum coating instrument has too large carbon particle size due to low vacuum degree, insufficient density, and a too large carbon film thickness (≥20 nm) will cause the carbon film to be difficult to fully unfold and is easy to fall off on the copper mesh. The present invention uses a high-vacuum coating instrument to evaporate a carbon film with a thickness of about 15 nm in a vacuum higher than 8×10 -5 mba. The higher the vacuum degree, the finer the carbon particles evaporated, and the better the density of the carbon film. The carbon film with a thickness of about 15 nm takes into account the toughness and adhesion of the carbon film. The carbon film has good integrity and strong adhesion, and is not easy to fall off from the copper mesh after being fished and dried by the copper mesh, and does not pollute the transmission electron microscope sample chamber.

[0028] 3. In the prior art, the electrolytic stripping reagent is a perchloric acid alcohol solution. Perchloric acid has strong corrosiveness, strong oxidizing property and instability, and is a state-controlled chemical drug. It needs to be purchased with limited quantity approved by the public security department and is expensive (the purchase price of a 500 ml bottle of perchloric acid is about 1000 yuan). At the same time, it is also an important hazard source in the laboratory. The electrolytic corrosion reagent adopted by the present invention is a nitric acid alcohol solution with a volume percentage concentration of about 4%. This solution is effective for most steel types (except stainless steel). Nitric acid has strong versatility in the physical and chemical analysis industry, and the preparation process of the corrosion solution is simple, safe and low-cost.

[0029] In short, the present invention is simple and easy to operate, the corrosion solution has good versatility, the corrosion solution and the electrolyte are simple to configure, cheap, highly practical, fast in stripping speed and the carbon film has a complete and strong form. Description of the Drawings

[0030] Figure 1 Effect diagram of cutting columnar samples from the steel for wire rod of the present invention.

[0031] Figure 2 Effect diagram of storing the carbon film in a weighing bottle after electrolytic stripping of the present invention.

[0032] Figure 3 Effect diagram of the complete carbon film of the present invention tightly adhering to the copper mesh.

[0033] Figure 4 Effect diagram of observing the extracted carbon replica sample under a transmission electron microscope of the present invention.

[0034] Figure 5 Effect diagram of storing the carbon film in a weighing bottle after electrolytic stripping of the prior art.

[0035] Figure 6 Effect diagram of preparing the carbon film and placing it in deionized water of the prior art.

[0036] Figure 7 Effect diagram of fixing the carbon film prepared by the prior art on the copper mesh. Detailed implementation method

[0037] The present invention discloses a method for preparing an extracted carbon replica of high-carbon wire rod steel. Those skilled in the art can draw on the content of this article and appropriately improve the process parameters to achieve it. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The method and application of the present invention have been described through preferred embodiments, and those related can obviously make changes or appropriate alterations and combinations to the methods and applications described in this article without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0038] A method for preparing an extracted carbon replica of high-carbon wire rod steel specifically includes the following steps:

[0039] Step 1: Cut the cylindrical wire rod sample into a cylinder with a height of about 15 mm, and mechanically grind the cylindrical surface of the sample successively with 200#, 500#, and 800# sandpapers, and mechanically polish it until there are no scratches on the surface, and repeatedly polish it with water until there is no residue of the polishing paste.

[0040] Step 2: Immerse the polished surface of the sample in a nitric acid alcohol solution with a concentration of 4% (volume percentage content) and corrode it until the surface of the sample changes color, that is, the metallographic structure can be faintly seen, quickly clean the corrosion solution on the surface of the sample with absolute ethanol and dry it, and place it in a sample box.

[0041] Step 3: Place the sample in the sample chamber of a Leica ACE600 high-vacuum coating instrument, evacuate to 8×10 -5Above MBA, deposit a carbon film with a thickness of about 15 nm on the sample surface, and take out the sample after releasing the vacuum.

[0042] Step 4: Use a blade to scratch small squares with a length and width of about 2 mm - 3 mm on the coated surface of the sample. Prepare 150 ml of nitric acid alcohol solution with a concentration of 4% (volume percentage) as the electrolyte, and use a NaiBo EP-06 type electrolytic polishing and etching instrument to remove the film electrolytically. The electrolysis time is about 5 - 15 min, until the carbon film falls off.

[0043] Step 5: After the carbon film falls off, use a grid to fish out the carbon film and put it into a weighing bottle containing anhydrous ethanol, and wash off the nitric acid alcohol on the carbon film. Usually, the carbon film needs to be washed with anhydrous ethanol more than twice until the anhydrous ethanol in the weighing bottle shows colorless, then cover the bottle cap and store it.

[0044] Step 6: Use a grid to transfer the carbon film to deionized water. After the carbon film is fully unfolded, use a Φ3 mm copper grid for a transmission electron microscope to fish up the carbon film and place it on a clean filter paper. The carbon film will adhere tightly to the copper grid.

[0045] Step 7: Bake the carbon film sample adhered to the copper grid under an infrared baking lamp for about 1 minute. After the sample is dried, it can be placed under the electron microscope for observation. The preparation of the steel extraction carbon replica sample of the high-carbon wire rod is completed.

[0046] Example 1:

[0047] In this example, the high-carbon wire rod is for ultra-high-strength stranded wire. This example is a preparation method for steel extraction carbon replica of the wire rod for ultra-high-strength stranded wire, which specifically includes the following steps:

[0048] Step 1: Cut the Φ10 mm stranded wire rod into cylindrical samples with a height of 15 mm, and mechanically grind the cylindrical surface of the samples successively with 200#, 500#, and 800# sandpapers, and mechanically polish until there are no scratches on the surface, and repeatedly polish with water until there is no residue of the polishing paste (as Figure 1 shown).

[0049] Step 2: Immerse the polished surface of the sample in a nitric acid alcohol solution with a concentration of 4% (volume percentage) and corrode for about 30 seconds. The metallographic structure can be faintly seen on the sample surface. Quickly clean the corrosion solution on the sample surface with anhydrous ethanol and blow it dry with a hair dryer, and place it in a sample box.

[0050] Step 3: Place the sample in the sample chamber of a Leica ACE600 high-vacuum coating instrument, evacuate to 8×10 -5 Above MBA, deposit a uniformly dense carbon film with a thickness of about 15 nm on the sample surface, and take out the sample after releasing the vacuum.

[0051] Step 4: Use a blade to scratch a small square with a length and width of about 3 mm on the coated surface of the sample. Prepare 150 ml of nitric acid alcohol solution with a concentration of 4% (volume percentage) as the electrolyte. Set the voltage to about 10 V and the current to about 0.3 A. Start the NaiBo EP-06 electrolytic polishing and etching instrument to remove the film electrolytically. The electrolysis time is about 5 - 15 min, until the carbon film falls off.

[0052] Step 5: After the carbon film falls off, use a specimen grid to fish out the carbon film and put it into a weighing bottle filled with anhydrous ethanol to wash off the nitric acid alcohol on the carbon film. Usually, the carbon film needs to be washed with anhydrous ethanol more than twice until the anhydrous ethanol in the weighing bottle shows colorless. Then cover the bottle cap and store it (as Figure 2 shown).

[0053] Step 6: Use a specimen grid to transfer the carbon film to deionized water. After the carbon film is fully unfolded, use a Φ3 mm copper grid for transmission electron microscopy to fish out the carbon film and place it on a clean filter paper. The carbon film will adhere tightly to the copper grid (as Figure 3 shown).

[0054] Step 7: Place the copper grid with the adhered sample under an infrared baking lamp and bake for about 1 min. After the sample is dried, place it under the electron microscope for observation (as Figure 4 shown). The preparation of the carbon replica sample of the wire rod for stranded wire by extraction is completed.

[0055] Example 2:

[0056] In this example, the high-carbon wire rod is the wire rod for spring steel wire. This example is a preparation method for extracting carbon replica of the steel for a wire rod for spring steel wire, which specifically includes the following steps:

[0057] Step 1: Cut the Φ5 mm spring steel wire into small columnar samples with a length of 10 mm. Mechanically grind the cylindrical surface of the samples successively with 250#, 600#, and 1000# sandpapers, and mechanically polish until there are no scratches on the surface. Repeatedly polish with water until there is no residue of the polishing paste.

[0058] Step 2: Immerse the polished surface of the sample in a nitric acid alcohol solution with a concentration of 3% (volume percentage) and corrode for about 45 seconds. The metallographic structure can be faintly seen on the surface of the sample. Quickly wash the corrosion solution on the surface of the specimen with anhydrous ethanol and blow it dry with a hair dryer, then place it in a sample box.

[0059] Step 3: Place the sample in the sample chamber of the Leica ACE600 high-vacuum coating instrument, evacuate to above 6×10 -5 mbar, and evaporate a layer of carbon film with a thickness of about 15 nm with uniform density and compactness on the surface of the sample. After releasing the vacuum, take out the sample.

[0060] Step 4: Use a blade to scratch small squares with a length and width of about 2 mm on the coated surface of the sample. Prepare 120 ml of nitric acid alcohol solution with a concentration of 4% (volume percentage) as the electrolyte. Set the voltage to about 8 V and the current to about 0.3 A, and start the NaiBo EP-06 type electrolytic polishing and etching instrument for electrolytic stripping. The electrolysis time is about 5 - 15 min, taking the carbon film falling off as the standard.

[0061] Step 5: After the carbon film falls off, use a carrier grid to fish out the carbon film and put it into a weighing bottle filled with anhydrous ethanol to wash off the nitric acid alcohol on the carbon film. Usually, the carbon film needs to be washed with anhydrous ethanol more than twice until the anhydrous ethanol in the weighing bottle shows colorless, then cover the bottle cap for storage.

[0062] Step 6: Use a carrier grid to transfer the carbon film to deionized water. After the carbon film is fully unfolded, use a Φ3 mm copper grid for transmission electron microscopy to fish out the carbon film and place it on a clean filter paper. The carbon film will adhere tightly to the copper grid.

[0063] Step 7: Bake the copper grid with the adhered sample under an infrared baking lamp for about 40 s. After the sample is dried, place it under the electron microscope for observation. The preparation of the carbon replica sample extracted from the coil rod for the spring steel wire is completed.

[0064] Example 3: In this example, the high-carbon coil rod is for prestressed steel wire. This example is a preparation method for extracting carbon replica of the steel for prestressed steel wire, specifically including the following steps:

[0065] Step 1: Cut the Φ3.5 mm prestressed steel wire into small columnar samples with a length of 12 mm. Mechanically grind the cylindrical surface of the sample successively with 200#, 500#, and 800# sandpapers, and mechanically polish it until there are no scratches on the surface. Repeatedly polish with water until there is no residue of the polishing paste.

[0066] Step 2: Prepare a mixed solution of 10% acetylacetone + 1% tetramethylammonium chloride + 89% methanol (mass fraction). Set the voltage to 2 V and the current to 0.04 A, and start the NaiBo EP-06 type electrolytic polishing and etching instrument for electrolytic corrosion for about 10 min. The metallographic structure can be faintly seen on the sample surface. Quickly wash the corrosion solution on the sample surface with anhydrous ethanol and blow it dry with a hair dryer, then place it in a sample box.

[0067] Step 3: Place the sample in the sample chamber of the Leica ACE600 high-vacuum coating instrument, evacuate to 5×10 -4 mbar, evaporate a carbon film with a thickness of about 25 nm on the sample surface, and take out the sample after releasing the vacuum.

[0068] Step 4: Use a blade to scratch small squares with a length and width of about 2 mm on the coated surface of the sample. Prepare 100 ml of perchloric acid alcohol solution with a concentration of 10% (volume percentage) as the electrolyte. Set the voltage to about 5 V and the current to about 0.15 A, and start the Naibo EP-06 electrolytic polishing and etching instrument for electrolytic demoulding. The electrolysis time is about 10 - 15 min, until the carbon film falls off.

[0069] Step 5: After the carbon film falls off, use a specimen grid to fish out the carbon film and put it into a weighing bottle filled with anhydrous ethanol to wash off the nitric acid alcohol on the carbon film. As Figure 5 shown, due to the low vacuum degree during evaporation coating and the excessive thickness of the carbon film, the carbon film curls together and cannot be fully unfolded.

[0070] Step 6: Use a specimen grid to transfer the carbon film to deionized water. As Figure 6 shown, the carbon film cannot be fully unfolded in deionized water. Even if part of the carbon film unfolds, its integrity is not ideal, making it difficult to meet the requirements of electron microscope observation.

[0071] Step 7: Use a Φ3 mm copper mesh for transmission electron microscopy to fish up the carbon film and place it on a clean filter paper, and bake it under an infrared baking lamp for about 40 s. As Figure 7 shown, the size of the carbon film on the copper mesh is very small, and the edges are upturned, making it easy to fall off and contaminate the sample chamber in the transmission electron microscope sample chamber.

[0072] Compared with the existing method for preparing carbon replica extraction of steel samples, the operation of the present invention is simple and easy to master, the corrosion liquid has good versatility, the preparation of the corrosion liquid and the electrolyte is simple, the price is cheap, the practicability is strong, the demoulding speed is fast, and the carbon film morphology is complete and firm.

[0073] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A preparation method for extracting carbon replica of steel for high-carbon wire rod, characterized in that, Specifically, it includes the following steps: S1: Cut the cylindrical wire rod sample into cylinders with a height of 13 - 16 mm, polish until the surface has no scratches, and repeatedly polish with water until there is no residue of the polishing paste. S2: Immerse the polished surface of the sample in a nitric acid - alcohol solution with a volume percentage concentration of 3 - 6%, corrode until the surface of the sample changes color, clean the corrosion solution on the surface of the sample and dry it, and place it in a sample box. S3: Place the sample in the sample chamber of a high-vacuum coating instrument, evacuate the air to above 8×10 -5 mbar, evaporate a carbon film with a thickness of 10 - 20 nm on the surface of the sample, and take out the sample after releasing the vacuum; S4: Scratch small squares with a length and width of 2 - 3 mm on the coated surface of the sample, prepare a nitric acid - alcohol solution with a volume percentage concentration of 3 - 6% as the electrolyte, and use an electrolytic polishing and etching instrument to electrolytically remove the film. The electrolysis time is 5 - 15 min, based on the carbon film falling off. S5: After the carbon film falls off, fish out the carbon film and put it into a weighing bottle filled with anhydrous ethanol, wash the nitric acid - alcohol on the carbon film until the anhydrous ethanol in the weighing bottle shows colorless, then cover the bottle cap and store it. S6: Transfer the carbon film to deionized water. After the carbon film is fully unfolded, use a copper mesh for transmission electron microscopy to fish up the carbon film and place it on filter paper. The carbon film will adhere tightly to the copper mesh. S7: Bake the carbon film sample adhered to the copper mesh for 30 - 60 s. After the sample is dried, it can be placed under the electron microscope for observation. The preparation of the carbon replica sample of high - carbon wire rod steel is completed.

2. A preparation method of a carbon replica extracted from high - carbon wire rod steel according to claim 1, characterized in that, In S1, mechanically grind the cylindrical surface of the sample successively with 150 - 240#, 400 - 600#, and 800 - 1200# sandpapers and mechanically polish until the surface has no scratches.

3. A preparation method of a carbon replica extracted from high - carbon wire rod steel according to claim 1, characterized in that, In S2, immerse the polished surface of the sample in a nitric acid - alcohol solution with a volume percentage concentration of 4%.

4. A preparation method of a carbon replica extracted from high - carbon wire rod steel according to claim 1, characterized in that, In S2, clean the corrosion solution on the surface of the sample with anhydrous ethanol.

5. A preparation method of a carbon replica extracted from high - carbon wire rod steel according to claim 1, characterized in that, In S3, the high - vacuum coating instrument uses a Leica ACE600 high - vacuum coating instrument.

6. A preparation method of a carbon replica extracted from high - carbon wire rod steel according to claim 1, characterized in that, In S4, prepare 100 - 200 ml of a nitric acid - alcohol solution with a volume percentage concentration of 3 - 6% as the electrolyte.

7. A preparation method of a carbon replica extracted from high - carbon wire rod steel according to claim 1, characterized in that, In S4, the electrolytic polishing and etching instrument uses a NaiBo EP - 06 type electrolytic polishing and etching instrument.

8. A preparation method of a carbon replica extracted from high - carbon wire rod steel according to claim 1, characterized in that, In S5, wash the carbon film with anhydrous ethanol more than twice until the anhydrous ethanol in the weighing bottle shows colorless.

9. A preparation method of a carbon replica extracted from high - carbon wire rod steel according to claim 1, characterized in that, In S6, the copper mesh is a Φ3 mm copper mesh.

10. A preparation method of a carbon replica extracted from high - carbon wire rod steel according to claim 1, characterized in that, In S7, bake the carbon film sample adhered to the copper mesh under an infrared baking lamp.

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