High-carbon stainless steel fine bar metallographic specimen preparation method and specimen thereof

Abstract

The invention relates to the technical field of metallographic specimen preparation, in particular to a high-carbon stainless steel fine bar metallographic specimen preparation method and a specimen thereof. The preparation method comprises the following steps: S1, embedding a sample; s2, grinding to 1 / 2 diameter of the longitudinal sample by a grinding machine; s3, performing polishing treatment on the surface of the sample on a rotary polishing machine by using metallographic abrasive paper; s4, preparing a polishing solution; and S5, holding the sample treated in the steps S1 to S3 with a hand, using water as a lubricant, using flannelette as polishing cloth, and using the polishing solution in the S4 to polish on a polishing disc of a polishing machine for 1-3 minutes, the polishing rotating speed being 300-700 revolutions per minute, the moving radius of the sample being 100-120 mm, and the downward pressure being 0.2-0.5 kg. According to the preparation method of the high-carbon stainless steel fine bar metallographic specimen and the specimen thereof, the effect of the prepared specimen greatly reduces the formation of black spots, so that the microscopic observation effect of the metallographic specimen is improved, and the loss caused by metallographic misjudgment is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of metallographic sample preparation, and in particular to a method for preparing a metallographic sample of a high-carbon stainless steel thin bar and the sample. Background Art

[0002] The existing high-efficiency metallographic mechanical polishing method prepares the sample according to the metallographic sample preparation standard, and uses water-grit sandpaper with particle sizes of 80 (180μm), 280 (54μm), 400 (38μm), and 600 (23μm) to grind the sample surface in turn, and then polish it with a polishing liquid. The polishing liquid is usually a suspension of aluminum oxide, chromium oxide, diamond, etc. or other polishing agents. The polishing effect is a combination of oxidizing, weak acidity and weak corrosion. Under the joint action of chromic anhydride and abrasive particles, the suspension polishing agent has a good polishing effect on the metal surface, and can prepare a bright and scratch-free surface that is better than electrolytic polishing, which meets the metallographic observation requirements of conventional materials. However, for the polishing of high-carbon stainless steel fine bars, the above-mentioned conventional polishing method not only has a poor polishing effect, but even has the following problems: Figure 1 and Figure 2 The adverse effects shown affect the metallographic structure observation of its inclusions.

[0003] Grinding and polishing are the most critical links in metallographic sample preparation. The quality of this process will directly affect the test results of the final sample. Therefore, the use method and specific steps of the metallographic grinder and polisher are crucial. On the one hand, the polishing step is to try to obtain the maximum polishing rate so as to remove the damaged layer generated during polishing as quickly as possible. On the other hand, it is also necessary to ensure that the polishing damaged layer will not affect the final organization observation, that is, it will not cause false organization. When using conventional metallographic polishing agents and methods to perform metallographic inclusion inspection on high-carbon stainless steel thin rod raw materials, the following will always appear after polishing. Figure 1 and Figure 2 The black spots shown are likely to affect the metallographic inspection work. Therefore, the original conventional metallographic polishing operation method is not suitable for the metallographic inspection of high-carbon stainless steel thin rods, especially the metallographic inspection of high-carbon stainless steel thin rods with a diameter of less than 10mm. Summary of the invention

[0004] The invention provides a method for preparing a metallographic sample of a high-carbon stainless steel thin rod and the sample, so as to solve the defects in the prior art that a polishing method using water sandpaper of different particle sizes to grind the sample surface and then using a polishing liquid for polishing has a poor polishing effect, black spots appear after polishing, and is not suitable for metallographic inspection of high-carbon stainless steel thin rods.

[0005] The present invention provides a method for preparing a metallographic sample of a high-carbon stainless steel thin bar, comprising: S1, mounted specimen; S2, grind with a grinding wheel to 1 / 2 diameter of the longitudinal specimen; S3, polishing the sample surface on a rotary polishing machine using metallographic sandpaper; S4, preparing polishing liquid; S5. Hold the sample treated by S1 to S3, use water as lubricant, flannel as polishing cloth, and polish on the polishing disk of the polishing machine with the polishing liquid of S4 for 1 to 3 minutes. The polishing speed is 300 to 700 rpm, the sample moving radius is 100 to 120 mm, and the downward pressure is 0.2 to 0.5 kg.

[0006] According to the method for preparing metallographic specimens of high-carbon stainless steel thin bars provided by the present invention, S1 specifically comprises: preparing edge-preserving hot-mounting resin-mounted specimens according to metallographic specimen preparation standards.

[0007] According to the method for preparing metallographic specimens of high-carbon stainless steel fine bars provided by the present invention, S2 specifically comprises: grinding with a grinding wheel to a position where the longitudinal inspection metal specimen has a diameter of 1 / 2.

[0008] According to the method for preparing metallographic samples of high-carbon stainless steel fine bars provided by the present invention, S3 specifically includes: polishing the sample surface on a rotary polishing machine using water sandpaper with a particle size of 120, 240, 320, 400, 600 and 800 meshes, and the polishing time of each particle size of water sandpaper is 15 to 25 seconds.

[0009] According to the method for preparing metallographic samples of high-carbon stainless steel fine bars provided by the present invention, S3 further includes: when using water-grit sandpaper with a particle size of 120 to perform the first rough grinding of the sample, the downward pressure is 0.5-1kg, the rotation speed is 600-700 r / min, and the time is 1-2min.

[0010] According to the method for preparing metallographic samples of high-carbon stainless steel fine bars provided by the present invention, S3 further comprises: grinding with water-sandpaper of various particle sizes to eliminate grinding marks and remove the deformation layer caused by the previous process.

[0011] According to the method for preparing metallographic specimens of high-carbon stainless steel fine bars provided by the present invention, the step S4 specifically comprises: dissolving high-grade alumina polishing powder in water and stirring for 1 to 2 minutes to obtain a polishing liquid.

[0012] According to the method for preparing metallographic specimens of high-carbon stainless steel thin bars provided by the present invention, the S4 specifically comprises: using a glaze stone spray polishing agent with a particle size of 0.5 microns.

[0013] According to the method for preparing a metallographic sample of a high-carbon stainless steel fine bar provided by the present invention, during the S5 polishing, new sandpaper is used and the polishing sandpaper is spread flat on the polishing disc, and damaged polishing sandpaper or polishing cloth is replaced in time.

[0014] The present invention also provides a high-carbon stainless steel thin bar metallographic sample, which is prepared by using the high-carbon stainless steel thin bar metallographic sample preparation method provided by the present invention.

[0015] The present invention provides a method for preparing a metallographic sample of a high-carbon stainless steel fine bar, which comprises: S1, mounting the sample; S2, grinding the sample with a grinding wheel to 1 / 2 of the diameter of the longitudinal sample; S3, polishing the sample surface on a rotary polishing machine using metallographic sandpaper; S4, preparing a polishing liquid; S5, holding the sample treated by S1 to S3, using water as a lubricant, using a flannel cloth as a polishing cloth, and polishing on the polishing disk of the polishing machine using the polishing liquid of S4 for 1 to 3 minutes, the polishing speed is 300 to 700 rpm, the sample moving radius is 100 to 120 mm, and the downward pressure is 0.2 to 0.5 kg. The present invention provides a method for preparing a metallographic sample of a high-carbon stainless steel fine bar, and the prepared sample effect greatly reduces the formation of black spots, thereby improving the microscopic observation effect of the metallographic sample and reducing the loss caused by metallographic misjudgment.

[0016] Furthermore, the present invention provides a high-carbon stainless steel thin bar metallographic sample, which is prepared by the high-carbon stainless steel thin bar metallographic sample preparation method of the present invention. The metallographic sample greatly reduces the formation of black spots, thereby improving the microscopic observation effect of the metallographic sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 This is the metallographic structure diagram of a high-carbon stainless steel thin rod using conventional polishing method after magnification 100 times.

[0019] Figure 2 This is the metallographic structure diagram of a high-carbon stainless steel thin rod magnified 500 times using conventional polishing methods.

[0020] Figure 3 It is a metallographic structure diagram of a high carbon stainless steel fine bar metallographic sample after being magnified 100 times and obtained by the high carbon stainless steel fine bar metallographic sample preparation method provided in one of the embodiments of the present invention.

[0021] Figure 4 This is a deformation diagram of the process of eliminating the surface deformation layer by sandpaper polishing in a method for preparing a metallographic sample of a high-carbon stainless steel fine rod provided in one of the embodiments of the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In the description of the present embodiment, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present embodiment and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present embodiment.

[0024] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this embodiment, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0025] In this embodiment, unless otherwise clearly specified and limited, the terms "set", "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in this embodiment can be understood according to specific circumstances.

[0026] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0027] High carbon stainless steel contains high carbon and a large amount of chromium, and is a type of ledeburite steel. Mn and Cr elements precipitate from the matrix in the form of carbides, and are prone to forming uneven eutectic carbides. Special methods must be used to prepare the metallographic specimens of this steel to achieve good results. First of all, the sample should be ground and polished for an appropriate time. If the grinding and polishing time is too long, the possibility of forming false images on the surface of the metal sample increases. Especially when polishing on a polishing cloth, most metal materials are prone to oxidation when in contact with air and water for a long time, resulting in pitting at the grain boundary, and slowly forming corrosion pits during the grinding and polishing process.

[0028] There are two reasons for this phenomenon: one is the difference in the morphology of carbides (mainly eutectoid and eutectic); the other is the small diameter. Although multiple samples are inlaid together, the metal continuity of the sample with a large diameter is poor, the sample stability is not good, and the shaking during polishing will cause the carbides to fall off partially. Excessive force during polishing causes the diamond abrasive to be embedded in the metal, and the polishing agent is embedded to form an alternation between the inlay and the eutectic carbide, resulting in different degrees of black spots (such as Figure 1 and Figure 2 Energy spectrum analysis of the black spots on the surface of the sample confirmed that the black spots on the surface were aluminum oxide and diamond in the polishing agent.

[0029] Combine the following Figure 3-Figure 4 The present invention describes a method for preparing a metallographic sample of a high-carbon stainless steel thin bar. The method comprises the following steps: S1, mounted specimen; S2, grind with a grinding wheel to 1 / 2 diameter of the longitudinal specimen; S3, polishing the sample surface on a rotary polishing machine using metallographic sandpaper; S4, preparing polishing liquid; S5. Hold the sample treated by S1 to S3, use water as lubricant, flannel as polishing cloth, and polish on the polishing disk of the polishing machine with the polishing liquid of S4 for 1 to 3 minutes. The polishing speed is 300 to 700 rpm, the sample moving radius is 100 to 120 mm, and the downward pressure is 0.2 to 0.5 kg.

[0030] Specifically, step S1 of mounting the sample is intended to fix the material sample to be analyzed in a solid base to facilitate subsequent grinding, polishing, and microscopic observation, etc.; it has the following functions: 1. Fixing the sample: Fixing the sample in a solid base to prevent the sample from shifting or being damaged during grinding and polishing; 2. Protecting the edge of the sample: Especially for brittle materials, mounting can protect the edge of the sample and prevent it from cracking during grinding; 3. Facilitating operation: The mounted sample is easier to hold and operate, which improves the efficiency of grinding and polishing. The mounting material can be thermosetting resin, cold mounting resin, or metal mounting.

[0031] Step S1: Mounting the sample generally includes the following steps: S11. Choose appropriate mounting materials: Choose appropriate mounting materials according to the material and requirements of the sample, such as thermosetting resin, cold mounting resin or metal mounting.

[0032] S12. Mix resin: Mix the resin and hardener according to the proportions in the instructions, stir evenly and ensure there are no bubbles.

[0033] S13. Place the sample: Place the sample in the mold and ensure that the sample is positioned correctly and fixed.

[0034] S14. Pour resin: Pour the mixed resin into the mold, making sure the resin completely covers the sample.

[0035] S15, curing: Place the mold in a hot press or cure at room temperature to ensure that the resin is fully cured.

[0036] Grinding the longitudinal specimen to the required size and shape using a grinder is an important step in metallographic specimen preparation. In step S2, the grinder is ground to 1 / 2 the diameter of the longitudinal specimen (as specified in the metallographic inspection standard); Generally, the following steps are included: starting the grinding machine, preliminary grinding, measuring dimensions, fine grinding, cooling and finishing grinding.

[0037] Polishing the sample surface using metallographic sandpaper on a rotary polisher is one of the key steps in metallographic sample preparation. Step S3 of polishing the sample surface using metallographic sandpaper on a rotary polisher generally includes the following steps: S31. Install sandpaper: Stick the sandpaper flat on the polishing disc, making sure the edges of the sandpaper fit tightly without bubbles or wrinkles. If using sandpaper with adhesive backing, first remove the adhesive protective film and then stick it on the polishing disc. If using sandpaper without adhesive backing, use a clamp or a special fixture to fix the sandpaper on the polishing disc.

[0038] S32. Preliminary grinding: Start the polisher and gently touch the specimen to the sandpaper surface to start preliminary grinding. Keep your hands steady and apply force evenly to avoid local overheating or uneven grinding. Move the specimen in a circular motion to ensure that the entire surface is evenly ground. After grinding for a while, check the surface of the specimen to ensure that there are no obvious scratches or damage.

[0039] S33, Gradual fine grinding: Replace the sandpaper with finer grits in turn, such as 120 (120μm), 240 (61μm), 320 (44μm), 400 (38μm), 600 (23μm), and 800 (18μm). After each change of sandpaper, repeat the above grinding steps to gradually remove the scratches and interference layer on the surface. When grinding on each grit sandpaper, try to keep the same direction to reduce the influence of cross scratches. Check the surface quality of the specimen regularly to ensure that the surface gradually becomes smooth.

[0040] S34. Use wet sandpaper: For finer grinding, wet sandpaper can be used. Soak the wet sandpaper in water for about 10 minutes to soften it. Place the wet sandpaper on the polishing disc, start the polisher, touch the specimen lightly to the surface of the sandpaper, and begin grinding. Keep your hands steady, apply force evenly, and move the specimen in a circular motion. Rinse the surface of the specimen with water regularly to remove grinding debris and keep the surface of the sandpaper clean.

[0041] S35. Check surface quality: After grinding on each grit sandpaper, use a magnifying glass or microscope to check the surface quality of the specimen. Make sure there are no obvious scratches or damage on the surface and the surface gradually becomes smooth.

[0042] In step S4, the polishing liquid can be prepared on site, such as dissolving high-grade aluminum oxide polishing powder in water and stirring for 1 to 2 minutes to obtain the polishing liquid; existing polishing liquid can also be used, such as directly using a gold polishing agent with a particle size of 0.5 microns.

[0043] After polishing in step S5, the final sample preparation effect is as follows: Figure 3 As shown in the figure, the formation of black spots is greatly reduced, thereby improving the microscopic observation effect of metallographic samples.

[0044] The present invention provides a method for preparing a metallographic sample of a high-carbon stainless steel fine bar, which comprises: S1, mounting the sample; S2, grinding the sample with a grinding wheel to 1 / 2 of the diameter of the longitudinal sample; S3, polishing the sample surface on a rotary polishing machine using metallographic sandpaper; S4, preparing a polishing liquid; S5, holding the sample treated by S1 to S3, using water as a lubricant, using a flannel cloth as a polishing cloth, and polishing on the polishing disk of the polishing machine using the polishing liquid of S4 for 1 to 3 minutes, the polishing speed is 300 to 700 rpm, the sample moving radius is 100 to 120 mm, and the downward pressure is 0.2 to 0.5 kg. The present invention provides a method for preparing a metallographic sample of a high-carbon stainless steel fine bar, and the prepared sample effect greatly reduces the formation of black spots, thereby improving the microscopic observation effect of the metallographic sample and reducing the loss caused by metallographic misjudgment.

[0045] In one of the embodiments of the present invention, the sample mounting step of S1 specifically includes: preparing an edge-preserving hot-mounting resin mounted sample according to the metallographic sample preparation standard. Edge-preserving hot-mounting resin is a material specially used for metallographic sample preparation, which can fix the sample in a solid base under high temperature and pressure while protecting the edge of the sample from damage. This resin is particularly suitable for brittle materials or situations where the edge of the sample needs to be accurately retained. Edge-preserving hot-mounting resin has the following characteristics: 1. Protecting the edge of the sample: It can effectively protect the edge of the sample to prevent cracking or damage during grinding and polishing; 2. High temperature curing: Curing under high temperature and pressure to form a solid base to ensure that the sample is firmly fixed; 3. High transparency: The cured resin has high transparency and does not affect microscopic observation; 4. Chemical resistance: It has good chemical resistance and is suitable for a variety of materials.

[0046] In one embodiment of the present invention, the grinding wheel machine of the above-mentioned S2 is ground to 1 / 2 diameter of the longitudinal sample (according to the metallographic inspection standard); the steps specifically include: the grinding wheel machine is ground to 1 / 2 diameter of the longitudinal inspection metal sample (according to the metallographic inspection standard), that is, the longitudinal sample is ground to half of its metal diameter using the grinding wheel machine.

[0047] In one embodiment of the present invention, the above-mentioned step of using metallographic sandpaper to polish the sample surface on a rotary polisher in S3 specifically includes: using water sandpaper with a particle size of 120 (120μm), 240 (61μm), 320 (44μm), 400 (38μm), 600 (23μm) and 800 (18μm) to polish the sample surface on a rotary polisher in sequence, and the grinding time of each water sandpaper with a particle size is 15 to 25 seconds, so as to quickly remove the influence of the interference layer. Specifically, the sample surface is polished in sequence using water sandpaper with a particle size ranging from coarse to fine, and the grinding time of each water sandpaper with a particle size is between 15 seconds and 25 seconds. When the water sandpaper with a particle size of 120 (120μm) is used for the first polishing, that is, the first rough grinding, the pressure and speed can be appropriately increased, and the rough grinding time can be appropriately extended.

[0048] In the above embodiment, the above step S3 also includes: when using water sandpaper with a particle size of 120 to perform the first rough grinding of the sample, the downward pressure is 0.5-1kg, the rotation speed is 600-700 r / min, and the time is 1-2min. Compared with the fine grinding and fine grinding process, the downward pressure of the first rough grinding in this embodiment is slightly larger, the rotation speed is slightly faster, and the time is slightly longer.

[0049] In one embodiment of the present invention, the above S3 further includes: using water sandpaper of various grain sizes to polish, eliminate the wear marks, and remove the deformed layer caused by the previous process. Figure 4 As shown in the figure, in the process of polishing the surface deformation layer with coarse to fine grains, (a), (b), (c) and (d) from top to bottom are the original structures of the severe deformation layer, large deformation layer, small deformation layer and no deformation layer, and 1, 2, 3 and 4 from the left are the deformation layer of the sample surface after the first step of polishing, the deformation layer of the sample surface after the second step of polishing, the deformation layer of the sample surface after the third step of polishing and the deformation layer of the sample surface after the fourth step of polishing. It can be seen that when using water sandpaper of different grains for polishing, not only the wear marks of the previous process must be removed, but also the deformation layer caused by the previous process must be removed.

[0050] In one embodiment of the present invention, the step of preparing the polishing liquid in S4 specifically comprises: dissolving the high-grade aluminum oxide polishing powder in water and stirring for 1 to 2 minutes to prepare the polishing liquid. In this embodiment, the polishing liquid can be prepared on-site for use in step S5.

[0051] In one embodiment of the present invention, the step of preparing the polishing liquid in step S4 specifically includes: using a 0.5 micron gold stone spray polishing agent. In this embodiment, the existing 0.5 micron gold stone spray polishing agent can be directly used as the polishing liquid in step S5.

[0052] In one embodiment of the present invention, when polishing by S5, new sandpaper is used and the polishing sandpaper is spread flat on the polishing disc, and damaged polishing sandpaper or polishing cloth is replaced in time to avoid damaging the sample. In this embodiment, new sandpaper is used for polishing, and secondary sandpaper is avoided for polishing, and new polishing sandpaper is spread flat on the polishing disc to ensure the polishing effect.

[0053] In the above embodiment, the method based on sandpaper, polishing agent (aluminum oxide, diamond) grinding disk has the following characteristics: 1. The grinding force is very strong and efficient. (High impact force)

[0054] 2. The surface flatness of the sample is guaranteed, and there will be no local depression similar to sandpaper.

[0055] 3. For hard materials, the grinding force should not be too large, and the grinding effect on the sample surface should be consistent as much as possible.

[0056] 4. Suitable for grinding hard materials such as 95Cr18. Use new sandpaper and avoid secondary sandpaper as much as possible.

[0057] The present invention also provides a high-carbon stainless steel thin bar metallographic sample. The high-carbon stainless steel thin bar metallographic sample is prepared by the high-carbon stainless steel thin bar metallographic sample preparation method in the above embodiment of the present invention.

[0058] The invention provides a high-carbon stainless steel thin bar metallographic sample, which is prepared by the high-carbon stainless steel thin bar metallographic sample preparation method of the invention. The metallographic sample greatly reduces the formation of black spots, thereby improving the microscopic observation effect of the metallographic sample.

[0059] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, i.e., they may be located in one place, or they may be distributed over multiple units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment. Those of ordinary skill in the art may understand and implement the present invention without creative effort.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a metallographic sample of a high carbon stainless steel thin bar, characterized in that: include: S1, mounted specimen; S2, grind with a grinding wheel to 1 / 2 diameter of the longitudinal specimen; S3, polishing the sample surface on a rotary polishing machine using metallographic sandpaper; S4, preparing polishing liquid; S5. Hold the sample treated by S1 to S3, use water as lubricant, flannel as polishing cloth, and polish on the polishing disk of the polishing machine with the polishing liquid of S4 for 1 to 3 minutes. The polishing speed is 300 to 700 rpm, the sample moving radius is 100 to 120 mm, and the downward pressure is 0.2 to 0.5 kg.

2. The method for preparing a metallographic sample of a high carbon stainless steel thin bar according to claim 1, characterized in that: The S1 specifically includes: preparing an edge-preserving hot-mounting resin-mounted specimen according to metallographic sample preparation standards.

3. The method for preparing a metallographic sample of a high carbon stainless steel thin bar according to claim 1, characterized in that: The S2 specifically includes: grinding with a grinding machine to a position where the longitudinal inspection metal sample has a diameter of 1 / 2.

4. The method for preparing a metallographic sample of a high carbon stainless steel thin bar according to claim 1, characterized in that: The S3 specifically includes: polishing the surface of the sample on a rotary polisher using water sandpaper with grits of 120, 240, 320, 400, 600 and 800 meshes, and the polishing time of each grit size of water sandpaper is 15-25s.

5. The method for preparing a metallographic sample of a high carbon stainless steel thin bar according to claim 4, characterized in that: The step S3 further comprises: when using water sandpaper with a particle size of 120 to perform the first rough grinding of the sample, the downward pressure is 0.5-1 kg, the rotation speed is 600-700 r / min, and the time is 1-2 min.

6. The method for preparing a metallographic sample of a high carbon stainless steel thin bar according to claim 4, characterized in that: The step S3 further includes: using water sandpaper of various grain sizes to polish, eliminate the grinding marks, and remove the deformed layer caused by the previous process.

7. The method for preparing a metallographic sample of a high carbon stainless steel thin bar according to any one of claims 1 to 6, characterized in that: The S4 specifically comprises: dissolving high-grade aluminum oxide polishing powder in water and stirring for 1 to 2 minutes to obtain a polishing liquid.

8. The method for preparing a metallographic sample of a high carbon stainless steel thin bar according to any one of claims 1 to 6, characterized in that: The S4 specifically includes: using a gold quartz spray polishing agent with a particle size of 0.5 microns.

9. The method for preparing a metallographic sample of a high carbon stainless steel thin bar according to any one of claims 1 to 6, characterized in that: When polishing by S5, new sandpaper is used and the polishing sandpaper is spread flat on the polishing disc, and damaged polishing sandpaper or polishing cloth is replaced in time.

10. A metallographic specimen of a high carbon stainless steel thin bar, characterized in that: The high carbon stainless steel thin bar metallographic specimen is prepared by the method for preparing the high carbon stainless steel thin bar metallographic specimen according to any one of claims 1 to 9.

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