Method for forming M42 high-speed steel gradient super wear-resistant layer through electron beam irradiation induction

Abstract

The invention discloses a method for forming an M42 steel gradient super wear-resistant layer through electron beam irradiation induction. The method comprises the following steps: firstly, pretreating an M42 steel workpiece, then preparing a sample, then carrying out electron beam irradiation treatment, and finally, carrying out structure and performance testing on the treated sample. Through the method, the gradient super-wear-resistant layer can be formed on the M42 steel surface through induction, the surface hardness and wear resistance of the M42 steel surface are remarkably improved, and the method has wide application prospects in the fields of machine manufacturing, mold machining and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of material surface modification, and particularly relates to a method for inducing the formation of a gradient super wear-resistant layer on the surface of M42 steel by electron beam irradiation. Background Art

[0002] In modern industry, mechanical components are facing increasingly harsh working conditions, and the requirements for the wear resistance of materials are constantly increasing. As a high-performance high-speed steel, M42 steel has high hardness, high toughness and good hot hardness, and is widely used in fields such as cutting tools and die manufacturing. However, under some extreme wear conditions, the wear resistance of M42 steel is still insufficient, which limits its service life and application range. Traditional surface treatment methods, such as quenching, tempering, carburizing, etc., although they can improve the surface properties of materials to a certain extent, have problems such as poor surface property uniformity after treatment, difficulty in forming a gradient structure, and complex processes. Moreover, some traditional processes consume a large amount of energy and pollute the environment, which do not meet the requirements of sustainable development. As a new means of material surface modification, electron beam irradiation technology has the advantages of high energy density, fast processing speed, strong controllability, etc. When the electron beam acts on the material surface, it can quickly melt and solidify the material surface, causing changes in the organizational structure and properties. Based on this, the present invention proposes to use electron beam irradiation to induce the formation of a gradient super wear-resistant layer on the surface of M42 steel to improve its wear resistance under complex working conditions. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for inducing the formation of a gradient super wear-resistant layer on M42 steel by electron beam irradiation. Through specific process steps, a super wear-resistant layer with a gradient structure is formed on the surface of M42 steel, improving its surface hardness and wear resistance, and extending the service life of M42 steel components. To achieve the above purpose, the technical solutions adopted by the present invention are as follows: Step 1: Pretreatment. Cut and mill the M42 steel workpiece into a specific size and shape, and then use an ultrasonic cleaning machine to clean it to remove surface oil stains and impurities; Step 2: Specimen preparation. Use a metallographic polishing machine to polish from 800-mesh sandpaper to 5000-mesh in sequence, and then perform polishing treatment; Step 3: Electron beam irradiation treatment. Place the specimen in the vacuum chamber of the electron beam processing equipment, evacuate to make the vacuum degree in the vacuum chamber reach 6.3×10⁻³ Pa. Set the electron beam process parameters, the acceleration voltage is 80 kV, the beam current is 1 mA, the scanning speed is 1 mm / s, and the electron beam spot diameter is 6 mm. After irradiation treatment, cut the specimen into appropriate small pieces, clean it with an ultrasonic cleaning machine, and then perform metallographic sample preparation to obtain the finished product; Step 4: Organization and performance testing. Use an S-4800 field emission scanning electron microscope to observe the microstructure of the specimen; use an MH-6 microhardness tester to measure the microhardness of the specimen at different depths with a load of 200 g, a test force of 1.962 N, and a loading time of 8 s; use a UMT-3 friction and wear tester to set the loading load at 30 N, the friction radius at 5 mm, the rotation speed at 400 r / min, and the test time at 20 min to conduct friction and wear testing on the surface of the specimen.

[0004] Compared with the prior art, the present invention has the following beneficial effects: Through electron beam irradiation treatment, a gradient super wear-resistant layer is successfully induced and formed on the surface of M42 steel. This gradient structure enables the hardness and wear resistance of the material to gradually change from the surface to the matrix, significantly improving the surface hardness, effectively resisting wear, and greatly enhancing the wear resistance of M42 steel.

[0005] The electron beam irradiation treatment is carried out in a vacuum environment, avoiding the contamination of the material by external impurities during the treatment process and ensuring the treatment quality. At the same time, the electron beam has a high energy conversion efficiency, and the treatment process is fast and controllable, which is conducive to large-scale industrial production.

[0006] After being treated by the present invention, the surface hardness of M42 steel is significantly improved. Compared with the original material, the surface microhardness is increased by 3 times. When a friction and wear test is carried out under a load of 30 N, the wear amount is reduced from 0.0625 to 0.00993, and the wear amount is significantly reduced, effectively extending the service life of M42 steel parts. Description of the Drawings

[0007] Figure 1 is the working principle diagram of electron beam irradiation of the present invention.

[0008] Figure 2 is the schematic cross-sectional structure diagram of the gradient super wear-resistant layer on the surface of M42 steel after the implementation of the present invention.

[0009] Figure 3 is the enlarged microstructural diagram of M42 steel before the implementation of the present invention.

[0010] Figure 4 is the friction and wear performance test diagram of M42 steel before the implementation of the present invention.

[0011] Figure 5 is the friction and wear performance test diagram of M42 steel after the implementation of the present invention. Detailed Embodiments

[0012] The following are specific embodiments of the present invention. The technical solutions of the present invention will be further described in detail in conjunction with the accompanying drawings, but the present invention is not limited to these embodiments.

[0013] A method for forming a gradient super wear-resistant layer on M42 steel induced by electron beam irradiation, the specific steps are as follows: Step 1: Pretreatment. Select a suitable M42 steel workpiece, cut and mill it into a test block of 10mm×10mm×10mm, then use an ultrasonic cleaner, add an appropriate amount of alkaline cleaning agent, and clean it at 40°C for 15 minutes to remove surface oil stains and impurities. After cleaning, rinse it with deionized water and dry it for later use. After the pretreatment is completed, proceed to Step 2.

[0014] Step 2: Specimen preparation. Fix the pretreated test block on a metallographic polishing machine and polish it successively with sandpapers of 800 mesh, 1200 mesh, 2000 mesh, 3000 mesh, and 5000 mesh. Keep the specimen surface wet during the polishing process to avoid overheating. After polishing, perform polishing treatment with diamond polishing paste until the specimen surface is as bright as a mirror. After the specimen preparation is completed, proceed to Step 3.

[0015] Step 3: Electron beam irradiation treatment. Place the prepared specimen into the vacuum chamber of the electron beam processing equipment, start the vacuum pump to make the vacuum degree in the vacuum chamber reach 6.3×10⁻³ Pa. Set the electron beam acceleration voltage to 80 kV, the beam current to 1 mA, the scanning speed to 1 mm / s, and the electron beam spot diameter to 6 mm. Use a spiral scanning method to irradiate the specimen surface. After irradiation, take out the specimen from the vacuum chamber, cut it into small pieces, clean it again with an ultrasonic cleaner, and then perform metallographic sample preparation. After the electron beam irradiation treatment is completed, proceed to Step 4.

[0016] Step 4: Microstructure and property testing. Use an S-4800 field emission scanning electron microscope to observe the microstructure of the specimen, and it is found that a distinct gradient super wear-resistant layer has formed on the surface. From the surface to the substrate, the grains gradually coarsen. Use an MH-6 microhardness tester to measure the microhardness of the specimen at different depths according to the set parameters. The results show that the surface hardness is the highest, and the hardness gradually decreases with the increase of depth, forming a gradient distribution. Use a UMT-3 friction and wear tester to conduct friction and wear tests on the specimen surface. After the test, analyze the friction coefficient and wear amount. The test data show that the friction coefficient of the treated M42 steel is significantly reduced, the wear amount is greatly reduced, and the wear resistance is greatly improved.

[0017] The above embodiments are only partial embodiments of the present invention. Based on the technical solution of the present invention, any equivalent changes or modified variations made based on the technical spirit of the present invention shall fall within the scope of patent protection of the present invention.

Claims

1. A method for inducing the formation of a gradient super wear-resistant layer of M42 steel by electron beam irradiation, characterized in that: The following steps are included: 1: Pretreatment, cutting and milling the M42 steel workpiece into a specific size and shape, and then using an ultrasonic cleaner to clean it to remove surface oil and impurities. After the pretreatment is completed, proceed to step 2; Step 2: Sample preparation, using a metallographic polisher to grind from 800 mesh sandpaper to 5000 mesh in sequence, and then polishing. After the sample preparation is completed, proceed to step 3; Step 3: Electron beam irradiation treatment, place the sample in the vacuum chamber of the electron beam processing equipment, and evacuate the vacuum chamber to reach a vacuum degree of 5×10⁻³Pa. Set the electron beam process parameters, the acceleration voltage is 80kV, the beam current is 5mA, the scanning speed is 8mm / s, and the electron beam spot diameter is 2mm. After irradiation treatment, cut the sample into suitable small pieces, clean it with an ultrasonic cleaner, and then perform metallographic sample preparation to obtain the finished product. After the electron beam irradiation treatment is completed, proceed to step 4; Step 4: Organization and performance testing, use S-4800 field emission scanning electron microscope to observe the microstructure of the sample; use MH-6 microhardness tester to measure the microhardness of the sample at different depths with 200g load, 1.962N test force, and 8s loading time; use UMT-3 friction and wear testing machine, set the loading load to 30N, friction radius to 5mm, rotation speed to 400r / min, and test time to 20min, and perform friction and wear test on the sample surface.

2. The method for forming a gradient super wear-resistant layer of M42 steel by electron beam irradiation induction according to claim 1, characterized in that: In step 1, the M42 steel workpiece is cut into test blocks of 10 mm × 10 mm × 10 mm, and a preliminary surface smoothing treatment is performed.

3. The method for forming a gradient super wear-resistant layer of M42 steel by electron beam irradiation induction according to claim 1, characterized in that: In step 3, a more uniform irradiation effect is achieved by adjusting the scanning mode of the electron beam, such as using spiral scanning or reciprocating scanning.

4. The method for forming a gradient super wear-resistant layer of M42 steel by electron beam irradiation induction according to claim 1, characterized in that: After step 3 treatment, a gradient distribution structure is formed on the surface of M42 steel, and the hardness and wear resistance change gradually from the surface to the matrix.

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