Bislate400 wear-resistant steel plate and surface modification method thereof

Abstract

The invention belongs to the technical field of metal material surface modification, and particularly relates to a Bisplate400 wear-resistant steel plate and a surface modification method thereof.The surface of the Bisplate400 wear-resistant steel plate is clad with a WNiFe coating through vacuum electron beams, good combination of the coating and a base body is achieved, then laser shock peening is utilized, the surface roughness of the coating is reduced, fatigue crack initiation is reduced, and the coating quality is improved; according to the method, the surface performance of a material can be improved in a shorter time, the machining efficiency can be improved, and compared with the surface of a Bisplate400 wear-resistant steel plate which is not subjected to surface modification, the surface performance of the Bisplate400 wear-resistant steel plate surface subjected to vacuum electron beam surface modification is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of metal material surface modification, in particular to a Bisplate 400 wear-resistant steel plate and a surface modification method thereof. Background Art

[0002] Bisplate 400 wear-resistant steel plate is a high-strength, high-hardness wear-resistant steel plate. Its outstanding wear resistance and excellent mechanical properties have made it widely used in various fields. Its unique alloy design and advanced heat treatment technology achieve a perfect combination of high hardness and high toughness. Bisplate 400 wear-resistant steel plate offers significantly higher wear resistance than ordinary steel plates, with both high yield strength and tensile strength, meeting the demands of various heavy-duty operating conditions. While maintaining hardness, Bisplate 400 wear-resistant steel plate also maintains excellent toughness, making it less susceptible to brittle fracture. Furthermore, Bisplate 400 wear-resistant steel plate offers excellent weldability and machinability. Bisplate 400 wear-resistant steel plate is particularly well-suited for use in mining machinery, such as wear-resistant components of excavators, loaders, crushers, and other equipment, including buckets, dipper arms, and breakers. However, during its application, Bisplate 400 wear-resistant steel plate was found to have poor corrosion resistance in humid and high-salt environments. With the development of science and technology and the global machinery industry, higher requirements are placed on the application of Bisplate400 wear-resistant steel plate, so the surface modification technology has been rapidly developed.

[0003] Currently, commonly used methods to improve material surface properties include vacuum electron beam cladding, laser cladding, physical vapor deposition, and plasma electrolytic oxidation. While these technologies can improve material surface properties to a certain extent, they present several technical difficulties in actual operation. These include the difficulty in optimizing process parameters, the need to precisely adjust energy density during the cladding process to avoid excessive melting of the substrate; coating defect control, and the risk of cracks caused by rapid solidification; uneven powder feeding during laser cladding, which can lead to porosity; and insufficient interface strength between the cladding coating and the substrate. Summary of the Invention

[0004] In order to solve the problems existing in the prior art, the main purpose of the present invention is to propose a Bisplate400 wear-resistant steel plate and a surface modification method thereof, using a vacuum electron beam to clad a WNiFe coating on the surface of the Bisplate400 wear-resistant steel plate to achieve a good combination of the coating and the substrate, and then using laser shock strengthening to reduce the surface roughness of the coating, reduce fatigue crack initiation, improve the coating quality, and make the coating have excellent corrosion resistance and wear resistance.

[0005] According to one aspect of the present invention, the present invention provides the following technical solutions:

[0006] A method for surface modification of Bisplate 400 wear-resistant steel plate comprises the following steps:

[0007] S1, coating powder pretreatment; the coating powder is WNiFe mixed powder, wherein the mass ratio of W powder, Ni powder and Fe powder is 70:20:10;

[0008] S2, preparing a surface coating of the Bisplate 400 wear-resistant steel plate; mixing the coating powder with a binder and a solvent to form a coating for spraying, spraying the coating on the surface of the Bisplate 400 wear-resistant steel plate, drying and curing the coating, and then cladding the cured coating with a vacuum electron beam to obtain a surface coating of the Bisplate 400 wear-resistant steel plate;

[0009] S3. Use short pulse laser to impact the surface coating of Bisplate400 wear-resistant steel plate to induce high-amplitude residual compressive stress in the surface layer, thereby achieving surface modification of Bisplate400 wear-resistant steel plate.

[0010] As a preferred embodiment of the surface modification method of Bisplate 400 wear-resistant steel plate described in the present invention, in step S1, the coating powder is pretreated by vibration ball milling, the ball-to-material ratio during ball milling is (5-10):1, and the ball milling time is 5-15h.

[0011] As a preferred embodiment of the surface modification method for Bisplate 400 wear-resistant steel plate described in the present invention, in step S1, after ball milling, the coating powder is screened using multiple layers of screens, gradually sieving from coarse to fine. The screen apertures used are 30 μm, 25 μm, 20 μm, and 15 μm, respectively. This removes insufficiently crushed coarse particles, ensures a uniform powder particle size distribution, and improves the density of the subsequent coating.

[0012] As a preferred embodiment of the surface modification method of Bisplate 400 wear-resistant steel plate described in the present invention, in step S1, the average particle size of the coating powder after ball milling is ≤15 μm.

[0013] As a preferred embodiment of the surface modification method of Bisplate 400 wear-resistant steel plate described in the present invention, in step S2, the mass ratio of the coating powder to the binder is 5:1.

[0014] As a preferred embodiment of the surface modification method of Bisplate 400 wear-resistant steel plate described in the present invention, in step S2, the mass ratio of the binder to the solvent is 7:3; the binder is acrylic resin powder, and the solvent is acetone.

[0015] As a preferred embodiment of the surface modification method of Bisplate 400 wear-resistant steel plate described in the present invention, in step S2, the drying temperature is 130-150° C. and the drying time is 20-30 min.

[0016] As a preferred embodiment of the surface modification method of Bisplate 400 wear-resistant steel plate described in the present invention, in step S2, the acceleration voltage of the vacuum electron beam is 70-80 kV, the beam current is 20-40 mA, the focusing current is 700-800 mA, and the scanning speed is 300-500 mm / min.

[0017] As a preferred embodiment of the surface modification method of Bisplate 400 wear-resistant steel plate described in the present invention, wherein: in the step S2, the vacuum degree during the vacuum electron beam cladding is less than 10 -3 Pa.

[0018] As a preferred embodiment of the surface modification method of Bisplate 400 wear-resistant steel plate described in the present invention, wherein: in step S3, the wavelength of the short pulse laser is 1000-1080nm, the pulse width is 8-12ns, and the energy density is 5-8J / cm 2 , the spot overlap rate is 40-60%.

[0019] According to another aspect of the present invention, the present invention provides the following technical solutions:

[0020] A Bisplate 400 wear-resistant steel plate is prepared by the above-mentioned Bisplate 400 wear-resistant steel plate surface modification method. The thickness of the surface coating of the Bisplate 400 wear-resistant steel plate is 2-3 mm. The surface hardness of the modified Bisplate 400 wear-resistant steel plate is ≥400 HV, and the wear rate is ≤0.7×10 -5 mm 3 / N·m.

[0021] The beneficial effects of the present invention are as follows:

[0022] The present invention proposes a Bisplate 400 wear-resistant steel plate and a surface modification method thereof. A WNiFe coating is clad on the surface of the Bisplate 400 wear-resistant steel plate using a vacuum electron beam to achieve good bonding between the coating and the substrate. Laser shock strengthening is then used to reduce the surface roughness of the coating, reduce fatigue crack initiation, improve the coating quality, and enable the coating to have excellent corrosion resistance and wear resistance. The present invention can improve the surface properties of the material and enhance processing efficiency in a shorter time. The surface properties of the Bisplate 400 wear-resistant steel plate surface modified by the vacuum electron beam are significantly improved compared to the surface of the Bisplate 400 wear-resistant steel plate without surface modification. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in 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 only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0024] Figure 1 This is a cross-sectional microscopic morphology of the Bisplate 400 wear-resistant steel plate after surface modification in Example 1 of the present invention.

[0025] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0026] The following will be a clear and complete description of the technical solutions in the embodiments. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0027] According to one aspect of the present invention, the present invention provides the following technical solutions:

[0028] A method for surface modification of Bisplate 400 wear-resistant steel plate comprises the following steps:

[0029] S1, coating powder pretreatment; the coating powder is WNiFe mixed powder, wherein the mass ratio of W powder, Ni powder and Fe powder is 70:20:10;

[0030] S2, preparing a surface coating of the Bisplate 400 wear-resistant steel plate; mixing the coating powder with a binder and a solvent to form a coating for spraying, spraying the coating on the surface of the Bisplate 400 wear-resistant steel plate, drying and curing the coating, and then cladding the cured coating with a vacuum electron beam to obtain a surface coating of the Bisplate 400 wear-resistant steel plate;

[0031] S3. Use short pulse laser to impact the surface coating of Bisplate400 wear-resistant steel plate to induce high-amplitude residual compressive stress in the surface layer, thereby achieving surface modification of Bisplate400 wear-resistant steel plate.

[0032] Preferably, in step S1, the coating powder is pretreated by vibratory ball milling, the ball-to-material ratio during ball milling is (5-10):1, and the ball milling time is 5-15 hours. Specifically, the ball-to-material ratio can be, for example, any one of 5:1, 6:1, 7:1, 8:1, 9:1, and 10:1, or a range between any two thereof; and the ball milling time can be, for example, any one of 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, and 15 hours, or a range between any two thereof.

[0033] Preferably, in step S1, after ball milling, the coating powder is screened using multiple layers of screens, gradually from coarse to fine, with the selected screen apertures being 30 μm, 25 μm, 20 μm, and 15 μm, respectively. This screening method can remove coarse particles that are not fully crushed, ensure a uniform powder particle size distribution, and improve the density of the subsequent coating. Further preferably, the average particle size of the coating powder after ball milling is ≤15 μm.

[0034] Preferably, in step S2, the mass ratio of the coating powder to the binder is 5:1; the mass ratio of the binder to the solvent is 7:3; the binder is acrylic resin powder, and the solvent is acetone.

[0035] Preferably, in step S2, the drying temperature is 130-150° C., and the drying time is 20-30 min. Specifically, the drying temperature can be, for example, any one of 130° C., 135° C., 140° C., 145° C., and 150° C., or a range between any two thereof; and the drying time can be, for example, any one of 20 min, 21 min, 22 min, 23 min, 24 min, 25 min, 26 min, 27 min, 28 min, 29 min, and 30 min, or a range between any two thereof.

[0036] Preferably, in step S2, the acceleration voltage of the vacuum electron beam is 70-80 kV, the beam current is 20-40 mA, the focusing current is 700-800 mA, and the scanning speed is 300-500 mm / min. Specifically, the acceleration voltage can be, for example, any one of 70 kV, 71 kV, 72 kV, 73 kV, 74 kV, 75 kV, 76 kV, 77 kV, 78 kV, 79 kV, and 80 kV, or a range between any two thereof; the beam current can be, for example, any one of 20 mA, 25 mA, 30 mA, 35 mA, and 40 mA, or a range between any two thereof; the focusing current can be, for example, 700 mA, 710 mA, 720 mA, 730 mA, 740 mA, or a range between any two thereof. A, 750mA, 760mA, 770mA, 780mA, 790mA, 800mA or a range between any two of them; the scanning speed can be, for example, 300mm / min, 325mm / min, 350mm / min, 375mm / min, 400mm / min, 425mm / min, 450mm / min, 475mm / min, 500mm / min or a range between any two of them.

[0037] Preferably, in step S2, the vacuum degree during the vacuum electron beam cladding is less than 10 -3 Pa.

[0038] Preferably, in step S3, the wavelength of the short pulse laser is 1000-1080 nm, the pulse width is 8-12 ns, and the energy density is 5-8 J / cm 2 , the spot overlap rate is 40-60%. Specifically, the wavelength can be, for example, any one of 1000nm, 1010nm, 1020nm, 1030nm, 1040nm, 1050nm, 1060nm, 1070nm, 1080nm, or a range between any two thereof; the pulse width can be, for example, any one of 8ns, 9ns, 10ns, 11ns, 12ns, or a range between any two thereof; the energy density can be, for example, 5J / cm 2 , 6J / cm 2 , 7J / cm 2 , 8J / cm 2 any one of or a range between any two of the above; the spot overlap rate can be, for example, 40%, 45%, 50%, 55%, 60% or any one of or a range between any two of the above.

[0039] According to another aspect of the present invention, the present invention provides the following technical solutions:

[0040] A Bisplate 400 wear-resistant steel plate is prepared by the above-mentioned Bisplate 400 wear-resistant steel plate surface modification method. The thickness of the surface coating of the Bisplate 400 wear-resistant steel plate is 2-3 mm. The surface hardness of the modified Bisplate 400 wear-resistant steel plate is ≥400 HV, and the wear rate is ≤0.7×10 -5 mm 3 / N·m.

[0041] The technical solution of the present invention is further described below with reference to specific embodiments.

[0042] Example

[0043] A surface modification method for a Bisplate 400 wear-resistant steel plate is disclosed. The composition of the Bisplate 400 wear-resistant steel plate is shown in Table 1 (weight percentage, wt%).

[0044] Table 1

[0045] C P Mn Si S Cr Mo B Ce Fe and inevitable impurity elements 0.20 0.025 1.5 0.25 0.008 0.30 0.25 0.002 0.50 margin

[0046] The steps include:

[0047] S1. Coating powder pretreatment: The coating powder is a WNiFe mixed powder, wherein the mass ratio of W powder, Ni powder, and Fe powder is 70:20:10. The coating powder is pretreated by vibratory ball milling, with a ball-to-material ratio of 8:1 and a milling time of 10 hours. After ball milling, the coating powder is sieved using multiple layers of screens, gradually from coarse to fine, with the selected screen apertures being 30 μm, 25 μm, 20 μm, and 15 μm, respectively. In step S1, the average particle size of the coating powder after ball milling is ≤15 μm.

[0048] S2. Preparation of the surface coating of Bisplate 400 wear-resistant steel plate: the coating powder is mixed with a binder and a solvent to form a spray coating, which is sprayed on the surface of the Bisplate 400 wear-resistant steel plate and then dried and cured. The mass ratio of the coating powder to the binder is 5:1; the mass ratio of the binder to the solvent is 7:3; the binder is acrylic resin powder and the solvent is acetone; the drying temperature is 130°C and the drying time is 25 minutes; the cured coating is then clad using a vacuum electron beam, and the vacuum degree during vacuum electron beam cladding is <10 -3 Pa, to obtain the surface coating of Bisplate400 wear-resistant steel plate;

[0049] S3. Use short pulse laser to impact the coating surface to induce high-amplitude residual compressive stress in the surface layer, thereby achieving surface modification of Bisplate 400 wear-resistant steel plate.

[0050] Figure 1The cross-sectional morphology of the coating of Example 1 under a low magnification electron microscope is shown. Figure 1 The yellow dotted line in (1) shows the cladding coating above and the Bisplate 400 wear-resistant steel substrate below. The results show that the interface between the coating and the substrate is well bonded, and the average thickness of the coating is about 2.56 mm. The vacuum electron beam cladding WNiFe coating has no cracks, but has a small amount of pores. Figure 1 (2)-(4) show the top, middle and bottom microstructures of the WNiFe coating. The particles and dendrite phases of the coating are concentrated in the top and middle regions of the coating ( Figure 1 (2)-(3)), where the polygonal particles are located in the top region and the dendritic phase is located in the middle region. This is because when the molten pool completely solidifies, the particles and dendritic phase fail to sink in time and ultimately remain mainly in the top and middle regions of the coating. In addition, as the degree of substrate melting increases, the Fe in the substrate dilutes the bottom of the molten coating, resulting in a decrease in the particles and dendritic phase at the bottom of the coating.

[0051] The parameters of the surface modification of the examples of the present invention and the comparative examples are shown in Table 2;

[0052] Table 2

[0053]

[0054]

[0055] The surface properties of the Bisplate 400 wear-resistant steel plates prepared in the embodiments of the present invention and the comparative examples are shown in Table 3;

[0056] Table 3

[0057] Hardness (HV) <![CDATA[Wear volume (mm 3 )]]> <![CDATA[Wear rate (×10 -5 mm 3 / N·m)]]> Example 1 400 0.2008 0.6128 Example 2 430 0.1785 0.5786 Example 3 450 0.1518 0.4785 Comparative Example 1 370 1.3135 4.2356 Comparative Example 2 390 0.3078 0.7197 Comparative Example 3 / / /

[0058] To test the surface hardness of the modified Bisplate 400 wear-resistant steel plate, a microhardness tester was used to test the surface modified area. The load was 3N and maintained for 10s. To reduce the error, three hardness measurements were performed at each location and the average value was taken. The results showed that as the scanning speed increased, the hardness of the material surface increased and the surface hardness of the material gradually increased. The surface hardness of the cladding layer of Example 3 reached a maximum of 450HV, which was 21.6% higher than the hardness of Comparative Example 1. In order to test the corrosion resistance of the surface of the modified Bisplate 400 wear-resistant steel plate, the coating area with the substrate was prepared into a 20×20×10mm sample using electric spark wire cutting, and a friction and wear test was carried out in a 3.5wt% NaCl solution environment (because the friction and wear test in the 3.5wt% NaCl solution environment mainly occurs during the friction and wear test, the wear volume and wear rate of the wear scar after the friction and wear test can be used to judge the corrosion resistance of the sample surface). First, the coating surface was polished to 2000 mesh using sandpaper, and then metallographic polishing and ultrasonic cleaning were performed. The modified Bisplate 400 wear-resistant steel plate was then tested for wear resistance in a 3.5% NaCl solution using a friction and wear tester. The wear scar volume was measured using a white light interferometer 3D surface profilometer. The results showed that the wear volume and wear rate of Example 3 were reduced by 88.44% and 88.70%, respectively, compared to the substrate. This indicates that the corrosion resistance of the modified Bisplate 400 wear-resistant steel plate has been significantly improved.

[0059] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention specification under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for surface modification of Bisplate 400 wear-resistant steel plate, characterized in that: The steps include: S1, coating powder pretreatment; the coating powder is WNiFe mixed powder, wherein the mass ratio of W powder, Ni powder and Fe powder is 70:20:10; S2, preparing a surface coating of the Bisplate 400 wear-resistant steel plate; mixing the coating powder with a binder and a solvent to form a coating for spraying, spraying the coating on the surface of the Bisplate 400 wear-resistant steel plate, drying and curing the coating, and then cladding the cured coating with a vacuum electron beam to obtain a surface coating of the Bisplate 400 wear-resistant steel plate; S3. Use short pulse laser to impact the surface coating of Bisplate400 wear-resistant steel plate to induce high-amplitude residual compressive stress in the surface layer, thereby achieving surface modification of Bisplate400 wear-resistant steel plate.

2. The surface modification method of Bisplate 400 wear-resistant steel plate according to claim 1, characterized in that: In the step S1, the coating powder is pretreated by vibrating ball milling, the ball-to-material ratio during ball milling is (5-10):1, and the ball milling time is 5-15 hours.

3. The surface modification method of Bisplate 400 wear-resistant steel plate according to claim 1, characterized in that: In the step S1, after ball milling, the coating powder is sieved with multiple layers of sieves, gradually from coarse to fine, and the pore sizes of the selected sieves are 30 μm, 25 μm, 20 μm, and 15 μm, respectively.

4. The surface modification method of Bisplate 400 wear-resistant steel plate according to claim 1, characterized in that: In the step S1, the average particle size of the coating powder after ball milling is ≤15 μm.

5. The surface modification method of Bisplate 400 wear-resistant steel plate according to claim 1, characterized in that: In step S2, the mass ratio of the coating powder to the binder is 5:

1.

6. The surface modification method of Bisplate 400 wear-resistant steel plate according to claim 1, characterized in that: In step S2, the mass ratio of the binder to the solvent is 7:3; the binder is acrylic resin powder, and the solvent is acetone.

7. The surface modification method of Bisplate 400 wear-resistant steel plate according to claim 1, characterized in that: In step S2, the drying temperature is 130-150° C., and the drying time is 20-30 minutes.

8. The surface modification method of Bisplate 400 wear-resistant steel plate according to claim 1, characterized in that: In step S2, the acceleration voltage of the vacuum electron beam is 70-80 kV, the beam current is 20-40 mA, the focusing current is 700-800 mA, and the scanning speed is 300-500 mm / min; the vacuum degree during the vacuum electron beam cladding is <10 -3 Pa.

9. The surface modification method of Bisplate 400 wear-resistant steel plate according to claim 1, characterized in that: In step S3, the wavelength of the short pulse laser is 1000-1080 nm, the pulse width is 8-12 ns, and the energy density is 5-8 J / cm 2 , the spot overlap rate is 40-60%.

10. A Bisplate 400 wear-resistant steel plate, characterized in that: The Bisplate400 wear-resistant steel plate is prepared by the surface modification method of any one of claims 1 to 9. The thickness of the surface coating of the Bisplate400 wear-resistant steel plate is 2-3 mm. The surface hardness of the modified Bisplate400 wear-resistant steel plate is ≥400 HV, and the wear rate is ≤0.7×10 -5 mm 3 / N·m.

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