Carbon steel composite material, and preparation method therefor and use thereof

Abstract

The present application belongs to the technical field of carbon steel processing, and particularly relates to a carbon steel composite material, and a preparation method therefor and the use thereof. Provided in the present application is the carbon steel composite material, which material comprises a carbon steel matrix and a high-entropy alloy coating located on the surface of the carbon steel matrix, wherein the high-entropy alloy coating comprises the following components: iron, cobalt, chromium, nickel, copper and boron. The carbon steel composite material provided in the present application has relatively high antifriction and wear-resistant effects at both room temperature and high temperatures. The carbon steel composite material provided in the present application has the high-entropy alloy coating, and the high-entropy alloy tends to form a simple solid solution instead of an intermetallic compound among alloy elements under the influence of a relatively high structural entropy thereof, such that the carbon steel composite material has good mechanical properties and tribological properties.

Description

A carbon steel composite material and its preparation method and application

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on May 16, 2024, with application number 202410610925.1 and invention name “A carbon steel composite material, its preparation method and application”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application belongs to the field of carbon steel processing technology, and specifically relates to a carbon steel composite material and a preparation method and application thereof. Background Art

[0003] Carbon steel is the earliest and most widely used basic material in modern industry. It is a carbon structural steel with excellent plasticity, toughness, and resistance to weld cracking. Its low price makes it widely used in construction, high-voltage power transmission towers, vehicles, ships, and other fields, and is also widely used in mechanical parts. However, carbon steel's poor wear resistance and friction reduction properties limit its use in moving parts. Summary of the Invention

[0004] The purpose of this application is to provide a carbon steel composite material and its preparation method and application. The carbon steel composite material provided in this application can effectively improve the friction reduction and wear resistance at room temperature and high temperature.

[0005] In order to achieve the above objectives, this application provides the following technical solutions:

[0006] The present application provides a carbon steel composite material, comprising a carbon steel substrate and a high-entropy alloy coating located on the surface of the carbon steel substrate; the high-entropy alloy coating comprises the following components: iron, cobalt, chromium, nickel, copper and boron.

[0007] Preferably, the molar ratio of the iron element, cobalt element, chromium element, nickel element, copper element and boron element is 1:1:1:1:1:0.1-0.5. This application adopts the above amount of boron element. When the addition amount of boron element is too low, its high-temperature friction reduction effect is not significantly improved. When the addition amount of boron element exceeds 0.5, its friction reduction performance is limited, and a large amount of boron element addition will affect the brittleness and hardness of the coating.

[0008] Preferably, the molar ratio of the iron element, the cobalt element, the chromium element, the nickel element, the copper element and the boron element is 1:1:1:1:1:0.3-0.5.

[0009] The present application also provides a method for preparing the carbon steel composite material described in the above scheme, comprising the following steps:

[0010] S1, mixing iron powder, cobalt powder, chromium powder, nickel powder, copper powder and boron powder, ball milling and drying to obtain a mixed powder;

[0011] S2. Using laser to clad the surface of a carbon steel substrate with the mixed powder to obtain the carbon steel composite material.

[0012] Preferably, the laser power of the laser cladding is 1200-2000 W, specifically 1200 W, 1400 W, 1600 W, 1800 W, 2000 W or a range consisting of any two of the above values.

[0013] Preferably, the ball milling speed is 400-800 r / min, specifically 600 r / min, and the ball milling time is 4 hours.

[0014] Preferably, the drying temperature is 60° C. and the holding time is 4 hours.

[0015] Preferably, the laser beam output spot of the laser cladding is 1 to 2 mm, specifically 1.8 mm.

[0016] Preferably, the scanning speed of the laser cladding is 4-8 mm / s, specifically 5 mm / s.

[0017] Preferably, the defocus amount of the laser cladding is -20 mm.

[0018] Preferably, the powder feeding rate of the laser cladding is 10.5 g / min.

[0019] Preferably, the particle sizes of the iron powder, cobalt powder, chromium powder, nickel powder and copper powder are independently selected from 45 to 105 μm.

[0020] Preferably, the particle size of the boron powder is 15 to 45 μm.

[0021] Preferably, the surface of the carbon steel substrate is treated to remove impurities.

[0022] Preferably, the carbon steel matrix is ​​at least one of Q235 ordinary carbon steel, Q345 high-quality carbon steel, No. 35 high-quality carbon steel and No. 45 high-quality carbon steel.

[0023] The present application also provides the use of the carbon steel composite material described in the above scheme or the carbon steel composite material obtained by the preparation method described in the above scheme in sports parts.

[0024] The present application provides a carbon steel composite material. The carbon steel composite material provided herein has high friction reduction and wear resistance at both room temperature and high temperature. The carbon steel composite material provided herein has a high-entropy alloy coating. Due to the high structural entropy of the high-entropy alloy, the alloying elements tend to form simple solid solutions rather than intermetallic compounds, resulting in excellent mechanical and tribological properties. The carbon steel composite material provided in the present application exhibits excellent wear resistance, which gives it an advantage in scenarios characterized by severe wear and abrasion; boron, as a non-metallic element with a large atomic size difference from Fe, Co, Cr, Ni and Cu, will cause severe lattice distortion when forming a solid solution, increase the dislocation density of the coating, and improve the mechanical properties; boron has a very high hardness and melting point, and can form high-strength, high-hardness, high-heat-resistant and high-corrosion-resistant metal borides with other metal or non-metallic elements at high temperatures. Borides also have lubricity and can effectively reduce the friction coefficient; the oxidation Gibbs free energy of boron B2O3 is low, it can exist stably, and has a low melting point. It melts at 510°C to form a low-viscosity liquid, forming a lubricating film, isolating the contact surface, which can directly reduce contact and adhesion. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] FIG1 is an XRD diagram of the carbon steel composite material of Examples 1 to 3 of the present application;

[0027] FIG2 is a cross-sectional microscopic morphology of the carbon steel composite material of Examples 1 to 3 of the present application;

[0028] FIG3 is a microhardness curve of the carbon steel composite material of Examples 1 to 3 of the present application;

[0029] FIG4 is a diagram showing contact angles and surface energies of Q235 ordinary carbon steel and the carbon steel composite materials of Examples 1 to 3 of the present application;

[0030] FIG5 is a graph showing the friction coefficients of Q235 ordinary carbon steel and the carbon steel composite materials of Examples 1 to 3 of the present application;

[0031] FIG6 is a graph showing the wear rates of Q235 ordinary carbon steel and the carbon steel composite materials of Examples 1 to 3 of the present application;

[0032] FIG7 is a diagram showing the wear surface morphology of Q235 ordinary carbon steel and the carbon steel composite materials of Examples 1 to 3 of the present application at room temperature;

[0033] FIG8 is a graph showing the surface morphology of Q235 ordinary carbon steel and the carbon steel composite materials of Examples 1 to 3 of the present application at room temperature after grinding ball wear;

[0034] FIG9 is a graph showing the wear surface morphology of Q235 ordinary carbon steel and the carbon steel composite materials of Examples 1 to 3 of the present application at 600° C.;

[0035] FIG10 is a surface morphology diagram of the wear of Q235 ordinary carbon steel and the carbon steel composite materials of Examples 1 to 3 of the present application on the grinding ball at 600°C. DETAILED DESCRIPTION

[0036] In order to further illustrate the present application, the scheme of the present application is described in detail below with reference to the accompanying drawings and embodiments, but they should not be understood as limiting the scope of protection of the present application.

[0037] Unless otherwise specified, the reagents, methods and equipment used in this application are conventional reagents, methods and equipment in this technical field.

[0038] Example 1

[0039] Example 1 provides a carbon steel composite material comprising a carbon steel substrate and a high-entropy alloy coating disposed on the surface of the carbon steel substrate; the high-entropy alloy coating comprises the following elements: iron, cobalt, chromium, nickel, copper, and boron. The molar amounts of each element are shown in Table 1. The preparation method is as follows:

[0040] S1. Weigh the powders according to the molar ratio using an electronic scale, and place the mixed powders in a DECO-PBM-V-0.4L ball mill for 4 h at a speed of 600 r / min. Then, dry the mixed powders at a constant temperature of 60°C for 4 h.

[0041] The Q235 ordinary carbon steel substrate was ground using sandpaper of different mesh sizes to remove surface impurities;

[0042] S2, using a fiber laser (YLS-3000) with an output power of 1600W to melt the composite coating in a synchronous powder feeding manner, the laser beam output spot is The scanning speed was 5 mm / s, the defocusing amount was -20 mm, and the powder feeding rate was 10.5 g / min. The carbon steel composite material (named B1) was obtained by adopting multi-channel continuous laser scanning technology with an overlap rate of 50%.

[0043] Examples 2-3

[0044] Examples 2 and 3 provide a series of carbon steel composite materials, the molar amounts of the various elements are shown in Table 1, and the preparation methods are the same as in Example 1. The prepared carbon steel composite materials are named B3 and B5, respectively.

[0045] Table 1 Molar dosage of each element in Examples 1 to 3

[0046] Example 4

[0047] This embodiment provides a carbon steel composite material, the molar dosage of each element and the preparation method are basically the same as those in Example 1, except that the laser power in the preparation method is 1200W.

[0048] Example 5

[0049] This embodiment provides a carbon steel composite material, the molar dosage of each element and the preparation method thereof are basically the same as those in Example 1, except that the laser power in the preparation method is 1400W.

[0050] Example 6

[0051] This embodiment provides a carbon steel composite material, the molar dosage of each element and the preparation method thereof are basically the same as those in Example 1, except that the laser power in the preparation method is 1800W.

[0052] Example 7

[0053] This embodiment provides a carbon steel composite material, the molar dosage of each element and the preparation method thereof are basically the same as those in Example 1, except that the laser power in the preparation method is 2000W.

[0054] Comparative Example 1

[0055] This comparative example provides a carbon steel composite material, the molar amounts of the elements and the preparation method thereof are the same as those in Example 1, except that the comparative example 1 does not contain the boron element.

[0056] Performance Testing

[0057] The high entropy alloy coatings of the carbon steel composite materials prepared in Examples 1 to 3 were subjected to XRD testing, and the results are shown in Figure 1. The coatings are mainly composed of FCC-type solid solutions. By selecting the strongest characteristic peak (111) crystal plane family in the spectrum for analysis, as the boron element increases, the intensity of the characteristic peak gradually decreases, and the peak gradually shifts to the left, the FWHM value increases, and the grain size of the coating decreases. In the coatings in Examples 2 and 3, XRD detected the precipitation of Cr2B, and its PDF card is: ICDD 01-089-4876. Cr2B has high hardness and strength, and Cr2B has a high melting point and thermal stability. These properties help the coating improve its tribological properties. In Example 1, due to the low boron content, the detection accuracy of XRD could not be detected.

[0058] Furthermore, SEM examination of the carbon steel composite materials prepared in Examples 1-3 was performed. The results are shown in Figure 2 (a, b, and c are microstructure images of Examples 1, 2, and 3, respectively). The boron element precipitates along the grain boundaries to form Cr2B, forming a network-like distribution and reducing the grain size. A portion of the boron element acts as a solute, forming a solid solution with other metal elements, resulting in lattice distortion. The evolution of the microstructure after the introduction of boron element indicates that its addition results in grain refinement, dispersion strengthening, and lattice distortion.

[0059] Furthermore, the hardness test of the carbon steel composite materials prepared in Examples 1 to 3 was carried out, and the results are shown in FIG3 . As can be seen from FIG3 , the average microhardness of the carbon steel composite materials B1, B3, and B5 are 236.53 HV 0.5 、266.29HV 0.5 and 343.98HV 0.5 , about Q235 ordinary carbon steel matrix (175.6HV 0.5 ) by 1.34 to 1.96 times. The coating hardness is improved to varying degrees, which can be attributed to the following three aspects: First, grain refinement. Element B can lower the phase transition temperature, which is beneficial for low-temperature rapid sintering, thereby reducing the grain size of the high-entropy alloy and increasing the density of grain boundaries and dislocation slip resistance. Second, dispersion strengthening. Borides precipitated after adding element B have high hardness and high melting point. As dispersion-strengthened precipitation phases, they can improve the wear resistance and creep resistance of the metal. In addition, their network distribution can hinder the movement of dislocations, thereby increasing the hardness and strength of the metal. Third, lattice distortion. Since the atomic radius of element B is much smaller than that of the other five metal elements, when it forms a solid solution as a solute, it will cause lattice distortion, increase the difficulty of dislocation slip, and improve the yield strength and tensile strength of the coating.

[0060] Furthermore, the surface energy of the coating was measured by the Owens two-liquid method using a JGW-360B contact angle meter, with deionized water and n-hexadecane (C 16 H 34 ) two liquids, and their properties are listed in Table 2. The test results of the contact angle and surface energy of Q235 ordinary carbon steel and B1, B3, and B5 carbon steel composites are shown in Figure 4. The contact angles of the three high-entropy alloy coatings are all greater than those of Q235 ordinary carbon steel, and the surface energies are all less than those of Q235 ordinary carbon steel. The periodic lattice structure of a solid is the lowest energy stable state formed spontaneously, and the surface of the material is equivalent to a two-dimensional defect, resulting in it having higher energy than the interior of the material. Therefore, the surface layer of low-surface-energy materials tends to reach an internal stable state. Studies have reported that lower surface energy can reduce the occurrence of adhesion. Since the friction process occurs on the surface of the material, the tribological properties of the material are improved.

[0061] Table 2 Surface energy determination liquid properties

[0062] Furthermore, to test the tribological properties of the carbon steel composite materials prepared in Examples 1-3 and Comparative Example 1, the present application used a ball-on-disc high-temperature friction and wear tester (HT-1000) to conduct tribological performance tests. The test parameters are shown in Table 3. The resulting friction factor curve is shown in Figure 5, where a is the friction factor at room temperature and b is the friction factor at 600°C. Detailed friction factor data are shown in Table 4. At room temperature, compared to Q235 ordinary carbon steel, although Comparative Example 1 has some friction reduction performance, it is not significant. However, the addition of element B has a significant friction reduction effect. The B5 coating, which has a significant friction reduction effect, has a friction coefficient reduced by 46.89% compared to Q235 ordinary carbon steel. When element B is present in the alloy, it can form a lubricating film on the surface of the alloy, which can reduce friction and wear between metal surfaces. This self-lubricating property is due to the good lubricity of the compound or oxide formed by element B and the metal surface, which can effectively reduce the friction coefficient. Furthermore, the three strengthening mechanisms introduced by the addition of element B significantly increase the coating's hardness. This increased hardness results in a smoother surface with less surface roughness, which reduces the contact area during friction, reducing the likelihood of adhesion and lowering the relative sliding resistance between the friction pairs. At 600°C, the friction coefficient curve is more stable than at room temperature. This is due to the intensified oxidation reaction, which leads to the rapid and extensive formation of a lubricating oxide film. This not only reduces the friction coefficient but also slows wear. The friction factors of the coating containing element B are lower than those of Comparative Example 1.

[0063] Table 3 Friction and wear parameters

[0064] Table 4 Average friction coefficients of Q235 ordinary carbon steel and three high entropy alloy coatings

[0065] The wear surface profile and wear volume of the carbon steel composite materials prepared in Examples 1 to 3 and Comparative Example 1 were measured using an M-500 probe wear scar measuring instrument. The wear rate values ​​calculated by the formula are shown in Table 5, and the comparison diagram is shown in Figure 6 ( Where W is the wear rate (mm 3 / N·m), F is the load (N), d is the sliding distance (m), and V is the wear volume (mm 3)), a is the wear rate at room temperature, and b is the wear rate at 600°C. The test results show that with the increase of the B element content, the wear resistance of the coating is significantly improved. The change in the wear resistance of the high-entropy alloy coating is closely related to the evolution of the microstructure. The precipitated boride plays an important role in the microstructure. First, it improves the microstructure of the alloy. Secondly, the boride precipitated at the grain boundary not only has a high hardness itself, but also effectively hinders the movement of dislocations, thereby improving the strength and hardness of the alloy. The addition of element B significantly improves the wear resistance of the high-entropy alloy coating.

[0066] Table 5 Wear rate of substrate and composite coating (×10 -5 mm 3 / N·m)

[0067] At room temperature, the wear surface morphologies of Q235 ordinary carbon steel and the carbon steel composite materials of Examples 1 to 3 are shown in Figure 7 ((a1 to a3) are Q235 ordinary carbon steel; (b1 to b3) are B1; (c1 to c3) are B3; (d1 to d3) are B5). The wear surface of Q235 ordinary carbon steel has a large amount of morphology formed by the peeling of coating surface materials after cold welding. The dark area is the oxide film, and the white fine powdery debris is mainly caused by oxidation wear and fatigue wear. Small scratches caused by micro-cutting can also be observed. The wear mechanism at room temperature is relatively complex, and the characteristics of multiple wear mechanisms appear. There is a small-sized oxide film and blocky wear debris on the wear surface of the B1 coating. In the area where there is no oxide film, there are obvious plowing grooves and fine scratches caused by micro-cutting. This is the wear morphology caused by the abrasive wear mechanism. There are a large number of cracks on the wear scar surface. When the material is subjected to cyclic loads or stresses, cracks form and expand on the surface or subsurface, leading to material spalling and the generation of abrasive particles. These cracks will expand with the increase in the number of cycles, eventually leading to material damage and wear. It can be inferred that the B1 coating has a certain degree of fatigue wear. Therefore, the main wear mechanism of the B1 coating is abrasive wear and fatigue wear. There is material spalling caused by adhesive wear on the wear scar of the B3 coating, and the oxide film has undergone layered spalling. There are scratches caused by cutting on the unflaked oxide film. That is, the main wear mechanism of the B3 coating is adhesive wear and slight abrasive wear. The wear scar width of the B5 coating is the smallest, and there is a discontinuous oxide film on the wear scar surface. The EDS results show that it is consistent with the B3 coating, and the B element content in the oxide film is enriched. The Gibbs free energy of the most stable oxides of Fe, Co, Cr, Ni, Cu, and B at room temperature is as follows: Fe2O3 (-742.5 kJ / mol), Co3O4 (-784.2 kJ / mol), Cr2O3 (-1041.0 kJ / mol), Ni3O4 (-763.6 kJ / mol), CuO (-129.7 kJ / mol), and B2O3 (-833 kJ / mol). Cr2O3 has the lowest Gibbs free energy, indicating that it is the most stable oxide, followed by B2O3. Cr2O3 and B2O3 can form oxide films with low friction coefficients during friction. Both Cr2O3 and B2O3 are high-temperature solid lubricants. Through thermal reaction or mechanical mixing at the friction interface, they can form composite oxide films with metals or other oxides. These films have a low friction coefficient, excellent wear resistance, and can effectively reduce the generation and conduction of frictional heat, thereby achieving a self-lubricating effect. The B5 coating also exhibits cracks in characteristic areas due to cyclic loads or stresses, and micro-cutting caused by abrasive particles. The main wear mechanisms of the B5 coating are slight abrasive wear and fatigue wear.

[0068] Figure 8 shows the wear morphologies of the grinding balls of Q235 plain carbon steel and the carbon steel composites of Examples 1-3 at room temperature ((a) Q235 plain carbon steel; (b) B1; (c) B3; (d) B5). As the molar ratio of element B increases, the wear area of ​​the grinding balls decreases significantly, indicating improved wear resistance. A large amount of material migrated from the B1 coating adheres to the grinding balls corresponding to the B1 coating. This material migration is significantly reduced in the B3 and B5 coatings, resulting in less coating material on the grinding balls. The B3 and B5 coatings are more stable during friction and exhibit less wear on the grinding balls. This is attributed to the precipitation of boride in the microstructure of the B3 and B5 coatings, which makes it difficult for the grinding balls to press into the coatings. This reduces the contact area between the friction pairs, resulting in less material sheared and exfoliated due to shear forces, and thus improves the overall wear resistance of the friction pairs. The addition of element B effectively inhibits adhesive wear, reduces the friction coefficient, enhances the overall wear resistance and friction reduction properties of the friction pairs, and extends the overall service life of the friction pairs.

[0069] Figure 9 shows the worn surface morphologies of Q235 plain carbon steel and the carbon steel composites of Examples 1-3 at 600°C ((a1 to a3) Q235 plain carbon steel; (b1 to b3) B1; (c1 to c3) B3; (d1 to d3) B5)). The results in the figure show that, compared to the wear morphology at room temperature, the wear scar surface is covered by a thicker oxide film. The wear scar surface is essentially covered by oxide. The worn surface of Q235 plain carbon steel is covered by a continuous, large-area oxide film. However, due to thermal expansion and internal stress, cracks appear on the oxide film surface, and the wear scar surface has distinct furrows. This is caused by the cutting action of hard abrasive particles formed by the shedding of oxide particles from the coating during wear, which then move across the coating surface and are subsequently filled with fine oxide debris. The main wear mechanisms are abrasive wear, adhesive wear, and oxidative wear. The B1 coating exhibits fine white debris scattered across its smooth oxide film, a result of oxidative wear. Small scratches are observed in characteristic areas. At the initial stage of friction, the various elements in the B1 coating spontaneously undergo oxidation reactions at high temperatures to form an oxide film. Under the crushing action of the grinding balls, the lower-hardness oxides are first broken and ground to powder by the grinding balls, while the other hard oxides participate in the friction process, causing three-body abrasive wear and resulting in small scratches on the oxide film. The primary wear mechanisms of the B1 coating are oxidative wear and abrasive wear. The wear morphology of the B3 coating is strikingly different from that of B1. The worn surface remains fully covered by the oxide film, but the area of ​​the broken oxide film is significantly larger, and the amount of powdered debris increases significantly. Severe cracks are present at the edges of the oxide film, which flakes off to form flaky fragments, while microcutting is significantly slowed. At the beginning of wear, the B3 coating's hardness increases due to the addition of element B, but this also leads to increased brittleness and reduced fatigue strength, making it more susceptible to brittle peeling. When the friction pair continues to slide relative to each other, the cyclic stress generated in the contact area exceeds the fatigue strength of the material, and cracks appear on the surface. The cracks then gradually expand, and then continue to crack and peel, forming flaky wear debris. The wear mechanism of the B3 coating changes from that of the B1 coating to oxidation wear and fatigue wear. The wear scar surface of the B5 coating is covered by a smooth and dense oxide film, and the fragmentation of the oxide film and the fine wear scars are significantly alleviated. Although the addition of element B can lead to a decrease in fatigue strength, the B content in the oxide film also increases significantly with the increase in the molar ratio of element B. The Gibbs free energy of the most stable oxides of Fe, Co, Cr, Ni, Cu and B elements at 600°C are: Fe2O3 (-1177.9 kJ / mol), Co3O4 (-1209.8 kJ / mol), Cr2O3 (-1568.0 kJ / mol), Ni3O4 (-1188.4 kJ / mol), CuO (-426.6 kJ / mol), and B2O3 (-1960.0 kJ / mol).B2O3 has the lowest Gibbs free energy, indicating that it is the most stable oxide and can be used as a high-temperature lubricant. The melting point of B2O3 is 510°C. At 600°C, B2O3 melts into a low-viscosity liquid, forming a lubricating film that isolates the contact surfaces and reduces direct contact and adhesion. The B2O3 liquid film has high fluidity and self-repairing ability, and can adjust to changes in the friction surface to maintain lubrication. It can also absorb and transfer some frictional heat, reducing the temperature of the friction surface and delaying the onset of oxidation and thermal fatigue. Therefore, the B5 coating's oxidation wear and fatigue wear are significantly suppressed at 600°C, and its main wear mechanisms are mild abrasive wear and fatigue wear.

[0070] Figure 10 shows the surface morphologies of the wear surfaces of Q235 plain carbon steel and the carbon steel composites of Examples 1-3 at 600°C ((a) Q235 plain carbon steel; (b) B1; (c) B3; (d) B5). Compared to room temperature, the wear area of ​​the grinding balls increases significantly, but also decreases with increasing molar ratio of the element B. From the perspective of material migration, the wear surface of the grinding balls corresponding to the B1 coating is likely covered by material migrating from the B1 coating, indicating significant adhesion between the B1 coating and the grinding balls. However, the wear morphology of the coating after wear is relatively smooth, lacking obvious signs of adhesive wear. This is because the oxide film formed is relatively thin in the initial wear phase, making it difficult to provide friction reduction and wear resistance. However, at 600°C, the coating softens at high temperatures and is more susceptible to adhesive wear. As the friction test progresses, the oxidation rate increases, gradually forming a stable friction layer composed of a dense oxide film. As the molar ratio of element B increases, its hardness increases. Furthermore, the friction pair, isolated by the liquid B2O3 high-temperature lubricant, reduces direct contact, effectively suppressing adhesion. This is reflected in a decrease in the area of ​​the wear surface of the corresponding grinding balls in the B3 and B5 coatings covered by the migrated material from the coating. Element B can effectively improve the friction compatibility of the friction pair.

[0071] Although the above embodiment provides a detailed description of the present application, it is only a part of the embodiments of the present application, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present application.

Claims

1. A carbon steel composite material, characterized in that, It includes a carbon steel matrix and a high-entropy alloy coating located on the surface of the carbon steel matrix; The high-entropy alloy coating includes the following components: iron element, cobalt element, chromium element, nickel element, copper element and boron element.

2. The carbon steel composite material according to claim 1, characterized in that, A solid solution is formed among the elements of the high-entropy alloy coating.

3. The carbon steel composite material according to claim 1, characterized in that, The molar ratio of the iron element to the boron element is 19.61:1.95 to 18.18:9.1; The molar ratio of the cobalt element to the boron element is 19.61:1.95 to 18.18:9.1; The molar ratio of the chromium element to the boron element is 19.61:1.95 to 18.18:9.1; The molar ratio of the nickel element to the boron element is 19.61:1.95 to 18.18:9.1; The molar ratio of the copper element to the boron element is 19.61:1.95 to 18.18:9.

1.

4. The carbon steel composite material according to claim 3, characterized in that, The molar ratio of the iron element to the boron element is 19.61:1.95 or 18.18:9.1; The molar ratio of the cobalt element to the boron element is 19.61:1.95 or 18.18:9.1; The molar ratio of the chromium element to the boron element is 19.61:1.95 or 18.18:9.1; The molar ratio of the nickel element to the boron element is 19.61:1.95 or 18.18:9.1; The molar ratio of the copper element to the boron element is 19.61:1.95 or 18.18:9.

1.

5. The carbon steel composite material according to claim 1 or 3, characterized in that, The molar ratio of the iron element to the boron element is 1:0.1 to 0.5; The molar ratio of the cobalt element to the boron element is 1:0.1 to 0.5; The molar ratio of the chromium element to the boron element is 1:0.1 to 0.5; The molar ratio of the nickel element to the boron element is 1:0.1 to 0.5; The molar ratio of the copper element to the boron element is 1:0.1 to 0.

5.

6. The preparation method of the carbon steel composite material according to any one of claims 1 to 5, characterized in that, It includes the following steps: S1. Mix, ball-mill and dry iron powder, cobalt powder, chromium powder, nickel powder, copper powder and boron powder to obtain a mixed powder; S2. Laser-clad the mixed powder on the surface of the carbon steel matrix to obtain the carbon steel composite material.

7. The preparation method of the carbon steel composite material according to claim 6, wherein, The laser power of the laser cladding is 1200 - 2000W.

8. The preparation method of the carbon steel composite material according to claim 6, wherein, The rotation speed of the ball-milling is 400 - 800r / min.

9. The method for preparing the carbon steel composite material according to claim 6 or 7, characterized in that, The output laser beam spot of the laser cladding is 1 - 2mm.

10. The preparation method of the carbon steel composite material according to claim 6, characterized in that, The particle sizes of the iron powder, cobalt powder, chromium powder, nickel powder and copper powder are independently selected from 45 - 105μm.

11. The preparation method of the carbon steel composite material according to claim 6, characterized in that, The particle size of the boron powder is 15 - 45μm.

12. The preparation method of the carbon steel composite material according to claim 6, characterized in that, The surface of the carbon steel matrix is subjected to impurity removal treatment.

13. The method for preparing the carbon steel composite material according to claim 6 or 8, characterized in that, The rotation speed of the ball-milling is 600r / min, and the ball-milling time is 4h.

14. The preparation method of the carbon steel composite material according to claim 6, characterized in that, The drying temperature is 60°C, and the heat preservation time is 4h.

15. The preparation method of the carbon steel composite material according to claim 9, characterized in that, The output laser beam spot of the laser cladding is 1.8mm.

16. The method for preparing a carbon steel composite material according to claim 6 or 7, characterized in that, The scanning speed of the laser cladding is 4 - 8mm / s.

17. The preparation method of the carbon steel composite material according to claim 16, characterized in that, The scanning speed of the laser cladding is 5mm / s.

18. The preparation method of the carbon steel composite material according to claim 6 or 7, characterized in that, The defocus amount of the laser cladding is -20mm.

19. The method for preparing the carbon steel composite material according to claim 6 or 7, characterized in that, The powder feeding rate of the laser cladding is 10.5g / min.

20. Application of the carbon steel composite material according to any one of claims 1 - 5 or the carbon steel composite material obtained by the preparation method according to any one of claims 6 - 19 in moving parts.

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