Modified light high-manganese wear-resistant steel and preparation method thereof

Abstract

The application discloses a modified light high-manganese wear-resistant steel and a preparation method thereof. The chemical components and mass percentage of the wear-resistant steel are as follows: C: 0.9-1.5%, Si: 0.3-0.6%, Mn: 11-14%, N: 0.004-0.025%, Cr: 1.5-2%, Al: 1-5%, O: 0.0005-0.0025%, P: less than or equal to 0.05%, S: less than or equal to 0.05%, F: less than or equal to 0.0005%, and the balance of Fe and inevitable impurity elements. In the preparation method, the powder metallurgy method is used to prepare the intermediate alloy by using fluorite powder, borax powder, corundum powder (Al2O3) and iron powder; the fluorite powder is used to reduce the melting point and promote the slag fluidity, and the oxide particle agglomeration is avoided. The application has the advantages of low cost, simple operation, and the like, and can effectively improve the wear resistance of the high-manganese steel under the medium and low stress while reducing the density of the high-manganese steel, and improve the hardness and service life of the high-manganese wear-resistant steel.

Description

Technical Field

[0001] This invention relates to the field of wear-resistant materials technology, specifically to a modified lightweight high-manganese wear-resistant steel and its preparation method. Background Technology

[0002] High manganese steel is one of the earliest widely used wear-resistant materials, with a history of over a century. It was developed by the Englishman Hadfield in 1882 by adding ferromanganese to pure iron, and patented in 1883; it is also known as Hadfield steel. The as-cast microstructure of high manganese steel mainly consists of austenite, carbides, and a small amount of pearlite. The carbides are typically distributed in a network along the austenite grain boundaries, making as-cast high manganese steel brittle and unsuitable for practical applications. To eliminate the network carbides, as-cast high manganese steel requires water quenching, which involves solution treatment at 1050–1100℃ to obtain a single-phase austenite structure, followed by water quenching. After water quenching, the strength, ductility, toughness, and work hardening capacity of high manganese steel are significantly improved.

[0003] Under heavy loads and strong impacts, water-toughened high-manganese steel undergoes a martensitic phase transformation, forming twin, stacking fault, and planar dislocation structures. The stressed surface experiences work hardening, increasing its hardness, while the core retains good toughness. Due to this excellent toughness and work hardening ability, high-manganese steel has always been the preferred material for high-stress impact wear. Although modern wear-resistant materials have developed rapidly, with various new types emerging, no single material can completely replace high-manganese steel for components subjected to high-stress impact wear conditions, such as excavator bucket teeth, ball mill liners, and railway switches.

[0004] However, considering the actual operating environments of wear-resistant steel, high-stress conditions account for less than 5% of the total. The vast majority of wear-resistant steel operates under medium to low stress conditions. Therefore, the work hardening capacity of traditional high-manganese steel cannot be fully utilized, failing to fully leverage its wear resistance and resulting in a shorter service life. Furthermore, when the C and Mn contents differ, a large amount of carbides still exists in the microstructure of traditional high-manganese steel after solution treatment, leading to brittleness. Moreover, with the increasing demands for high load-bearing capacity and large-scale equipment, today's wear-resistant steels weigh several tons to tens of tons, resulting in correspondingly high energy consumption and significant greenhouse gas emissions that severely impact the environment.

[0005] Therefore, developing modified high-manganese wear-resistant steel with good toughness, excellent work hardening ability, long service life, low density, and adaptability to medium- and low-stress working conditions has significant economic and social benefits. In recent years, relevant patents addressing the above issues have emerged. Patent CN116083803A discloses an age-hardening lightweight high-manganese steel and its preparation method. This patent obtains a lightweight, wear-resistant high-manganese steel by adding Al to high-manganese steel and then performing an aging treatment. However, the patent does not mention the changes in the microstructure of the high-manganese steel after the introduction of Al. Furthermore, the high-manganese steel prepared by this patent contains nearly 10% Al; excessively high aluminum content not only reduces the steel's fluidity and deteriorates its casting performance but also promotes ferrite precipitation, reducing toughness. Moreover, the aging treatment method in this patent is time-consuming and unsuitable for large-scale production.

[0006] Patent CN108070783A discloses a lightweight high-manganese steel liner for ball mills and its preparation method. This patent incorporates elements such as Al and Re into the high-manganese steel and achieves lightweight and high wear resistance through water toughening and shot peening treatments. However, this patent uses the depth of the work-hardened layer to evaluate wear resistance, and it cannot obtain information on wear resistance under medium and low loads.

[0007] Patent CN116397121B discloses a method for optimizing the microstructure and properties of high-speed tool steel. This invention introduces an oxide-based iron-based composite master alloy into high-speed tool steel W6Mo5Cr4V2, followed by homogenization heat treatment, quenching, and tempering, resulting in an oxide dispersion-strengthened high-speed steel with refined microstructure and excellent properties. Adding oxide particles to molten steel using a master alloy not only refines the microstructure through heterogeneous nucleation but also avoids oxide particle agglomeration. However, this patent does not mention whether the optimized high-speed tool steel improves wear resistance. Furthermore, during the smelting process, an oxide layer easily forms on the surface of the molten steel, preventing further contact between the molten steel and subsequent additives. Moreover, the master alloy in this patent consists only of iron powder, borax, and corundum. Although borax can promote the coating of Al2O3 particles by the molten steel, its ability to destroy the oxide film is weak, and it easily forms a viscous, glassy slag, reducing the fluidity of the slag and molten steel, thus failing to fundamentally solve the problem of the molten metal being coated by an oxide film. Summary of the Invention

[0008] The purpose of this invention is to address the limitations of current technologies by providing a modified lightweight high-manganese wear-resistant steel and its preparation method. This wear-resistant steel incorporates Al2O3 as an intermediate alloy, forming Al2O3-AlN-MnS composite inclusions within the steel matrix. These inclusions act as hard particles, improving wear resistance under medium to low loads. The preparation method employs powder metallurgy, first preparing an intermediate alloy from fluorite powder, borax powder, corundum powder (Al2O3), and iron powder. The addition of fluorite powder lowers the melting point, promotes slag fluidity, and prevents oxide particle agglomeration. This invention offers low cost, simple operation, and effectively improves the wear resistance of high-manganese steel under medium to low stress while reducing its density, thereby increasing its hardness and service life.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A modified lightweight high-manganese wear-resistant steel has the following chemical composition and mass percentage: C: 0.9% ~ 1.5%, Si: 0.3% ~ 0.6%, Mn: 11% ~ 14%, N: 0.004% ~ 0.025%, Cr: 1.5% ~ 2%, Al: 1% ~ 5%, O: 0.0005% ~ 0.0025%, P≤0.05%, S≤0.05%, F≤0.0005%, with the balance being Fe and unavoidable impurity elements.

[0010] The metallographic structure of the high-manganese steel after heat treatment is a single-phase austenitic structure.

[0011] After heat treatment, the above-mentioned high-manganese steel is processed according to T / CFA 010604-3 According to the 2016 standard "Test Method for Impact Abrasive Wear of Steel Materials", the wear amount is ≤0.1g, and the density is 7.30~7.48g / cm³. 3 Its hardness reaches 230HV or higher.

[0012] The method for preparing the modified lightweight high-manganese wear-resistant steel includes the following steps: (1) Ingredients: Prepare raw materials according to the following chemical composition by weight percentage: C: 0.9% ~ 1.5%, Si: 0.3% ~ 0.6%, Mn: 11% ~ 14%, N: 0.004% ~ 0.025%, Cr: 1.5% ~ 2%, Al: 1% ~ 5%, O: 0.0005% ~ 0.0025%, P≤0.05%, S≤0.05%, F≤0.0005%, with the balance being Fe and unavoidable impurity elements; The raw materials include basic raw materials, aluminum blocks, and intermediate alloys; the mass percentages of the raw materials are as follows: basic raw materials: 65%~85%; aluminum blocks: 2.5%~4.5%; and intermediate alloys: 15%~25%.

[0013] The basic raw materials are ordinary scrap steel, high-carbon manganese steel, medium-carbon manganese steel, and ferrochrome nitride. (2) Smelting: Add the basic raw materials and intermediate alloys to the medium frequency induction furnace for smelting. When the temperature of the molten steel reaches 1500~1650℃, add aluminum blocks and continue smelting. (3) Casting: When the temperature drops to 1410~1470℃, the casting is poured into the sand mold cavity. When the surface temperature does not exceed 450℃, the casting is separated.

[0014] Furthermore, the above castings are subjected to heat treatment: the electric furnace is heated from room temperature to a temperature range of 600-700℃ at a heating rate of 60-80℃ / h, and held for 0.5-2.0h; then heated to 1050-1100℃ at a heating rate of 100-150℃ / h, and held for 1.5-2.5h; finally, water quenching is performed.

[0015] The intermediate alloy is prepared by powder metallurgy and its components include: fluorite powder (CaF2), borax powder (B2O3), corundum powder (Al2O3), and iron powder; the mass percentage of each component in the intermediate alloy is: fluorite powder: 0.5%~2%; borax powder: 3.5%~6%; corundum powder: 2%~46%; iron powder: 50%~90%.

[0016] The preparation method of the intermediate alloy specifically includes the following steps: 1) Mix fluorite powder, borax powder, and corundum powder according to the component ratio and then ball mill them; 2) Add iron powder to the powder obtained in step 1) to obtain a mixed powder; The mixed powder is loaded into a medium-frequency induction furnace and heated to 1370℃~1530℃ at a rate of 10℃ / min~20℃ / min, and sintered for 90~200min. After cooling, an intermediate alloy is obtained.

[0017] The essential features of this invention are: 1) This invention adds aluminum blocks to traditional high-manganese steel. The Al element can inhibit the precipitation of carbides (see...). Figure 1 , Figure 2 The presence of Al (Al) leads to solid solution strengthening, which increases the hardness of high-manganese steel and thus improves its wear resistance under low to medium impact loads. Simultaneously, Al also reduces density.

[0018] 2) By adding an intermediate alloy to traditional high-manganese steel, a large number of large-sized Al2O3-AlN-MnS composite inclusions can be formed (see...). Figure 3 This composite inclusion can be dispersed in the matrix as hard particles, improving the wear resistance of high manganese steel under medium and low impact loads.

[0019] 3) This invention uses four powders—fluorite powder, borax powder, corundum powder, and iron powder—to prepare the intermediate alloy. Fluorite powder can lower the melting point of refractory materials CaO and SiO2, promote slag fluidity, and prevent oxide particle agglomeration. This is because SiO2 in the molten state forms a network or chain structure through Si-O-Si bonds. This structure is very stable, resulting in high slag viscosity and poor fluidity. When fluorite (CaF2) is added, the F ions released from its decomposition or dissociation at high temperatures can break the Si-O-Si bonds, reducing the size of the network or chain structure of SiO2 in the molten state, thereby reducing viscosity and improving fluidity. The mechanism for preventing agglomeration is as follows: the F ions in fluorite act as surface-active substances, reducing the interfacial tension between molten steel and Al2O3 particles. This improves the wettability of the molten steel to Al2O3 particles, making it easier for the molten steel to encapsulate these small Al2O3 particles. Since the molten steel is in a liquid phase, Al2O3 particles are less likely to agglomerate into large clusters.

[0020] Furthermore, since iron powder is the matrix in this patent and Al2O3 powder is introduced as a sparingly soluble particle, it can form composite hard particles to improve wear resistance. In view of the fact that an oxide layer is easily formed on the surface of molten steel during the smelting process, which prevents the molten steel from further contacting with subsequent additives, this invention uses the addition of fluorite to use fluoride ions to destroy the oxide film on the surface of the molten metal, allowing the remaining materials such as borax to play their normal role and play a role in desulfurization and dephosphorization during the smelting process, further purifying the molten steel.

[0021] This invention also incorporates carbon into high-carbon manganese steel, medium-carbon manganese steel, and high-carbon ferrochrome. This utilizes the large difference in radii between carbon atoms and iron atoms, which allows them to form interstitial solid solutions, resulting in lattice distortion, solid solution strengthening, and increased hardness of the steel, thereby improving its wear resistance.

[0022] The present invention further suppresses carbide precipitation by using aluminum and Al2O3, allowing more carbon atoms to dissolve in the matrix, resulting in solid solution strengthening and thus improving wear resistance.

[0023] The beneficial effects of this invention are as follows: 1. Compared with conventional high-manganese steel, the hardness of this modified lightweight high-manganese steel increases from 210 HV to over 230 HV. Simultaneously, the Al element also reduces the density; the density of this modified lightweight high-manganese steel is 7.30~7.48 g / cm³. 3Compared with the conventional high-manganese steel ZGMn13Cr2, the density is reduced by 3.4% to 5.7%, which improves the performance of the material and reduces energy consumption.

[0024] 2. Compared with conventional high-manganese steel, under a medium-low impact load of 2.5J, the wear amount of this modified lightweight high-manganese steel is ≤0.1g, the relative wear resistance is improved by 2~16%, and the service life of lightweight high-manganese steel is significantly improved.

[0025] 3. This modified high-manganese wear-resistant steel does not involve precious metals in its smelting process, resulting in lower costs and a higher cost-performance ratio. The heat treatment process is simple and suitable for large-scale production. Attached Figure Description

[0026] Figure 1 The metallographic structure of wear-resistant steel is shown in a comparative example (100x magnification). Figure 2 The metallographic structure of the modified lightweight high-manganese wear-resistant steel obtained in Example 1 (100x magnification). Figure 3 The morphology of the Al2O3-AlN-MnS composite inclusions obtained in Example 1 under the back-dispersion mode (5000x magnification). Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. The following embodiments are for illustrative purposes only and are not intended to limit the scope of application of this invention. Equivalent technical solutions in other application fields also fall within the scope of this invention, and the patent protection scope of this invention should be defined by the claims.

[0028] The roles and contents of each component in the modified lightweight high-manganese wear-resistant steel are determined based on the following: Carbon (C) is an austenitizing element in high-manganese steel, stabilizing and expanding the γ-phase region. Simultaneously, as an interstitial solid solution element, carbon strengthens the steel through solid solution, causing lattice distortion and increasing the hardness and yield strength of lightweight high-manganese steel, thus improving wear resistance. However, excessive carbon content can cause significant embrittlement, reduce toughness, and easily lead to subsurface or microcrack-type wear, resulting in a higher wear rate under dynamic loads. Furthermore, for every 1% by mass of carbon added to the steel, the density decreases by 5.2%. Therefore, the designed carbon content range is 0.9% ~ 1.5%.

[0029] Silicon (Si) plays a deoxidizing role in the casting process of high-manganese steel. The atomic radius of silicon is much smaller than that of the austenite phase, allowing it to dissolve into the austenite matrix, hindering dislocation movement and thus increasing the yield strength and hardness of the steel, further improving its wear resistance. However, silicon is a non-carbide-forming element in steel. Excessive Si content leads to the formation of more carbides at grain boundaries, requiring higher solution temperatures or longer holding times to dissolve the carbides, resulting in coarse grains and increased brittleness. Simultaneously, for every 1% by mass of Si added to the steel, the density decreases by 0.8%. Therefore, the designed range for silicon content is 0.3% to 0.6%.

[0030] Mn: In high-manganese steel, manganese can lower the martensitic transformation temperature, increase stacking fault energy, and stabilize and expand the austenite phase region. Most of the Mn in the steel is dissolved in the matrix, forming a substitutional solid solution, which improves wear resistance. With a constant carbon content, the strength, toughness, and hardness of high-manganese steel all increase with increasing Mn content, exhibiting good work hardening ability.

[0031] Furthermore, the manganese-to-carbon ratio is also a key indicator for evaluating the overall performance of high-manganese steel. When Mn / C > 10, it increases the stability of austenite and ensures the toughness of high-manganese steel; when Mn / C = 10, high-manganese steel has high strength; when Mn / C < 10, it further improves the wear resistance of the material. Therefore, the design range for manganese content is 11% ~ 14%.

[0032] Nitrogen (N) is an austenitic stabilizing element in high-manganese steel. Its distortion in the interstitial spaces of face-centered cubic crystals is greater than that of carbon (C) atoms, allowing for strong interactions with dislocations. N also enhances the alloy's strength through solid solution strengthening and grain boundary strengthening effects. Furthermore, N readily combines with al (Al) to form hard AlN particles, improving the wear resistance of high-manganese steel. Therefore, the designed N content range is 0.004% ~ 0.025%.

[0033] Chromium (Cr) is a strong carbide-forming element in high-manganese steel, forming more stable (Fe,Cr)3C type carbides than (Fe,Mn)3C. Simultaneously, Cr strengthens austenite, improving the steel's hardness, strength, and wear resistance. Steels containing Cr generally exhibit good tempering stability; however, when the Cr content exceeds 2.5%, it significantly increases the brittle-brittle transition temperature and promotes temper brittleness, reducing elongation and reduction of area. Therefore, the design range for chromium content is 1.5% to 2%.

[0034] Al (Al): Aluminum in high-manganese steel exhibits a solid solution strengthening effect, increasing yield strength and hardness. Increased hardness and yield strength improve the wear resistance of high-manganese steel. In lightweight high-manganese steel, the minimum aluminum content is limited by the required strength under aging conditions, while the maximum content is determined by the permissible low ductility and toughness. High aluminum content promotes the precipitation of nano-sized κ carbides, thereby increasing surface hardness and yield strength. However, excessive aluminum content promotes ferrite formation, reduces toughness, and increases the likelihood of brittle cracking during wear, thus reducing wear resistance. Simultaneously, for every 1% by mass of Al added to high-manganese steel, the density decreases by 1.3%. Therefore, the design range for aluminum content is 1% to 5%.

[0035] O: Oxygen is introduced through a master alloy. The Al₂O₃ in the master alloy typically forms composite inclusions with MnS. These inclusions, acting as hard particles, are dispersed throughout the high-manganese steel matrix, giving the lightweight high-manganese steel excellent wear resistance under impact loads. In this invention, the oxygen content is designed to range from 0.0005% to 0.0025%.

[0036] P: Phosphorus is a harmful element in high-manganese steel. Phosphorus has low solubility in austenite, and a high P content will form low-melting-point brittle eutectic phosphides with Fe, which are distributed between dendrites and grain boundaries. During solidification, cooling, and shrinkage, this will cause hot brittleness, resulting in a decrease in the strength and toughness of the steel. Therefore, the phosphorus content should be ≤0.05%.

[0037] Sulfur is a harmful element in high-manganese steel. Sulfur and manganese have a high affinity in high-manganese steel, with most S combining with Mn to form high-melting-point (1785℃) MnS. Most of the MnS enters the slag, resulting in a very low residual sulfur content in the steel. Sulfur mostly exists as spherical manganese sulfide inclusions, which have little impact on the steel's properties. Therefore, the sulfur content should be ≤0.05%. The common scrap steel, high-carbon manganese steel, medium-carbon manganese steel, and ferrochrome nitride involved in this invention are all known materials; among them, the common scrap steel is a known material, and the content of each component is calculated according to GB / T 4223-2017 Scrap Steel; the high-carbon manganese steel grade is FeMn74C7.5; the medium-carbon manganese steel grade is FeMn82C1.5; and the ferrochrome nitride grade is FeNCr3-B.

[0038] The aluminum block is pure aluminum. Purity ≥ 99%; The fluorite powder has a particle size of 75~300μm and a CaF2 content of ≥97%. The borax powder has a particle size of 50~200μm and a B2O3 content of ≥95%. The corundum powder has a particle size of 0.1~1.5mm and an Al2O3 content of ≥99%. The iron powder used as the base powder has a particle size of 18~150μm and an Fe content of ≥99.5%.

[0039] For impact wear testing, follow T / CFA 010604-3 The 2016 standard, "Test Method for Impact Abrasive Wear of Steel Materials," specifies the processing and testing of specimens. The impact hammer weighs 10 kg, the upper specimen is high-manganese steel, and the lower specimen is GCr15 bearing steel with a hardness of 60 HRC. The grinding is performed at a rotation speed of 200 r / min. Quartz sand with a particle size of 1-2 mm is used as the abrasive at a flow rate of 10 kg / h. The selected impact energy is 2.5 J, and the impact time is 60 min. Before and after the test, the specimens are cleaned with an alcohol solution in an ultrasonic cleaner. The weight loss is measured using an electronic balance with an accuracy of 0.1 mg. Each specimen is weighed three times, and the average value is taken as the wear amount of the specimen material under the impact energy.

[0040] The present invention will now be described in detail: Example 1: In this embodiment, the ingredients are first added sequentially into the medium-frequency induction furnace. The chemical composition and weight percentage of each component of the modified lightweight high-manganese wear-resistant steel obtained after casting are as follows: C: 1.15%, Si: 0.38%, Mn: 12.56%, N: 0.006%, Cr: 1.75%, Al: 3.46%, O: 0.0019%, P: 0.04%, S: 0.02%, F: 0.0002%, with the balance being Fe and unavoidable impurity elements.

[0041] (1) Melting and casting: Ordinary scrap steel, high carbon manganese steel, medium carbon manganese steel, ferrochrome nitride, and intermediate alloy are added to a medium frequency induction furnace for melting. When the temperature of the molten steel reaches 1550℃, aluminum blocks are added. When the temperature is 1415℃, the mixture is cast into shape.

[0042] The percentage of each raw material in the alloy by mass is as follows: scrap steel accounts for 45.5%, with an addition amount of 10 kg; high carbon manganese steel accounts for 13.6%, with an addition amount of 3 kg; medium carbon manganese steel accounts for 9%, with an addition amount of 2 kg; ferrochrome nitride accounts for 4.5%, with an addition amount of 1 kg; master alloy accounts for 22.7%, with an addition amount of 5 kg; and aluminum accounts for 4.5%, with an addition amount of 1 kg.

[0043] The mass content of each component in the intermediate alloy is as follows: fluorite powder: 1%; borax powder: 3.5%; corundum powder: 20%; iron powder: 75.5%.

[0044] The preparation method of the intermediate alloy specifically includes the following steps: 1) Mix fluorite powder, borax powder, and corundum powder according to the component ratio and then ball mill them; 2) Add iron powder to the powder obtained in step 1), with the mass fraction ratio of iron powder to powder obtained in step 1) being 3:1; The mixed powder was loaded into a medium-frequency induction furnace, heated to 1370°C at 10°C / min, and sintered for 90 min. After cooling, the intermediate alloy was obtained.

[0045] The oxygen content in the alloy is based on the amount provided by the master alloy, which primarily acts as a carrier to incorporate Al2O3 into the matrix. Fluorite provides the sulfur (F) element. C, Si, and other elements are provided by high-carbon manganese steel, medium-carbon manganese steel, etc.

[0046] (2) Heat treatment: The castings were heat treated using an electric furnace that could precisely control the heating rate, temperature, and holding time. The furnace was heated from room temperature to 630°C at a rate of 65°C / h and held for 1 hour. This holding time helped to eliminate casting stress. Then, the furnace was heated to 1055°C at a rate of 120°C / h and held for 2 hours. This holding time was to dissolve the carbides and homogenize the austenite composition as much as possible. The furnace door was then quickly opened, and the sample was placed in cold water for quenching.

[0047] By measuring the density, the carbide content in the microstructure of the wear-resistant steel sample in this embodiment was reduced, with a density of 7.44 g / cm³. 3 According to GB / T4340.1-2024 "Metallic materials - Vickers hardness test - Part 1: Test method" and T / CFA 010604-3 The mechanical properties of the wear-resistant steel in this embodiment were determined according to the 2016 standard "Test Method for Impact Abrasive Wear of Steel Materials".

[0048] The mechanical properties of the lightweight high-manganese wear-resistant steel obtained in this embodiment are as follows: surface hardness is 249HV; under an impact load of 2.5J, the wear amount is 0.0875g, and the relative wear resistance is 1.13.

[0049] Example 2: In this embodiment, the ingredients are first added sequentially into the medium-frequency induction furnace. After casting, the chemical composition and weight percentage of each component of the modified lightweight high-manganese wear-resistant steel are as follows: C: 1.27%, Si: 0.34%, Mn: 11.63%, N: 0.01%, Cr: 1.67%, Al: 3.06%, O: 0.0017%, P: 0.05%, S: 0.03%, F: 0.00015%, with the balance being Fe and unavoidable impurity elements.

[0050] (1) Melting and casting: Ordinary scrap steel, high carbon manganese steel, medium carbon manganese steel, ferrochrome nitride, and intermediate alloy are added to a medium frequency induction furnace for melting. When the temperature of the molten steel reaches 1600℃, aluminum blocks are added. When the temperature is 1435℃, the mixture is cast into shape.

[0051] (2) Heat treatment: The castings were heat treated using an electric furnace that could precisely control the heating rate, temperature, and holding time. The furnace was heated from room temperature to 650°C at a heating rate of 60°C / h and held for 1 hour. Then, the furnace was heated to 1050°C at a rate of 150°C / h and held for 2 hours. The furnace door was then quickly opened and the sample was placed in cold water for quenching.

[0052] By measuring the density, the carbide content in the microstructure of the wear-resistant steel sample in this embodiment was reduced, with a density of 7.35 g / cm³. 3 According to GB / T4340.1-2024 "Metallic materials - Vickers hardness test - Part 1: Test method" and T / CFA 010604-3 The mechanical properties of the wear-resistant steel in this embodiment were determined according to the 2016 standard "Test Method for Impact Abrasive Wear of Steel Materials".

[0053] The mechanical properties of the lightweight high-manganese wear-resistant steel obtained in this embodiment are as follows: surface hardness is 253HV; under an impact load of 2.5J, the wear amount is 0.0913g, and the relative wear resistance is 1.09.

[0054] Example 3: In this embodiment, the ingredients are first added sequentially into the medium-frequency induction furnace. The chemical composition and weight percentage of each component of the modified lightweight high-manganese wear-resistant steel obtained after casting are as follows: C: 1.22%, Si: 0.31%, Mn: 12.97%, N: 0.012%, Cr: 1.89%, Al: 2.98%, O: 0.0015%, P: 0.03%, S: 0.04%, F: 0.0002%, with the balance being Fe and unavoidable impurity elements.

[0055] (1) Melting and casting: Ordinary scrap steel, high carbon manganese steel, medium carbon manganese steel, ferrochrome nitride, and intermediate alloy are added to a medium frequency induction furnace for melting. When the temperature of the molten steel reaches 1620℃, aluminum blocks are added. When the temperature is 1440℃, the mixture is cast into shape.

[0056] (2) Heat treatment: The castings were heat treated using an electric furnace that could precisely control the heating rate, temperature, and holding time. The furnace was heated from room temperature to 680°C at a rate of 70°C / h and held for 1 hour. Then, the furnace was heated to 1065°C at a rate of 110°C / h and held for 2 hours. The furnace door was then quickly opened and the sample was placed in cold water for quenching.

[0057] By measuring the density, the carbide content in the microstructure of the wear-resistant steel sample in this embodiment was reduced, with a density of 7.41 g / cm³. 3According to GB / T4340.1-2024 "Metallic materials - Vickers hardness test - Part 1: Test method" and T / CFA 010604-3 The mechanical properties of the wear-resistant steel in this embodiment were determined according to the 2016 standard "Test Method for Impact Abrasive Wear of Steel Materials".

[0058] The mechanical properties of the lightweight high-manganese wear-resistant steel obtained in this embodiment are as follows: surface hardness is 242HV; under an impact load of 2.5J, the wear amount is 0.0891g, and the relative wear resistance is 1.11.

[0059] Comparative Example 1: In this comparative example, the ingredients were first added sequentially in a medium-frequency induction furnace. After casting, the chemical composition and weight percentage of each component of the modified lightweight high-manganese wear-resistant steel were as follows: C: 1.20%, Si: 0.53%, Mn: 12.74%, N: 0.02%, Cr: 1.56%, P: 0.05%, S: 0.01%, with the balance being Fe and unavoidable impurity elements.

[0060] (1) Smelting and casting: Ordinary scrap steel, high carbon manganese steel, medium carbon manganese steel, and ferrochrome nitride are added to a medium frequency induction furnace for smelting. When the temperature is 1420℃, casting is carried out. Before casting, rare earth silicon needs to be placed at the bottom of the ladle for modification treatment.

[0061] (2) Heat treatment: The castings were heat treated using an electric furnace that could precisely control the heating rate, temperature, and holding time. The furnace was heated from room temperature to 640°C at a heating rate of 60°C / h and held for 1 hour. Then, the furnace was heated to 1060°C at a rate of 130°C / h and held for 2 hours. The furnace door was then quickly opened and the sample was placed in cold water for quenching.

[0062] By measuring the density, the wear-resistant steel sample in this embodiment showed a relatively high carbide content, with a density of 7.74 g / cm³. 3 According to GB / T4340.1-2024 "Metallic materials - Vickers hardness test - Part 1: Test method" and T / CFA 010604-3 The mechanical properties of the wear-resistant steel in this embodiment were determined according to the 2016 standard "Test Method for Impact Abrasive Wear of Steel Materials".

[0063] The mechanical properties of the lightweight high-manganese wear-resistant steel obtained in this comparative example are as follows: surface hardness is 210HV; under an impact load of 2.5J, the wear amount is 0.0992g, and the relative wear resistance is 1. The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. The above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications or equivalent substitutions made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0064] Matters not covered in this invention are common knowledge.

Claims

1. A modified lightweight high-manganese wear-resistant steel, characterized in that, Its chemical composition and mass percentage are as follows: C: 0.9% ~ 1.5%, Si: 0.3% ~ 0.6%, Mn: 11% ~ 14%, N: 0.004% ~ 0.025%, Cr: 1.5% ~ 2%, Al: 1% ~ 5%, O: 0.0005% ~ 0.0025%, P≤0.05%, S≤0.05%, F≤0.0005%, with the balance being Fe and unavoidable impurity elements.

2. The modified lightweight high-manganese wear-resistant steel as described in claim 1, characterized in that, The metallographic structure of wear-resistant steel is a single-phase austenitic structure; The wear-resistant steel mentioned above is based on T / CFA 010604-3 According to the 2016 standard "Test Method for Impact Abrasive Wear of Steel Materials", the wear amount is ≤0.1g, and the density is 7.30~7.48g / cm³. 3 Its hardness reaches 230HV or higher.

3. The method for preparing modified lightweight high-manganese wear-resistant steel as described in claim 1, characterized in that, Includes the following steps: (1) Ingredients: Prepare raw materials according to the following chemical composition by weight percentage: C: 0.9% ~ 1.5%, Si: 0.3% ~ 0.6%, Mn: 11% ~ 14%, N: 0.004% ~ 0.025%, Cr: 1.5% ~ 2%, Al: 1% ~ 5%, O: 0.0005% ~ 0.0025%, P≤0.05%, S≤0.05%, F≤0.0005%, with the balance being Fe and unavoidable impurity elements; The raw materials include basic raw materials, aluminum blocks, and intermediate alloys; the mass percentages of the raw materials are as follows: basic raw materials: 65%~85%; aluminum blocks: 2.5%~4.5%; intermediate alloys: 15%~25%. The basic raw materials are ordinary scrap steel, high-carbon manganese steel, medium-carbon manganese steel, and ferrochrome nitride. (2) Smelting: Add the basic raw materials and intermediate alloys to the medium frequency induction furnace for smelting. When the temperature of the molten steel reaches 1500~1650℃, add aluminum blocks and continue smelting. (3) Casting: When the temperature drops to 1410~1470℃, it is poured into the sand mold cavity. When the surface temperature does not exceed 450℃, the casting is obtained.

4. The method for preparing modified lightweight high-manganese wear-resistant steel as described in claim 3, characterized in that, The master alloy is prepared by powder metallurgy and its components include: fluorite powder (CaF2), borax powder (B2O3), corundum powder (Al2O3), and iron powder; the mass percentage of each component in the master alloy is: fluorite powder: 0.5%~2%; borax powder: 3.5%~6%; corundum powder: 2%~46%; iron powder: 50%~90%. The preparation method of the intermediate alloy specifically includes the following steps: 1) Mix fluorite powder, borax powder, and corundum powder according to the component ratio and then ball mill them; 2) Add iron powder to the powder obtained in step 1) to obtain a mixed powder; The mixed powder is loaded into a medium-frequency induction furnace and heated to 1370℃~1530℃ at a rate of 10℃ / min~20℃ / min, and sintered for 90~200min. After cooling, an intermediate alloy is obtained.

5. The method for preparing modified lightweight high-manganese wear-resistant steel as described in claim 3, characterized in that, It also includes heat treatment: heating the electric furnace from room temperature to a temperature range of 600-700℃ at a heating rate of 60-80℃ / h, and holding it at that temperature for 0.5-2.0h; then heating it to 1050-1100℃ at a heating rate of 100-150℃ / h, and holding it at that temperature for 1.5-2.5h; and finally water toughening treatment.

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