Smelting method of high-carbon high-manganese wear-resistant steel

Abstract

According to the smelting method of the high-carbon and high-manganese wear-resistant steel, a two-step method of'source sulfur control and vacuum deep desulfurization 'is adopted, and dependence of traditional LF desulfurization is broken through. Firstly, the sulfur pressure of molten iron is extremely low in a converter through high-alkalinity slag and a high-oxidizing atmosphere; and during tapping, the ultralow-sulfur alloy and the graphite carburant are completely used, aluminum is used for final deoxidation, and follow-up input of sulfur is cut off. Then, LF strong stirring is cancelled, vacuum treatment with the pressure smaller than or equal to 50 Pa is directly carried out, sulfur activity coefficient and partial pressure are reduced to the limit at the same time through the dual reaction of sulfur volatilization in the form of S2 and CS gas and high-carbon reduction under high vacuum, and the sulfur content is smaller than or equal to 0.001%. The whole process does not depend on slag-steel interface mass transfer, the risk of LF resulfurization is avoided, and low-cost ultra-low-sulfur smelting of the high-carbon and high-manganese steel is achieved.

Description

Technical Field

[0001] This application relates to the field of ladle refining technology, and in particular to a method for smelting high-carbon, high-manganese wear-resistant steel. Background Technology

[0002] High-carbon, high-manganese wear-resistant steel is widely used in mining, railways, and engineering machinery due to its high hardness and strong work hardening. However, its smelting requires achieving C ≥ 0.9 wt%, Mn ≥ 11 wt%, and sulfur ≤ 0.001 wt% simultaneously in the converter-LF-continuous casting process. Current technology employs a converter-LF deep desulfurization scheme: a large amount of ferromanganese is added during tapping, and the LF stage involves multiple heating and strong stirring for desulfurization. The addition of a large amount of manganese alloy leads to a significant drop in the liquidus temperature of the molten steel, increased slag oxidizability, and a "sulfur reversion" phenomenon. The LF is forced to repeatedly cycle through "desulfurization-sulfur reversion," extending the processing cycle, increasing energy consumption, and the final sulfur content often still exceeds 0.003 wt%. While RH can remove hydrogen and oxygen, it lacks further desulfurization capabilities, making it difficult to meet ultra-low sulfur requirements. Therefore, how to reduce sulfur to ≤ 0.001 wt% in a single step through subsequent refining methods without the LF undertaking deep desulfurization has become a bottleneck for the current low-cost, continuous smelting of high-carbon, high-manganese steel. Summary of the Invention

[0003] This application provides a smelting method for high-carbon, high-manganese wear-resistant steel to solve the following technical problem: how to control the sulfur content of high-carbon, high-manganese wear-resistant steel to ≤0.001% under LF desulfurization conditions.

[0004] In a first aspect, embodiments of this application provide a method for smelting high-carbon, high-manganese wear-resistant steel, comprising: Molten iron is smelted to obtain molten steel; During the tapping process, all the required alloys and carburizing agents are added to the molten steel along with the flow, so that the carbon content of the molten steel is ≥0.9 wt% and the manganese content is ≥11 wt%, and aluminum is used to deoxidize the molten steel; The deoxidized molten steel is refined. During the refining process, only the composition of the molten steel is finely adjusted and the temperature is compensated. The molten steel is not subjected to strong stirring for the purpose of desulfurization. The refined molten steel is subjected to vacuum desulfurization under a vacuum degree ≤50 Pa to make the sulfur content of the molten steel ≤0.001 wt%. The molten steel after vacuum desulfurization is continuously cast to obtain a billet.

[0005] Optionally, the refining is carried out in an LF furnace, and the LF furnace maintains white slag throughout the process, wherein the white slag has (FeO+MnO) ≤ 1.0 wt%.

[0006] Optionally, the bottom-blown argon flow rate of the LF furnace is 150–300 NL / min during the heating phase and 400–500 NL / min during the non-heating phase, and is always ≤500 NL / min.

[0007] Optionally, the white slag is formed by adding 1000–1800 kg of quicklime and ≤200 kg of fluorite in batches to the LF furnace, and the basicity of the white slag CaO / SiO2 ≥2.5.

[0008] Optionally, the vacuum desulfurization is carried out in a VD furnace, the deep vacuum of the VD furnace is maintained for ≥18 min, and the bottom blowing argon flow rate is 150–200 NL / min during the deep vacuum stage.

[0009] Optionally, the VD furnace reduces the bottom-blown argon flow rate to 30–50 NL / min within 5 minutes of the start of vacuuming and 5 minutes before rupture, and maintains it at 150–200 NL / min for the remaining stages.

[0010] Optionally, the alloy includes at least two of electrolytic manganese flakes, medium-carbon ferromanganese, and high-carbon ferromanganese, and the alloy is added to the molten steel in 2–4 batches.

[0011] Optionally, the carbon additive consists of carbon powder and carbon wire. First, carbon powder is added to the molten steel to add carbon, and then carbon wire is fed to the molten steel for fine adjustment, so that the carbon content of the molten steel is ≤ ±0.02 wt%.

[0012] Optionally, after the vacuum desulfurization is completed, the molten steel is fed into a Ca-Si line at a rate of 200–250 m / 200 t and subjected to soft argon blowing for 15–20 min, wherein the argon flow rate of the soft argon blowing is 30–50 NL / min.

[0013] Optionally, the chemical composition of the billet, by mass fraction, is: C 0.95–1.05%, Mn 12.0–13.5%, Si 0.30–0.50%, P≤0.006%, S≤0.001%, Als 0.030–0.050%, with the balance being Fe and unavoidable impurities.

[0014] The technical solutions provided in this application have the following advantages compared with the prior art: This application provides a method for smelting high-carbon, high-manganese wear-resistant steel, employing a two-step approach of "source sulfur control + vacuum deep desulfurization" to overcome the reliance on traditional LF desulfurization. First, in the converter, the sulfur content of the molten iron is reduced to extremely low levels using high-basicity slag and a high-oxidizing atmosphere. During tapping, ultra-low sulfur alloys and graphite carburizing agents are used exclusively, with aluminum final deoxidation to cut off further sulfur input. Subsequently, the strong stirring of the LF process is eliminated, and the steel is directly subjected to a vacuum treatment of ≤50 Pa. Under high vacuum, sulfur volatilizes in the form of S2 and CS gases, and a high-carbon reduction occurs, simultaneously reducing the sulfur activity coefficient and partial pressure to their limits, resulting in a sulfur content of ≤0.001%. The entire process does not rely on slag-steel interface mass transfer, avoiding the risk of LF sulfur reversion and achieving low-cost, ultra-low sulfur smelting of high-carbon, high-manganese steel. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic flowchart illustrating a smelting method for high-carbon, high-manganese wear-resistant steel, provided as an embodiment of this application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] The range descriptions used herein, such as numerical ranges and proportional ranges, include all possible sub-ranges and single numerical values ​​within that range. For example, the range descriptions of "1 to 6" or "1 to 6" cover all sub-ranges (such as 1 to 3, 2 to 5, etc.) and single numbers (such as 1, 2, 3, 4, 5, 6) between 1 and 6. Unless otherwise specified, the terms "including" and "contains" as used herein mean "including but not limited to"; relational terms such as "first" and "second" are used only to distinguish different entities or operations and do not imply an actual order or relationship; "and / or" indicates that multiple situations can exist individually or simultaneously; expressions such as "at least one," "multiple," and "at least one" refer to any combination of the corresponding objects, including combinations of single or multiple objects. The proportional relationships mentioned herein, such as mass ratios and molar ratios, should be understood as the correspondence between the first and second terms of a proportional formula, according to the order of description. The raw materials, reagents, instruments, and equipment used herein can all be obtained through commercial purchase or prepared using existing methods.

[0020] Figure 1 This is a schematic flowchart illustrating a smelting method for high-carbon, high-manganese wear-resistant steel, provided as an embodiment of this application.

[0021] Please see Figure 1 In a first aspect, embodiments of this application provide a method for smelting high-carbon, high-manganese wear-resistant steel, comprising: S1. Molten iron is smelted to obtain molten steel; S2. During the tapping process, all the required alloys and carburizing agents are added to the molten steel along with the flow to make the carbon content of the molten steel ≥0.9 wt% and the manganese content ≥11 wt%, and aluminum is used to deoxidize the molten steel. S3. The deoxidized molten steel is refined. During the refining process, only the composition of the molten steel is finely adjusted and the temperature is compensated. The molten steel is not subjected to strong stirring for the purpose of desulfurization. S4. The refined molten steel is subjected to vacuum desulfurization under a vacuum degree ≤50 Pa to make the sulfur content of the molten steel ≤0.001 wt%. S5. The molten steel after vacuum desulfurization is continuously cast to obtain a billet.

[0022] Molten iron: Liquid pig iron produced after tapping from the blast furnace but before converter blowing, with a temperature of approximately 1250-1350 ℃ and a content of C≈4.3%, Si≈0.4-1.2%, and S≈0.02-0.05%. Molten steel: Liquid steel produced after decarburization and dephosphorization of molten iron through converter blowing, with a temperature of approximately 1600-1650 ℃, and target C and Mn close to the lower limit of specifications. Intense stirring: Refers to the intense kinetic conditions used for desulfurization, involving bottom blowing argon or electromagnetic stirring at ≥600 NL / min to fully mix slag and steel. Vacuum desulfurization: Utilizing vacuum in a vacuum tank to reduce the activity and partial pressure of sulfur, causing [S] to volatilize and be removed in the form of S2(g), CS(g), etc.

[0023] Working principle: Blowing: O2 jet oxidation of C, Si, and P generates CO↑, SiO2, and P2O5, which enter the slag phase. Simultaneously, the high basicity of the slag fixes FeS→CaS, achieving 20-40% desulfurization in one pass. In-flow alloying / carburizing agent addition: The impact of the tapping steel flow generates "self-stirring," rapidly dissolving the alloy and preventing secondary oxidation; Al reacts with O to form Al2O3, reducing oxygen activity a[O] and creating a low-oxygen site for subsequent vacuum desulfurization. Refining "fine-tuning": The LF deep desulfurization function is abandoned, reducing Ar stirring intensity to prevent sulfur re-dissolution in the slag; temperature drop is compensated only by electrode heating (approximately 1 ℃ / min). Vacuum degree ≤50 Pa: Corresponding to the equilibrium partial pressure of sulfur p_S2≈10 -4 Bar can ensure that [S] in steel is ≤0.001% (thermodynamic equilibrium value at 1600℃ ≈0.0003%). Continuous casting: Controlling superheat to 15-25℃ inhibits columnar crystal growth and reduces MnS inclusions at grain boundaries. Vacuum degree ≤50 Pa, including but not limited to: 50, 49, 48, ..., 1 Pa. C ≥0.9 wt%, including but not limited to: 0.90, 0.91, 0.92, ..., 1.20 wt%. Mn ≥11 wt%, including but not limited to: 11.0, 11.1, 11.2, ..., 15.0 wt%.

[0024] In some embodiments, the refining is carried out in an LF furnace, and the LF furnace maintains white slag throughout the process, wherein the white slag has (FeO+MnO) ≤ 1.0 wt%.

[0025] LF Furnace: Ladle Furnace, equipped with electric arc heating, bottom blowing argon, and slag formation functions. White Slag: Reducing slag with FeO+MnO≤1.0 wt%, white in color, with high interfacial tension, capable of adsorbing inclusions but hardly desulfurizing.

[0026] White slag with low FeO+MnO content reduces slag oxidizability and inhibits the driving force of sulfur mass transfer between slag and steel. Simultaneously, Al2O3 inclusions are easily captured and floated by the CaO-Al2O3-SiO2 slag system, resulting in pure molten steel. FeO+MnO ≤ 1.0 wt%, including but not limited to: 1.0, 0.9, 0.8, ..., 0.1 wt%.

[0027] In some embodiments, the bottom-blown argon flow rate of the LF furnace is 150–300 NL / min during the heating phase and 400–500 NL / min during the non-heating phase, and is always ≤500 NL / min.

[0028] Bottom-blown argon flow rate: The volume of argon gas blown into the ladle through the permeable brick per unit time, NL / min represents standard liters per minute.

[0029] During the heating stage, the flow rate is 150-300 NL / min: This ensures the circulation and uniform temperature of molten steel in the arc zone while preventing nitrogen absorption due to exposed slag surface. During the non-heating stage, the flow rate is 400-500 NL / min: Moderate stirring promotes the collision and growth of inclusions, but the flow rate is ≤500 NL / min, which is insufficient to produce strong slag-steel emulsification and prevent sulfur re-dissolution in the slag.

[0030] The bottom-blown argon flow rate during the heating phase includes, but is not limited to: 150, 170, 190, 210, 230, 250, 270, 290, and 300 NL / min. The bottom-blown argon flow rate during the non-heating phase includes, but is not limited to: 400, 420, 440, 460, 480, and 500 NL / min.

[0031] In some embodiments, the white slag is formed by adding 1000–1800 kg of quicklime and ≤200 kg of fluorite in batches to the LF furnace, wherein the basicity of the white slag CaO / SiO2 ≥2.5.

[0032] Quicklime: Calcined lime with an active CaO content ≥ 90%. Fluorite: CaF2, used to lower the melting point of slag and improve its fluidity. Basicity CaO / SiO2: The mass ratio of basic oxides to acidic oxides in the slag.

[0033] Add 1000-1800 kg of quicklime in batches → gradually melt to form a high-basicity framework, absorbing Al2O3 inclusions; add ≤200 kg of fluorite to lower the slag melting point to 1450-1500 ℃ and prevent slag crusting. A CaO / SiO2 ratio ≥2.5 ensures the slag phase is mainly C2S and C3A, with high interfacial tension, making inclusions easy to separate. Quicklime additions include, but are not limited to: 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800 kg. Fluorite additions include, but are not limited to: 0, 50, 100, 150, 200 kg. Basicity includes, but is not limited to: 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5.

[0034] In some embodiments, the vacuum desulfurization is carried out in a VD furnace, the deep vacuum of which is maintained for ≥18 min, and the bottom-blown argon flow rate is 150–200 NL / min during the deep vacuum phase.

[0035] VD Furnace: Vacuum Degassing furnace, capable of evacuating to a vacuum level of 0.5-50 Pa. Deep vacuum holding time: the duration of a vacuum level ≤50 Pa.

[0036] ≥18 min ensures sulfur diffusion kinetics are completed (diffusion coefficient D_S≈1×10) -8 m 2 / s, a 200 t ladle needs ≥15min to reach 95% equilibrium). 150-200 NL / min bottom-blowing argon: forms small bubbles, expands the gas-steel interface area, promotes [S]→S2(g) mass transfer, and does not cause molten steel splashing. Deep vacuum holding time includes, but is not limited to: 18, 19, 20, 21, 22, 23, 24, 25min. Bottom-blowing argon flow rate includes, but is not limited to: 150, 160, 170, 180, 190, 200 NL / min.

[0037] In some embodiments, the VD furnace reduces the bottom-blown argon flow rate to 30–50 NL / min within 5 minutes of the start of evacuation and 5 minutes before rupture, and maintains it at 150–200 NL / min for the remaining stages.

[0038] Within 5 minutes of the start of vacuuming: the initial stage where the vacuum level drops from atmospheric pressure to 50 Pa. Within 5 minutes before vacuum breaking: the final stage where the vacuum level rises from 50 Pa back to atmospheric pressure.

[0039] Weak stirring at 30-50 NL / min: Initially, this prevents violent churning of the molten steel, which could lead to slag entrainment; later, it reduces atmospheric intrusion, preventing secondary oxidation and the increase of oxygen and sulfur. Argon flow rates include, but are not limited to: 30, 35, 40, 45, and 50 NL / min.

[0040] In some embodiments, the alloy comprises at least two of electrolytic manganese flakes, medium-carbon ferromanganese, and high-carbon ferromanganese, and the alloy is added to the molten steel in 2–4 batches.

[0041] Electrolytic manganese flakes: Flake-shaped metallic manganese produced by electrolysis, with S≤0.02%. Medium-carbon ferromanganese: An alloy containing C≈1.0-2.0% and Mn≈75-85%. High-carbon ferromanganese: An alloy containing C≈6-8% and Mn≈75-85%.

[0042] At least two alloys are used in combination: utilizing the carbon and manganese gradients of different alloys reduces local component segregation; multiple batches are used to prevent excessive temperature drop and splashing.

[0043] In some embodiments, the carbon additive consists of carbon powder and carbon wire. First, carbon powder is added to the molten steel to add carbon, and then carbon wire is fed to the molten steel for fine adjustment, so that the carbon content of the molten steel is ≤ ±0.02 wt%.

[0044] Toner: Particle size 0.5-2 mm, carbon content ≥98%, S≤0.05%. Carbon wire: Carbon core wire covered with iron sheet, diameter 13 mm, wire feeding speed 2-4 m / s.

[0045] First, add carbon powder to quickly increase carbon content, and then use the impact of the steel flow to distribute it evenly; then feed carbon wire for precise fine-tuning, with a feeding depth of 1.5-2m, carbon recovery rate ≥95%, and ensure the final C accuracy ≤±0.02%.

[0046] In some embodiments, after the vacuum desulfurization is completed, the molten steel is fed into a Ca-Si line at a rate of 200–250 m / 200 t and subjected to soft argon blowing for 15–20 min, wherein the argon flow rate of the soft argon blowing is 30–50 NL / min.

[0047] Ca-Si wire: Cored wire with Ca≈28-32% and Si≈55-60% used to modify Al2O3 to a low-melting-point carbon. 12 A7, to prevent nozzle blockage. Soft argon blowing: Low-flow argon gas evenly floats inclusions without damaging the slag surface.

[0048] 200-250 m / 200 t Ca-Si line → Ca + Al2O3 → C 12 A7 has a melting point of 1400 ℃ and is easy to aggregate and float. Soft blowing for 15-20 min can remove ≥80% of inclusions while avoiding secondary oxidation.

[0049] In some embodiments, the chemical composition of the billet, by mass fraction, is: C 0.95–1.05%, Mn 12.0–13.5%, Si 0.30–0.50%, P ≤0.006%, S ≤0.001%, Als 0.030–0.050%, with the balance being Fe and unavoidable impurities.

[0050] Als: Acid-soluble aluminum, which is the Al content dissolved in steel, used to calculate the degree of deoxidation.

[0051] C 0.95-1.05%: Ensures high hardness and wear resistance; Mn 12.0-13.5%: Stabilizes austenite and improves work hardening rate; Low P ≤0.006% reduces grain boundary embrittlement; Ultra-low S ≤0.001% inhibits MnS inclusions and improves impact toughness; Als 0.030-0.050% provides sufficient deoxidation while avoiding AlN precipitation and coarsening. The mass fraction of C includes, but is not limited to: 0.95, 0.96, 0.97, 0.98, 0.99, 1.00, 1.01, 1.02, 1.03, 1.04, and 1.05%. The mass fraction of Mn includes, but is not limited to: 12.0, 12.1, 12.2, 12.3, 12.4, 12.5, 12.6, 12.7, 12.8, 12.9, 13.0, 13.1, 13.2, 13.3, 13.4, and 13.5%. The mass fraction of Si includes, but is not limited to: 0.30, 0.32, 0.34, 0.36, 0.38, 0.40, 0.42, 0.44, 0.46, 0.48, and 0.50%. The mass fraction of P includes, but is not limited to: 0.006, 0.005, 0.004, 0.003, 0.002, and 0.001%. The mass fraction of S includes, but is not limited to: 0.001, 0.0009, 0.0008, 0.0007, 0.0006, 0.0005, 0.0004, 0.0003, 0.0002, 0.0001%. The mass fraction of Als includes, but is not limited to: 0.030, 0.032, 0.034, 0.036, 0.038, 0.040, 0.042, 0.044, 0.046, 0.048, 0.050%.

[0052] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to industry standards. If there is no corresponding industry standard, then common international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0053] Example 1 (1) KR molten iron desulfurization: molten iron S=5 ppm, temperature 1360–1420 ℃.

[0054] (2) Converter blowing endpoint: C≥0.9 wt%, Mn≥11 wt%, P≤0.006 wt%, endpoint temperature 1620–1640℃.

[0055] (3) All alloys and carbon raisers are added with the tapping process and deoxidized with aluminum. The Als at the station is 0.030–0.060 wt%.

[0056] (4) LF furnace refining: only fine-tuning of composition and temperature compensation are performed. The bottom blowing argon flow rate is 150–300 NL / min during the heating stage and 400–500 NL / min during the non-heating stage, with a total flow rate of ≤500 NL / min. The white slag (FeO+MnO) is ≤1.0 wt%, and the CaO / SiO2 is ≥2.5. Strong stirring for desulfurization is not implemented.

[0057] (5) Vacuum desulfurization in VD furnace: vacuum degree ≤50 Pa, deep vacuum maintained for 18 min, bottom blowing argon 150–200 NL / min; 5 min before breaking the vacuum, reduce to 30–50 NL / min.

[0058] (6) Calcium treatment: Feed Ca-Si wire 200–250 m / 200 t, soft blowing argon 30–50 NL / min, 15–20 min.

[0059] (7) Continuous casting: ladle temperature 1450±5 ℃, final product S≤0.001 wt%.

[0060] Example 2 The process steps are the same as in Example 1, except that the deep vacuum holding time is changed to 19 min. All other parameters are within the range given in the claims.

[0061] Example 3 The process steps are the same as in Example 1, except that the basicity of the LF furnace white slag CaO / SiO2 is controlled at 3.0, and all other parameters are within the range given in the claims.

[0062] Comparative Example 1 (LF Strong Stirring Desulfurization) Steps (1)–(3) are the same as in Example 1.

[0063] (4) The LF furnace is subjected to deep desulfurization by bottom blowing argon at 600–800 NL / min with strong stirring. The white slag (FeO+MnO) is ≤0.5wt% and the CaO / SiO2 is ≥3.5. The rest is the same as in Example 1.

[0064] Comparative Example 2 (without VD deep vacuum desulfurization) Steps (1)–(4) are the same as in Example 1, but the vacuum desulfurization step in the VD furnace is omitted, and only soft blowing argon treatment is performed.

[0065] Comparative Example 3 (All alloys were not added in the LF furnace) Steps (1)–(3) are the same as in Example 1.

[0066] (4) Only a portion of the electrolytic manganese flakes were added to the LF furnace, and the remaining manganese alloy was added at the end of the VD furnace, resulting in insufficient temperature drop in the LF furnace, requiring additional electrode heating; the rest is the same as in Example 1.

[0067] The final products (cast billets) prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to effect experiments, and the results are shown in Table 1.

[0068] Experimental methods: Sulfur and alloying element content: GB / T 223.72-2008 High-frequency induction furnace - Infrared absorption method.

[0069] Total inclusions: GB / T 30834-2014 Metallographic mesh method, 5 points are taken on the same cross section of the billet for statistical average.

[0070] LF furnace processing time: real-time timing from the time the ladle enters the station to the time it leaves the station.

[0071] VD furnace deep vacuum holding time: continuous timing for vacuum degree ≤50 Pa.

[0072] Table 1

[0073] As shown in Table 1: 1. Examples 1–3 using the “LF non-desulfurization + VD deep vacuum desulfurization” process all achieved a final sulfur content ≤0.001 wt%; 2. The sulfur content of both Comparative Example 1 (LF strong stirring desulfurization) and Comparative Example 2 (VD removal deep desulfurization) was higher than 0.001 wt%; 3. Comparative Example 3 (alloy not fully added in LF) resulted in prolonged LF processing time and excessive sulfur content, proving that "LF only involves minor composition adjustments and temperature compensation" and one-time alloying is a necessary condition for controlling sulfur ≤0.001 wt%.

[0074] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for smelting high-carbon, high-manganese wear-resistant steel, comprising: Molten iron is smelted to obtain molten steel; During the tapping process, all the required alloys and carburizing agents are added to the molten steel along with the flow, so that the carbon content of the molten steel is ≥0.9 wt% and the manganese content is ≥11 wt%, and aluminum is used to deoxidize the molten steel; The deoxidized molten steel is refined. During the refining process, only the composition of the molten steel is finely adjusted and the temperature is compensated. The molten steel is not subjected to strong stirring for the purpose of desulfurization. The refined molten steel is subjected to vacuum desulfurization under a vacuum degree ≤50 Pa to make the sulfur content of the molten steel ≤0.001 wt%. The molten steel after vacuum desulfurization is continuously cast to obtain a billet.

2. The method according to claim 1, characterized in that, The refining is carried out in an LF furnace, and the LF furnace maintains white slag throughout the process, wherein the white slag has (FeO+MnO) ≤ 1.0 wt%.

3. The method according to claim 2, characterized in that, The bottom-blown argon flow rate of the LF furnace is 150–300 NL / min during the heating phase and 400–500 NL / min during the non-heating phase, and is always ≤500 NL / min.

4. The method according to claim 2, characterized in that, The white slag is formed by adding 1000–1800 kg of quicklime and ≤200 kg of fluorite in batches to the LF furnace, and the basicity of the white slag CaO / SiO2 ≥2.

5.

5. The method according to claim 1, characterized in that, The vacuum desulfurization is carried out in a VD furnace, the deep vacuum of the VD furnace is maintained for ≥18 min, and the bottom blowing argon flow rate is 150–200 NL / min during the deep vacuum stage.

6. The method according to claim 5, characterized in that, The VD furnace reduces the bottom-blown argon flow rate to 30–50 NL / min within 5 minutes of the start of vacuuming and 5 minutes before the vacuum is broken, and maintains it at 150–200 NL / min for the rest of the process.

7. The method according to claim 1, characterized in that, The alloy comprises at least two of electrolytic manganese flakes, medium-carbon ferromanganese, and high-carbon ferromanganese, and the alloy is added to the molten steel in 2–4 batches.

8. The method according to claim 1, characterized in that, The carbon-adding agent consists of carbon powder and carbon wire. First, carbon powder is added to the molten steel to add carbon, and then carbon wire is fed to the molten steel for fine adjustment so that the carbon content of the molten steel is ≤ ±0.02wt%.

9. The method according to claim 1, characterized in that, After the vacuum desulfurization is completed, the molten steel is fed into a Ca-Si line at a rate of 200–250 m / 200 t and subjected to soft argon blowing for 15–20 min, with an argon flow rate of 30–50 NL / min.

10. The method according to claim 1, characterized in that, The chemical composition of the billet, by mass fraction, is: C 0.95–1.05%, Mn 12.0–13.5%, Si 0.30–0.50%, P≤0.006%, S≤0.001%, Als 0.030–0.050%, with the balance being Fe and unavoidable impurities.

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