Smelting method of 40Cr13Mo6V2

Abstract

The application discloses a smelting method of 40Cr13Mo6V2, which comprises the following smelting steps: steel mixing, AOD primary reduction, AOD secondary reduction, LF station detection, LF refining preparation, LF component fine adjustment, LF refining deoxidation, LF calcium treatment and LF cerium addition, and 40Cr13Mo6V2 steel is prepared. The 40Cr13Mo6V2 steel prepared by the application has high hardness, high wear resistance and high corrosion resistance, and is suitable for manufacturing high-strength parts such as molds and cutters; and the process has the advantages of high stability, high repeatability and convenience for industrialized batch production.

Description

Technical Field

[0001] This invention relates to the field of stainless steel production technology, and more specifically to a smelting method for 40Cr13Mo6V2. Background Technology

[0002] Martensitic stainless steel is a type of hardenable stainless steel that, after appropriate heat treatment, has a martensitic matrix at room temperature. It exhibits a martensitic microstructure at room temperature. Commonly used grades include 1Cr13, 2Cr13, 3Cr13, and 3Cr13Mo.

[0003] Through heat treatment, the microstructure of martensitic stainless steel can be altered, thereby improving the physical and mechanical properties of the workpiece, such as strength, hardness, and wear resistance. Martensitic stainless steel exhibits varying strengths and toughnesses depending on its tempering temperature. Based on differences in chemical composition, microstructure, and strengthening mechanism, it can be used in various fields. Low-carbon and medium-carbon 13%Cr steels (such as 1Cr13 and 2Cr13) are suitable for manufacturing steam turbine blades, shafts, and tie rods for steam equipment; high-carbon steels (such as 4Cr13 and 9Cr18) are suitable for manufacturing medical devices, knives, measuring instruments, and springs. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a smelting method for 40Cr13Mo6V2, so that the prepared 40Cr13Mo6V2 martensitic stainless steel has better hardness and corrosion resistance, so as to be suitable for the production of high-strength parts such as molds and knives.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows.

[0006] A smelting method for 40Cr13Mo6V2 specifically includes the following steps: S1. Steel Addition: 20 tons of molten steel are added from a ladle at 800-1000℃ into an AOD refining furnace with a furnace temperature ≥800℃; the mass percentage of each component in the molten steel is C: 2.0%, Si: 0.60%, Mn: 1.00%, P: 0.035%, S: 0.045%, Cr: 13.20%, Mo: 0.82%, V: 0.25%, with the remainder being Fe; S2, AOD one-time reduction: Add ferrosilicon to the AOD refining furnace for reduction, the amount of ferrosilicon is 150kg, the reduction time is ≥7 minutes; after the reduction is completed, shake the furnace to measure the temperature and take samples. After the Si content reaches the control target of 0.20%, thoroughly remove the slag. S3, AOD secondary reduction: Add 600 kg of reducing slag quicklime and 200 kg of fluorite to the AOD refining furnace, adjust the fluidity, and then add reducing agent to reduce for ≥10 min; S4 and LF incoming inspection: Samples of the molten steel obtained from S3 are taken and the mass percentage of the composition is tested to see if it meets the following control targets: C 0.40-0.44%, Si 0.40-0.45%, Mn 0.9-1.20%, P ≤0.040%, S ≤0.002%, Cr 13.00-13.30%, Mo 0.80-0.85%, Nb 0.07%, V 0.20-0.30%, N 0.015-0.17%, Al ≤0.02%, with the remainder being Fe. S5, LF Refining Preparation: After passing the inspection, the LF refining furnace is connected to argon gas. The slag shell is broken by stirring with large argon gas for ≥10 minutes. After the ladle car is driven to the work station, the molten steel is poured from the AOD refining furnace into the baked ladle car. Temperature is measured and samples are taken. S6, LF fine-tuning composition: Add lime and fluorite to the LF furnace, 100-200 kg of lime and 30-100 kg of fluorite; adjust the slag fluidity, and fine-tune the composition according to the control target in step S4 based on the analysis results of step S5. S7, LF refining deoxidation: Add deoxidizer into the LF furnace for diffusion deoxidation, the amount added is 0.5-1.0 kg / t steel, and maintain a reducing atmosphere in the ladle; S8, LF calcium treatment: After the slag is fully whitened for ≥20 minutes and the temperature is ≥1550℃, stir with large argon gas for more than 3 minutes before taking a full analysis sample. Adjust the composition according to the internal control based on the analysis results. S9, LF Cerium Addition: After the molten steel that has passed the composition and temperature tests in step S8 is tested, it is gently blown with argon at a flow rate of 2-4 NL / min for ≥20min. Then, before tapping, cerium wire is fed in at 0.25% of the weight of the molten steel, and then gently blown with argon for 5min. The composition mass percentage is tested. After the molten steel meets the control target in step S4, it is tapped and transported to the continuous casting process for continuous casting.

[0007] To further optimize the technical solution, in step S3, the reducing agent is aluminum granules, and the amount of aluminum granules used is 1 kg / t steel.

[0008] To further optimize the technical solution, the argon gas volume in step S5 is 20-30 NL / min.

[0009] To further optimize the technical solution, the deoxidizer in step S7 is one of ferrosilicon powder, CaSi powder, or C wire, and the deoxidizer is added in small amounts multiple times.

[0010] To further optimize the technical solution, in step S8, the analysis result requires O ≤ 15ppm; if the analysis result shows O > 15ppm, Ca wire is fed into the molten steel, and the amount of Ca wire used is 4-6m / t steel.

[0011] To further optimize the technical solution, in step S9, the produced steel contains C 0.40-0.44%, Si 0.35-0.45%, Mn 0.90-1.20%, P ≤0.035%, S≤0.010%, Cr 13-13.3%, Ni 0.70%, Mo 0.82%, Nb≤0.10%, V 0.20-0.30%, N ≤0.20%, Ce 0.03-0.07%, Al ≤0.02%, with the remainder being Fe and unavoidable impurities.

[0012] Due to the adoption of the above technical solutions, the technical progress achieved by this invention is as follows.

[0013] This invention provides a smelting method for 40Cr13Mo6V2, a martensitic stainless steel. By controlling the alloy composition ratio, particularly the ratio of V, Cr, and Mo, this invention enables the stainless steel to possess excellent corrosion resistance. Cr significantly enhances the strength and hardness of the steel through solid solution strengthening. V primarily improves performance by refining grains, precipitation strengthening, and improving microstructure stability. Mo refines grains and inhibits grain boundary embrittlement, improves acoustic impact resistance, and forms stable carbides to enhance surface wear resistance. The rare earth element cerium (Ce) purifies the molten steel, removes impurities, refines grains, and microalloys. Combined with smelting processes including steel mixing, AOD primary reduction, AOD secondary reduction, LF incoming inspection, LF refining preparation, LF composition fine-tuning, LF refining deoxidation, LF calcium treatment, and LF cerium addition, the stainless steel grains are further refined, resulting in excellent machinability suitable for manufacturing high-strength components such as precision molds and cutting tools.

[0014] The 40Cr13Mo6V2 steel prepared by this invention has high hardness and high corrosion resistance, and is suitable for manufacturing high-strength parts such as molds and cutting tools. The process of this invention has the advantages of strong stability, high repeatability, and ease of industrial mass production. Attached Figure Description

[0015] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0016] A smelting method for 40Cr13Mo6V2 specifically includes the following steps: S1. Steel Addition: 20 tons of molten steel are added from a ladle at 800-1000℃ into an AOD refining furnace with a furnace temperature ≥800℃; the mass percentage of each component in the molten steel is C: 2.0%, Si: 0.60%, Mn: 1.00%, P: 0.035%, S: 0.045%, Cr: 13.20%, Mo: 0.82%, V: 0.25%, with the remainder being Fe.

[0017] S2, AOD one-time reduction: Add ferrosilicon to the AOD refining furnace for reduction, the amount of ferrosilicon is 150kg, the reduction time is ≥7 minutes; after the reduction is completed, shake the furnace to measure the temperature and take samples. After the Si content reaches the control target of 0.20%, thoroughly remove the slag.

[0018] S3, AOD secondary reduction: Add 600 kg of reducing slag (lime) and 200 kg of fluorite to the AOD refining furnace, adjust the fluidity, and then add the reducing agent for reduction for ≥10 min. The reducing agent is aluminum granules, and the dosage of aluminum granules is 1 kg / t of steel.

[0019] S4 and LF incoming inspection: Samples of the molten steel obtained from S3 are taken and the mass percentage of the composition is tested to see if it meets the following control targets: C 0.40-0.44%, Si 0.40-0.45%, Mn 0.90-1.20%, P ≤0.040%, S ≤0.002%, Cr 13.00-13.30%, Mo 0.80-0.85%, Nb 0.07%, V 0.20-0.30%, N 0.015-0.17%, Al ≤0.02%, with the remainder being Fe. S5, LF Refining Preparation: After passing the inspection, the LF refining furnace is connected to argon gas at a rate of 20-30 NL / min. The slag shell is broken by large argon gas stirring for ≥10 minutes. After the ladle car is driven to the work station, the molten steel is poured from the AOD refining furnace into the baked ladle car. Temperature is measured and samples are taken.

[0020] S6, LF fine-tuning composition: Add lime and fluorite to the LF furnace, 100-200 kg of lime and 30-100 kg of fluorite; adjust the slag fluidity, and fine-tune the composition according to the control target in step S4 based on the analysis results of step S5.

[0021] S7, LF Refining Deoxidation: A deoxidizer is added to the LF furnace for diffusion deoxidation at a rate of 0.5-1.0 kg / t of steel, maintaining a reducing atmosphere inside the ladle. The deoxidizer is one of ferrosilicon powder, CaSi powder, or C wire, and the addition of the deoxidizer follows the principle of small amounts multiple times.

[0022] S8, LF Calcium Treatment: After the slag has fully whitened for ≥20 minutes and the temperature is ≥1550℃, stir with argon gas for at least 3 minutes before taking a full analysis sample. Adjust the composition according to the internal control based on the analysis results. The analysis results require O ≤15ppm; if the analysis results show O >15ppm, feed Ca wire into the molten steel at a rate of 4-6 m / t steel.

[0023] S9, LF Cerium Addition: After the molten steel from step S8 has passed the composition and temperature tests, it is gently blown with argon at a flow rate of 2-4 NL / min for ≥20 min. Before tapping, cerium wire is added at 0.25% of the molten steel's weight, and then gently blown with argon for another 5 min. Samples are taken to test the composition percentage by mass. The molten steel must meet the following control targets: C 0.40-0.44%, Si 0.35-0.45%, Mn 0.90-1.20%, P ≤0.035%, S≤0.010%, Cr 13-13.3%, Ni 0.70%, Mo 0.82%, Nb≤0.10%, V 0.20-0.30%, N ≤0.20%, Ce 0.03-0.07%, Al ≤0.02%, with the remainder being Fe and unavoidable impurities. The steel is then tapped and transported to the continuous casting process for continuous casting.

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Example 1:

[0025] S1. Steel Transfer: 20 tons of molten steel are transferred from a ladle at 1000℃ into an AOD refining furnace at 1000℃. The mass percentages of the components in the molten steel are: C: 2.0%, Si: 0.60%, Mn: 1.00%, P: 0.035%, S: 0.045%, Cr: 13.20%, Mo: 0.82%, V: 0.25%, with the remainder being Fe.

[0026] S2, AOD one-time reduction: Add ferrosilicon to the AOD refining furnace for reduction, the amount of ferrosilicon is 150kg, the reduction time is 7 minutes; after the reduction is completed, shake the furnace to measure the temperature and take samples. After the Si content reaches the control target of 0.20%, remove the slag completely.

[0027] S3, AOD Secondary Reduction: Add 600 kg of reducing slag (lime) and 200 kg of fluorite to the AOD refining furnace, adjust the fluidity, and then add the reducing agent for 15 min of reduction. The reducing agent is aluminum granules, and the dosage of aluminum granules is 1 kg / t of steel.

[0028] S4 and LF incoming inspection: Samples of the molten steel obtained from S3 were taken and the mass percentage of the composition was tested as follows: C 0.40%, Si 0.40%, Mn 0.95%, P 0.040%, S 0.002%, Cr 13.30%, Mo 0.85%, Nb 0.07%, V 0.22%, N 0.17%, Al 0.02%, with the remainder being Fe, which meets the control targets.

[0029] S5, LF Refining Preparation: After passing the inspection, the LF refining furnace is connected to argon gas at a rate of 20 NL / min. The slag shell is broken by stirring with large amounts of argon gas for 15 minutes. After the ladle car is driven to the work station, the molten steel is poured from the AOD refining furnace into the preheated ladle car. Temperature is measured and samples are taken.

[0030] S6, LF fine-tuning composition: Add lime and fluorite to the LF furnace, 200 kg of lime and 50 kg of fluorite; adjust the slag fluidity, and fine-tune the composition according to the control target in step S4 based on the analysis results of step S5.

[0031] S7, LF Refining Deoxidation: A deoxidizer is added to the LF furnace for diffusion deoxidation at a rate of 1.0 kg / t steel, maintaining a reducing atmosphere inside the ladle. The deoxidizer is one of ferrosilicon powder, CaSi powder, or C wire, and the addition of the deoxidizer follows the principle of small amounts multiple times.

[0032] S8, LF calcium treatment: After the slag is fully whitened for 20 minutes and the temperature is ≥1550℃, stir with argon gas for more than 3 minutes and then take a full analysis sample. The analysis results show that O=14ppm.

[0033] S9, LF Cerium Addition: The molten steel that has passed the composition and temperature tests in step S8 is soft-blown with argon at a flow rate of 3NL / min for 20min; then, before tapping the steel, 0.25% of the molten steel weight is fed into the cerium wire, and soft-blown with argon is performed for another 5min; samples are taken to test the composition mass percentage, and after it meets the control target, the steel is tapped and transported to the continuous casting process for continuous casting.

[0034] The mass percentages of each component in the molten steel are as follows: C 0.40%, Si 0.38%, Mn 0.9%, P 0.03%, S 0.002%, Cr 13.3%, Ni 0.7%, Mo 0.85%, Nb 0.07%, V 0.22%, N 0.17%, Ce 0.03%, Al 0.02%, with the remainder being Fe and unavoidable impurities. Example 2:

[0035] S1. Steel Transfer: 20 tons of molten steel are transferred from a ladle at 900℃ into an AOD refining furnace at 900℃. The mass percentages of the components in the molten steel are: C: 2.0%, Si: 0.60%, Mn: 1.00%, P: 0.035%, S: 0.045%, Cr: 13.20%, Mo: 0.82%, V: 0.25%, with the remainder being Fe.

[0036] S2, AOD one-time reduction: Add ferrosilicon to the AOD refining furnace for reduction, the amount of ferrosilicon is 150kg, the reduction time is 8 minutes; after the reduction is completed, shake the furnace to measure the temperature and take samples. After the Si content reaches the control target of 0.20%, thoroughly remove the slag.

[0037] S3, AOD Secondary Reduction: Add 600 kg of reducing slag (lime) and 200 kg of fluorite to the AOD refining furnace, adjust the fluidity, and then add the reducing agent for 12 minutes. The reducing agent is aluminum granules, and the dosage of aluminum granules is 1 kg / t of steel.

[0038] S4 and LF incoming inspection: Samples of the molten steel obtained from S3 were taken and the mass percentage of the composition was tested as follows: C 0.44%, Si 0.40%, Mn 0.92%, P 0.038%, S 0.001%, Cr 13.20%, Mo 0.83%, Nb 0.07%, V 0.25%, N 0.16%, Al 0.01%, with the remainder being Fe; which meets the control targets.

[0039] S5, LF Refining Preparation: After passing the inspection, the LF refining furnace is connected to argon gas at a rate of 30 NL / min. The slag shell is broken by stirring with large amounts of argon gas for 12 minutes. After the ladle car is driven to the work station, the molten steel is poured from the AOD refining furnace into the preheated ladle car. Temperature is measured and samples are taken.

[0040] S6, LF fine-tuning composition: Add lime and fluorite to the LF furnace, 150 kg of lime and 100 kg of fluorite; adjust the slag fluidity, and fine-tune the composition according to the control target in step S4 based on the analysis results of step S5.

[0041] S7, LF Refining Deoxidation: A deoxidizer is added to the LF furnace for diffusion deoxidation at a rate of 0.8 kg / t steel, maintaining a reducing atmosphere inside the ladle. The deoxidizer is one of ferrosilicon powder, CaSi powder, or C wire, and the addition of the deoxidizer follows the principle of small amounts multiple times.

[0042] S8, LF calcium treatment: After the slag has been fully whitened for ≥20 minutes and the temperature is ≥1550℃, stir with argon gas for more than 3 minutes before taking a full analysis sample. The analysis result is O=15ppm.

[0043] S9, LF Cerium Addition: The molten steel that has passed the composition and temperature tests in step S8 is soft-blown with argon at a flow rate of 2NL / min for 30min; then, before tapping, cerium wire is fed in at 0.25% of the weight of the molten steel, and soft-blown with argon is performed for another 5min; samples are taken to test the composition mass percentage, and after it meets the control target, the steel is tapped and transported to the continuous casting process for continuous casting.

[0044] The mass percentages of each component in the molten steel are as follows: C 0.44%, Si 0.4%, Mn 0.92%, P 0.032%, S 0.001%, Cr 13.2%, Ni 0.70%, Mo 0.83%, Nb 0.07%, V 0.25%, N 0.16%, Ce 0.04%, Al 0.01%, with the remainder being Fe and unavoidable impurities. Example 3:

[0045] S1. Steel Transfer: 20 tons of molten steel are transferred from an 850℃ ladle into an AOD refining furnace at a furnace temperature of 800℃. The mass percentages of the components in the molten steel are: C: 2.0%, Si: 0.60%, Mn: 1.00%, P: 0.035%, S: 0.045%, Cr: 13.20%, Mo: 0.85%, V: 0.25%, with the remainder being Fe.

[0046] S2, AOD one-time reduction: Add ferrosilicon to the AOD refining furnace for reduction, the amount of ferrosilicon is 150kg, the reduction time is 10 minutes; after the reduction is completed, shake the furnace to measure the temperature and take samples. After the Si content reaches the control target of 0.20%, thoroughly remove the slag.

[0047] S3, AOD secondary reduction: Add 600 kg of reducing slag (lime) and 200 kg of fluorite to the AOD refining furnace, adjust the fluidity, and then add the reducing agent for 10 min of reduction. The reducing agent is aluminum granules, and the dosage of aluminum granules is 1 kg / t of steel.

[0048] S4 and LF incoming inspection: Samples of the molten steel obtained from S3 were taken and the mass percentage of the composition was tested as follows: C 0.43%, Si 0.42%, Mn 1.00%, P 0.036%, S 0.001%, Cr 13.10%, Mo 0.85%, Nb 0.07%, V 0.21%, N 0.15%, Al 0.01%, with the remainder being Fe; which meets the control targets.

[0049] S5, LF Refining Preparation: After passing the inspection, argon gas is connected to the LF refining furnace at a rate of 25 NL / min. The slag shell is broken by stirring with large amounts of argon gas for 15 minutes. After the ladle car is driven to the work station, the molten steel is poured from the AOD refining furnace into the preheated ladle car. Temperature is measured and samples are taken.

[0050] S6, LF fine-tuning composition: Add lime and fluorite to the LF furnace, 200 kg of lime and 30 kg of fluorite; adjust the slag fluidity, and fine-tune the composition according to the control target in step S4 based on the analysis results of step S5.

[0051] S7, LF Refining Deoxidation: A deoxidizer is added to the LF furnace for diffusion deoxidation at a rate of 0.5 kg / t steel, maintaining a reducing atmosphere within the ladle. The deoxidizer is one of ferrosilicon powder, CaSi powder, or C wire, and is added in small, multiple applications.

[0052] S8, LF calcium treatment: After the slag has been fully whitened for ≥20 minutes and the temperature is ≥1550℃, stir with argon gas for more than 3 minutes before taking a full analysis sample. The analysis result is O=15ppm.

[0053] S9, LF Cerium Addition: The molten steel that has passed the composition and temperature tests in step S8 is soft-blown with argon at a flow rate of 4 NL / min for 25 min; then, before tapping, cerium wire is fed in at 0.25% of the weight of the molten steel, and soft-blown with argon is performed for another 5 min; samples are taken to test the composition mass percentage, and after it meets the control target, the steel is tapped and transported to the continuous casting process for continuous casting.

[0054] The mass percentages of each component in the molten steel are as follows: C 0.43%, Si 0.42%, Mn 1.0%, P 0.036%, S 0.001%, Cr 13.1%, Ni 0.70%, Mo 0.85%, Nb 0.07%, V 0.21%, N 0.15%, Ce 0.07%, Al 0.01%, with the remainder being Fe and unavoidable impurities. Comparative Example 1:

[0055] The molten iron used in this comparative example is different from that used in step S1 of Example 1, but the smelting process steps are the same, and the control target of Example 1 is not set in the smelting process.

[0056] The stainless steel produced was tested, and the mass percentages of each component in the stainless steel were as follows: C = 0.060%, Mn = 1.40%, Si = 0.30%, Ni = 0.040%, Ti = 0.02%, V = 0.05%, Mo = 0.2%, Cr = 0.35%, N = 0.015%, Ce 0.06%, with the remainder being Fe and unavoidable impurities. Comparative Example 2:

[0057] The comparative example uses the same molten iron as in step S1 of Example 1. The difference is that the steelmaking process does not have the control target of Example 1, and in step S9, cerium wire is not fed in but argon is blown directly.

[0058] The stainless steel produced was tested, and the mass percentages of each component in the stainless steel were C=0.060%, Mn=1.40%, Si=0.30%, Ni=0.040%, Ti=0.02%, V=0.05%, Mo=0.2%, Cr=0.35%, N=0.015%, with the remainder being Fe and unavoidable impurities. Comparative Example 3:

[0059] Commercially available high-hardness, corrosion-resistant stainless steel SUP13Cr was purchased and its composition was tested. The mass percentage of the stainless steel composition was C=0.082%, Mn=0.670%, Si=0.20%, Ni=5.41%, Ti=0.02%, V=0.01%, Mo=0.12%, Cr=12.69%, N=0.015%, with the remainder being Fe and unavoidable impurities.

[0060] The hardness and corrosion resistance of the 40Cr13Mo6V2 steel prepared in Examples 1-3 and the stainless steel in Comparative Examples 1-3 were tested, and the test results are shown in the table below:

[0061] As can be seen from the table above, the Brinell hardness of Examples 1-3 is significantly lower than that of the comparative example.

[0062] In summary, this invention, by controlling the alloy composition ratio, especially the precise control of the ratio of V, Cr, and Mo elements, enables stainless steel to have excellent corrosion resistance. The addition of cerium plays a role in purifying molten steel, removing impurities, refining grains, improving intergranular corrosion resistance, and microalloying. Combined with the smelting process of steel mixing, AOD primary reduction, AOD secondary reduction, LF incoming inspection, LF refining preparation, LF composition fine-tuning, LF refining deoxidation, LF calcium treatment, and LF cerium addition, the grains of stainless steel are further refined, giving it excellent machinability and making it suitable for manufacturing high-strength components such as precision molds and cutting tools.

Claims

1. A smelting method for 40Cr13Mo6V2, characterized in that, Specifically, the following steps are included: S1. Steel Addition: 20 tons of molten steel are added from a ladle at 800-1000℃ into an AOD refining furnace with a furnace temperature ≥800℃; the mass percentage of each component in the molten steel is C: 2.0%, Si: 0.60%, Mn: 1.00%, P: 0.035%, S: 0.045%, Cr: 13.20%, Mo: 0.82%, V: 0.25%, with the remainder being Fe; S2, AOD one-time reduction: Add ferrosilicon to the AOD refining furnace for reduction, the amount of ferrosilicon is 150kg, the reduction time is ≥7 minutes; after the reduction is completed, shake the furnace to measure the temperature and take samples. After the Si content reaches the control target of 0.20%, thoroughly remove the slag. S3, AOD secondary reduction: Add 600 kg of reducing slag quicklime and 200 kg of fluorite to the AOD refining furnace to adjust the fluidity, and then add reducing agent to reduce for ≥10 min; S4 and LF incoming inspection: Samples of the molten steel obtained from S3 are taken to test whether the mass percentage of the composition meets the control targets. The control targets are: C 0.40-0.44%, Si 0.40-0.45%, Mn 0.90-1.20%, P ≤0.040%, S ≤0.002%, Cr 13.00-13.30%, Mo 0.80-0.85%, Nb 0.07%, V 0.20-0.30%, N 0.015-0.17%, Al ≤0.02%, and the remainder is Fe; S5, LF Refining Preparation: After passing the inspection, the LF refining furnace is connected to argon gas. The slag shell is broken by stirring with large argon gas for ≥10 minutes. After the ladle car is driven to the work station, the molten steel is poured from the AOD refining furnace into the baked ladle car. Temperature is measured and samples are taken. S6, LF fine-tuning composition: Add lime and fluorite to the LF furnace; 100-200 kg of lime and 30-100 kg of fluorite; adjust the slag fluidity, and fine-tune the composition according to the control target in step S4 based on the analysis results of step S5. S7, LF refining deoxidation: Add deoxidizer into the LF furnace for diffusion deoxidation, the amount added is 0.5-1.0 kg / t steel, and maintain a reducing atmosphere in the ladle; S8, LF calcium treatment: After the slag is fully whitened for ≥20 minutes and the temperature is ≥1550℃, stir with large argon gas for more than 3 minutes before taking a full analysis sample. Adjust the composition according to the internal control based on the analysis results. S9, LF Cerium Addition: After the molten steel that has passed the composition and temperature tests in step S8 is tested, it is gently blown with argon at a flow rate of 2-4 NL / min for ≥20min. Then, before tapping, cerium wire is fed in at 0.25% of the weight of the molten steel, and then gently blown with argon for 5min. The composition mass percentage is tested. After the molten steel meets the control target in step S4, it is tapped and transported to the continuous casting process for continuous casting.

2. The smelting method for 40Cr13Mo6V2 according to claim 1, characterized in that: In step S3, the reducing agent is aluminum granules, and the amount of aluminum granules used is 1 kg / t of steel.

3. The smelting method for 40Cr13Mo6V2 according to claim 1, characterized in that: In step S5, the argon gas flow rate is 20-30 NL / min.

4. The smelting method for 40Cr13Mo6V2 according to claim 1, characterized in that: In step S7, the deoxidizer is one of ferrosilicon powder, CaSi powder, or C wire, and the deoxidizer is added in small amounts multiple times.

5. The smelting method for 40Cr13Mo6V2 according to claim 1, characterized in that: In step S8, the analysis result requires O ≤ 15ppm; if the analysis result shows O > 15ppm, Ca wire is fed into the molten steel, and the amount of Ca wire used is 4-6m / t steel.

6. The smelting method for 40Cr13Mo6V2 according to claim 1, characterized in that: In step S9, the produced steel contains 0.40-0.44% C, 0.35-0.45% Si, 0.90-1.20% Mn, ≤0.035% P, ≤0.010% S, 13-13.3% Cr, 0.70% Ni, 0.82% Mo, ≤0.10% Nb, 0.20-0.30% V, ≤0.20% N, 0.03-0.07% Ce, ≤0.02% Al, with the remainder being Fe and unavoidable impurities.

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