AOD converter smelting process of 21Mn23AlSiMoV high manganese heat-resistant steel

Abstract

The application discloses an AOD converter smelting process of 21Mn23AlSiMoV high manganese heat-resistant steel. First, the molten iron in a blast furnace is pretreated in a dephosphorization converter, and the P content is reduced to below 0.015%, then the molten iron is poured into an AOD converter for smelting, the smelting process comprises a main decarburization stage, a manganese primary alloying stage, a dynamic decarburization stage, a manganese secondary alloying stage, a reduction stage and an aluminum alloying stage, and finally the composition and temperature of the molten iron are fine-tuned in an LF refining furnace. The AOD top side combined blowing high-efficiency decarburization and side blowing strong stirring dynamics condition are used, the smelting cycle can be controlled within 120 min, the total decarburization efficiency CRE of the AOD converter reaches above 90.1%, the Mn yield reaches above 97.35%, the aluminum yield reaches above 82.08%, and the production cost is greatly reduced.

Description

Technical Field

[0001] This invention belongs to the field of high manganese heat-resistant steel smelting technology, specifically relating to an AOD converter smelting process for 21Mn23AlSiMoV high manganese heat-resistant steel. Background Technology

[0002] High-manganese steel refers to alloy steel with a manganese content of over 10%. The market mainly offers high-manganese heat-resistant steels with manganese content greater than 10% and carbon content between 0.9% and 1.0%, such as 21Mn23AlSiMoV high-manganese heat-resistant steel, and high-manganese non-magnetic steels with manganese content greater than 17% and carbon content less than 1.0%, such as 20Mn23AlV. Compared to 20Mn23AlV high-manganese non-magnetic steel, 21Mn23AlSiMoV high-manganese heat-resistant steel maintains the original low magnetic permeability characteristics of high-manganese non-magnetic steel while effectively improving its heat resistance, high-temperature resistance, and corrosion resistance. It can be used not only in non-magnetic equipment such as transformers and flanges, but also in key parts such as the lower part of the feed pipe and the charging chute in submerged arc furnaces. Due to the efficient decarburization and strong side-blowing stirring kinetics of the AOD converter, the production of 20Mn23AlV high-manganese non-magnetic steel has been achieved through AOD converter smelting, effectively improving its manganese yield and decarburization efficiency. However, as a new type of high-manganese steel, 21Mn23AlSiMoV high-manganese heat-resistant steel is currently smelted using electric furnace → LF → die casting or electric furnace → VD → LF → die casting processes, which have low decarburization efficiency and low yield of Mn and Al metals. Summary of the Invention

[0003] The purpose of this invention is to solve the technical problems of low decarburization efficiency and low Mn and Al metal yield in existing 21Mn23AlSiMoV high-manganese heat-resistant steel smelting processes. It provides a process for smelting 21Mn23AlSiMoV high-manganese heat-resistant steel using a "dephosphorization converter + AOD converter + LF refining furnace" process. This process utilizes the efficient decarburization achieved by top-side combined blowing of the AOD converter and the strong stirring kinetics of side blowing to achieve efficient decarburization and improve the Mn and Al metal yield.

[0004] To achieve its purpose, the present invention adopts the following technical solution:

[0005] An AOD converter smelting process for 21Mn23AlSiMoV high-manganese heat-resistant steel includes the following steps:

[0006] The first step is to pretreat the blast furnace hot metal in a dephosphorization converter:

[0007] 1.1 The furnace charge includes iron oxide scale, lime, dolomite, etc.;

[0008] 1.2 During the oxygen blowing and slag forming stage, lime is added according to the silicon content of the blast furnace hot metal, and oxygen blowing and slag forming are carried out.

[0009] 1.3 During the dephosphorization stage, the phosphorus content is controlled below 0.015%, and the carbon content is between 2.8% and 3.5%.

[0010] 1.4 Tackling: The tackling temperature is controlled at 1400-1430℃.

[0011] The second step involves smelting 21Mn23AlSiMoV high-manganese heat-resistant steel in an AOD converter:

[0012] 2.1 Before adding molten steel, add 3% lime by weight of the molten steel, and blow argon throughout the smelting process;

[0013] 2.2 Main decarburization period: An argon-oxygen mixture with an O2:Ar ratio of 7:1 is blown into the furnace for 20-30 minutes. 25-30 kg / t of lime is added, and the furnace is spun with a top lance until carbon is reduced to 0.7-0.8%.

[0014] 2.3 Manganese primary alloying: After the main decarburization period, the molten steel temperature is raised to 1600℃, the top lance blowing is cancelled, and an argon-oxygen mixed gas with a ratio of O2:Ar=3:1 is blown into the furnace for 10 minutes. 25-30Kg / t of high-carbon ferromanganese and 15-20Kg / t of lime are added, and the carbon content is reduced to about 0.45%.

[0015] 2.4 Dynamic Decarburization Period 1: After the first alloying of manganese is completed, reduce the proportion of O2 in the side-blown oxygen-supplying mixed gas and blow an argon-oxygen mixed gas with a ratio of O2:Ar=1:1 into the furnace for 10-14 minutes. Add 10 kg / t of lime to decarburize to 0.25%.

[0016] 2.5 Dynamic decarburization period 2: Reduce the proportion of O2 in the side-blown oxygen-supplying mixed gas, and blow an argon-oxygen mixed gas with a ratio of O2:Ar=1:2 into the furnace for 8-10 minutes. Add 10 kg / t of lime to decarburize to 0.15%.

[0017] 2.6 Manganese secondary alloying: After the dynamic decarburization period, continue to reduce the proportion of O2 in the side-blown oxygen-supplying mixed gas and blow an argon-oxygen mixed gas with a ratio of O2:Ar=1:4 into the furnace for 10-15 minutes. Add 180-200 kg / t of electrolytic manganese in 3 batches, and add 15-20 kg / t of lime at the same time. The ternary basicity of the slag is controlled at 3.0 during this stage.

[0018] 2.7 Reduction period: After the secondary alloying stage of manganese, add 45-55 kg / t of aluminum particles and 6-7 kg / t of fluorite for slag deoxidation and aluminum alloying, and 5-6 kg / t of ferromolybdenum. After the reduction is completed, 40-50% of the slag is dumped, and temperature is measured and samples are taken. The composition is adjusted according to the test results. The ternary basicity of the slag is controlled at 2.3-2.8 during this stage.

[0019] 2.8 Tapping: Add 3-5 kg / t of ferrosilicon, stir evenly, and then tap the steel.

[0020] The third step involves adjusting the composition and temperature of the 21MnAlSiMoV high-manganese heat-resistant steel in the LF refining furnace:

[0021] 3.1 After the slag is removed, the molten steel enters the LF treatment station, where slag is melted, temperature is measured and samples are taken. Based on the test results, the composition of C, Mn, Al and other components in the molten steel is adjusted, and ferrovanadium is added.

[0022] 3.2 After controlling the composition and temperature of the molten steel to the internal control range, feed in 50m of calcium wire, control the temperature of the tundish within the range of 1430-1445℃, and then blow weakly for 30 minutes before casting on the platform.

[0023] The beneficial effects of this invention are as follows:

[0024] 1. This invention first pretreats blast furnace hot metal in a dephosphorization converter, then utilizes the efficient decarburization of AOD top-side combined blowing and the strong stirring kinetics of side blowing to achieve efficient decarburization and manganese alloying. Finally, the steel composition and temperature are finely adjusted in an LF refining furnace to obtain 21MnAlSiMoV high-manganese heat-resistant steel. Compared with 20Mn23AlV high-manganese non-magnetic steel, this 21MnAlSiMoV high-manganese heat-resistant steel maintains the original characteristics of low magnetic permeability while effectively improving its heat resistance, high-temperature resistance, and corrosion resistance, making it suitable for use in high-temperature, strong magnetic field, and corrosive environments.

[0025] 2. This invention uses a process of "dephosphorization converter + AOD converter + LF refining furnace" to smelt 21Mn23AlSiMoV high manganese heat-resistant steel. The total decarburization efficiency (CRE) of the AOD converter reaches over 90.1%, the manganese metal recovery rate reaches over 97.35%, and the aluminum metal recovery rate reaches over 82.08%, thus reducing production costs. Detailed Implementation

[0026] The present invention will now be described in detail through specific embodiments.

[0027] Example 1

[0028] 21MnAlSiMoV high manganese heat-resistant steel is smelted using a process of "dephosphorization converter + AOD converter + LF refining furnace".

[0029] The first step is to pretreat the blast furnace hot metal in a dephosphorization converter:

[0030] 1.1 Oxygen blowing and slagging stage: blast furnace molten iron is injected into the dephosphorization converter. The composition of the blast furnace molten iron, by weight percentage, is C 5.04%, Si 0.69%, Mn 0.83%, and P 0.07%. During the process, 2.2t of iron oxide scale, 1.4t of lightly calcined dolomite, 1.7t of active lime, 3.0t of quicklime, and 0.16t of fluorite are added, and oxygen is blown at 1570 Nm³. 3 Nitrogen 245 Nm 3 The basicity of binary slag is controlled at 2.1;

[0031] 1.2 Dephosphorization stage: Sampling and testing showed that the phosphorus content was 0.011% and the carbon content was 3.72%.

[0032] 1.3 Tapping: The temperature of the molten steel is 1429℃;

[0033] The second step involves smelting 21Mn23AlSiMoV high-manganese heat-resistant steel in an AOD converter:

[0034] 2.1 Adding lime: Add 3% lime by weight of molten steel to the AOD converter and add 1.3 molten steel. The composition of the molten steel entering the furnace is C 3.49%, Mn 0.34%, P 0.008%, S 0.018%, with an addition amount of 90.1t and a molten steel temperature of 1392℃.

[0035] 2.2 Main decarburization period: Add 30 kg / t of lime, blow an argon-oxygen mixture of O2:Ar=7:1 into the furnace, and blow with a top lance for 24 minutes until C is reduced to 0.8%;

[0036] 2.3 Manganese primary alloying: The temperature of molten steel is raised to 1600℃, the top lance blowing is cancelled, and side blowing oxygen supply is adopted. An argon-oxygen mixture of O2:Ar=3:1 is blown into the furnace and blown for 10 minutes. 51Kg / t of high carbon ferromanganese and 20Kg / t of lime are added, and the carbon content is reduced to 0.45%.

[0037] 2.4 Dynamic decarburization period 1: Reduce the proportion of O2 in the side-blown oxygen supply mixture, blow an argon-oxygen mixture of O2:Ar=1:1 into the furnace, blow for 12 minutes, add 10 kg / t of lime, and decarburize to 0.25%;

[0038] 2.5 Dynamic decarburization period 2: Further reduce the proportion of O2 in the side-blown oxygen supply mixture, blow an argon-oxygen mixture of O2:Ar=1:2 into the furnace, blow for 10 minutes, add 10 kg / t of lime, and decarburize to 0.15%;

[0039] 2.6 Manganese secondary alloying: Continue to reduce the proportion of O2 in the side-blown oxygen-supplying mixed gas, blow an argon-oxygen mixed gas with O2:Ar=1:4 into the furnace, blow for 15 minutes, add 181.0 kg / t of electrolytic manganese in 3 batches, add 20 kg / t of lime at the same time, and add 3 kg / t of aluminum granules to each batch to raise the temperature and reduce the heat loss caused by melting the alloy. During this stage, control the ternary basicity of the slag to 3.0.

[0040] 2.7 Reduction period: 22.6 kg / t of aluminum granules and 6.2 kg / t of fluorite are added for slag deoxidation and aluminum alloying. Then, 5.3 kg / t of ferromolybdenum is added for reduction. After the reduction is completed, 40% of the slag is dumped, and temperature is measured and samples are taken. The composition is adjusted according to the test results. During this stage, the ternary basicity of the slag is controlled at 2.5.

[0041] 2.8 Tapping: Add 2.7 kg / t of ferrosilicon, stir evenly, and then tap and remove slag; the composition of the tapped steel is shown in Table 1.

[0042]

[0043] The third step involves adjusting the composition and temperature of the 21MnAlSiMoV high-manganese heat-resistant steel in the LF refining furnace:

[0044] 3.1 After the slag removal process in 2.8 is carried out in the LF treatment station, slag is removed, temperature is measured and samples are taken. The content of C, Mn, Al and other components in the molten steel is adjusted according to the test results, and 1.0 kg / t ferrovanadium is added; the composition of the finished product is shown in Table 2.

[0045]

[0046] 3.2 After controlling the composition and temperature of the molten steel to the internal control range, 50m of calcium wire is fed in, the tapping temperature is 1476℃, and then the steel is weakly blown for 30 minutes before being cast on the platform to obtain 21Mn23AlSiMoV high manganese heat-resistant steel.

[0047] In this example, the AOD converter achieved a manganese recovery rate of 98.09% and an aluminum recovery rate of 83.02%, with a smelting cycle of 113 minutes and a total decarburization efficiency of 90.5%. This demonstrates the feasibility of using an AOD converter to smelt 21MnAlSiMoV high-manganese heat-resistant steel, with high decarburization efficiency and high Mn and Al metal recovery rates.

[0048] Example 2

[0049] 21MnAlSiMoV high manganese heat-resistant steel is smelted using a process of "dephosphorization converter + AOD converter + LF refining furnace".

[0050] The first step is to pretreat the blast furnace hot metal in a dephosphorization converter:

[0051] 1.1 Oxygen blowing and slagging stage: blast furnace molten iron is injected into the dephosphorization converter. The composition of the blast furnace molten iron, by weight percentage, is C 4.81%, Si 1.26%, Mn 0.89%, and P 0.08%. During the process, 4.2t of iron oxide scale, 1.4t of lightly calcined dolomite, 3.3t of active lime, 4.8t of quicklime, and 0.16t of fluorite are added, and oxygen is blown at 1879 Nm³. 3 Nitrogen 315 Nm 3 The basicity of binary slag is controlled at 2.1;

[0052] 1.2 Dephosphorization stage: Sampling and testing showed that the phosphorus content was 0.013% and the carbon content was 3.33%.

[0053] 1.3 Tapping: The temperature of the molten steel is 1438℃;

[0054] The second step involves smelting 21Mn23AlSiMoV high-manganese heat-resistant steel in an AOD converter:

[0055] 2.1 Adding lime: Add 3% lime by weight of molten steel to the AOD converter and add 1.3 molten steel. The composition of the molten steel entering the furnace is 3.19% C, 0.33% Mn, 0.012% P, and 0.017% S. The amount added is 90.3t, and the furnace temperature is 1380℃.

[0056] 2.2 Main decarburization period: Add 30 kg / t of lime, blow an argon-oxygen mixture of O2:Ar=7:1 into the furnace, and blow with a top lance for 25 minutes until C is reduced to 0.71%;

[0057] 2.3 Manganese primary alloying: The temperature of molten steel is raised to 1600℃, top lance blowing is eliminated, and side blowing oxygen supply is adopted. An argon-oxygen mixture of O2:Ar=3:1 is blown into the furnace and blown for 12 minutes. 53.6Kg / t of high-carbon ferromanganese and 15Kg / t of lime are added, and the carbon content is reduced to 0.5%.

[0058] 2.4 Dynamic decarburization period 1: Reduce the proportion of O2 in the side-blown oxygen supply mixture, blow an argon-oxygen mixture of O2:Ar=1:1 into the furnace, blow for 10 minutes, add 10 kg / t of lime, and decarburize to 0.25%;

[0059] 2.5 Dynamic decarburization period 2: Further reduce the proportion of O2 in the side-blown oxygen supply mixture, blow an argon-oxygen mixture of O2:Ar=1:2 into the furnace, blow for 8 minutes, add 10 kg / t of lime, and decarburize to 0.15%;

[0060] 2.6 Manganese secondary alloying: Continue to reduce the proportion of O2 in the side-blown oxygen-supplying mixed gas, blow an argon-oxygen mixed gas with O2:Ar=1:4 into the furnace, blow for 10 minutes, add 183.3 kg / t of electrolytic manganese in 3 batches, add 25 kg / t of lime at the same time, and add 3.1 kg / t of aluminum granules to each batch to raise the temperature and reduce the heat loss caused by melting the alloy. During this stage, control the ternary basicity of the slag to 3.0.

[0061] 2.7 Reduction period: 23.5 kg / t of aluminum granules and 6.0 kg / t of fluorite are added for slag deoxidation and aluminum alloying. Then, 5.1 kg / t of ferromolybdenum is added for reduction. After the reduction is completed, 45% of the slag is dumped, and temperature is measured and samples are taken. The composition is adjusted according to the test results. During this stage, the ternary basicity of the slag is controlled at 2.3.

[0062] 2.8 Tapping: Add 4.5 kg / t of ferrosilicon, stir evenly, and then tap and remove slag; the composition of the tapped steel is shown in Table 3.

[0063]

[0064] The third step involves adjusting the composition and temperature of the 21MnAlSiMoV high-manganese heat-resistant steel in the LF refining furnace:

[0065] 3.1 After the slag removal process in 2.8 is carried out in the LF treatment station, slag is removed, temperature is measured and samples are taken. The content of C, Mn, Al and other components in the molten steel is adjusted according to the test results, and 1.0 kg / t ferrovanadium is added; the composition of the finished product is shown in Table 4.

[0066]

[0067] 3.2 After controlling the composition and temperature of the molten steel to the internal control range, 50m of calcium wire is fed in, the tapping temperature is 1476℃, and then the steel is weakly blown for 30 minutes before being cast on the platform to obtain 21Mn23AlSiMoV high manganese heat-resistant steel.

[0068] In this example, the AOD converter achieved a manganese recovery rate of 97.35% and an aluminum recovery rate of 82.08%, with a smelting cycle of 114 minutes and a total decarburization efficiency of 90.1%. This demonstrates the feasibility of using an AOD converter to smelt 21MnAlSiMoV high-manganese heat-resistant steel, with high decarburization efficiency and high Mn and Al metal recovery rates.

[0069] Example 3

[0070] 21MnAlSiMoV high manganese heat-resistant steel is smelted using a process of "dephosphorization converter + AOD converter + LF refining furnace".

[0071] The first step is to pretreat the blast furnace hot metal in a dephosphorization converter:

[0072] 1.1 Oxygen blowing and slagging stage: blast furnace molten iron is injected into the dephosphorization converter. The composition of the blast furnace molten iron, by weight percentage, is C 4.94%, Si 0.55%, Mn 0.84%, and P 0.056%. During the process, 0.5t of iron oxide scale, 1.2t of lightly calcined dolomite, 1.6t of active lime, 1.1t of quicklime, and 0.15t of fluorite are added, and oxygen is blown at 1240 Nm³. 3 Nitrogen 253 Nm 3 The basicity of binary slag is controlled at 2.2;

[0073] 1.2 Dephosphorization stage: Sampling and testing showed that the phosphorus content was 0.025% and the carbon content was 3.91%.

[0074] 1.3 Tapping: The temperature of the molten steel is 1433℃;

[0075] The second step involves smelting 21Mn23AlSiMoV high-manganese heat-resistant steel in an AOD converter:

[0076] 2.1 Adding lime: Add 3% lime by weight of molten steel to the AOD converter and add 1.3 molten steel. The composition of the molten steel entering the furnace is 3.67% C, 0.34% Mn, 0.015% P, and 0.023% S. The amount added is 86.5t and the temperature of entering the furnace is 1335℃.

[0077] 2.2 Main decarburization period: Add 25 kg / t of lime, blow an argon-oxygen mixture of O2:Ar=7:1 into the furnace, and blow with a top lance for 30 minutes until C is reduced to 0.70%;

[0078] 2.3 Manganese primary alloying: The temperature of molten steel is raised to 1600℃, the top lance blowing is cancelled, and side blowing oxygen supply is adopted. An argon-oxygen mixture of O2:Ar=3:1 is blown into the furnace and blown for 12 minutes. 69Kg / t of high-carbon ferromanganese and 20Kg / t of lime are added, and the carbon content is reduced to 0.4%.

[0079] 2.4 Dynamic decarburization period 1: Reduce the proportion of O2 in the side-blown oxygen supply mixture, blow an argon-oxygen mixture of O2:Ar=1:1 into the furnace, blow for 14 minutes, add 10 kg / t of lime, and decarburize to 0.25%;

[0080] 2.5 Dynamic decarburization period 2: Further reduce the proportion of O2 in the side-blown oxygen supply mixture, blow an argon-oxygen mixture of O2:Ar=1:2 into the furnace, blow for 10 minutes, add 10 kg / t of lime, and decarburize to 0.15%;

[0081] 2.6 Manganese secondary alloying: Continue to reduce the proportion of O2 in the side-blown oxygen-supplying mixed gas, blow an argon-oxygen mixed gas with O2:Ar=1:4 into the furnace, blow for 15 minutes, add 214.8 kg / t of electrolytic manganese in 3 batches, add 30 kg / t of lime at the same time, and add 3.5 kg / t of aluminum granules to each batch to raise the temperature and reduce the heat loss caused by melting the alloy. During this stage, control the ternary basicity of the slag to 3.0.

[0082] 2.7 Reduction period: 22.4 kg / t of aluminum granules and 4.7 kg / t of fluorite are added for slag deoxidation and aluminum alloying. Then, 3.8 kg / t of ferromolybdenum is added for reduction. After the reduction is completed, 50% of the slag is dumped, and temperature is measured and samples are taken. The composition is adjusted according to the test results. During this stage, the ternary basicity of the slag is controlled at 2.8.

[0083] 2.8 Tapping: Add 1.2 kg / t of ferrosilicon, stir evenly, and then tap and remove slag; the composition of the tapped steel is shown in Table 5.

[0084]

[0085] The third step involves adjusting the composition and temperature of the 21MnAlSiMoV high-manganese heat-resistant steel in the LF refining furnace:

[0086] 3.1 After the slag is removed in step 2.8, the molten steel is fed into the LF treatment station for slag treatment, temperature measurement and sampling. The content of C, Mn, Al and other components in the molten steel is adjusted according to the test results, and 0.8 kg / t ferrovanadium is added; the composition of the finished product is shown in Table 6.

[0087]

[0088] 3.2 After controlling the composition and temperature of the molten steel to the internal control range, 50m of calcium wire is fed in, the tapping temperature is 1481℃, and then the steel is weakly blown for 30 minutes before being cast on the platform to obtain 21Mn23AlSiMoV high manganese heat-resistant steel.

[0089] In this example, the AOD converter achieved a manganese recovery rate of 98.98% and an aluminum recovery rate of 82.23%, with a smelting cycle of 110 minutes and a total decarburization efficiency of 90.5%. This demonstrates the feasibility of using an AOD converter to smelt 21MnAlSiMoV high-manganese heat-resistant steel, with high decarburization efficiency and high Mn and Al metal recovery rates.

Claims

1. An AOD converter smelting process for 21Mn23AlSiMoV high-manganese heat-resistant steel, characterized in that, Includes the following steps: Step 1: Pre-treat blast furnace hot metal in a dephosphorization converter: a. Oxygen blowing and slag forming stage: blast furnace molten iron is injected into the dephosphorization converter, and iron oxide scale, lightly calcined dolomite, active lime, quicklime and fluorite are added according to the silicon content of blast furnace molten iron to carry out oxygen blowing and slag forming, and the binary basicity of slag is controlled to be 2.1-2.

2. b. Dephosphorization stage: Control P content ≤ 0.015%, C content 3.7-3.95%; c. Tapping: Control the temperature of molten steel to 1425-1440℃; Step 2: Smelting 21Mn23AlSiMoV high-manganese heat-resistant steel in an AOD converter: a. Adding lime: Add 3% of the weight of the molten steel to the molten steel in step one (c); b. Main decarburization period: Add lime, blow an argon-oxygen mixture of O2:Ar=7:1 into the furnace, and blow with a top lance to decarburize to 0.7-0.8%; c. Manganese primary alloying: The temperature of the molten steel is raised to 1600℃, oxygen is supplied from the side, and an argon-oxygen mixture of O2:Ar=3:1 is blown into the furnace. 51-69 kg / t of high-carbon ferromanganese and 15-20 kg / t of lime are added to decarburize to 0.4-0.5%. d. Dynamic decarburization period 1: Inject an argon-oxygen mixture of O2:Ar=1:1 into the furnace, add lime, and decarburize to 0.25%; e. Dynamic decarburization period 2: An argon-oxygen mixture of O2:Ar=1:2 is blown into the furnace, and lime is added to decarburize to 0.15%; f. Secondary alloying of manganese: Inject argon-oxygen mixed gas with O2:Ar=1:4 into the furnace, add 180-215 kg / t of electrolytic manganese in 3 batches, and add 20-30 kg / t of lime at the same time. During this stage, control the ternary basicity of the slag to 3.

0. g. Reduction period: Add 22-24 kg / t of aluminum granules and 4.5-6.5 kg / t of fluorite for slag deoxidation and aluminum alloying, then add 3.5-5.5 kg / t of ferromolybdenum for reduction. After reduction, 40-50% of the slag is dumped, and temperature is measured and samples are taken. The composition is adjusted according to the test results. During this stage, the ternary basicity of the slag is controlled at 2.3-2.

8. h. Tapping: Add 1-4.5 kg / t of ferrosilicon, stir evenly, then tap the steel and remove the slag; Step 3: Adjust the composition and temperature of 21MnAlSiMoV high-manganese heat-resistant steel in the LF refining furnace: a. After the slag is removed in step two (h), the molten steel enters the LF treatment station, where slag is melted, temperature is measured and samples are taken. The C, Mn and Al content in the molten steel is adjusted according to the test results, and 1.0 kg / t ferrovanadium is added. b. After adjusting the composition and temperature of the molten steel to the internal control range, feed in 50m of calcium wire, control the tapping temperature at 1470-1485℃, then blow weakly for 30 minutes before casting on the platform to obtain 21Mn23AlSiMoV high manganese heat-resistant steel.

2. The AOD converter smelting process for 21Mn23AlSiMoV high-manganese heat-resistant steel as described in claim 1, characterized in that, In step 2(b), the amount of lime added is 25-30 kg / t of molten steel.

3. The AOD converter smelting process for 21Mn23AlSiMoV high-manganese heat-resistant steel as described in claim 2, characterized in that, In step 2(b), the blowing time is 20-30 minutes.

4. The AOD converter smelting process for 21Mn23AlSiMoV high-manganese heat-resistant steel as described in claim 3, characterized in that, In step two (c), the blowing time is 10-12 minutes.

5. The AOD converter smelting process for 21Mn23AlSiMoV high-manganese heat-resistant steel as described in claim 4, characterized in that, In step two (d), the blowing time is 10-14 minutes, and the amount of lime added is 10 kg / t of molten steel.

6. The AOD converter smelting process for 21Mn23AlSiMoV high-manganese heat-resistant steel as described in claim 5, characterized in that, In step two (e), the blowing time is 8-10 minutes, and the amount of lime added is 10 kg / t of molten steel.

7. The AOD converter smelting process for 21Mn23AlSiMoV high-manganese heat-resistant steel as described in claim 6, characterized in that, In step two (f), the blowing time is 10-15 minutes.

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