A clean deoxidization process based on ACD technology

Abstract

The present application belongs to the technical field of steel metallurgy, and particularly relates to a clean deoxidization process based on ACD technology. According to the carbon content requirement of the steel grade, carbon powder is added to the liquid surface of the ladle during the converter tapping process to preliminarily deoxidize. After the tapping is completed, the ladle enters the LF refining station to perform re-deoxidization through ladle bottom argon blowing. Three deoxidizations are performed in the late argon blowing stage in cooperation with slag modification, and electrode temperature control is performed in the process. After the deoxidization and slag adjustment are completed, alloying operation is performed. The technology fully utilizes carbon + bottom argon blowing deoxidization, can greatly reduce or cancel the consumption of deoxidizing alloy, reduce the generation amount of inclusions, improve the cleanliness of the molten steel, and has good metallurgical effect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of steel metallurgy, and particularly relates to a clean deoxidization process based on ACD technology. BACKGROUND

[0002] Converter blowing oxygen is a main means for removing impurity elements, and at the end of smelting, the content of impurity elements in the molten steel is reduced to trace amount, but a large amount of free oxygen exists in the molten steel. Oxygen has great harm to the quality of steel, and needs to be treated by deoxidization, and common deoxidizers include Al, Si, Mn and the like, but the deoxidization products cannot be completely removed and are left in the molten steel, which will have adverse effects on the product quality.

[0003] Carbon, as a clean deoxidizer, can react with free oxygen in the steel to generate CO at high temperature, and is separated from the molten steel system, and will not cause impact on the cleanliness of the molten steel. However, due to the factors of reaction kinetics and thermodynamics, the deoxidization speed and deoxidization limit of carbon are less than those of Al, Si, Mn and the like. Many studies show that vacuum condition is helpful to improve the deoxidization capacity of carbon, and when the vacuum degree is low enough, the deoxidization capacity of carbon is even stronger than that of Al, Si, Mn and the like. However, vacuum treatment needs a specific reactor, such as a VD furnace, an RH furnace and the like, and the operation cost is also relatively high. SUMMARY

[0004] In order to solve the problems in the prior art, the main purpose of the present application is to provide a clean deoxidization process based on ACD (Argon Carbon deoxidation) technology.

[0005] In order to solve the above technical problems, according to one aspect of the present application, the present application provides the following technical scheme:

[0006] A clean deoxidization process based on ACD technology, wherein carbon powder is added for preliminary deoxidization during the converter tapping process, the ladle enters the LF station after the converter tapping, secondary deoxidization is carried out by bottom argon blowing, and the temperature of the molten steel is maintained by an electrode, and finally final deoxidization is carried out by white slag making.

[0007] As a preferred scheme of the clean deoxidization process based on ACD technology, the process comprises the following steps:

[0008] S1. Oxygen is determined at the end of converter smelting;

[0009] S2. Carbon deoxidization is carried out during the converter tapping;

[0010] S3. Argon gas is blown at the bottom of the LF for deoxidization;

[0011] S4. Diffusion deoxidization is carried out in the LF;

[0012] S5. Alloying is carried out in the LF;

[0013] S6. Soft blowing.

[0014] As a preferred scheme of the clean deoxidization process based on ACD technology, in the step S1, the free oxygen content of the molten steel is obtained by means of the oxygen analyzer at the end of the converter smelting, and the carbon powder addition amount is determined.

[0015] As a preferred scheme of the clean deoxidization process based on ACD technology, in the step S2, the carbon powder is added to deoxidize the molten steel during the tapping process, and the carbon powder addition amount W C The calculation formula is as follows:

[0016] W C = W steel ×(C target -C 出钢 -C alloy )×k,

[0017] Wherein, W steel is the converter tapping amount, C target is the target carbon content of the steel grade, C 出钢 is the carbon content of the molten steel at the end of the converter, C alloy is the carbon increase after adding alloy, and k is the carbon powder addition amount calculation constant, which is 0.8-0.9.

[0018] As a preferred scheme of the clean deoxidization process based on ACD technology, in the step S2, in order to ensure safe production and avoid explosive spatter, the tapping process is divided into three nodes, namely, the tapping amount reaches 1 / 4, the tapping amount reaches 1 / 2, and the tapping amount reaches 3 / 4; wherein the molten steel spreads on the bottom of the ladle to the tapping amount reaches 1 / 4 as the first stage, the tapping amount reaches 1 / 4 to the tapping amount reaches 1 / 2 as the second stage, and the tapping amount reaches 1 / 2 to the tapping amount reaches 3 / 4 as the third stage; the carbon powder addition amount of each stage is determined according to the free oxygen content of the molten steel, and the specific process is as follows:

[0019] When the free oxygen content is greater than 500ppm, the carbon powder addition proportions of the three stages are 15-25%, 25-35%, and 45-55% respectively;

[0020] When the free oxygen content is between 300-500ppm, the carbon powder addition proportions of the three stages are 25-35%, 25-35%, and 35-45% respectively;

[0021] When the free oxygen content is less than 300ppm, the carbon powder addition proportions of the three stages are 45-55%, 25-35%, and 15-25% respectively;

[0022] It is required to add uniformly at each stage, and the bottom blowing flow is controlled at the soft blowing level.

[0023] As a preferred scheme of the clean deoxidization process based on the ACD technology, in the step S2, the slagging agent is added through the bin when the tapping amount reaches 3 / 4, and the slagging agent is lime + synthetic slag.

[0024] As a preferred scheme of the clean deoxidization process based on the ACD technology, in the step S3, the secondary deoxidization is performed through the bottom argon blowing after the ladle enters the LF station; the ladle is a porous ladle, and the bottom blowing holes are uniformly distributed on the circumference of the ladle bottom surface at R / 2; the bottom argon blowing flow is increased in a step-by-step manner, and the bottom blowing flow is opened to the hard blowing degree after 5-12 minutes of bottom blowing; if the molten steel temperature decreases during the bottom blowing, the temperature is compensated through the electrode heating.

[0025] As a preferred scheme of the clean deoxidization process based on the ACD technology, in the step S4, the bottom blowing is performed for 45-55 minutes, and then the modifying agent is added into the ladle to reduce the oxidizability of the refining slag to form the reducing white slag, and the modifying agent is carbide + silicon carbide + aluminum particles.

[0026] As a preferred scheme of the clean deoxidization process based on the ACD technology, in the step S5, after the refining slag is formed into the reducing white slag, the alloying is performed through the alloy bin; after the alloying, whether the calcium treatment is required is selected according to the steel type requirement.

[0027] As a preferred scheme of the clean deoxidization process based on the ACD technology, in the step S6, after the alloying, the soft blowing operation is required for at least 10 minutes before the ladle is lifted to the continuous casting.

[0028] The beneficial effects of the present application are as follows:

[0029] The present application provides a clean deoxidization process based on the ACD technology, which does not use aluminum deoxidization in the tapping process, and the preliminary deoxidization is completed through the carbon after the converter, and the final deoxidization is performed through the bottom argon blowing and the reducing slag after the ladle enters the LF refining furnace. The process can effectively reduce or cancel the deoxidization alloy consumption, improve the cleanliness of the molten steel, and has good metallurgical effect. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained according to the structures shown in the drawings without creative labor for those skilled in the art.

[0031] Figure 1The flow chart of the clean deoxidization process based on the ACD technology of the present application.

[0032] Figure 2 The distribution diagram of the porous ladle bottom blowing hole.

[0033] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments will be described below clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0035] The present application makes full use of carbon as a clean deoxidizer, and performs preliminary deoxidization by adding carbon powder in the converter tapping process. Under the premise of not using vacuum treatment equipment, the secondary deoxidization of the molten steel is realized by cooperating with the ladle bottom argon blowing. The argon bubbles in the molten steel are equivalent to a small vacuum chamber, which can effectively promote the deoxidization reaction, achieve the purpose of deoxidization, thereby greatly reducing or canceling the consumption of deoxidizing alloy and reducing the generation of inclusions.

[0036] According to one aspect of the present application, the present application provides the following technical solutions:

[0037] As shown in Figure 1 The clean deoxidization process based on the ACD technology adds carbon powder for preliminary deoxidization in the converter tapping process. After the converter tapping, the ladle enters the LF station, and the secondary deoxidization is performed by the bottom argon blowing, and the molten steel temperature is maintained by the electrode. Finally, the white slag is made to perform the final deoxidization.

[0038] Preferably, the process comprises the following steps:

[0039] S1. Determining the oxygen content at the end of the converter smelting;

[0040] S2. Carbon deoxidization in the converter tapping;

[0041] S3. LF bottom argon blowing deoxidization;

[0042] S4. LF diffusion deoxidization;

[0043] S5. LF alloying;

[0044] S6. Soft blowing.

[0045] Preferably, in the step S1, at the end of the converter smelting, the free oxygen content of the molten steel is obtained by means of the oxygen content meter, and the amount of carbon powder added is determined.

[0046] Preferably, in the step S2, the carbon powder is added to the molten steel during tapping to deoxidize the molten steel, and the amount of the carbon powder added W C The calculation formula is as follows:

[0047] W C = W steel ×(C target -C 出钢 -C alloy )×k,

[0048] wherein W steel is the tapping amount of the converter, C target is the target carbon content of the steel grade, C 出钢 is the carbon content of the molten steel at the end point of the converter, C alloy is the carbon increment after adding the alloy, and k is a calculation constant of the amount of the carbon powder added, and is 0.8-0.9.

[0049] Preferably, in the step S2, in order to ensure safe production and avoid explosive spatter, the tapping process is divided into three nodes, i.e., the tapping amount reaches 1 / 4, the tapping amount reaches 1 / 2, and the tapping amount reaches 3 / 4; wherein the molten steel spreads on the bottom of the ladle to the tapping amount reaching 1 / 4 is the first stage, the tapping amount reaching 1 / 4 to the tapping amount reaching 1 / 2 is the second stage, and the tapping amount reaching 1 / 2 to the tapping amount reaching 3 / 4 is the third stage; the addition of the carbon powder in each stage is determined according to the free oxygen content of the molten steel, and is as follows:

[0050] When the free oxygen content is greater than 500 ppm, the addition proportions of the carbon powder in the three stages are 15-25%, 25-35%, and 45-55%, respectively;

[0051] When the free oxygen content is between 300-500 ppm, the addition proportions of the carbon powder in the three stages are 25-35%, 25-35%, and 35-45%, respectively;

[0052] When the free oxygen content is less than 300 ppm, the addition proportions of the carbon powder in the three stages are 45-55%, 25-35%, and 15-25%, respectively;

[0053] The carbon powder is required to be added at a uniform speed in each stage, and the bottom blowing flow rate is controlled at a soft blowing level (80-160 L / min).

[0054] Preferably, in the step S2, when the tapping amount reaches 3 / 4, a slagging agent is added through a bin, the slagging agent is selected to be lime + synthetic slag, the lime is added in an amount of 3-3.5 kg / t 钢 , and the synthetic slag is added in an amount of 4-5 kg / t 钢 . The main components of the synthetic slag are CaO: 42-53 wt%, and Al2O3: 36-45 wt%.

[0055] Preferably, in the step S3, the ladle enters the LF station and is subjected to secondary deoxidation by bottom argon blowing; the ladle is a multi-hole ladle, and the bottom blowing holes are uniformly distributed on the circumference of the ladle bottom surface at R / 2 (as shown in Figure 2 , and the number of the bottom blowing holes can be adjusted as needed); the bottom argon flow is increased in steps, and the flow is opened to the hard blowing degree after 5-12 minutes of bottom blowing, and the gas flow is 600-800 L / min; if the temperature of the molten steel decreases during the bottom blowing, the temperature is compensated by electrode heating.

[0056] Preferably, in the step S4, the bottom blowing is performed for 45-55 minutes, and then a modifying agent is added to the ladle to reduce the oxidizing property of the refining slag to form reducing white slag, the modifying agent is carbide + silicon carbide + aluminum particles, the addition amount of the carbide is 0.8-1.2 kg / t 钢 , the addition amount of the silicon carbide is 0.7-0.9 kg / t 钢 , and the addition amount of the aluminum particles is 0.2-0.5 kg / t 钢 .

[0057] Preferably, in the step S5, after the refining slag is formed into reducing white slag, alloying is performed through an alloy bin; after the alloying, whether to perform calcium treatment is selected according to the requirements of the steel grade.

[0058] Preferably, in the step S6, after the alloying, the ladle needs to be subjected to soft blowing for at least 10 minutes before being lifted to the continuous casting, and the gas flow is 80-160 L / min.

[0059] The technical scheme of the present application is further described below in combination with specific examples.

[0060] Example 1

[0061] This example is an application of a clean deoxidation process based on ACD technology in the production of 45 steel, and a 100 t top and bottom combined blowing converter is used for smelting, and the tapping amount is 85.7 t, including the following steps:

[0062] S1. After the converter smelting is completed, the oxygen content is determined by using an oxygen meter, and the free oxygen content of the molten steel is 582 ppm;

[0063] S2. The converter is tapped, and after the oxygen determination is completed, the addition amount of the carbon powder is calculated to be 285 kg. After the converter is tapped, the 285 kg of carbon powder is evenly added in three batches in three stages, and the addition amount of each stage is 60 kg, 85 kg and 140 kg respectively, and no obvious spatter is observed on the molten steel surface. When the tapping amount reaches 3 / 4, 290 kg of lime and 350 kg of synthetic slag are added through the bin, and after the tapping is completed, the ladle car is opened away from the tapping position and enters the LF station.

[0064] S3. Bottom argon blowing deoxidation, after the ladle enters the LF station, further deoxidation is carried out by bottom argon blowing, the bottom blowing flow is gradually increased, and after 10 minutes of bottom blowing, the bottom blowing flow is adjusted to the hard blowing level (800 L / min). During the bottom blowing process, the temperature is measured and the electrode heating method is used to ensure that the temperature of the molten steel meets the requirements.

[0065] S4. Refining slag modification and diffusion deoxidation, after 50 minutes of bottom blowing, 90 kg of carbide, 70 kg of silicon carbide and 20 kg of aluminum particles are added to the slag surface to form reducing white slag.

[0066] S5. After the white slag is formed, 574 kg of silicon manganese is added to the molten steel through the alloy bin. After the composition of the molten steel meets the requirements, 60 m of calcium wire is fed to ensure the smooth casting of the molten steel.

[0067] S6. Soft blowing, after the wire feeding, the ladle is transferred to the soft blowing area for soft blowing (100 L / min), and the soft blowing time is 10 minutes. After the soft blowing is completed, the on-site sampling and automatic scanning of inclusions are carried out.

[0068] This process ensures that the steel composition is qualified, and the Al usage is reduced by about 75% compared with the traditional process, and the number of inclusions in the molten steel before the LF hanging ladle is reduced by 43.5%.

[0069] Example 2

[0070] This example is an application of a clean deoxidation process based on ACD technology in the production of 45 steel, using a 100 t top and bottom combined blowing converter for smelting, with a tapping amount of 86.5 t, including the following steps:

[0071] S1. Converter smelting end oxygen, the free oxygen content of the molten steel is 386 ppm;

[0072] S2. Converter tapping, after the oxygen setting is completed, the carbon powder addition amount is calculated as 220 kg, after the converter tapping starts, 220 kg of carbon powder is evenly added in three batches in three stages, and the addition amount of each stage is 70 kg, 70 kg and 80 kg respectively. When the tapping amount reaches 3 / 4, 300 kg of lime and 350 kg of refined synthetic slag are added through the bin, and after the tapping is completed, the ladle car is opened away from the tapping position and enters the LF station.

[0073] S3. Bottom argon blowing deoxidation, after the ladle enters the LF station, further deoxidation is carried out by bottom argon blowing, the bottom blowing flow is gradually increased, and after 5 minutes of bottom blowing, the bottom blowing flow is adjusted to the hard blowing level (800 L / min). During the bottom blowing process, the temperature is measured and the electrode heating method is used to ensure that the temperature of the molten steel meets the requirements,

[0074] S4. Refining slag modification and diffusion deoxidation, after 55 minutes of bottom blowing, 100 kg of carbide, 70 kg of silicon carbide and 20 kg of aluminum particles are added to the slag surface.

[0075] S5. Alloying, after the modification of the refining slag is completed, 584 kg of silicon manganese is added to the molten steel through the alloy bin to adjust the composition of the molten steel to the target range of the process card. In order to ensure the smooth casting of the molten steel, 55 m of calcium wire is fed.

[0076] S6. After the wire feeding, the ladle is transferred to the soft blowing area for soft blowing, and the soft blowing time is 12 min. After the soft blowing is completed, on-site sampling and automatic scanning of inclusions are performed.

[0077] This process reduces the Al usage by about 82% compared to the traditional process while ensuring that the steel composition is qualified, and the number of inclusions in the molten steel before LF ladle is reduced by 48.3%.

[0078] Example 3

[0079] This example is an application of a clean deoxidation process based on ACD technology in the production of 55 steel. A 100 t top and bottom combined blown converter is used for smelting, and the tapping amount is 87.5 t, including the following steps:

[0080] S1. The converter smelting is completed, and the free oxygen content of the molten steel is 471 ppm;

[0081] S2. Converter tapping, after the oxygen setting is completed, the carbon powder addition amount is calculated as 260 kg, and 260 kg of carbon powder is added evenly in three batches at three stages, with an addition amount of 80 kg, 80 kg, and 100 kg respectively. When the tapping amount reaches 3 / 4, 300 kg of lime and 360 kg of synthetic slag are added through the bin, and after the tapping is completed, the ladle car is opened away from the tapping position and enters the LF position.

[0082] S3. Bottom blowing argon deoxidation, after the ladle enters the LF position, bottom blowing argon is used for further deoxidation, and the bottom blowing flow is gradually increased. After 8 min of bottom blowing, the bottom blowing flow is adjusted to the hard blowing level (800 L / min). During the bottom blowing process, the temperature is measured and the electrode heating method is used to ensure that the temperature of the molten steel meets the requirements,

[0083] S4. Refining slag modification and diffusion deoxidation, 100 kg of calcium carbide, 75 kg of silicon carbide, and 20 kg of aluminum particles are added to the slag surface after 55 min of bottom blowing.

[0084] S5. Alloying, after the modification of the refining slag is completed, 568 kg of silicon manganese is added to the molten steel through the alloy bin. In order to ensure the smooth casting of the molten steel, 60 m of calcium wire is fed.

[0085] S6. After the wire feeding, the ladle is transferred to the soft blowing area for soft blowing, and the soft blowing time is 12 min. After the soft blowing is completed, on-site sampling and automatic scanning of inclusions are performed.

[0086] This process reduces the use of Al by about 82% compared with the traditional process, and reduces the number of inclusions in the molten steel before LF ladle by 42% under the premise of ensuring the composition of the steel.

[0087] Comparative Example 1

[0088] This comparative example is the application of a clean deoxidation process based on ACD technology in the production of 55 steel. The 100 t top and bottom combined blown converter is used for smelting, and the tapping amount is 85.5 t, including the following steps:

[0089] S1. The oxygen content of the molten steel is determined at the end of the converter smelting, and the free oxygen content is 456 ppm;

[0090] S2. Converter tapping, after the end of oxygen determination, the amount of carbon powder added is calculated as 255 kg, and 255 kg of carbon powder is added in three batches in three stages, and the amount of each stage is 75 kg, 75 kg and 105 kg. When the tapping amount reaches 3 / 4, 290 kg of lime and 360 kg of synthetic slag are added through the bin, and after the tapping is completed, the ladle car is opened away from the tapping position and enters the LF position.

[0091] S3. Bottom blowing argon deoxidation, after the ladle enters the LF position, further deoxidation is carried out by bottom blowing argon, and the bottom blowing flow is gradually increased. After 10 min of bottom blowing, the bottom blowing flow is adjusted to 400 L / min. During the bottom blowing process, the temperature is measured and the electrode heating method is used to ensure that the temperature of the molten steel meets the requirements.

[0092] S4. Refining slag modification and diffusion deoxidation, 100 kg of carbide, 75 kg of silicon carbide and 40 kg of aluminum particles are added to the slag surface after 75 min of bottom blowing.

[0093] S5. Alloying, after the modification of the refining slag is completed, 567 kg of silicon manganese is added to the molten steel through the alloy bin. In order to ensure the smooth casting of the molten steel, 55 m of calcium wire is fed.

[0094] S6. After the wire feeding, the ladle is transferred to the soft blowing area for soft blowing, and the soft blowing time is 15 min. After the soft blowing is completed, the on-site sampling and automatic scanning of inclusions are carried out.

[0095] In this comparative example, the bottom blowing argon deoxidation stage takes too long due to insufficient bottom blowing flow, reaching 75 min, which slows down the smelting rhythm. In addition, the Al consumption and the reduction effect of the number of inclusions are not as good as the above-mentioned examples. The use of Al is reduced by about 50% compared with the traditional process, and the number of inclusions in the molten steel before LF ladle is reduced by 19%.

[0096] Comparative Example 2

[0097] The present comparative example is an application of a clean deoxidization process based on ACD technology in 45 steel production, using a 100 t top and bottom combined blowing converter with a tapping capacity of 86.7 t, including the following steps:

[0098] S1. After the end of the converter smelting, the oxygen content of the molten steel is determined by an oxygen analyzer, and the free oxygen content is 462 ppm;

[0099] S2. Converter tapping, after the end of oxygen determination, the carbon powder addition amount is calculated as 257 kg. After the start of converter tapping, the carbon powder is uniformly added to the ladle. When the tapping amount reaches 3 / 4, 300 kg of lime and 350 kg of fine combined slag are added through the bin, and after the end of tapping, the ladle car is opened away from the tapping position and enters the LF position.

[0100] S3. Bottom argon blowing deoxidization, the bottom blowing flow rate is always maintained at a hard blowing level (700 L / min) from the start of converter tapping.

[0101] S4. Refining slag modification and diffusion deoxidization, 100 kg of calcium carbide, 75 kg of silicon carbide and 30 kg of aluminum particles are added to the slag surface after 55 min of bottom blowing to form reducing white slag.

[0102] S5. After the formation of white slag, 568 kg of silicon manganese is added to the molten steel through the alloy bin. After the composition of the molten steel meets the requirements, 60 m of calcium wire is fed to ensure the smooth casting of the molten steel.

[0103] S6. Soft blowing, after the wire feeding, the ladle is transferred to the soft blowing area for soft blowing (100 L / min), and the soft blowing time is 10 min.

[0104] In this comparative example, after the end of oxygen determination, the carbon powder addition strategy is not adjusted according to the oxygen value, resulting in excessive carbon powder addition in the early stage under high oxygen molten steel conditions, and the steel liquid in the ladle is boiling, and the molten steel droplets splash seriously, which is not conducive to safe production.

[0105] In the present application, aluminum deoxidization is not used during tapping, and preliminary deoxidization is completed by carbon after the converter, and final deoxidization is carried out by bottom argon blowing and reducing slag formation after the ladle enters the LF refining furnace. This process can effectively reduce or eliminate the consumption of deoxidizing alloy, improve the cleanliness of the molten steel, and has good metallurgical effect.

[0106] The above only describes the preferred embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation made by using the content of the present application specification, or direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A clean deoxygenation process based on ACD technology, characterized in that, Carbon powder is added during the converter tapping process for preliminary deoxidation. After the converter tapping, the ladle enters the LF station, where it undergoes secondary deoxidation by bottom blowing argon gas and the temperature of the molten steel is maintained by electrodes. Finally, white slag is produced for final deoxidation. The process includes the following steps: S1. Oxygen determination after converter smelting; S2. Converter tapping carbon deoxidation; the tapping process is divided into three stages: tapping volume reaches 1 / 4, tapping volume reaches 1 / 2, and tapping volume reaches 3 / 4; the first stage is from when the molten steel fills the bottom of the ladle to when the tapping volume reaches 1 / 4; the second stage is from when the tapping volume reaches 1 / 4 to when the tapping volume reaches 1 / 2; and the third stage is from when the tapping volume reaches 1 / 2 to when the tapping volume reaches 3 / 4. The amount of carbon powder added in each stage is determined based on the free oxygen content of the molten steel, as detailed below: The free oxygen content is greater than 500 ppm, and the toner addition ratios for the three stages are 15~25%, 25~35%, and 45~55%, respectively. The free oxygen content is between 300 and 500 ppm, and the toner addition ratios for the three stages are 25-35%, 25-35%, and 35-45%, respectively. The free oxygen content is less than 300 ppm, and the toner addition ratios for the three stages are 45-55%, 25-35%, and 15-25%, respectively. Toner is added at a uniform rate at each stage, and the bottom blowing flow rate is controlled at the soft blowing level. S3.LF bottom blowing argon deoxygenation; S4.LF diffusion deoxygenation; S5.LF alloying; S6. Soft blow.

2. The clean deoxygenation process based on ACD technology according to claim 1, characterized in that, In step S1, at the end of the converter smelting, the free oxygen content of the molten steel is obtained by using an oxygen analyzer to determine the amount of carbon powder to be added.

3. The clean deoxygenation process based on ACD technology according to claim 1, characterized in that, In step S2, during the tapping process, carbon powder is added to deoxidize the molten steel. The amount of carbon powder added is W. C The calculation formula is as follows: W C =W steel ×( C target - C 出钢 - C alloy )×k, Among them, W steel C represents the steel output from the converter. target For the target carbon content of the steel grade, C 出钢 C represents the carbon content of the molten steel at the final stage of the converter process. alloy The carbon increase after the alloy is added is denoted by k, which is a constant for calculating the amount of carbon powder added, and its value is 0.8~0.

9.

4. The clean deoxygenation process based on ACD technology according to claim 1, characterized in that, In step S2, when the steel output reaches 3 / 4, a slag-forming agent is added through the silo. The slag-forming agent is selected as lime + refining synthetic slag.

5. The clean deoxygenation process based on ACD technology according to claim 1, characterized in that, In step S3, after the ladle enters the LF station, it undergoes secondary deoxidation by bottom blowing argon. The ladle is a multi-hole ladle, with bottom blowing holes evenly distributed on the circumference at R / 2 of the bottom surface of the ladle. The bottom blowing argon flow rate is increased in a step-by-step manner, and after bottom blowing for 5~12 minutes, the bottom blowing flow rate is increased to the level of hard blowing. If the temperature of the molten steel drops during the bottom blowing process, it is replenished by electrode heating.

6. The clean deoxygenation process based on ACD technology according to claim 1, characterized in that, In step S4, bottom blowing is performed for 45-55 minutes, after which a modifier is added to the ladle to reduce the oxidizing properties of the refining slag and create reducing white slag. The modifier is calcium carbide + silicon carbide + aluminum particles.

7. The clean deoxygenation process based on ACD technology according to claim 1, characterized in that, In step S5, after the refining slag is converted into reducing white slag, it is alloyed through an alloy silo; after alloying, it is selected whether to perform calcium treatment according to the steel grade requirements.

8. The clean deoxygenation process based on ACD technology according to claim 1, characterized in that, In step S6, after alloying, the ladle needs to undergo a soft blowing operation for at least 10 minutes before being hoisted to the continuous casting station.

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