Clean deoxidation process based on ACD technology

Abstract

The invention belongs to the technical field of ferrous metallurgy, and particularly relates to a clean deoxidation process based on an ACD technology, which comprises the following steps of: adding carbon powder into the liquid level of a steel ladle in the tapping process of a converter according to the carbon content requirement of a steel grade after the converter; and after tapping is finished, the steel ladle enters an LF refining station, argon is blown from the bottom of the steel ladle for re-deoxidation, in the later period of argon blowing, the matched slag is modified for three times of deoxidation, and the temperature is controlled through an electrode in the process. And after deoxidation and slag adjustment are finished, alloying operation is carried out. According to the technology, carbon and argon bottom blowing are fully utilized for deoxidation, consumption of deoxidation alloy can be greatly reduced or eliminated, the generation amount of inclusions is reduced, the cleanliness of molten steel is improved, and a good metallurgical effect is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of iron and steel metallurgy, and specifically is a clean deoxidation process based on ACD technology. Background Art

[0002] Blowing oxygen in the converter is the main means of removing impurity elements. At the end of smelting, the content of impurity elements in the molten steel is reduced to trace amounts, but there is a large amount of free oxygen in the molten steel. Oxygen is extremely harmful to the quality of steel and needs to be deoxidized. Commonly used deoxidizers include Al, Si, Mn, etc., but their deoxidation products cannot be completely removed and remain in the molten steel, which will have an adverse effect on product quality.

[0003] As a clean deoxidizer, carbon can react with free oxygen in steel at high temperatures to generate CO, which will be separated from the molten steel system without affecting the cleanliness of the molten steel. However, limited by reaction kinetics and thermodynamic factors, the deoxidation rate and deoxidation limit of carbon are lower than those of Al, Si, Mn, etc. Many studies have shown that vacuum conditions help improve the deoxidation ability of carbon. When the vacuum degree is low enough, the deoxidation ability of carbon is even stronger than that of Al, Si, Mn, etc. However, vacuum treatment requires specific reactors, such as VD furnaces, RH furnaces, etc., and its operating costs are also relatively high. Summary of the invention

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

[0005] To solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solutions:

[0006] A clean deoxidation process based on ACD technology. Carbon powder is added during the converter steelmaking process for preliminary deoxidation. After the converter steelmaking, the ladle enters the LF station for secondary deoxidation by bottom blowing argon and maintaining the temperature of the molten steel with electrodes. Finally, white slag is made for final deoxidation.

[0007] As a preferred solution of the clean deoxidation process based on ACD technology described in the present invention, the process includes the following steps:

[0008] S1. Oxygen determination after converter smelting;

[0009] S2. Carbon deoxidation of converter steel;

[0010] S3.LF bottom blowing argon deoxidation;

[0011] S4.LF diffusion deoxidation;

[0012] S5.LF alloying;

[0013] S6. Soft blowing.

[0014] As a preferred solution of the clean deoxidation process based on ACD technology described in the present invention, wherein: in the step S1, when the converter smelting is completed, the free oxygen content of the molten steel is obtained by means of an oxygen meter to determine the amount of carbon powder to be added.

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

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

[0017] Among them, W steel is the output of converter steel, C target is the target carbon content of the steel grade, C 出钢 is the carbon content of the final steel liquid in the converter, C alloy is the amount of carbon added after the alloy is added, and k is the calculation constant for the amount of carbon powder added, with a value of 0.8 to 0.9.

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

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

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

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

[0022] It is required to add at a uniform speed in each stage and control the bottom blowing flow rate at the soft blowing level.

[0023] As a preferred solution of the clean deoxidation process based on ACD technology described in the present invention, wherein: in the step S2, when the steel output reaches 3 / 4, a slag-making agent is added through the silo, and the slag-making agent is selected from lime + refined synthetic slag.

[0024] As a preferred scheme of the clean deoxidation process based on ACD technology described in the present invention, wherein: in the step S3, after the ladle enters the LF station, secondary deoxidation is carried out by bottom blowing argon; the ladle adopts a porous ladle, and the bottom blowing holes are evenly distributed on the circumference of the bottom surface of the ladle at R / 2; the bottom blowing argon flow rate is increased in a step-by-step manner, and the bottom blowing flow rate is opened to the hard blowing level after 5 to 12 minutes of bottom blowing; if the temperature of the molten steel drops during the bottom blowing process, it is supplemented by electrode heating.

[0025] As a preferred scheme of the clean deoxidation process based on ACD technology described in the present invention, wherein: in the step S4, bottom blowing is performed for 45 to 55 minutes, and then a modifier is added to the ladle to reduce the oxidizability of the refined slag to produce reducing white slag, and the modifier is calcium carbide + silicon carbide + aluminum particles.

[0026] As a preferred solution of the clean deoxidation process based on ACD technology described in the present invention, wherein: in the step S5, after the refining slag is made into reducing white slag, alloying is carried out through an alloy silo; after alloying, whether to perform calcium treatment is selected according to the steel grade requirements.

[0027] As a preferred solution of the clean deoxidation process based on ACD technology described in the present invention, in said step S6, after alloying, the ladle needs to be soft-blown for at least 10 minutes before being hung for continuous casting.

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

[0029] The present invention proposes a clean deoxidation process based on ACD technology. In the steel-making process, aluminum deoxidation is not used. Initial deoxidation is completed by carbon after the converter. After the ladle enters the LF refining furnace, final deoxidation is performed by bottom blowing argon and making reducing slag. This process can effectively reduce or eliminate the consumption of deoxidation alloys, improve the cleanliness of molten steel, and has good metallurgical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0031] Figure 1It is a schematic diagram of the process of the clean deoxidation process based on ACD technology of the present invention.

[0032] Figure 2 Schematic diagram of the distribution of bottom blowing holes in a porous ladle.

[0033] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0034] The following will be described clearly and completely in conjunction with the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] The present invention makes full use of carbon as a clean deoxidizer, performs preliminary deoxidation by adding carbon powder during the converter steel tapping process, and realizes secondary deoxidation of molten steel by blowing argon gas from the bottom of the ladle without using vacuum treatment equipment. Argon bubbles in the molten steel are equivalent to small vacuum chambers, which can effectively promote the deoxidation reaction and achieve the purpose of deoxidation, thereby greatly reducing or eliminating the consumption of deoxidation alloys and reducing the generation of inclusions.

[0036] According to one aspect of the present invention, the present invention provides the following technical solution:

[0037] like Figure 1 As shown in the figure, a clean deoxidation process based on ACD technology is used. Carbon powder is added during the converter steelmaking process for preliminary deoxidation. After the converter steelmaking, the ladle enters the LF station, and secondary deoxidation is carried out by bottom blowing argon gas and the temperature of the molten steel is maintained by electrodes. Finally, final deoxidation is carried out by making white slag.

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

[0039] S1. Oxygen determination after converter smelting;

[0040] S2. Carbon deoxidation of converter steel;

[0041] S3.LF bottom blowing argon deoxidation;

[0042] S4.LF diffusion deoxidation;

[0043] S5.LF alloying;

[0044] S6. Soft blowing.

[0045] Preferably, in step S1, when converter smelting is finished, the free oxygen content of the molten steel is obtained by means of an oxygen meter to determine the amount of carbon powder to be added.

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

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

[0048] Among them, W steel is the output of converter steel, C target is the target carbon content of the steel grade, C 出钢 is the carbon content of the final steel liquid in the converter, C alloy is the amount of carbon added after the alloy is added, and k is the calculation constant for the amount of carbon powder added, with a value of 0.8 to 0.9.

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

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

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

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

[0053] It is required to add at a uniform speed in each stage and control the bottom blowing flow rate at the soft blowing level (80-160L / min).

[0054] Preferably, in step S2, when the steel output reaches 3 / 4, a slag-making agent is added through the silo, and the slag-making agent is lime + refined synthetic slag, and the amount of lime added is 3-3.5 kg / t 钢 , the amount of refined synthetic slag added is 4-5kg / t 钢 The refined synthetic slag is mainly composed of CaO: 42-53wt%, Al2O3: 36-45wt%.

[0055] Preferably, in step S3, the ladle is subjected to secondary deoxidation by bottom blowing argon after entering the LF station; the ladle is a porous ladle, and the bottom blowing holes are evenly distributed on the circumference of the bottom surface of the ladle at R / 2 (such as Figure 2 As shown, taking 4 bottom blowing holes as an example, the number of bottom blowing holes can be adjusted as needed); the bottom blowing argon flow rate is increased in a step-by-step manner. After 5 to 12 minutes of bottom blowing, the bottom blowing flow rate is opened to the hard blowing level, and the gas flow rate is 600 to 800 L / min; if the temperature of the molten steel drops during the bottom blowing process, it is heated by electrode heating.

[0056] Preferably, in step S4, bottom blowing is performed for 45 to 55 minutes, and then a modifier is added to the ladle to reduce the oxidizability of the refined slag to produce reducing white slag, the modifier is calcium carbide + silicon carbide + aluminum particles, and the amount of calcium carbide added is 0.8 to 1.2 kg / t 钢 , the amount of silicon carbide added is 0.7~0.9kg / t 钢 , the amount of aluminum particles added is 0.2~0.5kg / t 钢 .

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

[0058] Preferably, in step S6, after alloying, the ladle needs to be soft-blown for at least 10 minutes before being hoisted for continuous casting, with a gas flow rate of 80 to 160 L / min.

[0059] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0060] Example 1

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

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

[0063] S2. After the converter tapping, the amount of carbon powder added is calculated to be 285kg. After the converter tapping begins, 285kg of carbon powder is added evenly in three batches in three stages, with the amount added in each stage being 60kg, 85kg, and 140kg respectively. No obvious splashing is observed on the molten steel surface. When the tapping volume reaches 3 / 4, 290kg of lime and 350kg of refined synthetic slag are added through the silo. After the tapping is completed, the ladle car leaves the tapping position and enters the LF station.

[0064] S3. Bottom blowing argon deoxidation. After the ladle enters the LF station, argon is blown from the bottom for further deoxidation. The bottom blowing flow rate is gradually increased. After 10 minutes of bottom blowing, the bottom blowing flow rate is adjusted to the hard blowing level (800L / min). During the bottom blowing process, temperature measurement and electrode heating are used to ensure that the molten steel temperature meets the requirements.

[0065] S4. The refined slag is modified and diffused for deoxidation. After bottom blowing for 50 minutes, 90kg of calcium carbide, 70kg of silicon carbide and 20kg of aluminum particles are added to the slag surface to produce reducing white slag.

[0066] S5. After making white slag, add 574kg of silicon manganese into the molten steel through the alloy silo. After the molten steel composition meets the requirements, in order to ensure the smooth casting of the molten steel, feed 60m of calcium wire.

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

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

[0069] Example 2

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

[0071] S1. Oxygen determination after converter smelting, free oxygen content of molten steel is 386ppm;

[0072] S2. After the converter tapping, the amount of carbon powder added is calculated to be 220kg. After the converter tapping begins, 220kg of carbon powder is added evenly in three batches in three stages, with the amount added in each stage being 70kg, 70kg, and 80kg respectively. When the tapping volume reaches 3 / 4, 300kg of lime and 350kg of refined synthetic slag are added through the silo. After the tapping is completed, the ladle car leaves the tapping position and enters the LF station.

[0073] S3. Bottom blowing argon deoxidation. After the ladle enters the LF station, argon is blown from the bottom for further deoxidation. The bottom blowing flow rate is gradually increased. After 5 minutes of bottom blowing, the bottom blowing flow rate is adjusted to the hard blowing level (800L / min). During the bottom blowing process, temperature measurement and electrode heating are used to ensure that the temperature of the molten steel meets the requirements.

[0074] S4. After the refined slag is modified and diffused for deoxidation, 100kg of calcium carbide, 70kg of silicon carbide and 20kg of aluminum particles are added to the slag surface after bottom blowing for 55 minutes.

[0075] S5. Alloying, after completing the reform of the refined slag, add 584kg of silicon and manganese to the molten steel through the alloy silo 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, feed 55m of calcium wire.

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

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

[0078] Example 3

[0079] This embodiment is an application of a clean deoxidation process based on ACD technology in the production of 55 steel, using a 100t top and bottom combined blowing converter for smelting, with a steel output of 87.5t, including the following steps:

[0080] S1. Oxygen determination after converter smelting, free oxygen content of molten steel is 471ppm;

[0081] S2. After the converter tapping, the amount of carbon powder added is calculated to be 260kg. 260kg of carbon powder is added evenly in three batches in three stages, with the amount added in each stage being 80kg, 80kg, and 100kg respectively. When the tapping volume reaches 3 / 4, 300kg of lime and 360kg of refined synthetic slag are added through the silo. After the tapping is completed, the ladle car leaves the tapping position and enters the LF station.

[0082] S3. Bottom blowing argon deoxidation. After the ladle enters the LF station, argon is blown from the bottom for further deoxidation. The bottom blowing flow rate is gradually increased. After 8 minutes of bottom blowing, the bottom blowing flow rate is adjusted to the hard blowing level (800L / min). During the bottom blowing process, temperature measurement and electrode heating are used to ensure that the temperature of the molten steel meets the requirements.

[0083] S4. After the refined slag is modified and diffused for deoxidation, 100kg of calcium carbide, 75kg of silicon carbide and 20kg of aluminum particles are added to the slag surface after bottom blowing for 55 minutes.

[0084] S5. Alloying, after completing the reform of the refined slag, add 568kg of silicon manganese to the molten steel through the alloy silo. In order to ensure the smooth casting of the molten steel, feed 60m of calcium wire.

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

[0086] This process reduces the amount of Al used by about 82% compared with the traditional process while ensuring that the steel composition is qualified, and reduces the number of inclusions in the molten steel before LF ladle hanging by 42%.

[0087] Comparative Example 1

[0088] This comparative example is an application of a clean deoxidation process based on ACD technology in the production of 55 steel, using a 100t top and bottom combined blowing converter for smelting, with a steel output of 85.5t, and includes the following steps:

[0089] S1. Oxygen determination after converter smelting, free oxygen content of molten steel is 456ppm;

[0090] S2. After the converter tapping, the amount of carbon powder added is calculated to be 255kg. 255kg of carbon powder is added evenly in three batches in three stages, with the amount added in each stage being 75kg, 75kg, and 105kg respectively. When the tapping volume reaches 3 / 4, 290kg of lime and 360kg of refined synthetic slag are added through the silo. After the tapping is completed, the ladle car leaves the tapping position and enters the LF station.

[0091] S3. Bottom blowing argon deoxidation. After the ladle enters the LF station, argon is blown at the bottom for further deoxidation. The bottom blowing flow rate is gradually increased. After 10 minutes of bottom blowing, the bottom blowing flow rate is adjusted to 400L / min. During the bottom blowing process, temperature measurement and electrode heating are used to ensure that the molten steel temperature meets the requirements.

[0092] S4. After the refined slag is modified and diffused for deoxidation, 100kg of calcium carbide, 75kg of silicon carbide and 40kg of aluminum particles are added to the slag surface after bottom blowing for 75 minutes.

[0093] S5. Alloying, after completing the reform of the refined slag, add 567kg of silicon manganese to the molten steel through the alloy silo. In order to ensure the smooth casting of the molten steel, feed 55m of calcium wire.

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

[0095] In this comparative example, the deoxidation process took too long to reach 75 minutes due to insufficient bottom blowing flow rate during the bottom blowing argon deoxidation stage, which slowed down the smelting rhythm. In addition, the reduction effect of Al consumption and the number of inclusions was not as good as that of the above embodiment. The amount of Al used was reduced by about 50% compared with the traditional process, and the number of inclusions in the molten steel before the LF ladle was reduced by 19%.

[0096] Comparative Example 2

[0097] This comparative example is an application of a clean deoxidation process based on ACD technology in the production of 45 steel, using a 100t top and bottom combined blowing converter for smelting, with a steel output of 86.7t, including the following steps:

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

[0099] S2. After the converter tapping is completed and the oxygen setting is completed, the amount of carbon powder added is calculated to be 257kg. After the converter tapping begins, carbon powder is added to the ladle at a uniform speed. When the tapping volume reaches 3 / 4, 300kg of lime and 350kg of refined synthetic slag are added through the silo. After the tapping is completed, the ladle car leaves the tapping position and enters the LF position.

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

[0101] S4. The refined slag is modified and diffused for deoxidation. After bottom blowing for 55 minutes, 100kg of calcium carbide, 75kg of silicon carbide and 30kg of aluminum particles are added to the slag surface to produce reducing white slag.

[0102] S5. After making white slag, add 568kg of silicon manganese into the molten steel through the alloy silo. After the molten steel composition meets the requirements, in order to ensure the smooth casting of the molten steel, feed 60m of calcium wire.

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

[0104] After the oxygen setting was completed, the strategy of adding carbon powder in this comparative example was not adjusted according to the oxygen setting value, resulting in an excessive amount of carbon powder added in the early stage under high-oxygen molten steel conditions. In addition, the bottom blowing was still in a hard blowing state, the molten steel in the ladle was obviously boiling, and the molten steel droplets splashed severely, which was not conducive to safe production.

[0105] The present invention does not use aluminum deoxidation during the steel-making process. The primary deoxidation is completed by carbon after the converter, and the final deoxidation is carried out by bottom blowing argon and making reducing slag after the ladle enters the LF refining furnace. This process can effectively reduce or eliminate the consumption of deoxidation alloy, improve the cleanliness of molten steel, and has good metallurgical effects.

[0106] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A clean deoxidation process based on ACD technology, It is characterized in that Carbon powder is added during the converter steelmaking process for preliminary deoxidation. After the converter steelmaking process, the ladle enters the LF station for secondary deoxidation by bottom blowing argon and using electrodes to maintain the temperature of the molten steel. Finally, final deoxidation is carried out by making white slag.

2. The clean deoxidation process based on ACD technology according to claim 1, It is characterized in that The process comprises the following steps: S1. Oxygen determination after converter smelting; S2. Carbon deoxidation of converter steel; S3.LF bottom blowing argon deoxidation; S4.LF diffusion deoxidation; S5.LF alloying; S6. Soft blowing.

3. The clean deoxidation process based on ACD technology according to claim 2, It is characterized in that In the step S1, when the converter smelting is finished, the free oxygen content of the molten steel is obtained by means of an oxygen meter to determine the amount of carbon powder to be added.

4. The clean deoxidation process based on ACD technology according to claim 2, It is characterized in that In step S2, during the steel 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 is the output of converter steel, C target is the target carbon content of the steel grade, C 出钢 is the carbon content of the final steel liquid in the converter, C alloy is the amount of carbon added after the alloy is added, and k is the calculation constant for the amount of carbon powder added, with a value of 0.8 to 0.

9.

5. The clean deoxidation process based on ACD technology according to claim 2, It is characterized in that In step S2, the steel tapping process is divided into three nodes, the steel tapping reaches 1 / 4, the steel tapping reaches 1 / 2 and the steel tapping reaches 3 / 4; the first stage is when the molten steel covers the bottom of the ladle until the steel tapping reaches 1 / 4, the second stage is when the steel tapping reaches 1 / 4 to 1 / 2, and the third stage is when the steel tapping reaches 1 / 2 to 3 / 4; the addition of carbon powder in each stage is determined according to the free oxygen content of the molten steel, as follows: The free oxygen content is greater than 500ppm, and the proportions of carbon powder added in the three stages are 15-25%, 25-35%, and 45-55% respectively; The free oxygen content is between 300 and 500 ppm, and the proportions of carbon powder added in the three stages are 25-35%, 25-35%, and 35-45% respectively; The free oxygen content is less than 300ppm, and the proportions of carbon powder added in the three stages are 45-55%, 25-35%, and 15-25% respectively; Carbon powder is added at a uniform speed in each stage, and the bottom blowing flow rate is controlled at the soft blowing level.

6. The clean deoxidation process based on ACD technology according to claim 2, It is characterized in that In the step S2, when the steel output reaches 3 / 4, a slag-making agent is added through the silo, and the slag-making agent is selected from lime+refined synthetic slag.

7. The clean deoxidation process based on ACD technology according to claim 2, It is characterized in that In the step S3, after the ladle enters the LF station, secondary deoxidation is performed by bottom blowing argon; the ladle adopts a porous ladle, and the bottom blowing holes are evenly distributed on the circumference of the bottom surface of the ladle at R / 2; the bottom blowing argon flow rate is increased in a step-by-step manner, and the bottom blowing flow rate is opened to the hard blowing level after 5 to 12 minutes of bottom blowing; if the temperature of the molten steel drops during the bottom blowing process, it is supplemented by electrode heating.

8. The clean deoxidation process based on ACD technology according to claim 2, It is characterized in that In step S4, bottom blowing is performed for 45 to 55 minutes, and then a modifier is added to the ladle to reduce the oxidizability of the refined slag to produce reducing white slag, and the modifier is calcium carbide + silicon carbide + aluminum particles.

9. The clean deoxidation process based on ACD technology according to claim 2, It is characterized in that In step S5, after the slag is refined to produce reducing white slag, alloying is performed through an alloy silo; after alloying, whether calcium treatment is performed is selected according to the steel grade requirements.

10. The clean deoxidation process based on ACD technology according to claim 2, It is characterized in that In step S6, after alloying, the ladle needs to be soft-blown for at least 10 minutes before being hoisted for continuous casting.

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