A low-cost high-purity controlled stamping low-carbon steel production method

Abstract

The application discloses a low-cost high-cleanliness controlled stamping low-carbon steel production method and belongs to the technical field of steel metallurgy and steelmaking process. The method is suitable for a BOF+RH short process clean smelting process with a carbon content of 0.02%-0.010%, is based on precise carbon and oxygen control at the end of a converter, does not add any aluminum deoxidizer in the tapping process, adopts carbon particles to completely replace aluminum for deep deoxidization in the RH vacuum refining stage, generates CO gas phase products by the [C]-[O] reaction under vacuum, and avoids the generation of Al2O3 inclusions from the source; compared with a traditional BOF+LF+aluminum deoxidization+calcium treatment process, the application can greatly reduce aluminum consumption and smelting cost, the total amount of oxide inclusions in the steel is reduced by more than 50%, the total oxygen content of the casting blank is stably ≤20ppm, there is no Al2O3 nozzle clogging, there is no calcium abnormal inclusion, the liquid level is stable during the casting process of the casting machine, and stable production of low-carbon steel with low cost, high efficiency and high cleanliness is realized.

Description

Technical Field

[0001] This invention belongs to the field of steelmaking technology in iron and steel metallurgy, and particularly relates to a low-cost, high-cleanliness controlled stamping method for producing low-carbon steel. Background Technology

[0002] Low-carbon steel (carbon content 0.02%–0.10%) is one of the most widely used steel materials, extensively used in structural components, plates, wire rods, steel pipes, and welding steel. Currently, the mainstream production process in China typically involves: hot metal pretreatment → BOF converter → LF furnace refining (or RH vacuum treatment) → calcium treatment → continuous casting. This traditional process has the following significant drawbacks:

[0003] (1) High cost of aluminum deoxidation and prominent inclusion problem

[0004] With domestic aluminum prices continuing to rise, converter steelmaking and LF furnaces are increasingly using aluminum iron and aluminum wire for final deoxidation, leading to a continuous increase in the cost per ton of steel. Furthermore, this generates a large amount of Al2O3 inclusions in the steel. These inclusions are hard, prone to agglomeration, and difficult to float, not only reducing the cleanliness of the steel but also causing nozzle clogging and blockage, affecting the smooth operation of continuous casting and the internal quality of the steel. Therefore, it is imperative to adopt new processes and technologies to replace traditional deoxidation processes.

[0005] (2) The LF process has high energy consumption and a long process.

[0006] The process of heating the LF furnace, creating reducing slag, and adjusting the composition increases power consumption, as well as the consumption of electrodes, slag-forming agents, and alloys. This results in long process times, low production efficiency, and high overall costs.

[0007] (3) Calcium treatment is required, which is costly and results in unstable control of inclusions.

[0008] To modify Al2O3 inclusions and improve castability, the industry commonly uses calcium feeding lines for calcium treatment. Calcium treatment not only increases the cost of auxiliary materials, but also easily produces dot-like inclusions such as CaS and calcium aluminates, resulting in a narrow control window, large fluctuations, and unstable product performance.

[0009] (4) Limited level of cleanliness

[0010] Under the traditional aluminum deoxidation + calcium treatment route, the total oxygen content of the cast billet is mostly between 40 and 60 ppm, and the number and size of oxide inclusions are large, which makes it difficult to meet the high cleanliness requirements of high-end low carbon steel.

[0011] Existing technologies mostly employ a composite deoxidation mode of aluminum pre-deoxidation + carbon deep deoxidation, which still cannot eliminate aluminum consumption and Al2O3 inclusions. For cold-rolled or galvanized thin strip steel, oxide inclusions are the main cause of surface quality defects, and may even lead to the scrapping of entire coils of cold-rolled steel used in high-end automotive steel. Therefore, improving the cleanliness of molten steel and effectively controlling inclusions are key to solving the quality control of high-quality steel. In recent years, with the continuous improvement of users' requirements for product quality and quality control, source manufacturers have been forced to tighten product quality control. As steel product manufacturers, in order to improve the surface quality of strip steel, improving the cleanliness of molten steel can significantly improve the surface quality of steel strip to a certain extent. However, the improvement space of traditional processes is limited after many years of production. Developing clean control technology and new processes for molten steel processes is the key to solving the current bottleneck. Vacuum carbon deoxidation technology has feasibility from theoretical research and has attracted attention due to its advantages such as no solid inclusions in the reaction products and low cost. Therefore, developing a BOF+RH short-process clean smelting process that completely replaces aluminum deoxidation with carbon particles, eliminates LF refining, and eliminates calcium treatment has important engineering value and economic significance for the low-cost, high-efficiency, and high-cleanliness production of low-carbon steel.

[0012] A search of Patent 1: Chinese Invention Patent Application No. CN120442894A discloses a method for refining ultra-low carbon steel using RH. This patent achieves decarburization of molten steel by using CO as the booster gas at the end of the RH decarburization process, and also uses CO gas to reduce some iron oxide, reducing the amount of residual Al used in deoxidation, reducing the amount of Al2O3 inclusions generated, improving the cleanliness of molten steel, and reducing production costs. This invention, however, utilizes the [C]+[O]=(CO) reaction mechanism under deep vacuum RH conditions. After oxygen determination calculations, sufficient carbon particles are added to the vacuum tank, ensuring complete deoxidation of the molten steel while maintaining a slight surplus of residual carbon (which can be used as component carbon). This allows carbon particles to completely replace aluminum particles in deoxidation and calcium treatment processes, significantly reducing the deoxidation products of Al2O3 inclusions in the molten steel, ultimately improving the cleanliness of the molten steel, while reducing the consumption of aluminum and iron during deoxidation, thus achieving cost reduction and efficiency improvement in the smelting process.

[0013] A search revealed that Chinese invention patent application number CN120719080A discloses a production process for ultra-low carbon steel. This patent reduces the oxidizing properties of ladle slag by controlling oxygen throughout the converter + LF + RH process and using a carbonizing agent to adjust the slag. It also involves adding slag additives after the converter and during refining to adjust the CaO / Al2O3 ratio and (FeO) content of the ladle slag. While ensuring that the molten steel does not increase in carbon, it replaces some Al deoxidation with carbon deoxidation in the top slag, improving oxygen transfer at the steel-slag interface, effectively reducing the Al2O3 content in the molten steel, and further improving the cleanliness of the steel. This invention involves adding sufficient carbon particles to the molten steel in a vacuum tank under deep vacuum conditions. Utilizing the [C] + [O] = (CO) reaction mechanism under RH deep vacuum conditions, the residual carbon (which can be used as component carbon) is slightly abundant while ensuring complete deoxidation of the molten steel. This allows carbon particles to completely replace the traditional aluminum particle deoxidation and calcium treatment processes. Comparing the two patents, which use carbon particles to replace part of the aluminum particles, the two processes seem similar in principle, but the actual operations are completely different. The patent adds carbon particles to remove oxygen from the slag, which falls under the category of top slag modification. After slag modification, the oxygen transfer to the molten steel is indirectly reduced. In contrast, this patent uses carbon particles to react directly with oxygen in the molten steel. The two deoxidation methods belong to completely different process routes and processes. There is an order of magnitude difference in the deoxidation products of Al2O3 inclusions in the molten steel, resulting in a significant difference in the final steel cleanliness.

[0014] A search of patent 3 revealed a method for controlling the top slag of ultra-low carbon steel. This patent primarily involves adding a first aluminum-based modifier during converter tapping for initial modification, adding a second aluminum-based modifier to the molten steel after tapping, and simultaneously adding converter lime to the top slag. After RH refining, RH lime is added to the slag surface. The core of this process is to reduce the oxidizing properties of the slag through top slag modification, enhancing the top slag's ability to dissolve and adsorb Al2O3 inclusions in the steel, thereby improving the cleanliness of the molten steel during the smelting process. This invention, however, involves adding sufficient carbon particles to the molten steel in a vacuum tank under deep vacuum conditions. Utilizing the [C] + [O] = (CO) reaction mechanism under RH deep vacuum conditions, it ensures complete deoxidation of the molten steel while maintaining a slightly abundant residual carbon (which can be used as component carbon), thus completely replacing the traditional aluminum particle deoxidation and calcium treatment processes with carbon particles. By reducing the source of oxide inclusions, the cleanliness of the molten steel is improved.

[0015] The above three patents all involve methods for improving the cleanliness control of molten steel, enhancing the cleanliness of molten steel through indirect or direct means, and each has its own advantages compared to the content of this patent. This patent, however, optimizes the deoxidation process from the source of oxide inclusions, improving inclusion control while significantly reducing steelmaking costs compared to traditional aluminum alloy deoxidation processes. This achieves product quality improvement, cost reduction, and efficiency enhancement, effectively strengthening the product's market competitiveness. Summary of the Invention

[0016] In order to solve one or more problems existing in the prior art, the purpose of this invention is to provide a low-cost, high-cleanliness controlled stamping method for producing low-carbon steel.

[0017] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0018] This invention discloses a low-cost, high-cleanliness controlled production method for low-carbon steel stamping. It employs a BOF converter + RH vacuum refining process, eliminating the LF furnace refining step and the calcium treatment step. The RH process uses carbon particles to completely replace aluminum deoxidation. Specifically, it includes the following steps:

[0019] 1) Composition design: The composition of the low-carbon steel, by mass percentage, is C: 0.02~0.10%, Si: ≤0.03%, Mn: 0.10-0.50%, P: ≤0.030%, S: ≤0.020%, Al: 0.020-0.060%, N: ≤0.0040%, O: ≤0.0020%, with the remainder being Fe and unavoidable impurities;

[0020] 2) KR molten iron desulfurization: The temperature of the molten iron in the KR molten iron desulfurization process must be greater than 1330℃, and the silicon content in the molten iron must be 0.40-0.60%. The KR molten iron desulfurization process adopts a deep desulfurization process, with a stirring time of ≥15min. After stirring, the molten iron is allowed to stand for a period of time before the first slag removal, with a slag removal rate of greater than 95%. After the first slag removal, the molten iron is allowed to stand for ≥3min before the second slag removal, with a slag removal rate of greater than 95%. After the slag removal is completed, a sample is taken for temperature measurement. The sulfur content in the KR molten iron leaving the station is less than 0.001%, thus obtaining deep desulfurized molten iron.

[0021] 3) Converter smelting: The converter molten iron is the deep desulfurized molten iron obtained in step 2) and scrap steel, the sulfur content of which is less than 0.003%; the amount of scrap steel added is 15-30 tons / heat, and the total amount of converter molten iron is 285-290 tons / heat; during the converter smelting process, the amount of quicklime added is 5-12 tons / heat, the amount of dolomite added is 5-10 tons / heat, and the amount of iron-containing material added is 0-6 tons / heat; the final temperature of the converter smelting is controlled to be greater than 16 degrees Celsius. At 70℃, the oxygen content of the molten steel at the final stage should be controlled at 600-800ppm; before tapping, use a front-stop operation to avoid slag falling, and shake the converter to the tapping position and calm it for ≥10 seconds; when the steel volume reaches 1 / 5, add 0.5-1.5 tons / heat of top slag quicklime; after tapping, use a back-stop operation, and argon gas stirring is prohibited in the ladle throughout the tapping process; after tapping, use a distributor to add 0.1-0.5 tons / heat of modifier to make the modifier evenly cover the surface of the top slag;

[0022] 4) RH Vacuum Treatment: RH in-situ oxygen and temperature measurement. Considering that the [C]-[O] reaction is endothermic, when using carbon particles for deoxidation, the steel temperature should be appropriately increased by 10-20℃ based on the oxygen determination value to ensure that the RH in-situ temperature meets the superheat requirements of the casting machine. The in-situ temperature is 1620~1640℃ (for heating and oxygen blowing of 40~50m3, adding 80~90kg / furnace of heating aluminum particles), and temperature and oxygen determination are performed. Based on the oxygen determination value, the carbon content in the steel and the amount of deoxidizing carbon particles added are calculated. The amount added per furnace is 50~100kg, and deep vacuum treatment is performed. The deoxidation products escape in the form of CO gas. The RH high vacuum cycle is maintained for 8~15 min to ensure sufficient carbon and oxygen reaction, sufficient CO escape, and promote the polymerization and flotation of fine oxide inclusions. After deoxidation, aluminum particles, ferromanganese alloy and carbon raiser are added. After alloying, the mixture is circulated for ≥3 minutes and then the vacuum is broken. The total time for decarburization and vacuum treatment is ≥25 minutes. The RH off-site measurement temperature is 1590~1610℃. After the RH vacuum treatment, a secondary modification treatment is carried out. 200~300kg / furnace of modifier is evenly added to the surface of the top slag.

[0023] 5) CCM process: Before pouring, the tundish is purged with argon gas. During the pouring process, argon gas is continuously purged into the tundish while adding covering agent. After the ladle pouring is completed, slag detection equipment is used to prevent slag from falling into the ladle. The tundish overheating is controlled within the range of 15-30℃ during the pouring process. The production speed is 1.3-1.4m / min. The argon flow rate of the stopper rod during the pouring process is 4.0-10.0L / min.

[0024] Furthermore, it is applicable to the control of production of general stamping steel SPCC, DC01, DX51D+Z series low carbon steel grades.

[0025] Furthermore, compared with the traditional BOF+LF+aluminum deoxidation+calcium treatment process, aluminum consumption is reduced by more than 90%. With the continuous rise in aluminum alloy prices, the cost of deoxidizer, slag-forming agent, alloy and calcium treatment per ton of steel is significantly reduced, and the total amount of oxide inclusions in steel is reduced by more than 50%.

[0026] Furthermore, the carbon content of the smelted low-carbon steel products is stably controlled at 0.02% to 0.10%, making it suitable for high-quality carbon structural steel, low-carbon structural steel, low-carbon plates, bars and wires, and welding steel.

[0027] Furthermore, after RH deoxidation, the composition is fine-tuned, soft blowing is used to promote the floating of inclusions, and no calcium wire is fed or calcium treatment is performed throughout the process, and continuous casting is carried out directly.

[0028] Furthermore, the total oxygen content of the low-cost, high-cleanliness controlled stamping low-carbon steel is controlled to be less than 20ppm; the inclusions in hot-rolled coils are controlled to be grade 0 except for Class B coarse and fine inclusions of grade 0.5 and Class D fine inclusions of grade 0.5. The replacement of aluminum with carbon particles can reduce the cost of steel by more than 40 yuan / ton.

[0029] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0030] Based on the above technical solutions, a low-cost, high-cleanliness control method for producing low-carbon steel by stamping is provided. This method analyzes the generation and removal of inclusions during actual production processes such as converter processes, RH refining processes, and casting machine processes. It formulates processes to reduce inclusion generation and optimize inclusion removal. An innovative deep-vacuum carbon deoxidation process in RH refining replaces the traditional aluminum deoxidation + calcium treatment process in LF refining, achieving stable control of high cleanliness and low oxide inclusions in low-carbon steel. Before adopting this method, the control of oxide inclusions on the surface of cold-rolled and galvanized low-carbon steel coils was very unstable. Finished coils often suffered from defects such as peeling, cracking, and point-like or line-like defects due to oxide inclusions. In hot-rolled coils, the B-class oxide control was 0.5-3.0, indicating poor steel cleanliness. By adopting the method of this invention, the level of inclusion control is stably achieved throughout the year, reaching Class A, Class C, and Class DS 0 control, and Class B and Class D less than 0.5 control level. The total oxygen content in the steel is controlled to be less than 20ppm, the number of consecutive castings is stably controlled to 15 heats, the inclusion control reaches the industry-leading level, the surface quality defects of the test coil are significantly lower, and the high cleanliness of low carbon steel is stably controlled. Detailed Implementation

[0031] The following uses DC01 / SPCC steel grade as an example to illustrate the content of this invention. These embodiments are only used for the purpose of facilitating understanding and are not intended to limit the content of this invention.

[0032] Example 1 - Steel Grade DC01

[0033] KR deep desulfurization treatment was adopted, with the sulfur content of the molten iron arriving at the station being 0.032%. The treatment process involved heating 1.9 tons of desulfurizing agent, stirring for 20 minutes, and slag removal more than twice, achieving a slag removal rate greater than 95%. Deeply desulfurized molten iron was used for the converter feed, along with 26 tons of self-produced low-sulfur scrap (sulfur content less than 0.003%). The total feed volume of molten iron and scrap steel was controlled between 285 and 290 tons. The molten iron temperature was 1321℃, and the silicon content was 0.46%. During the converter smelting process, 8.1 tons of quicklime, 8.5 tons of dolomite, and 1.7 tons of iron filings were added to the slag. The final oxygen content of the converter was 720 ppm, the carbon content was 0.025%, and the final temperature was 1689℃. One ton of top slag quicklime was added during tapping, and 300 kg of modifier was added at the end of tapping. RH in-situ oxygen and temperature measurement: in-situ temperature 1630℃, oxygen content 480ppm. In deep vacuum mode, 55 kg of carbon particles were added from a high-level hopper. After 10 minutes of deep vacuum treatment, oxygen and temperature measurement was performed. Then, 120 kg of aluminum particles, 360 kg of high-carbon ferromanganese, 45 kg of carbon particles (deep vacuum treatment vacuum degree less than 2.5Mbar), 500 kg of small-particle quicklime, and 200 kg of modifier were added. The total deoxidation and vacuum treatment time was 20 minutes. RH out-of-situ measurement temperature was 1589℃. The superheat during casting was 20℃, the production speed was 1.2 m / min, and the argon blowing flow rate of the stopper rod was 4.6 L / min (maximum flow rate less than 10 L / min). The flow control stopper rod was stable during casting, with no turbulence. Therefore, the argon blowing flow rate of the stopper rod in this furnace was not adjusted.

[0034] Example 2 - SPCC Steel Grade

[0035] KR deep desulfurization treatment was adopted, with the sulfur content of the molten iron arriving at the station being 0.028%. The treatment process involved heating 1.7 tons of desulfurizing agent, stirring for 20 minutes, and slag removal more than twice, achieving a slag removal rate greater than 95%. Deeply desulfurized molten iron was used for the converter feed, along with 23 tons of self-produced scrap steel (low sulfur content less than 0.003%). The total feed volume of molten iron and scrap steel was controlled between 285 and 290 tons. The molten iron temperature was 1312℃, and the silicon content was 0.41%. During the converter smelting process, 8.9 tons of quicklime, 8.1 tons of dolomite, and 1.5 tons of iron filings were added to the slag. The final oxygen content of the converter was 820 ppm, the carbon content was 0.02%, and the final temperature was 1691℃. One ton of top slag quicklime was added during tapping, and 300 kg of modifier was added at the end of tapping. RH in-situ oxygen and temperature measurement: in-situ temperature 1632℃, oxygen content 550ppm. In deep vacuum mode, 60 kg of carbon particles were added from a high-level hopper. After 10 minutes of deep vacuum treatment, oxygen and temperature measurement was performed. Then, 140 kg of aluminum particles, 380 kg of high-carbon ferromanganese, 160 kg of carbon particles (deep vacuum treatment vacuum degree less than 2.5Mbar), 500 kg of fine lime, and 200 kg of modifier were added. The total deoxidation and vacuum treatment time was 20 minutes. RH out-of-situ measurement temperature was 1582℃. The superheat during casting was 16℃, the production speed was 1.4 m / min, and the argon blowing flow rate of the stopper rod was 4.2 L / min (maximum flow rate less than 10 L / min). The flow control stopper rod was stable during casting, with no turbulence. Therefore, the argon blowing flow rate of the stopper rod in this furnace was not adjusted.

[0036] The chemical composition content of DC01 / SPCC obtained in Examples 1 and 2 is shown in Table 1, and the results of the hot-rolled coil inclusion inspection are shown in Table 2.

[0037] Table 1 Chemical composition of finished product (wt%)

[0038]

[0039] Table 2 Inclusion Inspection of Hot-Rolled Coils

[0040]

[0041] As shown in Tables 1 and 2, by adopting the method of this invention, the chemical composition of the finished product and the control of inclusions in hot-rolled coils in the steelmaking and continuous casting processes both meet the target requirements. Oxygen content is controlled at a low level, with aluminum inclusion content below 10 ppm and total oxygen content below 20 ppm, achieving high cleanliness control in the molten steel. For hot-rolled coils of different thicknesses, inclusion control is at level 0 for all categories except for Class D fine inclusions (0.5 grade). Based on the 2026 aluminum granule price, by replacing aluminum granules with carbon granules and adding calcium, a rough calculation shows that a cost reduction of 50 yuan / ton can be achieved. Therefore, the method of this invention achieves a high level of cleanliness control for low-cost, high-cleanliness, low-carbon steel.

[0042] This invention has been applied to the actual production of low-carbon steel grades DC01, SPCC, and DX51D+Z in steelmaking and continuous casting processes. By employing the method of this invention, the goal of low-cost, low-inclusion, and high-purity stable control of molten steel is achieved. The process method of this invention utilizes precise carbon particle deoxidation control during RH vacuum treatment, replacing aluminum particles and calcium treatment processes with carbon particles. This reduces the generation of inclusions in molten steel from the source, improving the control of molten steel purity. The casting process ensures stable liquid level and stable production over long casting cycles.

[0043] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A low-cost, high-cleanliness controlled stamping method for producing low-carbon steel, characterized in that, The process route adopts BOF converter + RH vacuum refining, eliminating the LF furnace refining step and the calcium treatment step. The RH step completely replaces aluminum deoxidation with carbon particles, specifically including the following steps: 1) Composition design: The composition of the low-carbon steel, by mass percentage, is C: 0.02~0.10%, Si: ≤0.03%, Mn: 0.10-0.50%, P: ≤0.030%, S: ≤0.020%, Al: 0.020-0.060%, N: ≤0.0040%, O: ≤0.0020%, with the remainder being Fe and unavoidable impurities; 2) KR molten iron desulfurization: The temperature of the molten iron in the KR molten iron desulfurization process must be greater than 1330℃, and the silicon content in the molten iron must be 0.40-0.60%. The KR molten iron desulfurization process adopts a deep desulfurization process, with a stirring time of ≥15min. After stirring, the molten iron is allowed to stand for a period of time before the first slag removal, with a slag removal rate of greater than 95%. After the first slag removal, the molten iron is allowed to stand for ≥3min before the second slag removal, with a slag removal rate of greater than 95%. After the slag removal is completed, a sample is taken for temperature measurement. The sulfur content in the KR molten iron leaving the station is less than 0.001%, thus obtaining deep desulfurized molten iron. 3) Converter smelting: The converter molten iron is the deep desulfurized molten iron obtained in step 2) and scrap steel, the sulfur content of which is less than 0.003%; the amount of scrap steel added is 15-30 tons / heat, and the total amount of converter molten iron is 285-290 tons / heat; during the converter smelting process, the amount of quicklime added is 5-12 tons / heat, the amount of dolomite added is 5-10 tons / heat, and the amount of iron-containing material added is 0-6 tons / heat; the final temperature of the converter smelting is controlled to be greater than 16 degrees Celsius. At 70℃, the oxygen content of the molten steel at the final stage should be controlled at 600-800ppm; before tapping, use a front-stop operation to avoid slag falling, and shake the converter to the tapping position and calm it for ≥10 seconds; when the steel volume reaches 1 / 5, add 0.5-1.5 tons / heat of top slag quicklime; after tapping, use a back-stop operation, and argon gas stirring is prohibited in the ladle throughout the tapping process; after tapping, use a distributor to add 0.1-0.5 tons / heat of modifier to make the modifier evenly cover the surface of the top slag; 4) RH Vacuum Treatment: RH in-situ oxygen determination and temperature measurement are performed. Considering the endothermic [C]-[O] reaction, when using carbon particles for deoxidation, the steel temperature should be appropriately increased by 10-20℃ based on the determined oxygen value to ensure that the RH outlet temperature meets the superheat requirements for casting machine pouring. The in-situ temperature is 1620-1640℃, and temperature measurement and oxygen determination are conducted. Based on the determined oxygen value, the carbon content in the steel and the amount of deoxidizing carbon particles added are calculated. The amount added per furnace is 50-100 kg, and deep vacuum treatment is performed. The deoxidation products escape in the form of CO gas. The RH high vacuum cycle holding time is 8-15 minutes. min, to ensure full reaction of carbon and oxygen, full escape of CO, and promote the polymerization and flotation of fine oxide inclusions; after deoxidation, add aluminum particles, ferromanganese alloy and carburizing agent, and after alloying, circulate for ≥3 min and then break the air. The total time for decarburization and vacuum treatment is ≥25 min, and the RH off-site measurement temperature is 1590~1610℃; after the RH vacuum treatment, carry out secondary modification treatment, and uniformly add 200~300kg / furnace of modifier on the surface of the top slag. 5) CCM process: Before pouring, the tundish is purged with argon gas. During the pouring process, argon gas is continuously purged into the tundish while adding covering agent. After the ladle pouring is completed, slag detection equipment is used to prevent slag from falling into the ladle. The tundish overheating is controlled within the range of 15-30℃ during the pouring process. The production speed is 1.3-1.4m / min. The argon flow rate of the stopper rod during the pouring process is 4.0-10.0L / min.

2. The low-cost, high-cleanliness controlled stamping method for producing low-carbon steel according to claim 1, characterized in that, It is suitable for low-carbon steel with finished carbon content controlled between 0.02% and 0.10%.

3. The low-cost, high-cleanliness controlled stamping method for producing low-carbon steel according to claim 1, characterized in that, It is applicable to the control of production of general stamping steel SPCC, DC01, DX51D+Z series low carbon steel grades.

4. The low-cost, high-cleanliness controlled stamping method for producing low-carbon steel according to claim 1, characterized in that, Compared with the traditional BOF+LF+aluminum deoxidation+calcium treatment process, aluminum consumption is reduced by more than 90%. With the continuous rise in aluminum alloy prices, the cost of deoxidizer, slag-forming agent, alloy and calcium treatment per ton of steel is significantly reduced, and the total amount of oxide inclusions in steel is reduced by more than 50%.

5. The low-cost, high-cleanliness controlled stamping method for producing low-carbon steel according to claim 1, characterized in that, The carbon content of the smelted low-carbon steel products is stably controlled between 0.02% and 0.10%, making them suitable for high-quality carbon structural steel, low-carbon structural steel, low-carbon plates, bars and wires, and welding steel.

6. The low-cost, high-cleanliness controlled stamping method for producing low-carbon steel according to claim 1, characterized in that, After RH deoxidation, the composition is fine-tuned, and soft blowing is used to promote the floating of inclusions. No calcium wire is fed or calcium treatment is performed throughout the process, and continuous casting is carried out directly.

7. The low-cost, high-cleanliness controlled stamping method for producing low-carbon steel according to claim 1, characterized in that, The low-cost, high-cleanliness controlled stamping low-carbon steel uses a total oxygen content of less than 20ppm; the hot-rolled coil inclusions are controlled to grade 0 except for Class B coarse and fine inclusions of grade 0.5 and Class D fine inclusions of grade 0.

5. The replacement of aluminum with carbon particles can reduce the cost of steel by more than 40 yuan / ton.

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