A method for smelting high carbon steel

Abstract

The present application relates to a smelting method of high carbon steel, characterized in that the method includes converter steelmaking, LF refining, and continuous casting process; slag is poured at the set stage of converter steelmaking to reduce the total slag amount of the converter, and the converter endpoint parameter is controlled to reach the set value, and then the slag is poured and the amount of slag is controlled; after the slag is poured, the converter is shaken, and aluminum iron is added for deoxidation and alloying operation, and carbon powder is added for carbon alloying operation, and then slag blocking and steel tapping are performed; lime is added to the LF ladle during the slag blocking and steel tapping process, and argon gas is blown from the bottom; aluminum particles are added at the LF station for slag deoxidation, and the mass percentage of T.Fe in the slag is controlled. The method can reduce the fluctuation range of the C content of the final product and realize the efficient, batch, and low-cost production of high carbon steel.

Description

Technical Field

[0001] This application relates to the field of steelmaking technology, and more particularly to a method for smelting high-carbon steel. Background Technology

[0002] High-carbon steel generally refers to specialty steel with a carbon content of 0.60%-1.70%. Due to its high hardness and wear resistance, it is commonly used in the production of various tools such as drill bits, saw blades, and reamers. Because of its high carbon content, carbon segregation is unavoidable during continuous casting. Therefore, the most critical aspect of smelting technology is narrow composition control to minimize the fluctuation range of carbon content in the final product.

[0003] To ensure the quality of high-carbon steel smelting, electric furnaces are generally used. However, electric furnaces have low production efficiency and high production costs, making it difficult to achieve large-scale, low-cost production of high-carbon steel. There are also reports of using converter processes to produce high-carbon steel. However, due to the difficulty in controlling the oxidizing properties of the slag and the oxygen activity of the molten steel, multiple carbon adjustment processes are necessary for carbon alloying, impacting the production cycle. Summary of the Invention

[0004] This application provides a method for smelting high-carbon steel to solve the technical problems of low production efficiency, high production cost and long production cycle in existing high-carbon steel smelting methods.

[0005] In a first aspect, this application provides a method for smelting high-carbon steel, the method comprising converter steelmaking, LF refining, and continuous casting processes;

[0006] Slag removal is performed during the set-stage of converter steelmaking, and the converter endpoint parameters are controlled to reach the set values. Then, the furnace is shaken to remove slag and the amount of slag removed is controlled.

[0007] After the slag removal is completed, the converter is turned upright, then aluminum-iron is added for deoxidation and alloying, carbon powder is added for carbon alloying, and then slag is blocked and steel is tapped.

[0008] During the slag-blocking and steel tapping process, quicklime is added into the ladle, and argon gas is blown into the bottom of the ladle.

[0009] Aluminum particles are added at the LF station to deoxidize the slag, and the mass percentage of T.Fe in the slag is controlled.

[0010] Furthermore, the step of removing slag during the designated stage of converter steelmaking to reduce the total amount of slag in the converter includes:

[0011] When the oxygen supply to the converter reaches 25% to 30% of the total oxygen supply to the converter, the slag removal operation is carried out and the amount of slag removed is controlled to be 50% to 80% of the total slag.

[0012] Furthermore, the converter endpoint parameters include: a converter endpoint carbon content of 0.02-0.06%, a converter endpoint oxygen content of 400-1000 ppm, a converter endpoint temperature of 1600-1650℃, a converter final slag basicity of 3.0-3.5, and a T.Fe mass percentage of 18%-25% in the converter final slag; the amount of slag dumped is ≥90% of the total slag amount.

[0013] Furthermore, the deoxidation and alloying operation by adding aluminum and iron, and the carbon alloying operation by adding carbon powder, include:

[0014] Aluminum-iron is added for deoxidation and alloying, and the bottom blowing intensity of the converter is controlled to a set intensity. 2-3 minutes after the aluminum-iron is added, carbon powder is added for carbon alloying.

[0015] Furthermore, during the deoxidation and carbon alloying operations, the bottom blowing intensity of the converter is controlled to be 0.01-0.02 Nm. 3 / h.

[0016] Furthermore, the addition of quicklime to the ladle and the bottom blowing of argon gas during the slag-blocking and tapping process include:

[0017] A set amount of quicklime is added to the ladle before the steel output reaches the set output.

[0018] Argon gas is blown into the bottom online during the tapping process, and the flow rate of the blown gas is controlled to the set flow rate. Bottom blowing and stirring are performed after the tapping is completed.

[0019] Furthermore, the set steel output is 1 / 5 of the total steel output; the set mass is 2-3 kg / t steel.

[0020] Furthermore, the set flow rate is 200-300 Nm. 3 / h.

[0021] Furthermore, the mass percentage of T.Fe in the slag is <1%.

[0022] The technical solutions provided in this application have the following advantages compared with the prior art:

[0023] The high-carbon steel smelting method provided in this application embodiment involves slag removal during the set stage of converter steelmaking, controlling the converter endpoint parameters to reach the set values, followed by slag removal through furnace shaking and controlling the amount of slag removed to control the slag quantity and prevent the reaction between FeO and C in the slag, thus facilitating precise C control. By adding ferroaluminum for deoxidation and alloying, oxygen in the molten steel and FeO in the slag are removed, thereby reducing the reaction between carbon powder and oxygen in the molten steel and FeO in the slag during carbon alloying, achieving precise carbon content control. Adding quicklime prevents the molten steel from being exposed, thus preventing C oxidation and affecting the C alloying effect. Adding aluminum particles for slag deoxidation further reduces the reaction between the slag and C in the molten steel, preventing interference with precise C content. This method can reduce the fluctuation range of C content in the final product, achieving efficient, batch, and low-cost production of high-carbon steel. Attached Figure Description

[0024] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0026] Figure 1 This is a schematic flowchart of a high-carbon steel smelting method provided in an embodiment of this application. Detailed Implementation

[0027] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0028] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0029] like Figure 1 As shown in the embodiment of this application, a method for smelting high-carbon steel is provided, the method including converter steelmaking, LF refining, and continuous casting process;

[0030] Slag removal is performed during the set-stage of converter steelmaking, and the converter endpoint parameters are controlled to reach the set values. Then, the furnace is shaken to remove slag and the amount of slag removed is controlled.

[0031] After the slag removal is completed, the converter is turned upright, then aluminum-iron is added for deoxidation and alloying, carbon powder is added for carbon alloying, and then slag is blocked and steel is tapped.

[0032] During the slag-blocking and steel tapping process, quicklime is added into the ladle, and argon gas is blown into the bottom of the ladle.

[0033] Aluminum particles are added at the LF station to deoxidize the slag, and the mass percentage of T.Fe in the slag is controlled.

[0034] The high-carbon steel smelting method provided in this application embodiment involves slag removal during the set stage of converter steelmaking, controlling the converter endpoint parameters to reach the set values, followed by slag removal through furnace shaking and controlling the amount of slag removed to control the slag quantity and prevent the reaction between FeO and C in the slag, thus facilitating precise C control. By adding ferroaluminum for deoxidation and alloying, oxygen in the molten steel and FeO in the slag are removed, thereby reducing the reaction between carbon powder and oxygen in the molten steel and FeO in the slag during carbon alloying, achieving precise carbon content control. Adding quicklime prevents the molten steel from being exposed, thus preventing C oxidation and affecting the C alloying effect. Adding aluminum particles for slag deoxidation further reduces the reaction between the slag and C in the molten steel, preventing interference with precise C content. This method can reduce the fluctuation range of C content in the final product, achieving efficient, batch, and low-cost production of high-carbon steel.

[0035] As one embodiment of the present invention, the step of removing slag during a designated stage of converter steelmaking to reduce the total amount of converter slag includes:

[0036] When the oxygen supply to the converter reaches 25% to 30% of the total oxygen supply to the converter, the slag removal operation is carried out and the amount of slag removed is controlled to be 50% to 80% of the total slag.

[0037] In this application, by discarding most of the slag in the early stages of converter steelmaking, the total amount of slag in the converter can be reduced, thus reducing the failure of carbon replenishment due to excessive slag in the later stages. This is because FeO in the slag reacts with C, and the less slag there is, the lower the probability of this reaction occurring. Moreover, with a smaller total slag amount, the difficulty of slag disposal in the later stages is also significantly reduced.

[0038] As one embodiment of the present invention, the converter endpoint parameters include: converter endpoint carbon content of 0.02-0.06%, converter endpoint oxygen content of 400-1000ppm, converter endpoint temperature of 1600-1650℃, converter final slag basicity of 3.0-3.5, and T.Fe mass percentage in converter final slag of 18%-25%.

[0039] The amount of slag dumped is ≥ 90% of the total slag amount.

[0040] In this application, controlling the carbon and oxygen content at the converter endpoint within this range ensures a reasonable FeO content in the slag. This creates a balance between the oxygen in the molten steel and the FeO in the slag. Using this specific oxygen level in the molten steel ensures that the FeO content in the slag remains within a reasonable range. Controlling the slag basicity between 3.0 and 3.5, and the T.Fe content between 18% and 25%, guarantees effective dephosphorization of the molten steel. Reasonably controlling the slag melting point ensures that the slag is low-melting-point, facilitating thorough slag removal and ensuring a certain level of slag removal efficiency. This prevents incomplete slag removal, which could lead to FeO reacting with C, thus promoting precise C control. By controlling the amount of slag removed, reactions between the slag, molten steel, and alloys are reduced, thereby ensuring precise alloying.

[0041] As one embodiment of the present invention, the deoxidation and alloying operation of adding aluminum-iron and the carbon alloying operation of adding carbon powder include:

[0042] Aluminum-iron is added for deoxidation and alloying, and the bottom blowing intensity of the converter is controlled to a set intensity. 2-3 minutes after the aluminum-iron is added, carbon powder is added for carbon alloying.

[0043] In this application, the purpose of the deoxidation alloying operation is to remove oxygen from the molten steel and FeO from the slag, thereby reducing the reaction between carbon powder and oxygen in the molten steel and FeO in the slag during the carbon alloying operation, which could lead to unstable yield. Precise control of carbon content is achieved through carbon powder addition for carbon alloying.

[0044] In one embodiment of the present invention, during the deoxidation alloying and carbon alloying operations, the bottom blowing intensity of the converter is controlled to be 0.01-0.02 Nm. 3 / h.

[0045] In this application, the purpose of using this bottom blowing intensity is to ensure that the molten pool is fully mixed, and to avoid uneven mixing of molten steel and slag, which would lead to the presence of oxygen in some areas, which would then react with carbon powder and affect the overall effect.

[0046] As one embodiment of the present invention, the step of adding quicklime into the ladle and performing bottom blowing of argon gas into the ladle during the slag-blocking and steel tapping process includes:

[0047] A set amount of quicklime is added to the ladle before the steel output reaches the set output.

[0048] Argon gas is blown into the bottom online during the tapping process, and the flow rate of the blown gas is controlled to the set flow rate. Bottom blowing and stirring are performed after the tapping is completed.

[0049] In this application, the addition of quicklime prevents the molten steel from being exposed and avoids the oxidation of carbon, which would affect the alloying effect of carbon. Online bottom-blowing argon gas ensures uniform mixing of the molten steel, avoiding fluctuations in carbon content caused by inhomogeneity, which would affect accurate hitting.

[0050] In one embodiment of the present invention, the set steel output is 1 / 5 of the total steel output; the set mass is 2-3 kg / t steel.

[0051] As one embodiment of the present invention, the set flow rate is 200-300 Nm. 3 / h.

[0052] In one embodiment of the present invention, the mass percentage of T.Fe in the slag is <1%.

[0053] In this application, controlling the T.Fe content in the slag to be less than 1% can further reduce the reaction between the slag and the C in the molten steel, thus avoiding affecting the accurate targeting of C.

[0054] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards. If there is no corresponding national standard, then general international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0055] Example 1

[0056] A method for smelting high-carbon steel includes converter steelmaking, LF refining, and continuous casting processes, using a 300-ton top-and-bottom blown converter and an LF refining furnace for smelting, specifically:

[0057] (1) When the oxygen supply for converter steelmaking reaches 30% of the total oxygen supply for the converter, slag dumping operation is carried out, and the amount of slag dumped is controlled to account for 50% of the total slag amount.

[0058] (2) Control the C content at the converter endpoint to be 0.022%, the oxygen content at the converter endpoint to be 700ppm, and the converter endpoint temperature to be 1650℃; at the same time, control the basicity of the converter final slag to be 3.5 and control the T.Fe mass fraction in the converter final slag to be 25%.

[0059] (3) After the converter reaches the target composition and temperature at the end point, the slag dumping operation is carried out by shaking the furnace, and the amount of slag dumped is controlled to be 95% of the total slag amount;

[0060] (4) After the slag removal is completed, the converter is uprighted, aluminum-iron alloy is added for deoxidation and alloying, and the bottom blowing intensity of the converter is controlled to be 0.02 Nm at this time. 3 / h;

[0061] (5) Two minutes after adding aluminum and iron, add carbon powder to perform carbon alloying, and control the bottom blowing intensity of the converter at this time to be 0.02 Nm. 3 / h;

[0062] (6) The steel tapping process is carried out by slag-blocking tapping, and before the steel tapping amount reaches 1 / 5 of the total steel tapping amount, 3 kg / t steel of quicklime is added to the ladle;

[0063] (7) The tapping process uses online bottom-blowing argon gas, and the bottom-blowing gas flow rate is controlled at 300 Nm³. 3 / h, after steel tapping is completed, bottom blowing and stirring for 3 minutes;

[0064] (8) LF is added to the station to deoxidize the slag and the T.Fe content of the slag is controlled to be 0.5%.

[0065] Example 2

[0066] A method for smelting high-carbon steel includes converter steelmaking, LF refining, and continuous casting processes, using a 210-ton top-and-bottom blown converter and an LF refining furnace for smelting, specifically as follows:

[0067] (1) When the oxygen supply for converter steelmaking reaches 30% of the total oxygen supply for the converter, slag dumping operation is carried out, and the amount of slag dumped is controlled to account for 80% of the total slag amount.

[0068] (2) Control the C content at the converter endpoint to be 0.06%, the oxygen content at the converter endpoint to be 400ppm, and the converter endpoint temperature to be 1600℃; at the same time, control the basicity of the converter final slag to be 3.0 and control the T.Fe mass fraction in the converter final slag to be 18%.

[0069] (3) After the converter reaches the target composition and temperature at the end point, the slag dumping operation is carried out by shaking the furnace, and the amount of slag dumped is controlled to be 90% of the total slag amount;

[0070] (4) After the slag removal is completed, the converter is uprighted, aluminum-iron alloy is added for deoxidation and alloying, and the bottom blowing intensity of the converter is controlled to be 0.01 Nm at this time. 3 / h;

[0071] (5) Two minutes after adding aluminum and iron, add carbon powder to perform carbon alloying, and control the bottom blowing intensity of the converter at this time to be 0.01 Nm. 3 / h;

[0072] (6) The steel tapping process adopts the slag-blocking tapping method, and before the steel tapping amount reaches 1 / 5 of the total steel tapping amount, 2 kg / t steel of quicklime is added to the ladle;

[0073] (7) The tapping process uses online bottom-blowing argon gas, and the bottom-blowing gas flow rate is controlled at 200 Nm³. 3 / h, after steel tapping is completed, bottom blowing and stirring for 3 minutes;

[0074] (8) LF is added to the station to deoxidize the slag and the T.Fe content of the slag is controlled to be 0.8%.

[0075] Example 3

[0076] A method for smelting high-carbon steel includes converter steelmaking, LF refining, and continuous casting processes, using a 300-ton top-and-bottom blown converter and an LF refining furnace for smelting, specifically:

[0077] (1) When the oxygen supply for converter steelmaking reaches 25% of the total oxygen supply for the converter, slag dumping operation is carried out, and the amount of slag dumped is controlled to account for 70% of the total slag.

[0078] (2) Control the C content at the converter endpoint to be 0.04%, the oxygen content at the converter endpoint to be 1000ppm, and the converter endpoint temperature to be 1650℃; at the same time, control the basicity of the converter final slag to be 3.3 and control the T.Fe mass fraction in the converter final slag to be 22%.

[0079] (3) After the converter reaches the target composition and temperature at the end point, the slag dumping operation is carried out by shaking the furnace, and the amount of slag dumped is controlled to be 93% of the total slag amount;

[0080] (4) After the slag removal is completed, the converter is uprighted, aluminum-iron alloy is added for deoxidation and alloying, and the bottom blowing intensity of the converter is controlled to be 0.02 Nm at this time. 3 / h;

[0081] (5) Two minutes after adding aluminum and iron, add carbon powder to perform carbon alloying, and control the bottom blowing intensity of the converter at this time to be 0.02 Nm. 3 / h;

[0082] (6) The steel tapping process is carried out by slag-blocking tapping, and before the steel tapping amount reaches 1 / 5 of the total steel tapping amount, 3 kg / t steel of quicklime is added to the ladle;

[0083] (7) The tapping process uses online bottom-blowing argon gas, and the bottom-blowing gas flow rate is controlled at 300 Nm³. 3 / h, after steel tapping is completed, bottom blowing and stirring for 3 minutes;

[0084] (8) LF is added to the slag for deoxidation and the T.Fe content of the slag is controlled to be 0.9%.

[0085] Example 4

[0086] A method for smelting high-carbon steel includes converter steelmaking, LF refining, and continuous casting processes, using a 300-ton top-and-bottom blown converter and an LF refining furnace for smelting, specifically:

[0087] (1) When the oxygen supply for converter steelmaking reaches 27% of the total oxygen supply for the converter, slag dumping operation is carried out, and the amount of slag dumped is controlled to account for 65% of the total slag.

[0088] (2) Control the C content at the converter endpoint to be 0.03%, the oxygen content at the converter endpoint to be 600ppm, and the converter endpoint temperature to be 1630℃; at the same time, control the basicity of the converter final slag to be 3.2 and control the T.Fe mass fraction in the converter final slag to be 20%.

[0089] (3) After the converter reaches the target composition and temperature at the end point, the furnace shaking and slag dumping operation is carried out, and the amount of slag dumped is controlled to be 91% of the total slag amount;

[0090] (4) After the slag removal is completed, the converter is uprighted, aluminum-iron alloy is added for deoxidation and alloying, and the bottom blowing intensity of the converter is controlled to be 0.02 Nm at this time. 3 / h;

[0091] (5) Two minutes after adding aluminum and iron, add carbon powder to perform carbon alloying, and control the bottom blowing intensity of the converter at this time to be 0.02 Nm. 3 / h;

[0092] (6) The steel tapping process is carried out by slag-blocking tapping, and before the steel tapping amount reaches 1 / 5 of the total steel tapping amount, 3 kg / t steel of quicklime is added to the ladle;

[0093] (7) The tapping process uses online bottom-blowing argon gas, and the bottom-blowing gas flow rate is controlled at 250 Nm³. 3 / h, after steel tapping is completed, bottom blowing and stirring for 3 minutes;

[0094] (8) LF is added to the station to deoxidize the slag and the T.Fe content of the slag is controlled to be 0.8%.

[0095] Example 5

[0096] A method for smelting high-carbon steel includes converter steelmaking, LF refining, and continuous casting processes, using a 300-ton top-and-bottom blown converter and an LF refining furnace for smelting, specifically:

[0097] (1) When the oxygen supply for converter steelmaking reaches 28% of the total oxygen supply for the converter, slag dumping operation is carried out, and the amount of slag dumped is controlled to account for 75% of the total slag.

[0098] (2) Control the C content at the converter endpoint to be 0.05%, the oxygen content at the converter endpoint to be 800ppm, and the converter endpoint temperature to be 1620℃; at the same time, control the basicity of the converter final slag to be 3.3 and control the T.Fe mass fraction in the converter final slag to be 23%.

[0099] (3) After the converter reaches the target composition and temperature at the end point, the furnace shaking and slag dumping operation is carried out, and the amount of slag dumped is controlled to be 94% of the total slag amount;

[0100] (4) After the slag removal is completed, the converter is uprighted, aluminum-iron alloy is added for deoxidation and alloying, and the bottom blowing intensity of the converter is controlled to be 0.02 Nm at this time. 3 / h;

[0101] (5) Three minutes after adding aluminum and iron, add carbon powder to perform carbon alloying, and control the bottom blowing intensity of the converter at this time to be 0.02 Nm. 3 / h;

[0102] (6) The steel tapping process adopts the slag-blocking tapping method, and before the steel tapping amount reaches 1 / 5 of the total steel tapping amount, 2 kg / t steel of quicklime is added to the ladle;

[0103] (7) The tapping process uses online bottom-blowing argon gas, and the bottom-blowing gas flow rate is controlled at 270 Nm³. 3 / h, after steel tapping is completed, bottom blowing and stirring for 3 minutes;

[0104] (8) LF is added to the station to deoxidize the slag and the T.Fe content of the slag is controlled to be 0.8%.

[0105] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0106] In this application, unless otherwise stated, directional terms such as "upper" and "lower" specifically refer to the drawing directions in the accompanying drawings. Furthermore, in the description of this application, terms such as "comprising" and "including" mean "including but not limited to." In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this document, "and / or" describes the relationship between related objects, indicating that three relationships can exist; for example, A and / or B can represent: A alone, A and B simultaneously, or B alone. A and B can be singular or plural. In this document, "at least one" means one or more, and "more than one" means two or more. "At least one," "at least one of the following," or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c" or "at least one of a, b, and c" can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be a single or multiple.

[0107] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A method for smelting high carbon steel, characterized in that: The method includes converter steelmaking, LF refining, and continuous casting processes; During the set stage of converter steelmaking, slag is discharged and the converter endpoint parameters are controlled to reach the set value. Then, the slag is discharged by shaking the furnace and the amount of slag discharged is controlled. After the slag is removed from the shaking furnace, the converter is shaken straight, and then aluminum and iron are added for deoxidation and alloying, and carbon powder is added for carbon alloying, and then slag blocking and steel tapping are performed; During the slag blocking and steel tapping process, lime is added into the ladle and argon is blown from the bottom of the ladle; Adding aluminum particles at the LF station to deoxidize the slag and controlling the mass percentage of T.Fe in the slag; The slag removal is performed at the set stage of converter steelmaking to reduce the total slag volume of the converter, including: When the oxygen supply of converter steelmaking reaches 25%-30% of the total oxygen supply of converter, slag pouring operation is carried out and the slag pouring amount is controlled to be 50%-80% of the total slag amount; The converter endpoint parameters include: converter endpoint carbon content of 0.02-0.06%, converter endpoint oxygen content of 400-1000ppm, converter endpoint temperature of 1600-1650°C, converter final slag basicity of 3.0-3.5, and T.Fe mass percentage in converter final slag of 18%-25%; The slag discharge amount is ≥ 90% of the total slag amount, and the mass percentage of T.Fe in the slag is < 1%.

2. The method according to claim 1, characterized in that The adding of aluminum iron to perform deoxidation alloying operation and the adding of carbon powder to perform carbon alloying operation include: Aluminum and iron are added to perform deoxidation and alloying operations, and the bottom blowing intensity of the converter is controlled to be a set intensity. 2 to 3 minutes after the aluminum and iron are added, carbon powder is added to perform carbon alloying operations.

3. The method according to claim 1, characterized in that During the deoxidation alloying operation and carbon alloying operation, the bottom blowing intensity of the converter is controlled to be 0.01-0.02Nm 3 / h.

4. The method according to claim 1, characterized in that: The method of adding lime into the ladle during the slag blocking and steel tapping process and blowing argon gas from the bottom of the ladle comprises: Before the steel output reaches the set output, add a set amount of lime into the ladle; During the steel tapping process, argon is blown online at the bottom, and the bottom blowing gas flow rate is controlled to be the set flow rate. After the steel tapping is completed, bottom blowing and stirring are performed.

5. The method according to claim 4, characterized in that The set steel output is 1 / 5 of the total steel output; the set quality is 2-3 kg / t steel.

6. The method according to claim 4, characterized in that The set flow rate is 200-300Nm 3 / h.

Images