Alloy for deoxidation and carbon regulation as well as preparation method and use method of alloy

Abstract

The invention relates to an alloy for deoxidation and carbon regulation as well as a preparation method and a use method thereof, and belongs to the technical field of steelmaking refining. The alloy comprises the following chemical components in percentage by mass: 30%-35% of C, 30%-35% of CaO, 7%-8% of MgO, 15%-20% of Fe and the balance of inevitable impurities. The granularity of the alloy ranges from 20 mm to 40 mm. By reasonably designing the chemical components of the alloy for deoxidation and carbon regulation, the carbon content of the alloy for deoxidation and carbon regulation is reduced, the specific gravity of the alloy for deoxidation and carbon regulation is increased, the carbon element can enter molten steel, the carbon-oxygen reaction rate on the surface of the molten steel is properly controlled, and serious splashing of the molten steel is inhibited; and the carbon element is not easily pumped away under the negative pressure of a vacuum system, so that the absorption rate of the carbon element is improved.

Description

Technical Field

[0001] The present application relates to the technical field of steelmaking and refining, and in particular to an alloy for deoxidation and carbon adjustment and a preparation method and a use method thereof. Background Art

[0002] In the stage of continuous development of iron and steel metallurgy, the ability of steelmaking and refining process determines the development direction of steel varieties. Today's refining equipment is mainly based on RH vacuum refining to develop low-carbon and ultra-low-carbon high-strength steel. In the RH vacuum refining and smelting process, carbon powder particles have been used in the vacuum decarburization process and alloying process for deoxidation and carbon adjustment.

[0003] In the process of using carbon powder for deoxidation, due to the small particle size and light specific gravity of carbon powder, when added into the vacuum chamber, it will float on the surface of the molten steel and cannot enter the interior with the circulating molten steel, causing the carbon-oxygen reaction to proceed at the interface of the slag. The violent carbon-oxygen reaction causes the slag to splash, and with the help of the vacuum system exhaust airflow, it moves toward the exhaust channel of the vacuum system, gradually falls under the action of gravity, and adheres to the inner wall of the hot bend pipe and the exhaust pipe. Long-term repeated operation will cause the aperture of the vacuum pipe to become smaller or even blocked, thereby affecting the exhaust capacity of the vacuum system. In the process of using carbon powder for carbon adjustment, due to the negative pressure of RH vacuum refining, part of the carbon powder added into the vacuum chamber will be sucked away by the vacuum system exhaust airflow, and the added carbon powder cannot completely enter the molten steel, affecting the absorption rate of the carbon powder composition adjustment, resulting in instability of the composition adjustment. Summary of the invention

[0004] The present application provides an alloy for deoxidation and carbon adjustment and a preparation method and a use method thereof, in order to solve the following technical problem: how to improve the deoxidation and carbon adjustment efficiency of RH vacuum refining.

[0005] In a first aspect, the present application provides an alloy for deoxidation and carbon adjustment in steelmaking. The chemical composition of the alloy, calculated by mass fraction, is: C: 30% to 35%, CaO: 30% to 35%, MgO: 7% to 8%, Fe: 15% to 20%, and the remainder is unavoidable impurities.

[0006] Optionally, the particle size of the alloy is 20 mm to 40 mm.

[0007] In a second aspect, the present application provides a method for preparing the alloy for deoxidation and carbon adjustment described in the first aspect, the method comprising:

[0008] According to the chemical composition of the alloy, raw materials of petroleum coke, passivated lime and dolomite are ground to obtain a mixed powder;

[0009] The mixed powder, nail scraps and solvent are mixed to obtain a mixed slurry;

[0010] The mixed slurry is pressed into balls to obtain an alloy for deoxidation and carbon adjustment.

[0011] Optionally, calculated by mass fraction, the C content of the petroleum coke is ≥99.5%, and the particle size of the petroleum coke is ≤5mm; the CaO content of the passivated lime is ≥85%, and the particle size of the passivated lime is ≤5mm; the CaO content of the dolomite is 28%-32%, and the particle size of the dolomite is ≤5mm; the MgO content of the dolomite is 20%-22%; the Fe content of the nail chips is ≥99.5%, and the particle size of the nail chips is ≤2mm.

[0012] In a third aspect, the present application provides a method for using the alloy for deoxidation and carbon adjustment described in the first aspect, the method comprising:

[0013] Detecting the actual oxygen content and the actual carbon content of the molten steel arriving at the refined steelmaking station;

[0014] According to the actual oxygen content and the actual carbon content, the residual oxygen content of the molten steel arriving at the refined station is obtained;

[0015] If the residual oxygen content is ≤200ppm, adding the alloy to the refined molten steel to perform a first carbon adjustment treatment according to the target carbon content of the refined molten steel;

[0016] If the residual oxygen content is greater than 200 ppm, the alloy is added to the refined molten steel for deoxidation treatment, and then a second carbon adjustment treatment is performed according to the target carbon content of the refined molten steel.

[0017] Optionally, the relationship between the residual oxygen content of the refined molten steel at the station and the actual oxygen content and the actual carbon content is as follows:

[0018] O 剩余 =O 到站 -C 到站 *80;

[0019] In the formula, O 剩余 Indicates the residual oxygen content of molten steel at the refined station, O 到站 Indicates the actual oxygen content of molten steel at the refined station, C 到站 Indicates the actual carbon content of molten steel arriving at the refined station.

[0020] Optionally, the deoxidation treatment satisfies the following relationship:

[0021] A=(O 剩余 -200ppm)*0.25 / C 合金 ;

[0022] In the formula, A represents the mass of the alloy, O 剩余Indicates the residual oxygen content of molten steel at the refining station, C 合金 Indicates the actual carbon content of the alloy.

[0023] Optionally, the first carbon adjustment process and the second carbon adjustment process both satisfy the following relationship:

[0024] B=(C 目标 -C 到站 )*1000*molten steel volume / C 合金 ;

[0025] In the formula, B is the mass of the alloy, C 目标 It indicates the target carbon content of the refined molten steel, C 到站 Indicates the actual carbon content of molten steel after refining, C 合金 Indicates the actual carbon content of the alloy.

[0026] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0027] The present application provides an alloy for deoxidation and carbon adjustment in steelmaking. The chemical composition of the alloy is calculated by mass fraction: C: 30% to 35%, CaO: 30% to 35%, MgO: 7% to 8%, Fe: 15% to 20%, and the remainder is inevitable impurities. The particle size of the alloy is 20mm to 40mm. By rationally designing the chemical composition of the alloy for deoxidation and carbon adjustment, the carbon content of the alloy for deoxidation and carbon adjustment is reduced, and the specific gravity of the alloy for deoxidation and carbon adjustment is increased, so that the carbon element can enter the interior of the molten steel, the carbon-oxygen reaction rate on the surface of the molten steel is properly controlled, and the serious splashing of the molten steel is suppressed. At the same time, because the specific gravity of the alloy for deoxidation and carbon adjustment is relatively large, it is not easy to be sucked away under the negative pressure of the vacuum system, so that the absorption rate of the carbon element is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] 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.

[0029] In order to more clearly illustrate the embodiments of the present application 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, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0030] Figure 1 A schematic diagram of a process for preparing a deoxidation and carbon adjustment alloy provided in the present application;

[0031] Figure 2 A schematic diagram of a method for using a deoxidation and carbon adjustment alloy provided in this application;

[0032] Figure 3 The slag sticking condition of the hot top cover of the vacuum chamber provided in Example 1 of the present application;

[0033] Figure 4 This is the slag sticking situation of the hot top cover of the vacuum chamber provided in Comparative Example 1 of the present application. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0035] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be understood as a rigid limitation on the scope of the present application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within the 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., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which applies regardless of the range; in addition, whenever a numerical range is indicated in this document, it is meant to include any cited numbers (fractions or integers) within the indicated range.

[0036] In this document, the terms including "including" and "including" mean "including but not limited to". Relational terms such as "first" and "second" are only used 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. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone; where A and B can be singular or plural. "At least one" means one or more, and "plurality" 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 all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple. Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0037] In a first aspect, the present application provides an alloy for deoxidation and carbon adjustment in steelmaking, characterized in that, calculated by mass fraction, the chemical composition of the alloy is: C: 30% to 35%, CaO: 30% to 35%, MgO: 7% to 8%, Fe: 15% to 20%, and the remainder is unavoidable impurities.

[0038] The positive effect of controlling the C content to 30% to 35% is that C reacts with oxygen in the molten steel to remove excess oxygen in the steel. Adding too much C will cause the molten steel to react violently, splashing severely and causing a large temperature drop; adding too little C will result in an insignificant deoxidation effect and cause a temperature loss in the molten steel. For example, the C content can be 30%, 32%, 33%, 35%, etc.

[0039] The positive effect of controlling the CaO content to 30% to 35% is that CaO, as a carbon powder carrier, is mainly used for molding and bringing carbon powder into the molten steel. Adding too much will cause a large drop in the temperature of the molten steel; adding too little will cause the alloy to have low strength and be easy to pulverize. For example, the CaO content can be 30%, 32%, 33%, 35%, etc.

[0040] The positive effect of controlling the MgO content to 7% to 8%: MgO, as a slag-removing agent, can promote alloy melting. The MgO content of the present application is 7% to 8%. For example, the MgO content can be 7%, 7.2%, 7.4%, 7.8%, 8%, etc.

[0041] The positive effect of controlling the Fe content to 15% to 20% is that Fe, as an alloy weight, can promote the alloy to enter the molten steel. The Fe content of the present application is 15% to 20%. For example, the Fe content can be 15%, 17%, 18%, 20%, etc.

[0042] In some embodiments, the alloy has a particle size of 20 mm to 40 mm.

[0043] The particle size of the alloy for deoxidation and carbon adjustment is 20-40 mm. The positive effect is that if the particle size is too large, it is not easy to melt, which will lead to uneven composition; if the particle size is too small, it is easy to be wrapped in the slag, resulting in large burnout and low element recovery rate. For example, the particle size of the alloy for deoxidation and carbon adjustment is 20 mm, 24 mm, 30 mm, 36 mm, 40 mm, etc.

[0044] In the second aspect, the present application provides a method for preparing the alloy for deoxidation and carbon adjustment as described in the first aspect, see Figure 1 , the method comprising:

[0045] S1. Grinding raw materials of petroleum coke, passivated lime and dolomite according to the chemical composition of the alloy to obtain a mixed powder;

[0046] In some embodiments, the C content of the petroleum coke is ≥99.5% by mass, and the particle size of the petroleum coke is ≤5 mm;

[0047] The positive effect of controlling the C content of petroleum coke to ≥99.5% is: higher purity, preventing the introduction of excessive residual elements; the positive effect of controlling the particle size of petroleum coke to ≤5mm is: easy to crush, preventing the mixing of large particles and causing component segregation of the final product.

[0048] In some embodiments, the CaO content of the passivation lime is ≥ 85% by mass, and the particle size of the passivation lime is ≤ 5 mm;

[0049] The positive effect of controlling the CaO content of the passivation lime to ≥85% is: higher purity, preventing the introduction of excessive residual elements; the positive effect of controlling the particle size of the passivation lime to ≤5mm is: easy to crush, preventing the mixing of large particles causing component segregation of the end product.

[0050] In some embodiments, the CaO content of the dolomite is 28% to 32% by mass, and the particle size of the dolomite is ≤5 mm;

[0051] The positive effect of controlling the CaO content of dolomite to 28% to 32% is that it is a conventional raw material on the market and is relatively easy to purchase. The positive effect of controlling the particle size of dolomite to ≤5mm is that it is easy to crush and prevent the mixing of large particles from causing component segregation of the final product.

[0052] In some embodiments, the dolomite has a MgO content of 20% to 22% by mass.

[0053] The positive effect of controlling the MgO content of dolomite to 20% to 22% is to promote the rapid melting of the alloy into the molten steel.

[0054] In some embodiments, the Fe content of the nail chips is ≥99.5%, and the particle size of the nail chips is ≤2 mm.

[0055] S2, mixing the mixed powder, nail scraps and solvent to obtain a mixed slurry;

[0056] In some embodiments, the solvent may be water.

[0057] In some embodiments, the mass ratio of the sum of the mass of the mixed powder+nail scraps M1 to the mass of the solvent M2 is M1:M2=20:1.

[0058] The positive effect of controlling M1:M2=20:1: This ratio can ensure that petroleum coke, passivated lime and dolomite are fully combined, ensuring the strength after molding.

[0059] S3, pressing the mixed slurry into balls to obtain an alloy for deoxidation and carbon adjustment.

[0060] In the third aspect, based on a general inventive concept, such as Figure 2 As shown, the present application provides a method for using the alloy for deoxidation and carbon adjustment described in the first aspect, the method comprising:

[0061] Detecting the actual oxygen content and the actual carbon content of the molten steel arriving at the refined steelmaking station;

[0062] According to the actual oxygen content and the actual carbon content, the residual oxygen content of the molten steel arriving at the refined station is obtained;

[0063] If the residual oxygen content is ≤200ppm, adding the alloy to the refined molten steel to perform a first carbon adjustment treatment according to the target carbon content of the refined molten steel;

[0064] If the residual oxygen content is greater than 200 ppm, the alloy is added to the refined molten steel for deoxidation treatment, and then a second carbon adjustment treatment is performed according to the target carbon content of the refined molten steel.

[0065] An oxygen content of 200ppm is necessary to remove carbon from steel. When the oxygen content is lower than 200ppm, decarburization cannot be effectively achieved. When the oxygen content is higher than 200ppm, excess oxygen will result, and too many aluminum-oxygen inclusions will be produced during the deoxidation process.

[0066] In some embodiments, the relationship between the actual oxygen content and the actual carbon content to obtain the residual oxygen content of the refined molten steel is as follows:

[0067] O 剩余 =O 到站 -C 到站 *80;

[0068] In the formula, O 剩余 Indicates the residual oxygen content of molten steel at the refined station, O 到站 Indicates the actual oxygen content of molten steel at the refined station, C 到站 Indicates the actual carbon content of molten steel arriving at the refined station.

[0069] Relational formula O 剩余 The principle and positive role of the deoxidation process are: to measure the residual oxygen in the molten steel and determine whether deoxidation operation is needed.

[0070] In some embodiments, the deoxygenation treatment satisfies the following relationship:

[0071] A=(O 剩余 -200ppm)*0.25 / C 合金 ;

[0072] In the formula, A represents the mass of the alloy, O 剩余 Indicates the residual oxygen content of molten steel at the refining station, C 合金 Indicates the actual carbon content of the alloy.

[0073] The principle and positive effect of relational formula A are as follows: by using this formula, the amount of alloy required to remove excess oxygen while ensuring the decarburization effect (reserving 200ppm) can be accurately obtained.

[0074] In some embodiments, the first carbon adjustment process and the second carbon adjustment process both satisfy the following relationship:

[0075] B=(C 目标 -C 到站 )*1000*molten steel volume / C 合金 ;

[0076] In the formula, B is the mass of the alloy, C 目标 It indicates the target carbon content of the refined molten steel, C 到站 Indicates the actual carbon content of molten steel after refining, C 合金 Indicates the actual carbon content of the alloy.

[0077] The principle and positive effect of relational expression B is that the amount of alloy adjustment required to achieve the required molten steel composition when using this alloy can be accurately calculated.

[0078] The present application is further described below in conjunction with specific examples. The experimental methods in the following examples that do not specify specific conditions are usually measured according to industry standards; if there are no corresponding industry standards, they are carried out according to common international standards, conventional conditions, or conditions recommended by the manufacturer.

[0079] Example 1

[0080] The actual oxygen content of the refined steel at the steelmaking station was measured to be 756ppm, the actual carbon content of the refined steel at the steelmaking station was measured to be 0.0296%, and the residual oxygen content of the refined steel at the station was 520ppm; according to the deoxidation treatment relationship, 270kg of alloy for deoxidation and carbon adjustment was added at one time when the RH vacuum cycle was 7min, and the deoxidation was completed after 12min of vacuum, and the oxygen content in the steel was measured to be 207ppm. The slag sticking situation of the hot top cover of the vacuum chamber is as follows Figure 3 shown.

[0081] Example 2

[0082] The actual oxygen content of the refined molten steel arriving at the steelmaking station was measured to be 658ppm, the actual carbon content of the refined molten steel arriving at the steelmaking station was measured to be 0.032%, and the residual oxygen content of the refined molten steel arriving at the steelmaking station was obtained to be 402ppm; according to the deoxidation treatment relationship, 168kg of alloy for deoxidation and carbon adjustment was added at one time when the RH vacuum cycle was 8min, the deoxidation was completed after 14min of vacuum, and the oxygen content in the steel was measured to be 198ppm.

[0083] Example 3

[0084] The actual oxygen content of the refined molten steel arriving at the steelmaking station was measured to be 840ppm, the actual carbon content of the refined molten steel arriving at the steelmaking station was measured to be 0.0232%, and the residual oxygen content of the refined molten steel arriving at the steelmaking station was obtained to be 647ppm; according to the deoxidation treatment relationship, 380kg of deoxidation and carbon adjustment alloy was added at one time when the RH vacuum cycle was 6min, the deoxidation was completed after 13min of vacuum, and the oxygen content in the steel was measured to be 203ppm.

[0085] Comparative Example 1

[0086] The actual oxygen content of the refined steel at the steelmaking station was measured to be 729ppm, the actual carbon content of the refined steel at the steelmaking station was measured to be 0.0302%, and the residual oxygen content of the refined steel at the station was 520ppm; the first batch of carbon powder 30kg was added at 6min of RH vacuum cycle, the second batch of carbon powder 30kg was added at 8min of vacuum cycle, and the third batch of carbon powder 25kg was added at 10min of vacuum cycle. Deoxidation was completed at 15min of vacuum cycle, and the oxygen content in the steel was measured to be 248ppm. The slag sticking situation of the hot top cover of the vacuum chamber is as follows Figure 4 shown.

[0087] Example 4

[0088] The actual carbon content of the refined molten steel at the station was measured to be 0.0384%, and the target carbon content of the steel grade was determined in the range of 0.08-0.10%. According to the formula for the amount of alloy added for deoxidation and carbon adjustment in the carbon adjustment operation, the amount of alloy added was calculated to be 346 kg, and 345 kg of alloy for deoxidation and carbon adjustment was actually added. After 4 minutes of vacuum circulation, sampling was taken, and the carbon content was measured to be 0.0885%, and the absorption rate of carbon element was 98%.

[0089] Example 5

[0090] The actual carbon content of the refined molten steel arriving at the station was measured to be 0.0618%, and the target carbon content of the steel grade was determined in the range of 0.08-0.10%. According to the formula for the amount of alloy added for deoxidation and carbon adjustment in the carbon adjustment operation, the amount of alloy added was calculated to be 197 kg, and 198 kg of alloy for deoxidation and carbon adjustment was actually added. After 4 minutes of vacuum circulation, sampling was taken, and the carbon content was measured to be 0.0898%, and the absorption rate of carbon element was 98.9%.

[0091] Example 6

[0092] The actual carbon content of the refined molten steel arriving at the station was measured to be 0.7218%, and the target carbon content of the steel grade was determined to be in the range of 0.75-0.85%. According to the formula for the amount of alloy added for deoxidation and carbon adjustment in the carbon adjustment operation, the amount of alloy added was calculated to be 547 kg, and 551 kg of alloy for deoxidation and carbon adjustment was actually added. After 4 minutes of vacuum circulation, sampling was taken, and the carbon content was measured to be 0.7986%, and the absorption rate of carbon element was 97.6%.

[0093] Comparative Example 2

[0094] The actual carbon content of the refined molten steel was measured to be 0.0452%, the target carbon content of the steel grade was determined to be in the range of 0.08-0.10%, and the amount of carbon powder added for carbon adjustment was calculated. 104 kg of carbon powder should be added, but 105 kg of carbon powder was actually added. After 4 minutes of vacuum circulation, the sample was taken and the carbon content was measured to be 0.0854%, and the absorption rate of carbon element was 89%.

[0095] It can be seen from Examples 1 to 3 and Comparative Example 1 that when the alloy for deoxidation and carbon adjustment is used instead of carbon powder for deoxidation, the deoxidation effect is better and less slag is adhered to the hot top cover of the vacuum chamber.

[0096] It can be seen from Examples 4 to 6 and Comparative Example 2 that the use of the deoxidation and carbon adjustment alloy has a better carbon adjustment effect, can improve the absorption rate of the carbon element during the carbon adjustment process, and ensure the stability of the composition adjustment.

[0097] Attached Figure 3-4 Detailed description:

[0098] Attached Figure 3 The figure of the vacuum chamber hot cover sticking residue provided in Example 1 of the present application; Figure 3 As shown, there is less slag sticking to the hot top cover of the vacuum chamber, reflecting that the splashing of molten steel in the vacuum chamber is suppressed.

[0099] Attached Figure 4 The vacuum chamber hot top cover sticking residue diagram provided in comparative example 1 of the present application; Figure 4 As shown, there is a lot of slag stuck to the hot top cover of the vacuum chamber, reflecting that the molten steel splashing in the vacuum chamber is serious.

[0100] One or more technical solutions in the embodiments of the present application also have at least the following technical effects or advantages:

[0101] The alloy for deoxidation and carbon adjustment provided in the embodiment of the present application can reduce the carbon-oxygen reaction capacity of the steel slag interface in the vacuum chamber, reduce the amount of steel slag splashing, and increase the service life of the hot bending pipe and the exhaust pipe, thereby ensuring the exhaust capacity of the vacuum system. At the same time, the absorption rate of carbon element can be increased during the carbon adjustment process to ensure the stability of the composition adjustment.

[0102] The above is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. It will be apparent to those skilled in the art that various modifications to these embodiments are possible, and the general principles defined in the present application can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown in the present application, but will conform to the widest scope consistent with the principles and novel features applied for by the present application.

Claims

1. An alloy for steelmaking deoxidation and carbon adjustment, characterized in that: Calculated by mass fraction, the chemical composition of the alloy is: C: 30% to 35%, CaO: 30% to 35%, MgO: 7% to 8%, Fe: 15% to 20%, and the remainder is inevitable impurities.

2. The alloy for deoxidation and carbon adjustment according to claim 1, characterized in that: The particle size of the alloy is 20 mm to 40 mm.

3. A method for preparing an alloy for deoxidation and carbon adjustment according to any one of claims 1 to 2, characterized in that: The method comprises: According to the chemical composition of the alloy, raw materials of petroleum coke, passivated lime and dolomite are ground to obtain a mixed powder; The mixed powder, nail scraps and solvent are mixed to obtain a mixed slurry; The mixed slurry is pressed into balls to obtain an alloy for deoxidation and carbon adjustment.

4. The method according to claim 3, characterized in that Calculated by mass fraction, the C content of the petroleum coke is ≥ 99.5%, and the particle size of the petroleum coke is ≤ 5 mm; and / or, The CaO content of the passivation lime is ≥85%, and the particle size of the passivation lime is ≤5mm; and / or, The CaO content of the dolomite is 28% to 32%, and the particle size of the dolomite is ≤5 mm; and / or, The MgO content of the dolomite is 20% to 22%; and / or, The Fe content of the nail scraps is ≥99.5%, and the particle size of the nail scraps is ≤2mm.

5. A method for using the alloy for deoxidation and carbon adjustment according to any one of claims 1 to 2, characterized in that: The method comprises: Detecting the actual oxygen content and the actual carbon content of the molten steel arriving at the refined steelmaking station; According to the actual oxygen content and the actual carbon content, the residual oxygen content of the molten steel arriving at the refined station is obtained; If the residual oxygen content is ≤200ppm, adding the alloy to the refined molten steel to perform a first carbon adjustment treatment according to the target carbon content of the refined molten steel; If the residual oxygen content is greater than 200 ppm, the alloy is added to the refined molten steel for deoxidation treatment, and then a second carbon adjustment treatment is performed according to the target carbon content of the refined molten steel.

6. The method according to claim 5, characterized in that The relationship between the actual oxygen content and the actual carbon content and the residual oxygen content of the molten steel at the refined station is as follows: O 剩余 =O 到站 -C 到站 *80; In the formula, O 剩余 Indicates the residual oxygen content of molten steel at the refined station, O 到站 Indicates the actual oxygen content of molten steel at the refined station, C 到站 Indicates the actual carbon content of molten steel arriving at the refined station.

7. The method according to claim 5, characterized in that The deoxidation treatment satisfies the following relationship: A=(O 剩余 -200ppm)*0.25 / C 合金 ; In the formula, A represents the mass of the alloy, O 剩余 Indicates the residual oxygen content of molten steel at the refining station, C 合金 Indicates the actual carbon content of the alloy.

8. The method according to claim 5, characterized in that The first carbon adjustment process and the second carbon adjustment process both satisfy the following relationship: B=(C 目标 -C 到站 )*1000*molten steel volume / C 合金 ; In the formula, B is the mass of the alloy, C 目标 It indicates the target carbon content of the refined molten steel, C 到站 Indicates the actual carbon content of molten steel after refining, C 合金 Indicates the actual carbon content of the alloy.

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