Continuous casting method of high carbon steel and high carbon steel

Abstract

The present application relates to a continuous casting method of high carbon steel and high carbon steel. The continuous casting method of high carbon steel comprises the following steps: converter smelting: molten steel is subjected to converter smelting so that the carbon content of the molten steel at the end of converter smelting is greater than or equal to 0.1%; alloy is added after the converter is tapped, and the amount of alloy added accounts for 30%-45% of the total alloy addition; LF refining: the molten steel after converter smelting is subjected to LF refining, and carburizer and alloy are added in batches during the LF refining process, and the amount of alloy added each time accounts for 4%-10% of the total amount of alloy added; RH refining: the molten steel after LF refining is subjected to RH refining, the RH refining time is greater than or equal to 13min, and the outlet temperature of the RH refined molten steel is T+30℃ to T+70℃, where T is the liquidus temperature of the molten steel; continuous casting: the molten steel after RH refining is subjected to continuous casting treatment to obtain a continuous casting billet. The method provided in the present application can reduce the interruption of continuous casting of high carbon steel.

Description

Technical Field

[0001] The present application relates to the field of steel technology, and in particular to a continuous casting method of high-carbon steel and high-carbon steel. Background Art

[0002] High carbon steel is also often called tool steel. Its carbon content is between 0.6% and 1.7%. After proper heat treatment or cold drawing hardening, it has high strength and hardness, high elastic limit and fatigue limit, and acceptable cutting performance, but poor welding performance and cold plastic deformation ability. The traditional high carbon steel production process is generally: electric arc furnace (EAF) → ladle refining (LF) / vacuum degassing (VD) → die casting → (electroslag re-furnace (ESR)) → forging or blanking → rolling. The advantages of the traditional die casting process for producing high carbon steel include the ability to manufacture parts with complex shapes, flexible processes, simple production equipment, etc., but the disadvantages are low production efficiency, which is not conducive to large-scale production and manufacturing, low yield rate for the production of plates, wires, bars, etc., and high production costs.

[0003] With the advancement of continuous casting equipment and technology, more and more high carbon steel production processes have been transformed into: EAF / oxygen top-blown converter (BOF) → LF → RH → continuous casting (CC) → rolling. The continuous casting process simplifies the high carbon steel production process, improves production efficiency, greatly increases production line capacity, and reduces production costs. However, the continuous casting process for producing high carbon steel also has production accidents and quality accidents such as continuous casting leakage and slab cracks. In particular, when the continuous casting machine uses a large ladle for long-term casting to produce high carbon steel, it is easy to have a problem of continuous casting large ladle water outlet or medium ladle water outlet interruption in the later stage of casting, resulting in a series of problems such as interruption of continuous casting machine production and subsequent high carbon steel molten steel having no destination, which brings great pressure to the production organization, increases production costs, and reduces production efficiency. Summary of the invention

[0004] In view of the problems existing in the prior art, the embodiments of the present application provide a continuous casting method of high carbon steel and high carbon steel.

[0005] In a first aspect, the present application provides a continuous casting method for high carbon steel, comprising the following steps:

[0006] Converter smelting: smelting the molten steel in a converter so that the carbon content of the molten steel at the end of converter smelting is greater than or equal to 0.1%; adding alloy after the steel is tapped from the converter, the amount of alloy added accounts for 30%-45% of the total amount of alloy added;

[0007] LF refining: LF refining is performed on the molten steel after converter smelting. During the LF refining process, carburizer and alloy are added in batches, and the amount of alloy added each time accounts for 4%-10% of the total amount of alloy added;

[0008] RH refining: the molten steel after LF refining is subjected to RH refining, the RH refining time is greater than or equal to 13 minutes, the outlet temperature of the RH refined molten steel is T+30°C to T+70°C, T is the liquidus temperature of the molten steel;

[0009] Continuous casting: The molten steel after RH refining is continuously cast to obtain continuous casting billets.

[0010] According to the embodiments of the present application, by accurately controlling the amount of alloy added and the time of alloy addition during the converter steelmaking process, the alloy can be prevented from solidifying into a mass at the bottom of the ladle; by accurately controlling the amount of alloy added and the time of alloy addition during the LF furnace refining process, all alloys added to the high-carbon steel liquid can be completely melted within the LF furnace refining time; by controlling the RH furnace refining time and the molten steel outlet temperature, the alloy added during the RH furnace refining process can be prevented from continuing to melt during the continuous casting of the molten steel from this furnace, thereby reducing the continuous casting interruption accident caused by the low temperature of the molten steel in the later stage of continuous casting; the continuous casting machine can use a constant pulling speed to cast high-carbon steel liquid, thereby preventing a low pulling speed from extending the casting time of high-carbon steel, increasing the temperature drop of the high-carbon steel liquid, and causing a continuous casting interruption accident due to excessively low temperature in the later stage of casting.

[0011] In some embodiments, in the converter smelting step, the alloy is added 1 min to 6 min after the converter taps the steel.

[0012] In some embodiments, in the converter smelting step, argon blowing is performed during the converter smelting process, and the argon flow rate is 400L / min-2000L / min.

[0013] In some embodiments, in the LF refining step, the temperature of the molten steel is 1500°C-1560°C.

[0014] In some embodiments, in the LF refining step, the interval between the addition time of the last batch of alloy and the time when the molten steel is discharged from the furnace is 10 min-20 min.

[0015] In some embodiments, in the LF refining step, argon stirring is performed after adding the alloy, and the compressed gas flow rate is 600L / min-1500L / min.

[0016] In some embodiments, in the RH refining step, alloy is continuously added during the RH refining process, and the amount of alloy added accounts for 0.1%-4% of the total amount of alloy added.

[0017] In some embodiments, the continuous casting step adopts a constant casting speed, and the continuous casting speed is 0.7m / min-1.5m / min.

[0018] In some embodiments, the alloy comprises one or more of ferrosilicon, ferromanganese, ferrochrome, and aluminum.

[0019] In some embodiments, the recarburizer includes carbon powder.

[0020] In a second aspect, the present application provides a high carbon steel, the chemical composition of which is expressed in weight percentage and includes: C: 0.85-0.95%, Si: 1.2-1.6%, Mn: 0.3-0.6%, P: 0-0.025%, S: 0-0.010%, Cr: 0.95-1.25%, Al: 0-0.06%, and the rest are Fe and unavoidable impurity elements. DETAILED DESCRIPTION

[0021] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the present application. However, it is obvious to those skilled in the art that the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application. In the following description, at least part of the known structures and technologies are not shown to avoid unnecessary ambiguity in the present application; and, for clarity, the size of some structures may be exaggerated. In addition, the features, structures or characteristics described below may be combined in one or more embodiments in any suitable manner.

[0022] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish an entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. In the description of the present application, it should be noted that, unless otherwise specified, the meaning of "multiple" is more than two. Moreover, the term "include", "comprise" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only include those elements, but also include other elements not clearly listed, or also include elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements limited by the sentence "include..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements.

[0023] High carbon steel continuous casting process, whether it is a billet continuous casting machine or a slab continuous casting machine, has greatly improved the production efficiency of high carbon steel smelting and reduced the cost of high carbon steel smelting. Compared with the traditional mold casting of high carbon steel liquid, the amount of molten steel used in the continuous casting machine for high carbon steel is relatively small, and the ladle capacity is larger, which prolongs the casting time of a bag of molten steel flowing through the nozzle, increases the temperature difference between the early and late stages of casting a bag of high carbon steel liquid, and increases the temperature drop before and after the high carbon steel liquid in the same ladle. This causes the temperature of the high carbon steel liquid in the ladle to approach the liquidus temperature of the molten steel in the late stage of continuous casting, making the continuous casting of high carbon steel have the risk of continuous casting interruption, and the interruption phenomenon is more common when casting with a large ladle. Some high carbon steel grades that have strict requirements on the internal quality of high carbon steel ingots and products need to be cast with low superheat in the middle ladle, which increases the probability of interruption accidents in the production of high carbon steel by the continuous casting machine.

[0024] In view of this, an embodiment of the present application provides a continuous casting method for high carbon steel, which produces high carbon steel liquid through a converter high carbon drawing process, and by controlling the process parameters of each process, it is possible to effectively reduce the continuous casting interruption accidents caused by low temperature of high carbon steel liquid in the same furnace in the later stage of continuous casting.

[0025] [Continuous casting method of high carbon steel]

[0026] The embodiment of the first aspect of the present application provides a continuous casting method of high carbon steel, comprising the following steps:

[0027] S10, converter smelting: performing converter smelting on the molten steel, so that the carbon content of the molten steel at the end of the converter smelting is greater than or equal to 0.1%; adding alloy after the steel is tapped from the converter, and the amount of alloy added accounts for 30%-45% of the total amount of alloy added;

[0028] S20, LF refining: LF refining is performed on the molten steel after converter smelting. During the LF refining process, carburizer and alloy are added in batches, and the amount of alloy added each time accounts for 4%-10% of the total amount of alloy added;

[0029] S30, RH refining: RH refining is performed on the molten steel after LF refining. The RH refining time is greater than or equal to 13 minutes. The outlet temperature of the RH refined molten steel is T+30℃ to T+70℃, and T1 is the liquidus temperature of the molten steel.

[0030] S40, continuous casting: the molten steel after RH refining is continuously cast to obtain a continuous casting billet.

[0031] In the embodiment of the present application, high-carbon steel liquid is produced by implementing the high-carbon drawing process in the converter, and the amount and time of alloy addition to the converter and LF furnace are strictly and accurately controlled to ensure the refining time of the RH furnace and the outlet temperature, prevent the high-carbon steel liquid temperature from fluctuating greatly, and reduce the continuous casting interruption accidents caused by low temperature of high-carbon steel liquid in the same furnace in the later stage of continuous casting.

[0032] The embodiment of the present application can produce high carbon steel hot rolled strip by using the production process of 210 ton oxygen converter → 210 ton LF refining furnace → 210 ton RH furnace → conventional double-strand slab continuous casting machine → 210 mm thick slab → hot rolling → finished product. The technical solution of this process is to smelt high carbon steel with high carbon drawing in a 210 ton converter, reduce the problem of a large amount of carbonizer added during the converter steel tapping process causing the temperature of the molten steel to drop significantly, and the high temperature molten steel is conducive to the rapid melting of the added alloy, which can reduce the risk of the added alloy agglomerating into a mass at the bottom of the ladle due to insufficient temperature during the steel tapping process. Furthermore, the alloy can be prevented from solidifying into a mass at the bottom of the ladle by precisely controlling the amount of alloy added and the time of alloy addition during the converter steelmaking process; all alloys added to the high-carbon molten steel can be completely melted within the LF furnace refining time by precisely controlling the amount of alloy added and the time of alloy addition during the LF furnace refining process; the alloy added during the RH furnace refining process can be prevented from continuing to melt during the continuous casting of the molten steel from this furnace by controlling the RH furnace refining time and the molten steel outlet temperature, thereby reducing the continuous casting interruption accident caused by the low molten steel temperature in the later stage of continuous casting; the continuous casting machine can adopt a constant pulling speed to cast the high-carbon steel molten steel, thereby preventing the low pulling speed from extending the casting time of the high-carbon steel, increasing the temperature drop of the high-carbon steel molten steel, and preventing the continuous casting interruption accident caused by the excessively low temperature in the later stage of casting.

[0033] In an embodiment of the present application, alloy is added after steel is tapped from the converter, and the amount of alloy added accounts for 30%-45% of the total alloy added, for example, it can be 30%, 32%, 35%, 38%, 40%, 42%, 45%, or a range consisting of any of the above values, which can be selected as 35%-40%.

[0034] In some embodiments, in the converter smelting step, after the previous batch of molten steel for smelting high carbon steel in the converter is discharged, 2-5 tons of converter slag can be retained in the converter, that is, the converter slag retention operation; after the converter is blown for a period of time, the previous high P slag is poured out, that is, the front slag pouring operation; thereby ensuring that the carbon content at the end of the converter smelting is ≥0.1%, that is, the converter performs a high carbon drawing operation.

[0035] In some embodiments, alloy can be added 1 minute after the converter taps steel to ensure that the amount of alloy added after the converter is ≤5 tons, and the amount of slag-forming agents such as lime added after the converter is ≤2 tons, and argon is blown throughout the converter tapping process.

[0036] In some embodiments, the time for adding the alloy after the steel is tapped from the converter may be 1 min to 6 min after the steel is tapped from the converter.

[0037] In some embodiments, in the converter smelting step, argon blowing treatment is performed during the converter smelting process, and the argon flow rate can be 400L / min-2000L / min, for example, it can be 400L / min, 500L / min, 600L / min, 700L / min, 800L / min, 900L / min, 1000L / min, 1200L / min, 1500L / min, 2000L / min, or a range consisting of any of the above numerical values.

[0038] In some embodiments, in the LF refining step, after the ladle containing high carbon steel liquid enters the LF refining furnace, it is immediately powered on to increase the temperature, and lime is added in batches during the heating process; the amount of lime added in each batch is ≤0.5 tons.

[0039] In some embodiments, the temperature of the high carbon steel liquid is raised to above 1500°C, optionally 1500°C-1560°C, at one time.

[0040] In some implementations, the recarburizer and alloy are added in batches according to the composition of the molten steel, the alloy added in each batch is ≤1.0 ton, and the interval time from the last batch of alloy addition to the molten steel leaving the LF refining furnace is ≥10 minutes, which can be selected as 10 minutes to 20 minutes.

[0041] In some embodiments, after adding the carburizer and the alloy to the LF refining furnace, a large amount of argon stirring is performed, and the argon flow rate is ≥600 L / min, and can be selected to be 600 L / min-1500 L / min.

[0042] In some embodiments, in the RH refining step, the high carbon steel liquid is refined in the RH refining furnace for ≥13 minutes.

[0043] In some implementations, the amount of alloy added in the RH refining furnace accounts for 0.1%-4% of the total amount of alloy added, and the time for adding the alloy in the RH refining furnace can be within the first 5 minutes of the refining process.

[0044] In some embodiments, the outlet temperature of high carbon molten steel can be T+30°C to T+70°C, where T is the liquidus temperature of the molten steel.

[0045] In some embodiments, in the continuous casting step, the double-strand slab continuous casting machine casts high carbon steel at a constant drawing speed rhythm, and the casting machine drawing speed can be 0.7m / min-1.5m / min, for example, it can be 0.7m / min, 0.8m / min, 0.9m / min, 1.0m / min, 1.1m / min, 1.2m / min, 1.3m / min, 1.4m / min, 1.5m / min, or a range composed of any of the above numerical values.

[0046] In some embodiments, the alloy may include one or more of ferrosilicon, ferromanganese, ferrochrome, and aluminum blocks, for example, one or more of 74% ferrosilicon, ferromanganese containing 74% or 97% manganese, ferrochrome containing 56% chromium, and aluminum blocks containing 99% aluminum.

[0047] In some embodiments, the recarburizer may include carbon powder, for example, carbon powder with a carbon content of 95%.

[0048] The embodiment of the present application can prevent the occurrence of interruption accidents when the continuous casting machine casts high carbon steel by controlling the high carbon steel smelting production. Its main advantages are: 1. The high carbon drawing of the converter to smelt high carbon steel can reduce the use of carburizer in the subsequent smelting process, while reducing the temperature drop of the high carbon steel molten steel, shortening the smelting time, saving energy and protecting the environment, and reducing the smelting cost; 2. It can effectively prevent the alloy added after the converter from agglomerating at the bottom of the ladle and blocking the argon holes of the ladle, which is beneficial to the subsequent smelting of high carbon steel, improves the production rhythm, reduces power consumption, and prevents the entire furnace of molten steel from being returned to the furnace for re-smelting; 3. By strictly controlling The amount and time of adding alloys in LF and RH refining furnaces can make all added alloys completely melted, improve the alloy recovery rate, save alloy cost and production cost; 4. The continuous casting of high carbon steel using constant pulling speed can reduce the internal quality problems of the ingot and flat slag defects caused by large fluctuations in molten steel temperature, and prevent continuous casting interruption accidents caused by low temperature in the later stage of casting; 5. It can effectively prevent the continuous casting machine from interrupting the casting of high carbon steel, ensure a steady production rhythm, avoid the return of high carbon steel to the furnace, etc., greatly improve the smelting efficiency of high carbon steel and reduce the smelting cost of high carbon steel.

[0049] [High Carbon Steel]

[0050] The embodiment of the second aspect of the present application provides a high carbon steel, which can be produced by the method of the embodiment of the first aspect of the present application.

[0051] In some embodiments, high carbon steel includes the following chemical composition in weight percentage: C: 0.85-0.95%, Si: 1.2-1.6%, Mn: 0.3-0.6%, P: 0-0.025%, S: 0-0.010%, Cr: 0.95-1.25%, Al: 0-0.06%, and the rest are Fe and unavoidable impurity elements.

[0052] Example

[0053] The present application is described below with reference to specific examples. It should be noted that the embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. Where specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be obtained commercially.

[0054] Example 1

[0055] The components and weight percentage of 9SiCr slab steel produced by the conventional slab continuous casting machine of 210 converter plant are: C: 0.9084%, Si: 1.3326%, Mn: 0.4791%, P: 0.0131%, S: 0.0012%, Cr: 1.0149%, Al: 0.0204%, and the rest are Fe and unavoidable impurity elements. The specific control process is as follows:

[0056] 210-ton oxygen converter process: After the previous batch of molten steel for smelting high-carbon steel 9SiCr in the converter is tapped, about 3 tons of converter slag are retained in the converter for converter slag retention operation; after the converter is charged with molten iron and scrap steel, the converter is blown for 5-10 minutes, and the converter pours out the previous high-P slag; after the converter pours out the previous slag, the converter continues to add materials and blow high-carbon steel. The carbon content at the end of the converter smelting is 0.1586%, the end temperature of the converter is 1612℃, and the phosphorus content at the end of the converter is 0.0089%, that is, the converter high-carbon drawing operation; alloy is added 1 minute after the converter taps steel, that is, 2 tons of ferrochrome, 2 tons of ferrosilicon, 0.3 tons of ferromanganese, 0.2 tons of aluminum blocks, and 0.4 tons of lime are added after the converter, and argon is blown throughout the converter tapping process to ensure that all the alloys are melted.

[0057] 210-ton LF refining furnace process: After the ladle containing high-carbon 9SiCr molten steel enters the LF refining furnace, the operator supplies electricity to raise the temperature according to the regulations, and adds lime in batches during the heating process, with about 0.3 tons of lime added in each batch; the LF refining furnace operator raises the temperature of the high-carbon 9SiCr molten steel to 1560℃ at one time, and adds recarburizer and alloy in batches according to the composition of the molten steel, adding 0.5 tons of alloy in each batch, ensuring that the interval time from the last batch of alloy addition to the 9SiCr molten steel leaving the LF refining furnace is ≥10 minutes; after adding the recarburizer and alloy, the LF refining furnace operator must use a large amount of argon gas for stirring, with an argon gas flow rate of ≥600L / min, to ensure that the alloy and recarburizer are quickly melted into the molten steel and the molten steel has a uniform composition; after the composition and ingredients of the high-carbon 9SiCr molten steel meet the requirements, it leaves the station and goes to the next process 210-ton RH refining furnace.

[0058] 210-ton RH refining furnace process: After the high-carbon steel 9SiCr molten steel arrives at the 210-ton RH refining furnace, it is refined according to the operating procedures to ensure that the refining time is ≥13 minutes; no alloy is added to the high-carbon steel 9SiCr molten steel in the RH refining furnace; the high-carbon steel 9SiCr molten steel leaves the station when the temperature is 1488℃ and is sent to the next process for continuous casting.

[0059] Conventional slab continuous casting process: After the high carbon steel 9SiCr molten steel reaches the continuous casting platform, the continuous casting operator performs production according to the continuous casting operating procedures; the conventional double-strand slab continuous casting machine gradually increases the casting machine pulling speed, and casts the high carbon steel 9SiCr at a constant pulling speed of 1.0m / min. The final temperature of the casting machine in the ladle is 1462℃, and no continuous casting interruption accidents are found.

[0060] Example 2

[0061] The components and weight percentage of SK85 slab steel produced by the conventional slab continuous casting machine of the 210 converter plant are: C: 0.8599%, Si: 0.1867%, Mn: 0.321%, P: 0.0133%, S: 0.002%, Al: 0.0258%, and the rest are Fe and unavoidable impurity elements. The specific control process is as follows:

[0062] 210-ton oxygen converter process: After the previous batch of molten steel for smelting high-carbon steel SK85 in the converter is tapped, about 3 tons of converter slag are retained in the converter for converter slag retention operation; after the converter is charged with molten iron and scrap steel, the converter is blown for 5-10 minutes, and the converter pours out the previous high-P slag, which is the previous slag pouring operation; after the converter pours out the previous slag, the converter continues to add materials and blow high-carbon steel. The carbon content at the end of the converter smelting is 0.2104%, the end temperature of the converter is 1602℃, and the phosphorus content at the end of the converter is 0.0093%, which is the converter high-drawing carbon operation; alloy is added 1 minute after the converter taps steel, that is, 0.3 tons of ferrosilicon, 0.5 tons of ferromanganese, 0.3 tons of aluminum blocks, and 0.4 tons of lime are added after the converter, and argon is blown throughout the converter tapping process to ensure that all the alloys are melted.

[0063] 210-ton LF refining furnace process: After the ladle containing high-carbon SK85 molten steel enters the LF refining furnace, it is powered on for heating according to the regulations. During the heating process, lime is added in batches, with about 0.3 tons of lime added in each batch; the LF refining furnace operator raises the temperature of the high-carbon SK85 molten steel to 1554℃ at one time, and adds recarburizer and alloy in batches according to the composition of the molten steel, with about 0.5 tons of alloy added in each batch, ensuring that the interval from the addition of the last batch of alloy to the time when the SK85 molten steel leaves the LF refining furnace is ≥10 minutes; after adding the recarburizer and alloy, the LF refining furnace operator must use a large amount of argon gas for stirring, with an argon gas flow rate of ≥600L / min, to ensure that the alloy and recarburizer are quickly melted into the molten steel and the composition of the molten steel is uniform; after the composition and ingredients of the high-carbon SK85 molten steel meet the requirements, it leaves the station and goes to the next process 210-ton RH refining furnace.

[0064] 210-ton RH refining furnace process: After the high-carbon steel SK85 molten steel arrives at the 210-ton RH refining furnace, the high-carbon steel SK85 molten steel is refined according to the operating procedures to ensure that the refining time is ≥13 minutes; no alloy is added to the high-carbon steel SK85 molten steel in the RH refining furnace; the high-carbon steel SK85 molten steel leaves the station when the temperature is 1505℃ and goes to the next process for continuous casting for casting.

[0065] Conventional slab continuous casting process: After the high carbon steel SK85 molten steel reaches the continuous casting platform, the continuous casting operator performs production according to the continuous casting operating procedures; the conventional double-strand slab continuous casting machine gradually increases the casting machine pulling speed, and casts the high carbon steel SK85 at a constant pulling speed of 1.1m / min. The final temperature of the casting machine in the ladle is 1484℃, and no continuous casting interruption accidents are found.

[0066] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A continuous casting method for high carbon steel, characterized in that: The following steps are involved: Converter smelting: smelting the molten steel in a converter so that the carbon content of the molten steel at the end of converter smelting is greater than or equal to 0.1%; adding alloy after the steel is tapped from the converter, the amount of alloy added accounts for 30%-45% of the total amount of alloy added; LF refining: LF refining is performed on the molten steel after converter smelting. During the LF refining process, carburizer and alloy are added in batches, and the amount of alloy added each time accounts for 4%-10% of the total amount of alloy added; RH refining: the molten steel after LF refining is subjected to RH refining, the RH refining time is greater than or equal to 13 minutes, the outlet temperature of the RH refined molten steel is T+30°C to T+70°C, T is the liquidus temperature of the molten steel; Continuous casting: The molten steel after RH refining is continuously cast to obtain continuous casting billets.

2. The method according to claim 1, characterized in that: In the converter smelting step, the alloy is added 1 min to 6 min after the converter taps the steel.

3. The method according to claim 1, characterized in that In the converter smelting step, argon blowing treatment is performed during the converter smelting process, and the argon flow rate is 400L / min-2000L / min.

4. The method according to claim 1, characterized in that: In the LF refining step, the temperature of the molten steel is 1500°C-1560°C.

5. The method according to claim 1, characterized in that In the LF refining step, the interval between the addition time of the last batch of alloy and the time when the molten steel is discharged from the furnace is 10 minutes to 20 minutes.

6. The method according to claim 1, characterized in that In the LF refining step, argon stirring is performed after the alloy is added, and the compressed gas flow rate is 600L / min-1500L / min.

7. The method according to claim 1, characterized in that In the RH refining step, alloy is continuously added during the RH refining process, and the amount of alloy added accounts for 0.1%-4% of the total amount of alloy added.

8. The method according to claim 1, characterized in that The continuous casting step adopts a constant casting speed, and the continuous casting casting speed is 0.7m / min-1.5m / min.

9. The method according to any one of claims 1 to 8, characterized in that The alloy comprises one or more of ferrosilicon, ferromanganese, ferrochrome and aluminum blocks; The recarburizer includes carbon powder.

10. A high carbon steel, characterized in that: The high carbon steel is prepared by the method according to any one of claims 1 to 9, wherein the chemical composition of the high carbon steel includes, by weight percentage: C: 0.85-0.95%, Si: 1.2-1.6%, Mn: 0.3-0.6%, P: 0-0.025%, S: 0-0.010%, Cr: 0.95-1.25%, Al: 0-0.06%, and the rest are Fe and unavoidable impurity elements.