A method for improving the stable casting of high-carbon steel by controlling oxides in a twin-roller thin strip

Abstract

The present application belongs to the technical field of steel metallurgy, and relates to a method for improving the stable casting and rolling of double-roller thin strip high-carbon steel by controlling oxides. The technical scheme of the present application comprises: smelting qualified molten steel through a converter or an electric furnace, a vacuum furnace and a refining furnace, distributing the molten steel to a molten pool composed of a pair of counter-rotating water-cooled copper casting rollers and a pair of side sealing plates through a tundish and a transition ladle, forming a cast strip with a certain thickness, and the thickness of the cast strip is 1.7-2.5 mm. The method effectively improves the deposition state of oxides on the surface of the casting roller, improves the stability of the casting and rolling of the thin strip high-carbon steel, and realizes multi-furnace continuous production.

Description

Technical Field

[0001] This invention relates to the field of iron and steel metallurgy technology, and to a method for improving the stable casting and rolling of twin-roll thin strip high-carbon steel by controlling oxides. Background Technology

[0002] Twin-roll thin strip continuous casting technology is a process in which molten steel enters a molten pool formed by a pair of counter-rotating casting rolls and side sealing plates through a flow outlet. The molten steel comes into contact with the cooler surface of the casting rolls, forming a solid shell. As the casting rolls rotate, the steel is discharged from the surface of the casting rolls, forming a continuous casting strip. This technology has advantages such as a short process and low energy consumption.

[0003] Chinese patent document CN114703416A discloses a 50 steel hot-rolled plate and its production method, which solves the problem of casting roll vibration during the casting process and improves the fluidity and wettability of molten steel by utilizing S and O elements to enhance strip formation. Chinese patent document CN115233081A discloses a method for producing 30CrMo hot-rolled thin strip steel based on twin-roll casting. This method uses two counter-rotating copper casting rolls, the molten pool is protected by an inert atmosphere, and continuous casting is performed to form a strip with a thickness of 1.4–2.1 mm. Chinese patent document CN116426813A discloses a method for reducing the crack occurrence probability in the production of weathering steel by twin-roll casting. By optimizing the chemical composition of weathering steel and the casting process, the crack incidence rate of twin-roll thin strip weathering steel is reduced to no more than 1.0%. Chinese patent document CN116287942A discloses a method for reducing the cracking rate in the production of medium-carbon high-strength steel. By adjusting the chemical composition of molten steel, roller brush torque, vibration amplitude, surface roughness of casting rolls, thickness of casting strip, and hot rolling reduction rate, the method reduces the surface cracking rate of steel coils when producing medium-carbon high-strength steel using a twin-roll casting process.

[0004] However, existing twin-roll thin strip continuous casting technology still faces significant technical bottlenecks in the production of high-carbon steel. Unlike traditional continuous casting processes, twin-roll thin strip casting machines use inert gas protection in the molten pool without protective slag, resulting in insufficient oxide deposits and film on the surface of the casting rolls during high-carbon steel production. This lack of sufficient oxide deposits leads to poor heat conduction between the high-carbon steel strip and the casting rolls, poor lubrication, and high strength and incidence of white lines (bright strips) in the casting strip. This phenomenon easily causes uneven thickness and strength of the high-carbon steel strip shell, resulting in a high rate and frequency of strip breakage during continuous casting. In a 130-ton ladle casting process, strip breakage occurs more than 10 times in a single furnace, hindering efficient coiling and causing unstable continuous production of thin strip high-carbon steel, with an average of less than two consecutive furnaces, severely impacting production efficiency and economic benefits. Summary of the Invention

[0005] To address this problem, this invention proposes a method for improving the stable casting and rolling of high-carbon strip steel using twin-roll casting. This method solves the technical problems of frequent white lines and high strip breakage rates caused by insufficient oxide deposition on the casting roll surface during the continuous casting of high-carbon steel using twin-roll casting. This method effectively improves the oxide deposition state on the casting roll surface, enhances the casting and rolling stability of high-carbon strip steel, and enables continuous production across multiple furnaces.

[0006] Specifically, the technical solution adopted in this invention is as follows:

[0007] According to a first aspect of the present invention, a method for improving the stable casting and rolling of twin-roll thin strip high-carbon steel by controlling oxides is provided, characterized in that the method comprises the following steps:

[0008] (1) Smelting in a converter or electric furnace:

[0009] The final oxygen content of the molten steel smelted in the converter is 400~700ppm, and the final carbon content is 0.04~0.06%; the balance is Fe and unavoidable residual elements and impurities.

[0010] The final oxygen content of the molten steel smelted in the electric furnace is 500~800ppm, and the final carbon content is 0.03~0.05%; the balance is Fe and unavoidable residual elements and impurities.

[0011] (2) VD vacuum furnace treatment:

[0012] The primary molten steel is vacuum treated in a VD vacuum furnace for more than 20 minutes. Before treatment, the free oxygen content is controlled at 400~800ppm and the carbon content is controlled at 0.03~0.06%. During the process, silicon-manganese alloy is used for deoxidation, followed by desulfurization. The composition and basicity of the refining slag are adjusted by adding lime, fluorite and synthetic slag. The amount of lime added is controlled at 4~5.5kg and the amount of fluorite added is controlled at 1.5~2.5kg. After vacuum furnace treatment, molten steel with S≤0.0050% is obtained.

[0013] (3) LF refining process:

[0014] The molten steel treated by VD vacuum treatment is then subjected to LF refining. The LF-refined molten steel has the following composition: C: 0.40~0.60%, Si: 0.20~0.35%, Mn: 0.50~0.80%, S≤0.0030%, and free oxygen content≥40ppm. The basicity R of the final LF refining slag is 1.0~2.5. 30~110m of calcium wire is fed in before soft stirring. The soft stirring time is controlled at ≥5min.

[0015] (4) Twin-roll continuous casting:

[0016] The steel is smelted into qualified molten steel in a refining furnace. The molten steel flows through an intermediate ladle and a transition ladle into a molten pool consisting of a pair of counter-rotating water-cooled copper casting rolls and a pair of side sealing plates, forming a casting strip with a thickness of 1.7~2.5mm. The casting strip is rolled into a strip of the target thickness in a single pass or directly coiled without being tied.

[0017] According to the method of improving the stable casting and rolling of twin-roll thin strip high carbon steel by controlling oxides according to the present invention, preferably, in step (3), the basicity R of the LF refining slag is controlled to be 1.5~2.5.

[0018] According to the method of improving the stable casting and rolling of twin-roll thin strip high-carbon steel by controlling oxides according to the present invention, preferably, in step (3), the oxygen blowing rate per ton of steel is controlled to be 1.0~1.2m³. 3 The oxygen blowing pressure is controlled at 1.1~1.3MPa.

[0019] According to the method of improving the stable casting and rolling of twin-roll thin strip high carbon steel by controlling oxides according to the present invention, preferably, in step (3), the calcium wire feed is controlled to be ≥0.25m / t.

[0020] According to the method of improving the stable casting and rolling of twin-roll thin strip high carbon steel by controlling oxides according to the present invention, preferably, in step (3), the LF refining temperature is controlled at 1665±10℃.

[0021] According to the method of improving the stable casting and rolling of twin-roll thin strip high carbon steel by controlling oxides according to the present invention, preferably, in step (4), the molten pool level is controlled to be 175±5mm by using the casting speed and the opening of the tundish slide plate.

[0022] According to the method of improving the stable casting and rolling of twin-roll thin strip high carbon steel by controlling oxides according to the present invention, preferably, in step (4), the opening of the tundish slide is controlled to be 60~80%.

[0023] According to the method of improving the stable casting and rolling of twin-roll thin strip high-carbon steel by controlling oxides according to the present invention, preferably, in step (4), the oxygen content of the molten steel in the tundish is determined intermittently during the casting process. When the free oxygen content is <35ppm, oxygen blowing is performed in the tundish, and the oxygen blowing volume in a single operation is not less than 5m³. 3 When white lines with an intensity greater than 2 frequently appear in the twin-roll casting signal during the casting process, oxygen blowing operation is performed in the tundish.

[0024] According to the method of improving the stable casting and rolling of twin-roll thin strip high-carbon steel by controlling oxides according to the present invention, preferably, the oxygen blowing amount in each tundish is ≥5m³. 3 The oxygen blowing pressure is controlled at 0.4~0.6MPa.

[0025] According to the method of improving the stable casting and rolling of twin-roll thin strip high carbon steel by controlling oxides according to the present invention, preferably, in step (4), the temperature of the tundish is controlled to be 1600±10℃ by ladle heat preservation and tundish auxiliary heating technology, and the casting speed is controlled to be 30~55m / min.

[0026] According to the method of improving the stable casting and rolling of twin-roll thin strip high carbon steel by controlling oxides according to the present invention, preferably, in step (4), the rotation speed of the twin-roll brush during the initial casting and normal casting processes is 400±10 rpm, and the torque gradually increases from 0 to 220±10 N•m within 30 min of the initial casting.

[0027] According to the method of improving the stable casting and rolling of high carbon steel strip by controlling oxides according to the present invention, preferably, the roller brush parameters are adjusted according to the casting stability, with the rotation speed controlled at 370~410 rpm and the torque controlled at 165~230 N•m.

[0028] According to the method of improving the stable casting and rolling of twin-roll thin strip high carbon steel by controlling oxides according to the present invention, preferably, in step (4), when the molten steel in the tundish needs to be bleached with oxygen and after bleaching, the speed of the roller brush is gradually reduced to 380±10 rpm, and the torque is adjusted from 220±10 N•m during normal casting to 175±10 N•m.

[0029] According to the method of improving the stable casting and rolling of high carbon steel strip by controlling oxides according to the present invention, preferably, the roller brush parameters are adjusted according to the oxygen blowing situation, the rotation speed is controlled at 370~410 rpm, and the torque is controlled at 165~230 N•m.

[0030] According to a second aspect of the invention, a twin-roll thin strip high carbon steel is provided, which is produced using a method having one or more of the aforementioned features.

[0031] Beneficial technical effects

[0032] By controlling the composition and free oxygen content of the molten steel in the tundish, and by controlling the torque and speed of the roller brushes, the oxide deposits (deposit film) on the surface of the twin-roll continuous casting rolls during the solidification process of twin-roll thin strip high-carbon steel are controlled. These oxide deposits improve lubrication between the high-carbon steel strip and the casting rolls, improve heat conduction between the strip and the roll surfaces, and reduce the incidence and strength of white lines (bright strips) on the strip surface, thereby improving the stability of twin-roll thin strip high-carbon steel casting and rolling. Compared with existing technologies, this invention can reduce the strip breakage rate during the continuous casting process of thin strip high-carbon steel from more than 10 times / heat to no more than 2 times / heat, and increase the number of consecutive casting heats from less than two heats to four heats. It effectively increases the number of consecutive casting heats and the large coil ratio in the production of high-carbon steel using twin-roll thin strip casting and rolling technology, reduces production costs, and improves production efficiency and casting and rolling stability. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0034] Figure 1 A schematic diagram of the process for producing high-carbon steel twin-roll thin strip continuous casting.

[0035] Figure 2 This is a schematic diagram illustrating the white line phenomenon that occurs during the twin-roll continuous casting process of high-carbon steel strip.

[0036] Figure 3 A schematic diagram of the plate surface during stable casting in the twin-roll continuous casting process of high carbon steel strip. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0038] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0039] To address the shortcomings of existing technologies and solve the technical problems of "the inert gas protection and lack of protective slag in the molten pool of the twin-roll thin strip casting machine, resulting in insufficient oxide deposits and film on the surface of the casting rolls during the production of high-carbon steel, leading to poor heat conduction and lubrication between the high-carbon steel strip and the casting rolls, high strength and high occurrence rate of white lines (bright strips) in the casting strip during casting of high-carbon steel, easily causing uneven thickness and strength of the high-carbon steel strip shell, high incidence and frequency of strip breakage during continuous casting (more than 10 times in a 130-ton ladle casting process), difficulty in efficient coiling, and unstable continuous production of thin strip high-carbon steel, with an average of less than two heats cast consecutively," this paper aims to achieve... "This invention provides a method for improving the stability of twin-roll casting and rolling of high-carbon steel. It can effectively improve the casting and rolling stability of high-carbon steel produced by twin-roll casting and rolling process, control and reduce the strip breakage rate during the continuous casting of thin strip high-carbon steel, with the strip breakage rate not exceeding 2 times / heat, and realize four-heat continuous casting. It effectively increases the number of continuous casting heats and the large coil rate of high-carbon steel produced by twin-roll thin strip casting and rolling technology, reduces production costs and improves production efficiency, greatly reduces the white line and strip breakage phenomena during the casting process of thin strip high-carbon steel, solves the problem that thin strip high-carbon steel cannot be continuously cast in multiple heats due to frequent white lines and strip breakage, improves the continuity of thin strip high-carbon steel production and reduces production costs."

[0040] The technical solution adopted by the present invention to solve its technical problem is as follows: molten steel is smelted into qualified molten steel in a converter, electric furnace, vacuum furnace, or refining furnace, and then distributed through an intermediate ladle and transition ladle to a molten pool composed of a pair of counter-rotating water-cooled copper casting rolls and a pair of side sealing plates to form a casting strip of a certain thickness, which is 1.7~2.5mm thick.

[0041] The following are embodiments of the present invention. The described embodiments are only a part of the embodiments of the present invention. All other embodiments that can be obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0042] The technical solution of the present invention will be further described in detail below through specific embodiments.

[0043] Example 1

[0044] This embodiment uses a converter smelting process to produce thin strip high-carbon steel. The specific process flow is as follows:

[0045] Step 1: Steel smelting

[0046] The steel is smelted in a converter, with the final oxygen content strictly controlled at 400-700 ppm and the final carbon content at 0.04-0.06%. The balance in the molten steel is Fe and unavoidable residual elements and impurities. After converter smelting, the molten steel is transported to a VD vacuum furnace for vacuum treatment, with the treatment time controlled to be no less than 20 minutes. During the vacuum treatment, a silicon-manganese deoxidizing alloy is added sequentially for deoxidation, followed by the addition of lime and fluorite for desulfurization. After vacuum furnace treatment, molten steel with S ≤ 0.0050% is obtained.

[0047] Step Two: LF Refining Process

[0048] The molten steel treated by vacuum distillation (VD) is transferred to the LF furnace for refining. The chemical composition of the LF-refined steel is: C: 0.40~0.60%, Si: 0.20~0.35%, Mn: 0.50~0.80%, S≤0.0030%, and free oxygen content≥40ppm. The basicity R of the final LF refining slag is controlled within the range of 1.0~2.5. Calcium wire of 30~110m is fed in before soft stirring, and the soft stirring time is controlled to be no less than 5min.

[0049] Step 3: Twin-roll continuous casting

[0050] The refined molten steel flows into the molten pool through the tundish and transition ladle. The molten pool level is precisely controlled at 175±5mm by controlling the casting speed and the opening of the tundish slide plate. Tundish auxiliary heating technology is used to control the tundish temperature at 1600±10℃, while the casting speed is controlled within the range of 30~55m / min.

[0051] Step 4: Casting and Rolling

[0052] The molten steel in the pool forms a strip of a certain thickness on the surface of the casting roll, with the thickness controlled between 1.7 and 2.5 mm. The strip is then rolled into a strip of the target thickness in a single pass or directly coiled without rolling.

[0053] Step 5: Stabilize Casting and Rolling Control

[0054] During the initial pouring and normal pouring processes, the rotation speed of the twin roller brush was set to 400±10 rpm, and the torque gradually increased from 0 to 220±10 N•m within 30 minutes of the initial pouring.

[0055] Step Six: Oxygenation of Intermediate Batch

[0056] Oxygen content in the molten steel is intermittently monitored during the casting process. When the oxygen content is found to be <35ppm, oxygen blowing is immediately initiated in the tundish, with a single blowing volume of no less than 5m³. 3 When white lines with an intensity greater than 2 frequently appear in the twin-roll casting signal during the casting process, tundish oxygen blowing is also required, with a single oxygen blowing volume of not less than 5m³. 3 The oxygen blowing pressure is set to 0.4~0.6 MPa.

[0057] Step 7: Adjusting the roller brush parameters

[0058] When oxygen blowing is required for molten steel in the tundish and after oxygen blowing, the roller brush parameters are actively adjusted: the roller brush speed is gradually reduced to 380±10rpm, and the torque is adjusted from 220±10N•m during normal casting to 175±10N•m.

[0059] Through the above process, the coordinated control of tundish oxygen replenishment and roller brush parameters was achieved, effectively controlling the deposition state of oxides on the surface of the casting rolls, meeting the requirements for stable casting of thin strip high carbon steel, and successfully realizing the continuous and stable production of twin-roll thin strip high carbon steel, completing four consecutive heats.

[0060] By controlling the deposition state of oxides on the surface of the casting rolls through tundish oxygen supplementation and roller brush synergy, the requirements for stable casting of thin strip high-carbon steel can be met (see...). Figure 3 This enables four consecutive furnaces of twin-roll thin strip high-carbon steel to be cast.

[0061] Example 2

[0062] This embodiment uses an electric furnace smelting process to produce thin strip high-carbon steel. Compared with Embodiment 1, this embodiment uses a different smelting process path in the steel smelting stage.

[0063] Step 1: Steel smelting

[0064] This embodiment employs an electric arc furnace (EAF)-VD furnace-LF furnace smelting process. In EAF smelting, the final oxygen content is strictly controlled to be 500-800 ppm, and the final carbon content to be 0.03-0.05%. Compared to converter smelting, EAF smelting produces steel with a higher final oxygen content range and a slightly lower final carbon content range. The nominal capacity of the EAF ladle is smaller, at 100t. The steel composition contains the remainder of Fe and unavoidable residual elements and impurities. Subsequent processes after EAF smelting, such as VD vacuum treatment and LF refining, are the same as in Embodiment 1.

[0065] Steps 2 to 7: Subsequent Processes

[0066] The process parameters and operating methods for molten steel smelted in electric arc furnaces, including VD vacuum furnace treatment, LF refining treatment, twin-roll continuous casting, casting and rolling forming, stable casting and rolling control, tundish oxygen replenishment operation, and roller brush parameter adjustment, are exactly the same as in Example 1.

[0067] By adopting the smelting process path of electric arc furnace-VD furnace-LF furnace, the coordinated control of tundish oxygen supplementation and roller brush parameters can also be achieved, effectively controlling the deposition state of oxides on the surface of the casting rolls, meeting the requirements for stable casting of thin strip high-carbon steel, and completing 5 consecutive heats. The electric arc furnace smelting process provides another feasible smelting path for the production of thin strip high-carbon steel, expanding the applicability of this method.

[0068] Example 3

[0069] This embodiment provides a twin-roll continuous casting method for producing thin strip high-carbon steel, specifically including the following steps:

[0070] Step 1: Steel smelting

[0071] The steel is smelted in a converter, with the final oxygen content controlled at 400-600 ppm and the final carbon content controlled at 0.04-0.06%. After tapping, the molten steel is transported to a VD vacuum furnace for vacuum treatment. During this process, silicon-manganese alloy is added for deoxidation. After deoxidation, lime and fluorite are added for desulfurization. The molten steel obtained after vacuum furnace treatment has an S ≤ 0.0050%. After VD vacuum treatment, the molten steel is transferred to LF for refining. The composition of the LF-refined steel is C: 0.40-0.60%, Si: 0.20-0.35%, Mn: 0.50-0.80%, S ≤ 0.0030%, and free oxygen content ≥ 40 ppm. The tapping temperature of the LF refining process is controlled at 1665±5℃.

[0072] Step 2: Control of Oxygen Blowing Process

[0073] Throughout the entire production process, the oxygen blowing process parameters for the LF ladle are strictly controlled, with an oxygen blowing volume of 1.0~1.2m³ per ton of steel. 3The oxygen blowing pressure is 1.1~1.3MPa. Precise control of these oxygen blowing process parameters can ensure a reasonable distribution of oxygen content in the molten steel, avoiding excessive fluctuations in oxygen content that could affect the surface quality and internal structure uniformity of the cast strip.

[0074] Step 3: Twin-roll continuous casting

[0075] The refined molten steel flows into the molten pool through the tundish and transition ladle. The molten pool level is controlled at 175±5mm using the casting speed and the opening of the tundish slide gate. The casting speed is controlled at 30~55m / min, decreasing at the beginning of casting and stabilizing after successful casting. The molten steel temperature in the tundish is controlled at 1600±10℃.

[0076] Step 4: Casting and Rolling

[0077] Molten steel forms a strip of a certain thickness on the surface of the casting roll. The thickness of the strip is controlled to be 1.7~2.5mm. The strip is rolled into a strip of the target thickness by a single-pass rolling mill or directly coiled without rolling.

[0078] Step 5: Stabilize casting and rolling

[0079] It includes two key steps: oxygen blowing in the tundish and adjustment of roller brush parameters.

[0080] Regarding tundish oxygen blowing, the oxygen content of the molten steel in the tundish is intermittently determined during the casting process. Oxygen blowing is initiated when the free oxygen content is less than 35 ppm. The oxygen blowing volume in each tundish operation is ≥5 m³ / min. 3 The oxygen blowing pressure is 0.4~0.6MPa. When the twin-roll casting signal frequently shows a white line with an intensity >2, tundish oxygen blowing is also performed, with a single oxygen blowing volume of no less than 5m³. 3 Oxygen blowing in the tundish can effectively regulate the oxygen content in the molten steel, prevent casting instability caused by excessively low oxygen content, and ensure the stability of the cast strip quality.

[0081] Regarding roller brush parameter adjustment, the roller brush speed during the initial casting and normal casting processes is 400±10 rpm, and the torque gradually increases from 0 to 220±10 N•m within 30 minutes of initial casting. Based on casting stability and oxygen blowing conditions, the roller brush parameters are adjusted, with the speed controlled between 370~410 rpm and the torque between 165~230 N•m. When casting is unstable, oxygen blowing is required in the tundish, or after oxygen blowing, the roller brush is actively adjusted, with the roller brush speed gradually reduced to 380±10 rpm and the torque adjusted from 220±10 N•m during normal casting to 175±10 N•m.

[0082] By controlling the deposition of oxides on the casting roll surface through tundish oxygen supplementation and roller brush synergy, the cleanliness and temperature distribution of the casting roll surface can be effectively controlled, preventing surface defects caused by oxide accumulation. Simultaneously, the stability of the molten pool level is ensured, meeting the requirements for stable casting of thin-strip high-carbon steel. This enables continuous and stable production of thin-strip high-carbon steel using twin-roll casting, completing four consecutive heats with a large coil ratio exceeding 70%. This method, through precise process parameter control and multi-stage synergy, significantly improves the production stability and product quality of thin-strip high-carbon steel.

[0083] The above description is merely a specific embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for improving the stable casting and rolling of twin-roll thin strip high-carbon steel by controlling oxides, characterized in that, The method includes the following steps: (1) Smelting in a converter or electric furnace: The final oxygen content of the molten steel smelted in the converter is 400~700ppm, and the final carbon content is 0.04~0.06%; the balance is Fe and unavoidable residual elements and impurities. The final oxygen content of the molten steel smelted in the electric furnace is 500~800ppm, and the final carbon content is 0.03~0.05%; the balance is Fe and unavoidable residual elements and impurities. (2) VD vacuum furnace treatment: The primary molten steel is vacuum treated in a VD vacuum furnace for more than 20 minutes. Before treatment, the free oxygen content is controlled at 400~800ppm and the carbon content is controlled at 0.03~0.06%. During the process, silicon-manganese alloy is used for deoxidation, followed by desulfurization. The composition and basicity of the refining slag are adjusted by adding lime, fluorite and synthetic slag. The amount of lime added is controlled at 4~5.5kg and the amount of fluorite added is controlled at 1.5~2.5kg. After vacuum furnace treatment, molten steel with S≤0.0050% is obtained. (3) LF refining process: The molten steel treated by VD vacuum treatment is then subjected to LF refining. The LF-refined molten steel has the following composition: C: 0.40~0.60%, Si: 0.20~0.35%, Mn: 0.50~0.80%, S≤0.0030%, and free oxygen content≥40ppm. The basicity R of the final LF refining slag is 1.0~2.

5. 30~110m of calcium wire is fed in before soft stirring. The soft stirring time is controlled at ≥5min. (4) Twin-roll continuous casting: The steel is smelted into qualified molten steel in a refining furnace. The molten steel flows through an intermediate ladle and a transition ladle into a molten pool consisting of a pair of counter-rotating water-cooled copper casting rolls and a pair of side sealing plates, forming a casting strip with a thickness of 1.7~2.5mm. The casting strip is rolled into a strip of the target thickness in a single pass or directly coiled without being tied.

2. The method for improving the stable casting and rolling of twin-roll thin strip high-carbon steel by controlling oxides according to claim 1, characterized in that: In step (3), the basicity R of the LF refining residue is controlled to be 1.5~2.

5.

3. The method for improving the stable casting and rolling of twin-roll thin strip high-carbon steel by controlling oxides according to claim 1, characterized in that: In step (3), the oxygen blowing rate per ton of steel is controlled to be 1.0~1.2m³. 3 The oxygen blowing pressure is controlled at 1.1~1.3MPa.

4. The method for improving the stable casting and rolling of twin-roll thin strip high-carbon steel by controlling oxides according to claim 1, characterized in that: In step (3), the amount of calcium wire fed is controlled to be ≥0.25m / t.

5. The method for improving the stable casting and rolling of twin-roll thin strip high-carbon steel by controlling oxides according to claim 1, characterized in that: In step (3), the LF refining temperature is controlled at 1665±10℃.

6. The method for improving the stable casting and rolling of twin-roll thin strip high-carbon steel by controlling oxides according to claim 1, characterized in that: In step (4), the molten pool level is controlled to be 175±5mm by using the pulling speed and the opening of the tundish slide plate.

7. The method for improving the stable casting and rolling of twin-roll thin strip high-carbon steel by controlling oxides according to claim 1, characterized in that: In step (4), the opening of the intermediate package slide is controlled to be 60-80%.

8. The method for improving the stable casting and rolling of twin-roll thin strip high-carbon steel by controlling oxides according to claim 1, characterized in that: In step (4), the oxygen content of the molten steel in the tundish is intermittently determined during the casting process. When the free oxygen content is less than 35 ppm, oxygen blowing is performed in the tundish, with a single oxygen blowing volume of not less than 5 m³. 3 When white lines with an intensity greater than 2 frequently appear in the twin-roll casting signal during the casting process, oxygen blowing operation is performed in the tundish.

9. The method for improving the stable casting and rolling of twin-roll thin strip high-carbon steel by controlling oxides according to claim 8, characterized in that: Oxygen blowing volume of ≥5m³ per tundish 3 The oxygen blowing pressure is controlled at 0.4~0.6MPa.

10. The method for improving the stable casting and rolling of twin-roll thin strip high-carbon steel by controlling oxides according to claim 1, characterized in that: In step (4), the temperature of the tundish is controlled to be 1600±10℃ by steel ladle insulation and tundish auxiliary heating technology, and the pulling speed is controlled to be 30~55m / min.

11. The method for improving the stable casting and rolling of twin-roll thin strip high-carbon steel by controlling oxides according to claim 1, characterized in that: In step (4), the rotation speed of the double roller brush during the initial casting and normal casting processes is 400±10 rpm, and the torque gradually increases from 0 to 220±10 N•m within 30 minutes of the initial casting.

12. The method for improving the stable casting and rolling of twin-roll thin strip high-carbon steel by controlling oxides according to claim 11, characterized in that: Adjust the roller brush parameters according to the casting stability, with the rotation speed controlled at 370~410rpm and the torque controlled at 165~230N•m.

13. The method for improving the stable casting and rolling of twin-roll thin strip high-carbon steel by controlling oxides according to claim 1, characterized in that: In step (4), when oxygen blowing is required for molten steel in the tundish and after oxygen blowing, the roller brush speed is gradually reduced to 380±10rpm, and the torque is adjusted from 220±10N•m during normal casting to 175±10N•m.

14. The method for improving the stable casting and rolling of twin-roll thin strip high-carbon steel by controlling oxides according to claim 13, characterized in that: Adjust the roller brush parameters according to the oxygen blowing situation, with the rotation speed controlled at 370~410rpm and the torque controlled at 165~230N•m.

15. A type of double-roll thin strip high-carbon steel, characterized in that, The twin-roll thin strip high-carbon steel is produced using the method described in any one of claims 1 to 14.

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