A ladle and a method for efficiently removing inclusions from molten steel

Abstract

The application discloses a ladle and a method for efficiently removing inclusions in molten steel, wherein four air bricks are evenly and dispersedly arranged at the bottom of the ladle, one taphole is arranged between any two adjacent air bricks, and the air bricks are distributed at the position of 50-60% of the radius of the ladle. The method comprises the following steps: connecting the molten steel with the ladle provided with the four air bricks, adding alloy and carbon powder deoxidation alloying to the ladle in the process of tapping from a converter or an electric furnace, then adding lime and fluorite to build slag, and then transporting the molten steel to LF refining for treatment after the tapping is completed; adjusting the composition and temperature of the molten steel and the composition of the slag in the process of LF refining; after reaching the standard, carrying out calcium treatment through aluminum deoxidization, then carrying out soft stirring, directly carrying out soft stirring treatment on the silicon-manganese deoxidized steel, and directly transporting the molten steel to continuous casting for pouring after the soft stirring is completed. The application solves the problem of excessive inclusions caused by the fact that the molten steel has many dead angles in the process of soft blowing of the ladle and the inclusions are not sufficiently floated.

Description

Technical Field

[0001] This invention relates to a ladle and a method for efficiently removing inclusions from molten steel, belonging to the technical field of inclusion removal in the steelmaking process. Background Technology

[0002] Traditional steel ladles typically use one or two permeable bricks. After steel smelting, the soft blowing process results in numerous dead zones within the molten steel, leading to insufficient inclusion flotation and excessive inclusion analysis. Conventional ladles with a capacity of 120 tons or more employ a double bottom-blowing structure. After steel refining, the flow rate of the permeable bricks is adjusted for soft blowing, primarily to remove inclusions. However, due to the generally large diameter of ladles with a capacity of 120 tons or more, and the relatively consistent flow rates of the two permeable bricks during the soft stirring process, significant dead zones still exist within the molten steel, resulting in incomplete inclusion flotation and removal. Summary of the Invention

[0003] To address the aforementioned problem of poor inclusion removal during the steelmaking process, leading to excessive inclusions in the product, this invention discloses a ladle and a method for efficiently removing inclusions from molten steel. The specific technical solution is as follows:

[0004] A steel ladle, wherein four permeable bricks are evenly distributed around the bottom circumference of the ladle, and a steel outlet is provided between two adjacent permeable bricks. The line connecting two adjacent permeable bricks to the center of the ladle forms a 90° angle. o The permeable bricks are distributed at the corners, about 50-60% of the outer radius of the steel ladle. The four permeable bricks are numbered sequentially as permeable brick 1, permeable brick 2, permeable brick 3, and permeable brick 4.

[0005] Furthermore, the interior of the permeable brick is a permeable core, which is conical in shape. The outer diameter of the permeable core on the side in contact with molten steel is 130mm, and the outer diameter on the side of the permeable core connected to the air pipe is 188mm. The permeable slits on the side connected to the air pipe are distributed in a circle around the inner diameter of the permeable core, which is 88mm in diameter. The length of the permeable slits on the side connected to the air pipe is 20-30mm, and the width is ≤1.5mm. The height of the slits in the permeable core is 410mm. The bottom of the slits in the permeable core is connected to a porous permeable base brick, which is 110mm high. The base brick is sealed and installed inside the permeable brick together with the permeable brick. The center of the base brick is connected to an air blowing pipe to blow air into the permeable core.

[0006] Furthermore, the steel ladle has a diameter of 3200mm, and the permeable brick has a height × length × width of 550mm × 320mm × 320mm.

[0007] A method for efficiently removing inclusions from molten steel based on the aforementioned ladle: After converter or electric furnace smelting, molten steel is poured into a ladle and then transported to LF refining. After refining, soft stirring is performed to remove inclusions, and then the steel is transported to continuous casting. High-carbon steel is controlled during tapping from the converter or electric furnace. A ladle with four permeable bricks is used to receive the molten steel. During tapping, alloys and carbon powder are added to the ladle for deoxidation and alloying. Then, lime and fluorite are added to form slag. After tapping, the steel is transported to LF refining for further processing. During LF refining, the composition and temperature of the molten steel and the composition of the slag are adjusted. After reaching the required standards, aluminum-deoxidized steel undergoes calcium treatment and then soft stirring. Silicon-manganese-deoxidized steel undergoes soft stirring directly. After soft stirring, the molten steel is directly transported to continuous casting for pouring.

[0008] Furthermore, the molten steel tapped from the converter or electric furnace has a temperature ≥1620℃, a C content of 0.05-0.35%, an O content of 0.015-0.035%, and a slag-blocking mechanism is used during the tapping process, with a slag discharge rate of ≤2.5kg per ton of steel.

[0009] Furthermore, during the process of adding alloys and carbon powder during steel tapping from the converter or electric furnace, the flow rates of permeable bricks No. 1 and No. 4 are 800-1000 NL / min, and the flow rates of permeable bricks No. 2 and No. 3 are 400-600 NL / min. Air is blown and stirred for 30-60 seconds. The flow rates of permeable bricks No. 1 and No. 4 are adjusted to 400-600 NL / min, and the flow rates of permeable bricks No. 2 and No. 3 are adjusted to 800-1000 NL / min. This process is automatically adjusted by the bottom blowing flow control system until steel tapping is completed, there is no accumulated alloy or carbon powder on the slag surface of the ladle, the slag is uniformly melted, bottom blowing is stopped, and the ladle is transported to the LF refining furnace.

[0010] Furthermore, during the LF refining process, when adding alloys, carbon powder, lime, and fluorite to adjust the composition of molten steel and slag, the flow rates of permeable bricks No. 1 and No. 4 are 300-500 NL / min, and the flow rates of permeable bricks No. 2 and No. 3 are 150-250 NL / min. After blowing and stirring for 30-60 seconds, the flow rates of permeable bricks No. 1 and No. 4 are adjusted to 150-250 NL / min, and the flow rates of permeable bricks No. 2 and No. 3 are adjusted to 300-500 NL / min. The bottom blowing flow control system automatically adjusts the flow rate according to this pattern 4-6 times and then stops adjusting.

[0011] Furthermore, during the LF refining process, when the power is applied and the temperature is raised, the flow rate of permeable bricks No. 1 and No. 2 is 400-600 NL / min, and the flow rate of permeable bricks No. 3 and No. 4 is 200-300 NL / min. The air is blown and stirred for 30-60 seconds. The flow rate of permeable bricks No. 1 and No. 2 is adjusted to 200-300 NL / min, and the flow rate of permeable bricks No. 3 and No. 4 is adjusted to 400-600 NL / min. The bottom blowing flow control system automatically adjusts according to this pattern. After the power is applied for a certain period of time, the temperature is measured. Once the temperature reaches the target, the adjustment is stopped.

[0012] Furthermore, after the LF refining is completed, the aluminum is calmed and subjected to calcium treatment. During calcium treatment, the wire feeding position is between the No. 1 and No. 2 permeable bricks. When feeding the wire, the flow rate of the No. 1 and No. 3 permeable bricks is 200-300 NL / min, and the flow rate of the No. 2 and No. 4 permeable bricks is 100-150 NL / min. The air is blown and stirred for 30-60 seconds. The flow rate of the No. 1 and No. 3 permeable bricks is adjusted to 100-150 NL / min, and the flow rate of the No. 2 and No. 4 permeable bricks is adjusted to 200-300 NL / min. The bottom blowing flow control system automatically adjusts the flow rate according to this pattern until the calcium treatment is completed, and then soft stirring treatment is performed.

[0013] Furthermore, after the calcium treatment, the aluminum-killed steel undergoes soft stirring treatment. After LF refining, the silicon-manganese-killed steel undergoes soft stirring treatment directly. During the soft stirring treatment, the flow rate of permeable bricks No. 1, No. 2, and No. 3 is 50-100 NL / min, and the flow rate of permeable brick No. 4 is 30-50% lower. During the soft blowing process, the slag surface of the ladle vibrates slightly, and the molten steel is not exposed. The soft stirring time is ≥15 minutes, and then the steel is tapped and transported to continuous casting for pouring.

[0014] Furthermore, the casting is carried out using a 140mm×140mm square billet continuous casting machine, with full protection during the continuous casting process.

[0015] Furthermore, the continuously cast billet is sampled, and cross-sectional samples are analyzed using scanning electron microscopy to count inclusions, with a statistical area of ​​1000 mm². 2 The number of oxide inclusions larger than 1 micrometer was statistically analyzed, and the number of inclusions with a size ≥15 micrometers was <0.005 per mm. 2 The maximum size should not exceed 35μm, and the total number of inclusions larger than 1μm should be ≤8.5 per mm. 2 .

[0016] The working principle of this invention is:

[0017] This invention firstly employs a high-carbon steelmaking process in converter or electric furnace tapping to reduce the oxygen content of the molten steel and decrease the total amount of inclusions generated during deoxidation and alloying in the tapping process. Secondly, it innovatively uses four permeable bricks evenly distributed at the bottom of the ladle. Different bottom-blowing flow rates are allocated according to different operating steps in the converter or electric furnace tapping and LF refining processes. Simultaneously, the flow rate at different locations is adjusted during stirring to accelerate composition and temperature uniformity and promote the flotation and removal of inclusions.

[0018] When adding alloys and carbon powder to adjust the steel composition during the tapping stage of converters or electric furnaces and the refining stage of LF (Leaf Processing) steelmaking, using two relatively opposing permeable bricks with the same flow rate, continuously and uninterruptedly adjusting their flow rates, can prevent alloys, especially carbon powder, from accumulating in a certain area of ​​the slag surface. The difference in flow rate creates circulation, allowing the alloys to be quickly entrained into the molten steel. At the same time, switching the flow rate of the permeable bricks in different directions accelerates the homogenization of the composition, thereby improving refining efficiency. Traditional double or triple permeable brick control methods, with each having the same flow rate, can cause insufficient local mixing, dead zones, and very slow homogenization of composition and temperature.

[0019] During the LF refining heating stage, adjacent permeable bricks are switched continuously with the same flow rate, and the total flow rate is higher than that used for adjusting the composition in LF refining. This is because the LF refining process has a longer total time, allowing sufficient time for composition homogenization. However, during the heating stage, the surface temperature of the ladle is very high. If the high-temperature molten steel is not quickly cooled and drawn to the bottom to homogenize the temperature, a large amount of heat will be lost to the air, resulting in uneven steel temperature, significant energy loss, increased power consumption, and a substantial increase in production costs.

[0020] In the calcium refining stage, the wire is fed between a high-flow-rate and a low-flow-rate permeable brick, which easily forms a circulation, accelerating the entrainment of Ca elements into the molten steel. Under the action of the circulation of the other two permeable bricks, Ca elements are quickly and evenly distributed. The total flow rate of the permeable bricks is significantly reduced in this stage, avoiding a large amount of molten steel being exposed, which would cause Ca elements to oxidize in the air and result in losses. This stabilizes the calcium treatment effect and obtains the target inclusion composition.

[0021] Finally, during the LF refining soft stirring stage, the overall flow rate of the permeable bricks is significantly reduced to avoid breaking the slag surface and exposing the molten steel. At the same time, three of the permeable bricks have relatively large flow rates, while one permeable brick has a smaller flow rate, forming a stable circulation that promotes the uniform and stable flotation and removal of inclusions. This avoids switching the flow rate back and forth, which would cause the inclusions to be evenly dispersed and distributed, which would be detrimental to the overall removal of inclusions.

[0022] The method described in this invention represents a significant technological advancement in terms of uniform steel composition and temperature, slag removal, and inclusion removal, achieving a simultaneous improvement in LF refining efficiency and steel cleanliness.

[0023] The beneficial effects of this invention are:

[0024] (1) The uniform distribution scheme of the bottom-blown permeable bricks of the steel ladle designed in this invention avoids the problem of large dead zone caused by two or three permeable bricks in the traditional steel ladle, and improves the efficiency and effect of bottom-blown agitation of the steel ladle.

[0025] (2) The steel ladle is uniformly distributed with permeable bricks. The innovative use of separate operation and precise flow control mode has achieved the control objectives of efficient and uniform steel composition and temperature, and rapid removal of inclusions, thus realizing efficient and high-quality smelting. Attached Figure Description

[0026] Figure 1 This is a schematic diagram showing the distribution of the four permeable bricks at the bottom of the steel ladle according to the present invention.

[0027] Figure 2 This is a schematic diagram of the breathable brick of the present invention.

[0028] Figure 3 This is a schematic diagram of the base of the present invention.

[0029] List of reference numerals in the attached diagram: 1—permeable brick, 2—steel outlet, 3—bottom of steel ladle, 4—permeable core, 5—base, 6—air pipe. Detailed Implementation

[0030] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0031] Combined with appendix Figure 1-3 This patent describes a steel ladle with four breathable bricks 1. Four breathable bricks are evenly spaced around the bottom circumference 3 of the ladle. The line connecting two opposing breathable bricks 1 passes through the center of the bottom 3, and the two sets are connected at a 90° angle. The outlet 2 is located on a diameter of the bottom 3, and this diameter lies on the midline of the angle between the two breathable bricks 1 on either side and the center of the circle.

[0032] Combination Figure 2 This paper introduces the structural design of the breathable brick 1 of this patent. The breathable brick has a breathable core inside, which is conical in shape. The outer diameter of the breathable core on the side in contact with molten steel is 130mm, and the outer diameter on the side of the breathable core connected to the air pipe is 188mm. Breathable slits on the side connected to the air pipe are distributed around the inner diameter of the breathable core in a circle of 88mm. The length of the breathable slits on the side connected to the air pipe is 20-30mm, and the width is ≤1.5mm. The height of the slits in the breathable core is 410mm. The bottom of the slits in the breathable core is connected to a porous breathable base brick, which is 110mm high and is sealed inside the breathable brick together with it. An air blowing pipe is connected to the center of the base brick to blow air into the breathable core.

[0033] Combination Figure 3 This patent describes the structure of the base 5. A raised ring is provided on the outer side of the base 5 to reinforce connection stability and effectively prevent the base from wobbling or moving. Narrow slits for ventilation are provided on both the upper and lower surfaces of the base 5. Airflow enters these slits, disperses evenly around the circumference, then enters the upward-conical channel, then the upper narrow slit, and finally reaches the upper part of the ventilation core.

[0034] The overall process of this invention is as follows: After the converter or electric furnace smelting is completed, the molten steel is poured into a ladle and then transported to the LF refining process. After refining, soft stirring is performed to remove inclusions, and then the steel is transported to continuous casting for pouring. The core is the control of high-carbon steel tapping in the converter or electric furnace. A ladle with four permeable bricks is used to receive the molten steel. During the tapping process, alloys and carbon powder are added to the ladle for deoxidation and alloying. Then, lime and fluorite are added to form slag. After tapping, the steel is transported to the LF refining process for further treatment. During the LF refining process, the composition and temperature of the molten steel and the composition of the slag are adjusted. After reaching the required standards, aluminum-deoxidized steel undergoes calcium treatment and then soft stirring. Silicon-manganese-deoxidized steel undergoes soft stirring directly. After soft stirring, the molten steel is directly transported to continuous casting for pouring.

[0035] The temperature of molten steel tapped from the converter or electric furnace is ≥1620℃, the carbon content is 0.05-0.35%, the oxygen content is 0.015-0.035%, the slag is blocked by a sliding plate during tapping, and the amount of slag discharged is ≤2.5kg per ton of steel.

[0036] During the process of adding alloys and carbon powder during steel tapping from the converter or electric furnace, the flow rate of permeable bricks No. 1 and No. 4 is 800-1000 NL / min, and the flow rate of permeable bricks No. 2 and No. 3 is 400-600 NL / min. After blowing and stirring for 30-60 seconds, the flow rate of permeable bricks No. 1 and No. 4 is adjusted to 400-600 NL / min, and the flow rate of permeable bricks No. 2 and No. 3 is adjusted to 800-1000 NL / min. The bottom blowing flow control system automatically adjusts according to this pattern until the steel tapping is completed. When there is no accumulation of alloys and carbon powder on the slag surface of the ladle and the slag is melted evenly, the bottom blowing is stopped, and the ladle is transported to the LF refining furnace.

[0037] When adding alloys, carbon powder, lime, and fluorite to adjust the composition of molten steel and slag during the LF refining process, the flow rate of permeable bricks No. 1 and No. 4 is 300-500 NL / min, and the flow rate of permeable bricks No. 2 and No. 3 is 150-250 NL / min. After blowing and stirring for 30-60 seconds, the flow rate of permeable bricks No. 1 and No. 4 is adjusted to 150-250 NL / min, and the flow rate of permeable bricks No. 2 and No. 3 is adjusted to 300-500 NL / min. The bottom blowing flow control system automatically adjusts the flow rate according to this pattern 4-6 times and then stops adjusting.

[0038] During the LF refining process, when the power is applied and the temperature is raised, the flow rate of permeable bricks No. 1 and No. 2 is 400-600 NL / min, and the flow rate of permeable bricks No. 3 and No. 4 is 200-300 NL / min. After blowing and stirring for 30-60 seconds, the flow rate of permeable bricks No. 1 and No. 2 is adjusted to 200-300 NL / min, and the flow rate of permeable bricks No. 3 and No. 4 is adjusted to 400-600 NL / min. The bottom blowing flow control system automatically adjusts according to this pattern. After the power is applied for a certain period of time, the temperature is measured, and the adjustment is stopped once the temperature reaches the target.

[0039] After LF refining is completed, aluminum is treated with calcium. During calcium treatment, the wire feed position is between permeable bricks No. 1 and No. 2. When feeding wire, the flow rate of permeable bricks No. 1 and No. 3 is 200-300 NL / min, and the flow rate of permeable bricks No. 2 and No. 4 is 100-150 NL / min. Air blowing and stirring are performed for 30-60 seconds. The flow rate of permeable bricks No. 1 and No. 3 is adjusted to 100-150 NL / min, and the flow rate of permeable bricks No. 2 and No. 4 is adjusted to 200-300 NL / min. The bottom blowing flow control system automatically adjusts according to this pattern until the calcium treatment is completed, and then soft stirring treatment is performed.

[0040] After calcium treatment, the aluminum-killed steel undergoes soft stirring. After LF refining, the silicon-manganese-killed steel undergoes soft stirring directly. During the soft stirring process, the flow rate of permeable bricks No. 1, No. 2, and No. 3 is 50-100 NL / min, and the flow rate of permeable brick No. 4 is 30-50% lower. During the soft blowing process, the slag surface of the ladle vibrates slightly, and the molten steel is not exposed. The soft stirring time is ≥15 minutes. Then the steel is tapped and transported to continuous casting for pouring.

[0041] The casting was carried out using a 140mm×140mm square billet continuous casting machine, with full protection during the continuous casting process.

[0042] The method provided by this invention innovatively uses four permeable bricks. According to the control requirements of the molten steel flow field, the four permeable bricks adopt different flow rates to accelerate the removal of inclusions in the molten steel. At the same time, it also has the beneficial effect of promoting the uniformity of steel composition and temperature, which is beneficial to shortening the smelting time and improving the cleanliness of molten steel.

[0043] The technical means disclosed in this invention are not limited to those disclosed above, but also include technical solutions composed of any combination of the above technical features.

[0044] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for efficiently removing inclusions from molten steel, wherein after converter or electric furnace smelting, the molten steel is poured into a ladle, then transported to LF refining, where soft stirring is performed to remove inclusions after refining, and then the steel is transported to continuous casting for pouring, characterized in that, Four permeable bricks are evenly distributed around the bottom circumference of the ladle, with a steel outlet located between two adjacent permeable bricks. The line connecting two adjacent permeable bricks to the center of the ladle forms a 90-degree angle. o At the corner, the permeable bricks are distributed at a position close to 50-60% of the outer radius of the steel ladle. The four permeable bricks are numbered sequentially as permeable brick 1, permeable brick 2, permeable brick 3, and permeable brick 4. High-carbon steel is controlled during tapping in converters or electric furnaces. The molten steel is received in a ladle as described above. During the tapping process, alloys and carbon powder are added to the ladle for deoxidation and alloying. Then, lime and fluorite are added to form slag. After tapping, the steel is transported to the LF refining process for further treatment. During the LF refining process, the composition and temperature of the molten steel and the composition of the slag are adjusted. After meeting the standards, aluminum-deoxidized steel undergoes calcium treatment and then soft stirring. Silicon-manganese-deoxidized steel undergoes soft stirring directly. After soft stirring, the molten steel is directly transported to the continuous casting for pouring. During the process of adding alloys and carbon powder during steel tapping from the converter or electric furnace, the flow rate of permeable bricks No. 1 and No. 4 is 800-1000 NL / min, and the flow rate of permeable bricks No. 2 and No. 3 is 400-600 NL / min. The air is blown and stirred for 30-60 seconds. The flow rate of permeable bricks No. 1 and No. 4 is adjusted to 400-600 NL / min, and the flow rate of permeable bricks No. 2 and No. 3 is adjusted to 800-1000 NL / min. The bottom blowing flow control system automatically adjusts according to this pattern until the steel tapping is completed. There is no accumulation of alloys and carbon powder on the slag surface of the ladle, and the slag is melted evenly. The bottom blowing is then stopped, and the ladle is transported to the LF refining furnace. After the LF refining process is completed, the aluminum is calmed and subjected to calcium treatment. During calcium treatment, the wire feeding position is between permeable bricks No. 1 and No.

2. When feeding the wire, the flow rate of permeable bricks No. 1 and No. 3 is 200-300 NL / min, and the flow rate of permeable bricks No. 2 and No. 4 is 100-150 NL / min. The air is blown and stirred for 30-60 seconds. The flow rate of permeable bricks No. 1 and No. 3 is adjusted to 100-150 NL / min, and the flow rate of permeable bricks No. 2 and No. 4 is adjusted to 200-300 NL / min. The bottom blowing flow control system automatically adjusts the flow rate according to this pattern until the calcium treatment is completed, and then soft stirring treatment is performed.

2. The method for efficiently removing inclusions from molten steel according to claim 1, characterized in that, The inside of the permeable brick is a permeable core, which is conical in shape. The outer diameter of the permeable core on the side in contact with molten steel is 130mm, and the outer diameter on the side of the permeable core connected to the air pipe is 188mm. The permeable slits on the side connected to the air pipe are distributed in a circle around the inner diameter of the permeable core of 88mm. The length of the permeable slits on the side connected to the air pipe is 20-30mm, and the width is ≤1.5mm. The height of the slits in the permeable core is 410mm. The bottom of the slits in the permeable core is connected to a porous permeable base brick, which is 110mm high and is sealed inside the permeable brick together with it. An air blowing pipe is connected to the center of the base brick to blow air into the permeable core.

3. The method for efficiently removing inclusions from molten steel according to claim 1, characterized in that, The steel ladle has a diameter of 3200mm, and the permeable brick has a height × length × width of 550mm × 320mm × 320mm.

4. The method for efficiently removing inclusions from molten steel according to claim 1, characterized in that, The molten steel tapping temperature of the converter or electric furnace is ≥1620℃, the C content is 0.05-0.35%, the O content is 0.015-0.035%, the tapping process adopts a sliding plate to block slag, and the slag discharge amount is ≤2.5kg per ton of steel.

5. The method for efficiently removing inclusions from molten steel according to claim 1, characterized in that, When adding alloys, carbon powder, lime, and fluorite to adjust the composition of molten steel and slag during the LF refining process, the flow rate of permeable bricks No. 1 and No. 4 is 300-500 NL / min, and the flow rate of permeable bricks No. 2 and No. 3 is 150-250 NL / min. After blowing and stirring for 30-60 seconds, the flow rate of permeable bricks No. 1 and No. 4 is adjusted to 150-250 NL / min, and the flow rate of permeable bricks No. 2 and No. 3 is adjusted to 300-500 NL / min. The bottom blowing flow control system automatically adjusts the flow rate according to this pattern 4-6 times and then stops adjusting.

6. The method for efficiently removing inclusions from molten steel according to claim 1, characterized in that, When the LF refining process is energized and heated, the flow rate of permeable bricks No. 1 and No. 2 is 400-600 NL / min, and the flow rate of permeable bricks No. 3 and No. 4 is 200-300 NL / min. After blowing and stirring for 30-60 seconds, the flow rate of permeable bricks No. 1 and No. 2 is adjusted to 200-300 NL / min, and the flow rate of permeable bricks No. 3 and No. 4 is adjusted to 400-600 NL / min. The bottom blowing flow control system automatically adjusts according to this pattern. After being energized for a certain period of time, the temperature is measured, and the adjustment is stopped once the temperature reaches the target.

7. The method for efficiently removing inclusions from molten steel according to claim 1, characterized in that, After the calcium treatment is completed, the aluminum-killed steel undergoes soft stirring. After LF refining is completed, the silicon-manganese-killed steel undergoes soft stirring directly. During the soft stirring process, the flow rate of permeable bricks No. 1, No. 2, and No. 3 is 50-100 NL / min, and the flow rate of permeable brick No. 4 is 30-50% lower than 50-100 NL / min. During the soft blowing process, the slag surface of the ladle vibrates slightly, and the molten steel is not exposed. The soft stirring time is ≥15 minutes, and then the steel is tapped and transported to continuous casting for pouring.

8. The method for efficiently removing inclusions from molten steel according to claim 1, characterized in that, The casting was carried out using a 140mm×140mm square billet continuous casting machine, with full protection during the continuous casting process.

9. The method for efficiently removing inclusions from molten steel according to claim 1, characterized in that, Samples were taken from the continuously cast billet, and cross-sectional samples were analyzed using scanning electron microscopy to count inclusions, with a statistical area of ​​1000 mm². 2 The number of oxide inclusions larger than 1 micrometer was statistically analyzed, and the number of inclusions with a size ≥15 micrometers was <0.005 per mm. 2 The maximum size should not exceed 35μm, and the total number of inclusions larger than 1μm should be ≤8.5 per mm. 2 .

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