Method for deoxidizing and controlling boron element of boron-added steel

Abstract

The invention belongs to the technical field of steelmaking refining, and particularly relates to a method for controlling boron element through deoxidation of boron-added steel, which comprises the following steps: S1, during converter tapping, molten steel is subjected to deoxidation treatment, and during tapping, a special slag surface deoxidizer is added for treatment, and 50-300kg of special slag surface deoxidizer is added; s2, LF refining deep deoxidation treatment is conducted, the aluminum content of molten steel ranges from 0.010% to 0.50%, and a special slag surface deoxidizing agent is used; s3, decarburization treatment is conducted through an RH vacuum furnace, and the decarburization oxygen blowing amount of the vacuum furnace is 50-300 Nm < 3 >; the method cooperates with vacuum breaking of an RH furnace for slag surface deoxidation again, protection of an ultra-low carbon heat preservation agent, stirring time, improvement of the internal quality of a continuous casting blank and good blank shape, the more important effect is achieved, the problem that the boron element of boron-added steel is low is solved in time, good fluidity of tundish molten steel can be continuously kept, the production efficiency is improved, and the production cost is reduced. And therefore, the quality of the ultra-low carbon boron-added steel continuous casting billet is obviously improved, and the production cost is directly and indirectly reduced.

Description

Technical Field

[0001] This invention relates to the field of steelmaking and refining technology, and in particular to a method for controlling boron content in boron-added steel during deoxidation. Background Technology

[0002] Boron, as an alloying element in steel, not only improves the hardenability of steel but also enhances its hardness, high-temperature strength, and strengthens grain boundaries. Small amounts of boron in steel can replace some nickel, molybdenum, and chromium. Given the abundance of boron ore resources, boron-containing steel offers considerable economic benefits and has broad application prospects. Stabilizing boron element control in boron-added steel and improving the quality of continuously cast billets to prevent cracking and leaks is a common technical challenge faced by the steel industry today.

[0003] A Chinese patent with publication number CN117965839A discloses a process for smelting ultra-low boron steel in a converter, including the following control steps: in the converter smelting process, controlling the temperature in the converter to remain within the range of 1398-1518℃ for as long as possible; in the deoxidation and alloying process after tapping, controlling the materials to prevent boron accumulation in the molten steel; in the LF and VD refining processes, preventing boron from being reduced from the refining slag into the molten steel; and in the continuous casting process, using low-boron refractory materials in the ladle to prevent boron accumulation in the molten steel. This ingenious design eliminates the need for slag removal, saving costs by controlling the extremely low boron content of the molten steel tapped from the converter and preventing boron accumulation in the materials. Combined with precise control of the steelmaking process, it can control the residual boron in the steel to below 2ppm, producing high-quality ultra-low boron steel with narrow hardenability and good low-temperature impact toughness.

[0004] In current technologies, low-carbon steel produced by converters is deoxidized using lime and aluminum, followed by refining and extensive deoxidation and slag formation. However, for low-carbon boron-containing steel products with low carbon and boron content, boron is easily oxidized and difficult to control when the steel deoxidation is inadequate. Furthermore, the slag formation process for steel grades requires a large amount of slag, and the slag leaving the refining station has poor fluidity. The slag arriving at the RH station is viscous, and when ferroboron is added, it easily enters the slag instead of the molten steel, making it difficult to control the boron composition. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the problems of the prior art, thereby providing a method for controlling boron element in deoxidation of boron-added steel.

[0006] To solve the above-mentioned technical problems, the present invention provides a method for controlling boron content during deoxidation of boron-added steel, comprising the following steps:

[0007] S1: When tapping steel from the converter, the molten steel undergoes deoxidation treatment. A special slag surface deoxidizer is added during tapping, with 50–300 kg of the special slag deoxidizer used.

[0008] S2: LF refining deep deoxidation treatment, with an aluminum content of 0.010-0.50% in molten steel, and using a special slag surface deoxidizer;

[0009] S3: RH vacuum furnace decarburization treatment, vacuum furnace decarburization oxygen blowing rate 50-300 Nm 3 The content of element B is 0.006-0.015%;

[0010] S4: After the RH vacuum furnace is ventilated, add an appropriate amount of special slag surface deoxidizer and ultra-low carbon heat preservation agent for protection, and stir for 5-15 minutes.

[0011] In one embodiment of the present invention, when the converter in S1 taps steel, it is poured into a ladle; the top of the ladle is provided with a cover plate, and two storage cylinders are symmetrically arranged at both ends of the cover plate, with the bottom ends of the storage cylinders connected and fixed to the cover plate; a first motor is fixedly connected to the top of each storage cylinder, and the output shaft of the first motor is rotatably connected to the cover plate through bearings, and a spiral blade is fixedly connected to the output shaft of the first motor; a solenoid valve and a flow sensor are installed at the bottom of each storage cylinder; a second motor is fixedly connected to the top of the cover plate through an L-shaped plate, and a rotating rod is fixedly connected to the output shaft of the second motor, and the rotating rod is rotatably connected to the cover plate through bearings; a baffle is fixedly connected to the outer wall of the rotating rod, and the top of the baffle is tightly fitted to the bottom of the storage cylinder; multiple discharge ports are arranged circumferentially on the baffle, and the storage cylinders cooperate with the discharge ports.

[0012] In one embodiment of the present invention, a plurality of stirring paddles are fixedly connected to the outer wall of the bottom end of the rotating rod; an oxygen blowing pipe is inserted into the inside of the rotating rod, the top end of the oxygen blowing pipe extends to the outside of the rotating rod, and a one-way valve is installed thereon.

[0013] In one embodiment of the present invention, a fixing plate is fixedly connected to the top of the cover plate, a cylinder is fixedly connected to the bottom of the fixing plate, a vertical plate is fixedly connected to the output end of the cylinder, and an oxygen lance is fixedly connected to the side wall of the vertical plate on the same side as the cylinder; two sliding rods are fixedly connected to the inner side wall of the fixing plate, and the vertical plate is slidably connected on the two sliding rods.

[0014] In one embodiment of the present invention, two mounting brackets are symmetrically fixed to the outer wall of the top of the ladle tank. A first lead screw is rotatably connected between the two inner side walls of the mounting brackets via bearings. A connecting plate is threaded onto each of the first lead screws, and the connecting plates are fixed to the outer wall of the cover plate. A third motor is fixed to the top of each mounting bracket. The output shaft of the third motor is fixed to the top of the first lead screw. Two guide rods are fixed between the two inner side walls of the mounting bracket, and the connecting plates are slidably connected to the two guide rods respectively.

[0015] In one embodiment of the present invention, a fixing frame is fixedly connected to one end of the cover plate away from the fixing plate. A second lead screw is rotatably connected between the fixing frame and the cover plate via a bearing. A lifting plate is threaded onto the second lead screw. A connecting rod is fixedly connected to the bottom of the lifting plate. A connecting frame is fixedly connected to the bottom of the connecting rod. A sampling cylinder is rotatably connected to the bottom end of the connecting frame via a pin. A fourth motor is fixedly connected to the top of the fixing frame. The output shaft of the fourth motor is fixedly connected to the top of the second lead screw. Two vertical rods are fixedly connected between the fixing frame and the cover plate. The lifting plate is slidably connected on the two vertical rods.

[0016] In one embodiment of the present invention, the sampling cylinder penetrates through the cover plate, and the baffle plate has a through hole, through which the sampling cylinder slides.

[0017] In one embodiment of the present invention, an electric push rod is fixedly connected to the top of the cover plate, a push plate is fixedly connected to the output end of the electric push rod, two limiting rods are fixedly connected to the bottom of the push plate, two limiting grooves are opened on the top of the cover plate, and the limiting rods slide in the limiting grooves; a receiving groove is inserted into the side wall of the push plate, and the receiving groove is arranged on the same side as the electric push rod.

[0018] In one embodiment of the present invention, the bottom of the ladle tank is connected to two mounting pipes, the bottom of each mounting pipe is connected to a branch pipe, one end of the two branch pipes is connected to a main pipe, a main control valve is installed on the main pipe, and a branch control valve and a flow meter are installed on each branch pipe.

[0019] In one embodiment of the present invention, the inner wall of the ladle tank is provided with a heat insulation layer, and multiple heating wires are fixedly connected to the heat insulation layer; a support plate is rotatably connected to the outer wall of the ladle tank via a rotating shaft; a ladle transport vehicle is provided below the ladle tank, and the support plates are all fixedly connected to the ladle transport vehicle; a drive motor is provided on the outer side of the rotating shaft.

[0020] Compared with the prior art, the above-described technical solution of the present invention has the following advantages:

[0021] The present invention describes a method for controlling boron element content in boron-added steel through deoxidation. This method, combined with RH furnace deoxidation and slag surface deoxidation, ultra-low carbon insulating agent protection, and improved stirring time, significantly enhances the internal quality and shape of the continuously cast billet. Furthermore, it effectively addresses the issue of low boron content in the boron-added steel, maintaining good fluidity of the molten steel in the tundish and improving production efficiency. Consequently, the quality of the ultra-low carbon boron-added steel continuously cast billet is significantly improved, directly and indirectly reducing production costs. Calculations show that using this invention, the continuous casting of ultra-low carbon boron-added steel in the tundish can be improved by approximately five times, indirectly increasing production efficiency.

[0022] This invention discloses a method for controlling boron element content in the deoxidation of boron-added steel. A baffle is installed, and a second motor is activated. The output shaft of the second motor drives a rotating rod to rotate, which in turn drives the baffle to rotate. During rotation, the discharge port on the baffle periodically passes below the storage cylinder, and the width of the discharge port is greater than the diameter of the discharge end of the storage cylinder. The bottom of the baffle is in close contact with the inner wall of the ladle to prevent molten steel from splashing. Then, by activating the corresponding first motor, solenoid valve, and flow sensor, the first motor drives the spiral blades to rotate, discharging a special slag surface deoxidizer from the storage cylinder. The material is quantitatively conveyed to the discharge port on the baffle inside the cylinder, and the spiral blades facilitate the unblocking of the special slag surface deoxidizer. The flow of the special slag surface deoxidizer in the storage cylinder is controlled by a solenoid valve, and the amount of special slag surface deoxidizer used is monitored by a flow sensor. The special slag surface deoxidizer then flows through the discharge port intermittently and closes, which facilitates intermittent feeding and is beneficial for stirring the special slag surface deoxidizer. This prevents a large amount of special slag surface deoxidizer from sticking together when it encounters high-temperature molten steel, making it difficult to disperse and affecting the treatment of molten steel by the special slag surface deoxidizer.

[0023] This invention discloses a method for controlling boron element content in boron-added steel during deoxidation. The method involves setting up a sampling cylinder and a receiving trough. A fourth motor is activated, and its output shaft drives a second lead screw to rotate. The second lead screw then moves a lifting plate, which in turn moves a connecting rod. The connecting rod then moves a connecting frame, which in turn moves the sampling cylinder. When the sampling cylinder moves downwards into the molten steel, it samples the molten steel in the ladle. After sampling, the cylinder moves upwards above the cover plate to remove the sampled molten steel. An electric push rod is then activated, and its output end drives a push plate, which in turn moves the receiving trough. During this movement, the push plate presses against the sampling cylinder, causing it to tilt and allowing the molten steel inside to flow into the receiving trough. The receiving trough is then removed using a tool, allowing for the testing of the molten steel inside. Attached Figure Description

[0024] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0025] Figure 1 This is a flowchart of a method according to an embodiment of the present invention;

[0026] Figure 2 This is a perspective view of the present invention;

[0027] Figure 3 This is a sectional view of the present invention;

[0028] Figure 4 This is a schematic diagram of the baffle structure in this invention;

[0029] Figure 5This is a schematic diagram of the structure of the cover plate and connecting plate in this invention;

[0030] Figure 6 This is a schematic diagram of the sampling tube in this invention;

[0031] Figure 7 This is a schematic diagram of the receiving groove in this invention;

[0032] Figure 8 This is a schematic diagram of the oxygen blowing pipe in this invention;

[0033] Figure 9 This is a schematic diagram of the main pipe and branch pipes in this invention;

[0034] Figure 10 This is a schematic diagram of the structure of the fixing plate in this invention.

[0035] Explanation of reference numerals in the accompanying drawings: 1. Ladle transport vehicle; 11. Support plate; 12. Drive motor; 2. Ladle tank; 21. Cover plate; 22. Storage cylinder; 23. First motor; 24. Spiral blade; 25. Rotating rod; 251. Oxygen blowing pipe; 252. One-way valve; 253. Agitator; 26. Baffle; 27. Discharge port; 28. Second motor; 29. ​​Solenoid valve; 210. Heating wire; 3. Mounting bracket; 31. First lead screw; 32. Guide rod; 33. Third motor; 3 4. Connecting plate; 4. Fixing frame; 41. Sampling cylinder; 42. Connecting frame; 43. Connecting rod; 44. Lifting plate; 45. Second lead screw; 46. Vertical rod; 47. Fourth motor; 5. Receiving groove; 51. Push plate; 52. Electric push rod; 53. Limiting rod; 6. Installation pipe; 61. Branch pipe; 62. Branch control valve; 63. Flow meter; 64. Main pipe; 65. Main control valve; 7. Fixing plate; 71. Cylinder; 72. Vertical plate; 73. Oxygen lance; 74. Slide rod. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0037] Example 1:

[0038] like Figure 1 As shown in the embodiment of the present invention, a method for controlling boron content in boron-added steel during deoxidation includes the following steps:

[0039] S1: When tapping steel from the converter, the molten steel undergoes deoxidation treatment. A special slag surface deoxidizer of 50 kg is added during tapping.

[0040] S2: LF refining deep deoxidation treatment, with an aluminum content of 0.010% in the molten steel, and using a special slag surface deoxidizer;

[0041] S3: RH vacuum furnace decarburization treatment, vacuum furnace decarburization oxygen blowing amount 50Nm3, B element content 0.006%;

[0042] S4: After the RH vacuum furnace is ventilated, add an appropriate amount of special slag surface deoxidizer and ultra-low carbon heat preservation agent for protection, and stir for 5 minutes.

[0043] Example 2:

[0044] like Figure 1 As shown in the embodiment of the present invention, a method for controlling boron content in boron-added steel during deoxidation includes the following steps:

[0045] S1: When tapping steel from the converter, the molten steel undergoes deoxidation treatment. A special slag surface deoxidizer is added during tapping, with 175 kg of the special slag deoxidizer used.

[0046] S2: LF refining deep deoxidation treatment, with an aluminum content of 0.255% in the molten steel, and using a special slag surface deoxidizer;

[0047] S3: RH vacuum furnace decarburization treatment, vacuum furnace decarburization oxygen blowing amount 175Nm3, B element content 0.0105%;

[0048] S4: After the RH vacuum furnace is ventilated, add an appropriate amount of special slag surface deoxidizer and ultra-low carbon heat preservation agent for protection, and stir for 10 minutes.

[0049] Example 3:

[0050] like Figure 1 As shown in the embodiment of the present invention, a method for controlling boron content in boron-added steel during deoxidation includes the following steps:

[0051] S1: When tapping steel from the converter, the molten steel undergoes deoxidation treatment. A special slag surface deoxidizer is added during tapping, with 300 kg of the special slag deoxidizer used.

[0052] S2: LF refining deep deoxidation treatment, with molten steel aluminum content of 0.50%, and using a special slag surface deoxidizer;

[0053] S3: RH vacuum furnace decarburization treatment, vacuum furnace decarburization oxygen blowing amount 300Nm3, B element content 0.015%;

[0054] S4: After the RH vacuum furnace is ventilated, add an appropriate amount of special slag surface deoxidizer and ultra-low carbon heat preservation agent for protection, and stir for 15 minutes.

[0055] The deoxidation method for controlling boron content in boron-added steel provided by this invention involves the following steps during the converter tapping process: When molten steel is poured into the ladle 2, 50-300 kg of a special slag surface deoxidizer is added to form a protective slag layer and perform initial deoxidation. The ladle is then fed into an LF refining furnace, where heating and slag-forming deep deoxidation are performed to adjust the aluminum content of the molten steel to 0.010-0.50%, while simultaneously replenishing the special slag surface deoxidizer to stabilize the oxygen content. Next, in an RH vacuum furnace, the molten steel in the ladle is evacuated and 50-300 Nm³ of oxygen is blown in for decarburization, controlling the boron content to 0.006-0.015%. Finally, after RH vacuum treatment and restoration to atmospheric pressure, the special slag surface deoxidizer and ultra-low carbon are added to the ladle surface again. The heat-insulating agent is stirred for 5-15 minutes with a stirring paddle 253 to ensure uniform composition and prevent secondary oxidation. By sampling the molten steel in the above three examples, the sample obtained in Example 3 contains 300 kg of special slag deoxidizer, 0.50% aluminum content in the molten steel, 300 Nm3 of decarburization oxygen blowing in the vacuum furnace, and 0.015% boron content. This can promptly eliminate and solve the problem of low boron content in boron-added steel, which is conducive to maintaining good fluidity of molten steel in the tundish, improving production efficiency, and thus significantly improving the quality of ultra-low carbon boron-added steel continuous casting billets. This directly and indirectly reduces production costs. It is estimated that using the technology of this invention to continuously cast ultra-low carbon boron-added steel in the tundish about 5 times can indirectly increase production benefits by 3.25 million yuan / year.

[0056] like Figures 2 to 4 As shown, when the steel is tapped from the converter in S1, it is poured into the ladle 2; the top of the ladle 2 is provided with a cover plate 21, and two storage cylinders 22 are symmetrically arranged at both ends of the cover plate 21. The bottom ends of the storage cylinders 22 are connected and fixed to the cover plate 21; a first motor 23 is fixedly connected to the top of each storage cylinder 22, and the output shaft of the first motor 23 is rotatably connected to the cover plate 21 through bearings. A spiral blade 24 is fixedly connected to the output shaft of each first motor 23; the storage cylinder 22... Solenoid valves 29 and flow sensors are installed at the bottom of each device; a second motor 28 is fixedly connected to the top of the cover plate 21 via an L-shaped plate, and a rotating rod 25 is fixedly connected to the output shaft of the second motor 28. The rotating rod 25 is rotatably connected to the cover plate 21 via bearings. A baffle 26 is fixedly connected to the outer wall of the rotating rod 25, and the top of the baffle 26 is tightly fitted to the bottom of the storage cylinder 22. Multiple discharge ports 27 are arranged circumferentially on the baffle 26, and the storage cylinder 22 cooperates with the discharge ports 27.

[0057] The baffle 26 provided by this invention is used for intermittent discharge from the storage cylinders 22. The two storage cylinders 22 contain a special slag surface deoxidizer and an ultra-low carbon heat-insulating agent, respectively. When needed, the second motor 28 is turned on, and the output shaft of the second motor 28 drives the rotating rod 25 to rotate, which in turn drives the baffle 26 to rotate. When the baffle 26 rotates, the discharge port 27 on the baffle 26 periodically passes under the storage cylinders 22, and the width of the discharge port 27 is greater than the diameter of the discharge end of the storage cylinder 22. The bottom of the baffle 26 is in close contact with the inner wall of the ladle to prevent molten steel from splashing. Then, the corresponding first motor 23, solenoid valve 29, and flow sensor are turned on, and the discharge is controlled by the first motor... The machine 23 drives the spiral blades 24 to rotate, quantitatively conveying the special slag surface deoxidizer from the storage cylinder 22 to the discharge port 27 on the baffle 26. Under the action of the spiral blades 24, it is easy to unblock the discharge of the special slag surface deoxidizer. The flow of the special slag surface deoxidizer in the storage cylinder 22 is controlled by the solenoid valve 29. The flow sensor is used to monitor the amount of special slag surface deoxidizer used. Then, the special slag surface deoxidizer flows and closes intermittently through the discharge port 27, which facilitates intermittent feeding and is beneficial to the stirring of the special slag surface deoxidizer. It prevents a large amount of special slag surface deoxidizer from sticking together when it encounters high-temperature molten steel, making it difficult to disperse and affecting the treatment of molten steel by the special slag surface deoxidizer.

[0058] like Figure 3 and Figure 8 As shown, a plurality of stirring paddles 253 are fixedly connected to the bottom outer wall of the rotating rod 25; an oxygen blowing pipe 251 is inserted into the inside of the rotating rod 25, the top end of the oxygen blowing pipe 251 extends to the outside of the rotating rod 25, and a one-way valve 252 is installed thereon.

[0059] The stirring paddle 253 provided by this invention is used to agitate molten steel during RH treatment to promote decarburization reaction; the oxygen blowing pipe 251 is inserted into the rotating rod 25, with its top end extending above the cover plate 21. The oxygen flow is controlled by the one-way valve 252 to prevent backflow of molten steel. When oxygen blowing is required, oxygen is blown from the top of the oxygen blowing pipe 251 and flows out from the bottom of the rotating rod 25, which makes it easy to control the oxygen flow from the bottom of the molten steel and prevent it from being too high, making it difficult to react fully with carbon.

[0060] like Figure 10 As shown, a fixing plate 7 is fixedly connected to the top of the cover plate 21, a cylinder 71 is fixedly connected to the bottom of the fixing plate 7, a vertical plate 72 is fixedly connected to the output end of the cylinder 71, and an oxygen blowing gun 73 is fixedly connected to the side wall of the vertical plate 72 on the same side as the cylinder 71; two sliding rods 74 are fixedly connected to the inner side wall of the fixing plate 7, and the vertical plate 72 is slidably connected on the two sliding rods 74.

[0061] The oxygen lance 73 provided by this invention is used to supply oxygen to the oxygen lance 251. When oxygen blowing is needed, the oxygen lance 251 is rotated to one side of the oxygen lance 73 by the rotating rod 25. The cylinder 71 is opened, and the output end of the cylinder 71 drives the vertical plate 72 to move. The vertical plate 72 drives the oxygen lance 73 to move until the nozzle of the oxygen lance 73 is inserted into the oxygen lance 251. Then the one-way valve 252 is opened, and oxygen can be blown into the oxygen lance 251 through the oxygen lance 73. During the movement, the vertical plate 72 slides on two sliding rods 74, and the sliding rods 74 limit the vertical plate 72 to move in the horizontal direction. The oxygen lance 73 is connected to an external oxygen source, and the oxygen blowing time and flow rate are controlled by a PLC to cooperate with the RH vacuum decarbonization process.

[0062] like Figure 5 As shown, two mounting brackets 3 are symmetrically fixed to the outer wall of the top of the steel ladle tank 2. A first lead screw 31 is rotatably connected between the two inner walls of the mounting bracket 3 via bearings. A connecting plate 34 is threaded onto the first lead screw 31. The connecting plates 34 are fixed to the outer wall of the cover plate 21. A third motor 33 is fixed to the top of the mounting bracket 3. The output shaft of the third motor 33 is fixed to the top of the first lead screw 31. Two guide rods 32 are fixed between the two inner walls of the mounting bracket 3. The connecting plates 34 are slidably connected to the two guide rods 32 respectively.

[0063] The first lead screw 31 provided by this invention is used to drive the lifting and lowering of the cover plate 21 during use. At the same time, two third motors 33 are turned on. The output shafts of the third motors 33 drive the first lead screw 31 to rotate, and the first lead screw 31 drives the connecting plate 34 to move. When the two connecting plates 34 move upward, they drive the cover plate 21 to move upward, thereby separating the cover plate 21 from the ladle tank 2, which facilitates steel tapping. When the two connecting plates 34 move downward, they drive the cover plate 21 to move downward until the ladle tank 2 is tightly covered, which facilitates deoxidation, decarburization and other treatment operations. During the movement, the connecting plate 34 slides on the guide rod 32, and the guide rod 32 limits the movement of the connecting plate 34 in the vertical direction.

[0064] like Figure 2 and Figure 6As shown, a fixing frame 4 is fixedly connected to one end of the cover plate 21 away from the fixing plate 7. A second lead screw 45 is rotatably connected between the fixing frame 4 and the cover plate 21 via a bearing. A lifting plate 44 is threadedly connected to the second lead screw 45. A connecting rod 43 is fixedly connected to the bottom of the lifting plate 44. A connecting frame 42 is fixedly connected to the bottom of the connecting rod 43. A sampling cylinder 41 is rotatably connected to the bottom end of the connecting frame 42 via a pin. A fourth motor 47 is fixedly connected to the top of the fixing frame 4. The output shaft of the fourth motor 47 is fixedly connected to the top of the second lead screw 45. Two vertical rods 46 are fixedly connected between the fixing frame 4 and the cover plate 21. The lifting plate 44 is slidably connected to the two vertical rods 46.

[0065] The second lead screw 45 provided by this invention is used to drive the lifting and lowering of the sampling cylinder 41. By turning on the fourth motor 47, the output shaft of the fourth motor 47 drives the second lead screw 45 to rotate, which in turn drives the lifting plate 44 to move. The lifting plate 44 drives the connecting rod 43 to move, which in turn drives the connecting frame 42 to move. The connecting frame 42 then drives the sampling cylinder 41 to move. When the sampling cylinder 41 moves downward into the molten steel, it can sample the molten steel in the ladle 2. After sampling, it moves upward to above the cover plate 21, where the sampled molten steel can be taken out for testing. During the movement, the lifting plate 44 slides on the vertical rod 46, which limits the movement of the lifting plate 44 in the vertical direction.

[0066] like Figure 4 and Figure 5 As shown, the sampling cylinder 41 penetrates the cover plate 21, and the baffle 26 has a through hole, through which the sampling cylinder 41 slides.

[0067] When the sampling cylinder 41 provided by the present invention is used, a high-temperature resistant ceramic sleeve is embedded in the through hole of the baffle 26, and the gap between the outer diameter of the sampling cylinder 41 and the sleeve is ≤1mm to prevent molten steel leakage; the sampling cylinder 41 is made of tungsten alloy, which can withstand a high temperature of 1600℃, and the single sampling amount is controlled at 50-100g.

[0068] like Figure 7 As shown, an electric push rod 52 is fixedly connected to the top of the cover plate 21, and a push plate 51 is fixedly connected to the output end of the electric push rod 52. Two limiting rods 53 are fixedly connected to the bottom of the push plate 51. Two limiting grooves are opened on the top of the cover plate 21, and the limiting rods 53 slide in the limiting grooves. A receiving groove 5 is inserted into the side wall of the push plate 51, and the receiving groove 5 is arranged on the same side as the electric push rod 52.

[0069] The receiving groove 5 provided by the present invention is used to receive molten steel in the sampling cylinder 41. By turning on the electric push rod 52, the output end of the electric push rod 52 drives the push plate 51 to move, and the push plate 51 drives the receiving groove 5 to move. When the push plate 51 moves, it squeezes the sampling cylinder 41, thereby tilting the sampling cylinder 41. The molten steel in the sampling cylinder 41 flows into the receiving groove 5. Then, the receiving groove 5 can be removed with the help of tools, and the molten steel inside can be tested.

[0070] like Figures 1 to 2 As shown, the bottom of the ladle tank 2 is connected to two installation pipes 6, and the bottom of each installation pipe 6 is connected to a branch pipe 61. One end of each branch pipe 61 is connected to a main pipe 64. A main control valve 65 is installed on the main pipe 64, and a branch control valve 62 and a flow meter 63 are installed on each branch pipe 61.

[0071] The main pipe 64 and branch pipe 61 provided by this invention are used for bottom blowing argon. During steel tapping, auxiliary argon blowing can be performed in a timely manner when bottom blowing argon is insufficient, ensuring smooth production and avoiding the impact of excessively increasing the bottom blowing argon flow rate on the service life of the ladle. Opening only one side of branch pipe 61 is suitable for small-capacity ladle tank 2 or local stirring needs. Opening both branch pipes 61 simultaneously achieves uniform stirring of molten steel through differentiated flow rates. Data is collected in real time by flow meter 63 and fed back to the PLC system to dynamically adjust the opening of branch control valve 62. When the flow deviation of a branch pipe 61 exceeds ±5%, an audible and visual alarm is triggered and the backup pipeline is activated. This achieves reasonable control of the blowing argon amount, effectively improves the composition of molten steel, enhances steel quality, and reduces production costs.

[0072] like Figure 3 As shown, the inner wall of the ladle tank 2 is provided with a heat insulation layer, and multiple heating wires 210 are fixedly connected inside the heat insulation layer; the outer wall of the ladle tank 2 is rotatably connected to a support plate 11 via a rotating shaft; a ladle transport vehicle 1 is provided below the ladle tank 2, and the support plate 11 is fixedly connected to the ladle transport vehicle 1; a drive motor 12 is provided on the outer side of the rotating shaft.

[0073] When in use, the insulation layer provided by the present invention is filled with alumina hollow spheres and the heating wire 210 has a power density of 2kW / m² to maintain the temperature of the ladle. The ladle tank 2 is rotated by the drive motor 12 to facilitate the pouring out of the molten steel from the ladle milk.

[0074] Working Principle: This method utilizes deoxidation to control boron levels, combined with RH furnace degassing and slag surface deoxidation, ultra-low carbon insulating agent protection, and stirring time. Improving the internal quality and shape of the continuously cast billet is also crucial. This patent provides a technical method for controlling boron levels in boron-added steel through deoxidation, promptly eliminating the problem of low boron content in boron-added steel. This helps maintain good fluidity of molten steel in the tundish, improving production efficiency. Consequently, the quality of ultra-low carbon boron-added steel continuously cast billets is significantly improved, directly and indirectly reducing production costs. Calculations show that using this invention, ultra-low carbon boron-added steel tundish continuous casting can be improved by approximately 5 times, indirectly increasing production benefits.

[0075] Two storage cylinders 22 contain a special slag surface deoxidizer and an ultra-low carbon heat-insulating agent, respectively. When needed, the second motor 28 is turned on, and the output shaft of the second motor 28 drives the rotating rod 25 to rotate, which in turn drives the baffle 26 to rotate. When the baffle 26 rotates, the discharge port 27 on the baffle 26 periodically passes under the storage cylinder 22, and the width of the discharge port 27 is greater than the diameter of the discharge end of the storage cylinder 22. The bottom of the baffle 26 is in close contact with the inner wall of the ladle to prevent molten steel from splashing. Then, the corresponding first motor 23, solenoid valve 29, and flow sensor are turned on, and the first motor 23 drives the spiral blade 24 to rotate, thus... The special slag surface deoxidizer is quantitatively conveyed from the storage cylinder 22 to the discharge port 27 on the baffle 26. Under the action of the spiral blades 24, the discharge of the special slag surface deoxidizer is facilitated. The flow of the special slag surface deoxidizer in the storage cylinder 22 is controlled by the solenoid valve 29. The flow sensor is used to monitor the amount of special slag surface deoxidizer used. Then, the special slag surface deoxidizer flows and closes intermittently through the discharge port 27, which facilitates intermittent feeding and is beneficial to the stirring of the special slag surface deoxidizer. This prevents a large amount of special slag surface deoxidizer from sticking together when it encounters high-temperature molten steel, making it difficult to disperse and affecting the treatment of molten steel by the special slag surface deoxidizer.

[0076] When oxygen blowing is required, the oxygen blowing pipe 251 is rotated to one side of the oxygen blowing gun 73 by the rotating rod 25. The cylinder 71 is opened, and the output end of the cylinder 71 drives the vertical plate 72 to move. The vertical plate 72 drives the oxygen blowing gun 73 to move until the nozzle of the oxygen blowing gun 73 is inserted into the oxygen blowing pipe 251. Then the one-way valve 252 is opened, and oxygen can be blown into the oxygen blowing pipe 251 through the oxygen blowing gun 73. During the movement, the vertical plate 72 slides on two sliding rods 74, and the sliding rods 74 limit the vertical plate 72 to move in the horizontal direction. The oxygen blowing gun 73 is connected to an external oxygen source, and the oxygen blowing time and flow rate are controlled by PLC to cooperate with the RH vacuum decarbonization process.

[0077] By activating the fourth motor 47, the output shaft of the fourth motor 47 drives the second lead screw 45 to rotate, which in turn drives the lifting plate 44 to move. The lifting plate 44 then drives the connecting rod 43 to move, which in turn drives the connecting frame 42 to move. The connecting frame 42 then drives the sampling cylinder 41 to move. When the sampling cylinder 41 moves downward into the molten steel, it can sample the molten steel in the ladle 2. After sampling, it moves upward to above the cover plate 21, and the sampled molten steel can be removed. Then, the electric push rod 52 is activated, and the output end of the electric push rod 52 drives the push plate 51 to move. The push plate 51 then drives the receiving groove 5 to move. When the push plate 51 moves, it squeezes the sampling cylinder 41, causing the sampling cylinder 41 to tilt. The molten steel in the sampling cylinder 41 flows into the receiving groove 5. Then, the receiving groove 5 is removed with the help of tools, and the molten steel inside can be tested.

[0078] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for controlling boron content during deoxidation of boron-added steel, characterized in that: Includes the following steps: S1: When tapping steel from the converter, the molten steel undergoes deoxidation treatment. A special slag surface deoxidizer is added during tapping, with 50–300 kg of the special slag deoxidizer used. S2: LF refining deep deoxidation treatment, with an aluminum content of 0.010-0.50% in molten steel, and using a special slag surface deoxidizer; S3: RH vacuum furnace decarburization treatment, vacuum furnace decarburization oxygen blowing rate 50-300 Nm 3 The content of element B is 0.006-0.015%; S4: After the RH vacuum furnace is ventilated, add an appropriate amount of special slag surface deoxidizer and ultra-low carbon heat preservation agent for protection, and stir for 5-15 minutes.

2. The method for controlling boron element content in deoxidation of boron-added steel according to claim 1, characterized in that: When the S1 converter taps steel, it is poured into a ladle (2); the top of the ladle (2) is provided with a cover plate (21), and two storage cylinders (22) are symmetrically provided at both ends of the cover plate (21). The bottom ends of the storage cylinders (22) are all fixedly connected to the cover plate (21); the top of each storage cylinder (22) is fixedly connected to a first motor (23), and the output shaft of the first motor (23) is rotatably connected to the cover plate (21) through bearings. The output shaft of the first motor (23) is fixedly connected to a spiral blade (24); the bottom ends of each storage cylinder (22) are all fixedly connected to the cover plate (21). The cover plate (21) is equipped with a solenoid valve (29) and a flow sensor; the top of the cover plate (21) is fixedly connected to a second motor (28) via an L-shaped plate, and the output shaft of the second motor (28) is fixedly connected to a rotating rod (25). The rotating rod (25) is rotatably connected to the cover plate (21) via a bearing. A baffle (26) is fixedly connected to the outer wall of the rotating rod (25). The top of the baffle (26) is tightly fitted to the bottom of the storage cylinder (22). Multiple discharge ports (27) are arranged circumferentially on the baffle (26), and the storage cylinder (22) is matched with the discharge ports (27).

3. The method for controlling boron element content in deoxidation of boron-added steel according to claim 2, characterized in that: Multiple stirring paddles (253) are fixed to the bottom outer wall of the rotating rod (25); an oxygen blowing pipe (251) is inserted into the inside of the rotating rod (25), the top end of the oxygen blowing pipe (251) extends to the outside of the rotating rod (25), and a one-way valve (252) is installed thereon.

4. The method for controlling boron element content in deoxidation of boron-added steel according to claim 3, characterized in that: A fixing plate (7) is fixed to the top of the cover plate (21), a cylinder (71) is fixed to the bottom of the fixing plate (7), a vertical plate (72) is fixed to the output end of the cylinder (71), and an oxygen lance (73) is fixed to the side wall of the vertical plate (72) on the same side as the cylinder (71); two sliding rods (74) are fixed to the inner side wall of the fixing plate (7), and the vertical plate (72) is slidably connected on the two sliding rods (74).

5. The method for controlling boron element content in deoxidation of boron-added steel according to claim 4, characterized in that: Two mounting brackets (3) are symmetrically fixed to the top outer wall of the steel ladle tank (2). A first lead screw (31) is rotatably connected between the two inner side walls of the mounting bracket (3) through bearings. A connecting plate (34) is threaded onto the first lead screw (31). The connecting plate (34) is fixed to the outer wall of the cover plate (21). A third motor (33) is fixed to the top of the mounting bracket (3). The output shaft of the third motor (33) is fixed to the top of the first lead screw (31). Two guide rods (32) are fixed between the two inner side walls of the mounting bracket (3). The connecting plate (34) is slidably connected to the two guide rods (32).

6. The method for controlling boron element content in deoxidation of boron-added steel according to claim 5, characterized in that: A fixing frame (4) is fixedly connected to one end of the cover plate (21) away from the fixing plate (7). A second lead screw (45) is rotatably connected between the fixing frame (4) and the cover plate (21) through a bearing. A lifting plate (44) is threadedly connected to the second lead screw (45). A connecting rod (43) is fixedly connected to the bottom of the lifting plate (44). A connecting frame (42) is fixedly connected to the bottom of the connecting rod (43). A sampling cylinder (41) is rotatably connected to the bottom of the connecting frame (42) through a pin. A fourth motor (47) is fixedly connected to the top of the fixing frame (4). The output shaft of the fourth motor (47) is fixedly connected to the top of the second lead screw (45). Two vertical rods (46) are fixedly connected between the fixing frame (4) and the cover plate (21). The lifting plate (44) is slidably connected on the two vertical rods (46).

7. The method for controlling boron element content in deoxidation of boron-added steel according to claim 6, characterized in that: The sampling tube (41) passes through the cover plate (21), and the baffle (26) has a through hole, through which the sampling tube (41) slides.

8. The method for controlling boron element content in deoxidation of boron-added steel according to claim 7, characterized in that: An electric push rod (52) is fixedly connected to the top of the cover plate (21). A push plate (51) is fixedly connected to the output end of the electric push rod (52). Two limiting rods (53) are fixedly connected to the bottom of the push plate (51). Two limiting grooves are opened on the top of the cover plate (21). The limiting rods (53) slide in the limiting grooves. A receiving groove (5) is inserted into the side wall of the push plate (51). The receiving groove (5) is set on the same side as the electric push rod (52).

9. The method for controlling boron element content in deoxidation of boron-added steel according to claim 8, characterized in that: The bottom of the steel ladle tank (2) is connected to two installation pipes (6), and the bottom of each installation pipe (6) is connected to a branch pipe (61). One end of each branch pipe (61) is connected to a main pipe (64). A main control valve (65) is installed on the main pipe (64), and a branch control valve (62) and a flow meter (63) are installed on each branch pipe (61).

10. A method for controlling boron element content in deoxidation of boron-added steel according to claim 9, characterized in that: The steel ladle tank (2) has an insulation layer inside its wall, and multiple heating wires (210) are fixed inside the insulation layer; support plates (11) are rotatably connected to the outer wall of the steel ladle tank (2) via a rotating shaft; a steel ladle transport vehicle (1) is provided below the steel ladle tank (2), and the support plates (11) are fixed to the steel ladle transport vehicle (1); a drive motor (12) is provided on the outside of the rotating shaft.

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