A blocking alloy structure for a ladle tapping and a method for a ladle tapping

Abstract

The application relates to a plugging alloy structure for ladle tapping and a ladle tapping method. The plugging alloy structure for ladle tapping comprises a cylinder part, a graphite assembly and plugging alloy powder. The cylinder part is coaxially and detachably installed in a tapping hole of a ladle base brick. The graphite assembly is located in a cylinder cavity of the cylinder part. The plugging alloy powder is filled in a cavity surrounded by the cylinder cavity of the cylinder part and the graphite assembly. The plugging alloy powder is mixed powder comprising graphite powder and metal powder. The metal powder can be melted under the action of induction heat generated by an induction coil located on the ladle base brick. By installing the plugging alloy structure for ladle tapping on the tapping hole of the ladle base brick, the flow sand can be replaced, the rapid pouring and smooth tapping of the ladle can be realized, and the secondary pollution problem of the poured liquid steel caused by using the flow sand in the existing ladle tapping technology can be eliminated.

Description

Technical Field

[0001] This invention relates to the field of iron and steel metallurgy technology, and in particular to a sealing alloy structure for ladle tapping and a ladle tapping method. Background Technology

[0002] With the rapid development of high-end equipment manufacturing, rail transportation, and new energy industries, increasingly stringent requirements have been placed on the purity and mechanical properties of steel materials. High-quality clean steel production technology has become the core development direction of modern steelmaking processes. As is well known, the initial pouring of steel in the ladle is a crucial step in the steelmaking-continuous casting process, and its cleanliness directly affects the pouring rhythm of molten steel and the final quality of the steel. Currently, the traditional ladle pouring method using sprue sand has become the most widely used pouring method both domestically and internationally due to its simple structure and convenient operation. However, whether in continuous casting or ingot casting, the traditional sprue sand pouring method still has significant limitations. First, sprue sand is prone to problems such as excessive sintering and clogging of the nozzle, resulting in a pouring rate that does not reach 100%. Second, the use of sprue sand inevitably introduces non-metallic inclusions and increases the oxygen content in the molten steel, severely reducing the cleanliness of the original molten steel.

[0003] To address the aforementioned problems, existing technologies primarily focus on reducing the amount of diverting sand, developing automatic feeding devices, external sand collection devices, long nozzle sand interception, and setting up slag-blocking dams in the ladle. While these methods can reduce steel contamination and improve steel cleanliness to some extent, they do not fundamentally eliminate the dependence on diverting sand, nor can they completely eliminate the secondary contamination caused by diverting sand. To achieve cleaner steel casting, researchers have recently proposed applying electromagnetic induction heating technology to the ladle casting process. This technology uses an Fe-C alloy to replace traditional diverting sand to seal the molten steel, while an induction heating coil is placed inside the bottom brick of the ladle to melt the sealing alloy through induction heating. This method avoids the use of diverting sand and has certain advantages in improving steel cleanliness. However, in actual industrial practice, the high melting point of the Fe-C alloy results in a large power requirement for melting. Meanwhile, during the continuous casting process, the ladle is in a hot service state for a long time. The coil itself has a high temperature and is prone to burn-out or even melting when subjected to a large induction heating power, which eventually leads to the failure of the electromagnetic tapping system and makes it extremely difficult for the ladle to start casting smoothly.

[0004] Furthermore, in the iron and steel metallurgical process, the alloying of molten steel is almost entirely carried out in converter steelmaking and ladle refining, with no further alloying treatment occurring during the steel casting process. However, in actual production, issues such as refractory erosion in the ladle and secondary oxidation of the molten steel can cause slight fluctuations in the cleanliness and compositional stability of the molten steel. Therefore, maintaining the stability of the molten steel's composition while ensuring its cleanliness during the subsequent steel casting process has become a major bottleneck problem that researchers in this field urgently need to overcome in recent years. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0006] Therefore, this invention provides a novel sealing alloy structure and method for ladle tapping. By installing the sealing alloy structure on the outlet of the ladle seat brick, the operational difficulty of the original electromagnetic tapping technology can be reduced, and it is beneficial to achieve rapid pouring and smooth tapping of the ladle. At the same time, it can also eliminate the problem of secondary pollution of the molten steel caused by the use of diversion sand in the existing ladle tapping technology, and it also plays a positive role in maintaining the stability of the molten steel composition.

[0007] According to a first aspect of the present invention, a sealing alloy structure for ladle tapping includes a cylindrical portion, a graphite assembly, and sealing alloy powder. The cylindrical portion is coaxially and detachably installed inside the tapping opening of the ladle seat brick. The graphite assembly is located inside the cylindrical cavity of the cylindrical portion, and the sealing alloy powder fills the cavity formed by the cylindrical cavity of the cylindrical portion and the graphite assembly. The sealing alloy powder is a mixed powder comprising graphite powder and metal powder, wherein the metal powder is a powder that can melt under the action of induced heat generated by an induction coil located on the ladle seat brick.

[0008] Optionally, the cylindrical section is made of metal; the graphite assembly is made of high-density graphite, and the graphite assembly includes: The graphite tube is coaxially installed inside the tube section, and the outer wall of the graphite tube is in contact with the inner wall of the tube section. The mandrel is located inside the graphite cylinder and is coaxially arranged with the graphite cylinder, and the length of the mandrel is the same as the length of the graphite cylinder; the graphite cylinder and the mandrel form a first cavity, which is used to fill the sealing alloy powder.

[0009] Optionally, the mass ratio of metal powder to graphite powder in the sealing alloy powder in the first cavity is 100:1~5; the particle size of the metal powder in the sealing alloy powder in the first cavity is not higher than 2 mm, and the particle size of the graphite powder in the sealing alloy powder in the first cavity is not higher than 0.2 mm.

[0010] Optionally, the wall thickness of the graphite cylinder shall not exceed 5 mm, and the diameter of the core rod shall not exceed 5 cm.

[0011] Optionally, the first end of the graphite tube is disposed near the first end of the tube portion, and the second end of the graphite tube is disposed near the second end of the tube portion; the second end of the graphite tube is higher than the second end of the tube portion; the cavity region in the tube portion between the second end of the graphite tube and the second end of the tube portion is a second cavity, and the second cavity is used to fill the sealing alloy powder.

[0012] Optionally, the mass ratio of metal powder to graphite powder in the sealing alloy powder in the second cavity is 100:2~10; the particle size of the metal powder in the sealing alloy powder in the second cavity is not higher than 5 mm, and the particle size of the graphite powder in the sealing alloy powder in the second cavity is not higher than 0.2 mm.

[0013] Optionally, the first end of the graphite tube is lower than the first end of the tube portion; the cavity region in the tube portion between the first end of the graphite tube and the first end of the tube portion is a third cavity, and the third cavity is used to fill one or more powders of zirconium oxide, aluminum oxide, chromium oxide, magnesium oxide, silicon dioxide, ferrosilicon and graphite.

[0014] Optionally, the height ratio between the first cavity, the second cavity, and the third cavity is 15~80:2~15:3~15.

[0015] Optionally, the metal powder is aluminum powder.

[0016] Optionally, the cylindrical portion includes: The cylindrical body has open ends; A cover plate is placed over the opening at the top of the cylinder; the cover plate is made of iron, aluminum, or zirconium. The encapsulation layer, located on the opening at the bottom of the cylinder, is used to encapsulate the sealing alloy powder within the cavity formed by the cylinder cavity and the graphite assembly; the encapsulation layer is made of a flammable material.

[0017] A method for tapping steel from a ladle according to a second aspect of the present invention includes the following steps: (1) Install the above-mentioned steel ladle steel discharge sealing alloy structure inside the steel discharge port to seal the steel discharge port, and then close the sliding plate located at the bottom of the steel ladle; (2) When casting molten steel in a ladle, open the slide plate at the bottom of the ladle and apply alternating current to the induction coil on the ladle seat brick so that the metal powder in the sealing alloy powder melts under the electromagnetic induction heating effect of the induction coil. After the outflow of the sealing alloy reaches the limit of the static pressure of the molten steel, the ladle can automatically discharge steel.

[0018] One of the above technical solutions has at least the following advantages or beneficial effects: (1) By sealing the ladle outlet with the sealing alloy structure provided by this invention, the molten steel outlet can be replaced by the diversion sand used in traditional molten steel tapping technology. This effectively suppresses the secondary pollution of molten steel caused by diversion sand, ensuring clean casting and production of molten steel. Furthermore, the ladle equipped with this sealing alloy structure can not only achieve rapid casting and smooth tapping under low-power, short-time induction heating, but also, after the metal powder in the sealing alloy powder melts and enters the molten steel, achieve secondary deoxidation and alloying of the molten steel inside the ladle, further improving the cleanliness of the molten steel and achieving the technical effect of ensuring alloy composition yield and composition stability. At the same time, the added graphite powder, as an antioxidant, can prevent the metal powder (especially aluminum) from premature sintering before induction heating and prevent the oxidation of metal powder (especially aluminum) when the ladle is opened for casting. On the other hand, carbon, as an indispensable solute component in steel, will not cause any pollution to the molten steel due to the introduction of trace amounts of graphite during the casting process.

[0019] (2) The ladle tapping method provided by the present invention is simple and easy to implement in industry, and does not affect the production rhythm and safety of existing processes. Moreover, the ladle tapping sealing alloy structure used in the present invention can be prefabricated and only needs to be filled before the ladle is filled with molten steel. This greatly reduces the problem of a large amount of sand leakage at the top of the sealing layer caused by conventional diversion sand filling, as well as the cumbersome filling of other non-diversion sand technologies.

[0020] (3) The sealing alloy structure for ladle tapping provided by this invention can provide strong electromagnetic coupling during induction heating, thereby solving the bottleneck of metal powder, especially aluminum, which is a weak magnetic material and requires higher induction intensity and has a slow heating rate. Furthermore, graphite powder itself can also act as an induction heating element, effectively improving the induction heating melting effect of metal powder, especially aluminum, achieving rapid and uniform induction heating of the metal powder, and ensuring smooth tapping and casting of the ladle under short-term and low-power conditions. At the same time, the reduced heating intensity can further improve the cycle life of the induction coil. Moreover, the sealing alloy structure and filling method for ladle tapping provided by this invention can also help prevent molten steel inside the ladle from penetrating deep into the sealing alloy structure under static pressure, thereby causing changes in the alloy composition within the sealing alloy structure, which in turn increases the heating power and time required for induction heating, and even leads to the problem of the ladle being unable to achieve smooth casting.

[0021] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This diagram illustrates a structural schematic of a ladle seat brick equipped with a sealing alloy structure for ladle tapping, according to an embodiment of the present invention. Figure 2 A schematic diagram of the structure of a steel ladle seat brick according to an embodiment of the present invention is shown; Figure 3 A schematic diagram of a sealing alloy structure for steel ladle tapping according to an embodiment of the present invention is shown.

[0023] Explanation of reference numerals in the attached figures 1. Brick body; 101. Steel spout; 2. Induction coil; 3. Steel ladle tapping sealing alloy structure, 301, cylinder, 302, graphite cylinder, 303, mandrel, 304, first cavity, 305, second cavity, 306, third cavity, 3011, cylinder body, 3012, cover plate, 3013, sealing layer. Detailed Implementation

[0024] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] The following describes, with reference to the accompanying drawings, some embodiments of the steel ladle seat bricks and their preparation methods provided according to the present invention.

[0026] See Figures 1 to 3 The present invention provides a sealing alloy structure for steel ladle tapping, the structure comprising a cylindrical part 301, a graphite assembly, and sealing alloy powder. The cylindrical part 301 is coaxially and detachably installed inside the steel discharge port 101 of the ladle seat brick. The graphite assembly is located inside the cylindrical cavity of the cylindrical part 301, and the sealing alloy powder fills the cavity formed by the cylindrical cavity of the cylindrical part 301 and the graphite assembly. The sealing alloy powder is a mixed powder comprising graphite powder and metal powder, wherein the metal powder is a powder that can melt under the action of the induced heat generated by the induction coil 2 located on the ladle seat brick.

[0027] It should be noted that the ladle support brick here is used to install at the bottom of the ladle; the ladle support brick includes a brick body 1 and an induction coil 2. The brick body 1 is provided with a steel discharge port 101, the first end of the steel discharge port 101 is located on the upper surface of the brick body 1, and the second end of the steel discharge port 101 is located on the lower surface of the brick body 1; the induction coil 2 is located inside the brick body 1 and is coaxially arranged with the steel discharge port 101.

[0028] Here, by pre-embedding and fixing the induction coil 2 inside the brick body 1 and coaxially arranging it with the steel outlet 101, and coaxially installing the steel ladle steel outlet sealing alloy structure 3 inside the steel outlet 101, the steel ladle steel outlet sealing alloy structure 3 is arranged coaxially with the steel outlet 101 and the induction coil 2. This ensures that the alternating magnetic field generated by the induction coil 2 uniformly surrounds the steel ladle steel outlet sealing alloy structure 3 installed inside the steel outlet 101, thereby ensuring that the alternating coupling generated by the induction coil 2 is without deviation. Consequently, the heating area corresponding to the induced heat generated by the induction coil 2 is concentrated at the position corresponding to the steel ladle steel outlet sealing alloy structure 3. This allows the metal powder in the sealing alloy powder to melt under the action of the induced heat generated by the induction coil 2, thereby releasing the sealing alloy powder from the cavity formed by the cylinder 301 and the graphite assembly, and thus releasing the sealing alloy structure 3 from the steel outlet 101.

[0029] By placing the graphite assembly inside the cylinder cavity of the cylinder section 301, the graphite assembly provides strong electromagnetic coupling capability when the induced heat generated by the induction coil 2 heats the sealing alloy powder in the ladle tapping sealing alloy structure 3. This solves the problem that when the metal powder in the sealing alloy powder is a weakly magnetic material, a higher induction intensity is required and the heating rate is slow. Furthermore, the graphite assembly itself can also act as an induction heating element, effectively improving the induction heating and melting effect of the metal powder, achieving a rapid and uniform induction heating effect for the metal powder. This ensures that the ladle equipped with the ladle seat brick of this invention can smoothly tap and start casting under short-term and low-power conditions. At the same time, due to the setting of the graphite assembly, the heating intensity required for the sealing alloy powder is reduced, which can further improve the cycle life of the induction coil 2.

[0030] Furthermore, by fixing the ladle tapping sealing alloy structure 3 to the tapping spout 101 in a detachable installation manner, the ladle tapping sealing alloy structure 3 can be used as an independent pre-assembled component. After pre-filling graphite components and sealing alloy powder inside it, it can be installed as a whole into the tapping spout 101 on site, which can replace the process of on-site bulk sand filling. This eliminates the problem of sand leakage at the top of the diversion sand filling, and the filling process is simple and does not disrupt the original steelmaking and continuous casting production rhythm.

[0031] It should be noted that the sealing alloy powder is selected as a mixed powder including graphite powder and metal powder. Graphite powder can serve as an antioxidant, which can prevent premature sintering of the metal powder before it melts under the induced heat generated by the induction coil 2, and also prevent oxidation of the metal powder when the ladle is started to pour. On the other hand, as an indispensable solute component in steel, the introduction of graphite powder into the molten steel in the ladle will not cause any contamination to the molten steel.

[0032] The working principle of the steel ladle tapping sealing alloy structure 3 provided by the present invention is as follows: Before the steel ladle is filled with molten steel, the steel ladle tapping sealing alloy structure 3 is coaxially installed on the steel outlet 101 of the brick body 1; after the molten steel is filled into the steel ladle, without the induction coil 2 being energized, the sealing alloy powder is filled into the cavity formed by the cylinder cavity of the cylinder 301 and the graphite component, and the steel outlet 101 can be sealed without the need for drainage sand; when the steel ladle is opened for pouring, an alternating current is passed into the induction coil 2 embedded in the brick body 1, so that the induction coil 2 generates an alternating magnetic field. After the alternating magnetic field acts on the graphite component and the sealing alloy powder in the cylinder 3011, the graphite component is used as an auxiliary heating body to quickly generate heat by utilizing the excellent conductivity and magnetic permeability of graphite, and the metal powder in the sealing alloy powder is quickly heated, so that the metal powder melts after being heated and loses its sealing ability, thereby opening the steel outlet 101 and allowing the molten steel to flow out smoothly from the steel outlet 101 to complete the pouring.

[0033] In this embodiment, by installing the steel ladle tapping sealing alloy structure 3 on the tapping port 101 on the brick body 1, the metal powder in the sealing alloy powder of the steel ladle tapping sealing alloy structure 3 can be rapidly heated and melted under the action of the induced heat generated by the induction coil 2 located inside the brick body 1, and under the action of the graphite component and the graphite powder as an auxiliary heating medium. This releases the blockage of the cylinder cavity of the cylinder 301 and the cavity surrounded by the graphite component, thereby realizing the opening of the tapping port 101, so that the molten steel can smoothly flow out of the tapping port. With the steel flow from outlet 101 completed, the pouring process is complete. This demonstrates that the ladle equipped with the sealing alloy structure 3 for steel tapping, as disclosed in this invention, can solve the technical problem of achieving clean pouring in existing technologies. Furthermore, it meets the urgent need for secondary alloying of molten steel. The ladle equipped with the sealing alloy structure 3 for steel tapping not only enables rapid pouring and smooth tapping under low-power, short-time induction heating conditions, but also completely eliminates the secondary contamination problem of the poured molten steel caused by the use of diversion sand in existing ladle tapping technologies.

[0034] In some possible embodiments, the cylindrical portion 301 is made of metal; the graphite assembly is made of high-density graphite, and the graphite assembly includes a graphite cylinder 302 and a mandrel 303. The graphite cylinder 302 is coaxially mounted inside the cylindrical portion 301, and the outer side wall of the graphite cylinder 302 is in contact with the inner side wall of the cylindrical portion 301; the mandrel 303 is located inside the graphite cylinder 302 and is coaxially arranged with the graphite cylinder 302, and the length of the mandrel 303 is the same as the length of the graphite cylinder 302; the graphite cylinder 302 and the mandrel 303 form a first cavity 304, which is used to fill the sealing alloy powder.

[0035] Here, the metal used to prepare the cylinder 301 can be iron. The height of the cylinder 301 is the same as the height of the steel discharge port 101, and the outer diameter of the cylinder 301 and the inner diameter of the steel discharge port 101 are the same. After the cylinder 301 is installed in the steel discharge port 101, the outer wall of the cylinder 301 fits against the inner wall of the steel discharge port 101, wherein the thickness of the cylinder wall of the cylinder 301 does not exceed 3 mm.

[0036] It should be noted that by making the graphite component from high-density graphite, the electrical and thermal conductivity and eddy current heating capacity of high-density graphite can be utilized to make the eddy current heating efficiency of the alternating magnetic field generated by the induction coil 2 in the energized state higher, and a large amount of heat can be generated quickly under low power induction conditions.

[0037] In this design, the graphite cylinder 302 is coaxially fitted inside the cavity of the cylinder portion 301, with its outer wall tightly fitted to the inner wall of the metal cylinder portion 301. This allows the graphite cylinder 302 to function as an annular graphite heating layer, serving as the outer heating ring surrounding the filling area. The mandrel 303 is arranged inside the graphite cylinder 302, coaxially with it, and with its axial length exactly equal to that of the graphite cylinder 302. This allows the mandrel 303 to function as the central graphite heating column along the entire sealing and filling area. Therefore, by selecting a graphite assembly that includes the graphite cylinder 302 and the mandrel 303, the sealing alloy powder filled in the first cavity 304 formed by the graphite cylinder 302 and the mandrel 303 can rapidly melt under the heat generated by the graphite cylinder 302 and the mandrel 303 acting as auxiliary heating elements.

[0038] In some possible embodiments, the mass ratio between metal powder and graphite powder in the sealing alloy powder in the first cavity 304 is 100:1~5; the particle size of the metal powder in the sealing alloy powder in the first cavity 304 is not higher than 2 mm, and the particle size of the graphite powder in the sealing alloy powder in the first cavity 304 is not higher than 0.2 mm.

[0039] Here, the mass ratio between the metal powder and the graphite powder in the sealing alloy powder in the first cavity 304 can be one of 100:1, 100:2, 100:3, 100:4, or 100:5, but is not limited to this.

[0040] In this embodiment, by selecting a mass ratio of metal powder to graphite powder in the sealing alloy powder in the first cavity 304 of 100:1~5, a small amount of graphite powder can be uniformly dispersed in the gaps between the metal powders. This not only isolates the surface of the metal powder from the air, suppressing oxidation of the metal powder during heating, but also utilizes the magnetic and electrical properties of graphite powder to independently generate eddy current heat under the induced magnetic field generated by the induction coil 2. This compensates for the slow heating due to weak magnetic field of the metal powder, thereby increasing the overall heating rate of the sealing alloy powder. The sealing alloy powder in the first cavity 304 can be melted without high-power heating, thus reducing the load on the induction coil 2 and extending its service life.

[0041] Furthermore, by selecting a metal powder particle size of ≤2mm, not only can the packing gaps between the metal powders be minimized, allowing the metal powder filling the first cavity 304 to prevent molten steel from seeping into the interior of the first cavity 304 and thus preventing the molten steel from prematurely altering the material ratio within the first cavity 304, but metal powder with this particle size also requires less heat during melting. Therefore, using metal powder with this particle size can also improve the self-opening rate of the ladle. Selecting a graphite powder particle size of ≤0.2mm not only allows the graphite powder to fill the gaps between the metal powders uniformly, without localized graphite enrichment or deficiency, ensuring uniform heating and heat conduction throughout the entire annular first cavity 304 and eliminating localized areas of lag in heating; simultaneously, graphite powder with this particle size has a larger specific surface area, resulting in a wider thermal and oxygen-barrier coverage area and a larger heat transfer contact area, allowing heat to be quickly transferred to adjacent metal powders, further shortening the heating time for the metal powders.

[0042] In some possible embodiments, the wall thickness of the graphite cylinder 302 does not exceed 5 mm, and the diameter of the mandrel 303 does not exceed 5 cm.

[0043] Here, by selecting a wall thickness of no more than 5mm for the graphite cylinder 302, the graphite cylinder 302 surrounding the sealing alloy powder is selected as a thin-walled structure. At the same time, the diameter of the core rod 303 is limited to no more than 5cm, and it is arranged in the center of the graphite cylinder 302 and is coaxial with the graphite cylinder 302 of the same length. This makes the core rod 303 a central columnar heating element. When the induction coil 2 generates an alternating magnetic field, the graphite cylinder 302 with a thin-walled structure and the core rod 303 generate eddy current heat synchronously. The thin-walled graphite cylinder 302 has good magnetic field penetration, and the core rod 303 is of moderate size and will not excessively occupy the filling space. Thus, with the cooperation of the inner and outer heating elements formed by the graphite cylinder 302 and the core rod 303, the sealing alloy powder can be filled to the maximum extent in a limited space, while ensuring that the graphite component generates heat efficiently and the heat is quickly transferred to the metal powder.

[0044] In some possible embodiments, the first end of the graphite cylinder 302 is disposed near the first end of the cylinder portion 301, and the second end of the graphite cylinder 302 is disposed near the second end of the cylinder portion 301; the second end of the graphite cylinder 302 is higher than the second end of the cylinder portion 301; the cavity region in the cylinder portion 301 between the second end of the graphite cylinder 302 and the second end of the cylinder portion 301 is a second cavity 305, which is used to fill the sealing alloy powder.

[0045] Since the static pressure of the molten steel in the ladle first acts on the material at the top of the ladle tapping sealing alloy structure 3 after the steel ladle is filled with molten steel, the first cavity 304 in the middle of the ladle tapping sealing alloy structure 3 relies on the bidirectional wrapping of the graphite cylinder 302 and the core rod 303 to rapidly melt under the action of the induced heat generated by the induction coil 2. Therefore, a second cavity 305 is added near the bottom of the ladle tapping sealing alloy structure 3, and the second cavity 305 is filled with thickened sealing alloy powder to form a sealed buffer section near the bottom of the ladle tapping sealing alloy structure 3. When pouring molten steel, the magnetic field generated by the induction coil 2 preferentially heats the sealing alloy powder in the first cavity 304 located in the middle of the cylinder 301. The metal powder in the sealing alloy powder in the first cavity 304 melts first and flows with the molten steel to the second end of the cylinder 301, so that the first cavity 304 forms a flow channel for molten steel. At the same time, the sealing alloy powder (liquid metal + graphite powder) flowing out of the first cavity 304 is washed by the molten steel and continues to melt with residual heat, ensuring the continuity of the steel discharge port 101. In addition, the sealing alloy powder filled in the second cavity 305 melts at a slightly slower rate because it is not wrapped by the graphite cylinder 302. Therefore, this part of the sealing alloy powder melts gradually with the molten steel, and there will be no situation where the whole collapses instantly and causes debris to block the steel discharge port 101. This makes the molten steel flow stable and continuous, and improves the stability of continuous casting.

[0046] In some possible embodiments, the mass ratio between metal powder and graphite powder in the sealing alloy powder in the second cavity 305 is 100:2~10; the particle size of the metal powder in the sealing alloy powder in the second cavity 305 is not higher than 5 mm, and the particle size of the graphite powder in the sealing alloy powder in the second cavity 305 is not higher than 0.2 mm.

[0047] Here, the mass ratio between the metal powder and the graphite powder in the sealing alloy powder in the second cavity 305 can be one of 100:2, 100:3, 100:4, 100:5, 100:6, 100:7, 100:8, 100:9, or 100:10, but is not limited to this.

[0048] In this embodiment, by selecting metal powder with a larger particle size than the metal powder in the first cavity 304, the metal powder can be stacked in the second cavity 305 to form a stable skeleton structure. This makes its overall resistance to compaction and penetration better than that of fine powder, thereby effectively preventing the upper molten steel from penetrating downward into the bottom second cavity 305 under static pressure and preventing the molten steel from changing the material ratio. In addition, by selecting graphite powder with a particle size of no more than 0.2 mm, after the graphite powder is uniformly filled in the large gaps in the metal powder, the large specific surface area of ​​the graphite powder can be used to avoid the problem of local graphite agglomeration or absence. This makes the heating and heat conduction of the entire second cavity 305 uniform, and there are no dead zones that are difficult to melt.

[0049] Furthermore, the first end of the graphite cylinder 302 is lower than the first end of the cylinder portion 301; the cavity region in the cylinder portion 301 between the first end of the graphite cylinder 302 and the first end of the cylinder portion 301 is a third cavity 306, and the third cavity 306 is used to fill one or more powders of zirconium oxide, aluminum oxide, chromium oxide, magnesium oxide, silicon dioxide, ferrosilicon and graphite.

[0050] It should be noted that the cavity formed by the cylindrical cavity of the cylindrical part 301 and the graphite assembly includes a first cavity 304, a second cavity 305 and a third cavity 306 that are interconnected.

[0051] Here, the third cavity 306 is located at the top of the first cavity 304, and the third cavity 306 is filled with any one or more mixed powders of zirconium oxide, aluminum oxide, chromium oxide, magnesium oxide, silicon dioxide, ferrosilicon, and graphite, so as to form a high-temperature resistant and fire-resistant powder system at the top of the first cavity 304. This powder system can directly face the molten steel and withstand the static pressure of the molten steel to prevent the molten steel from penetrating downwards and intruding into the sealing powder filled in the first cavity 304.

[0052] Furthermore, the height ratio between the first cavity 304, the second cavity 305, and the third cavity 306 is 15~80:2~15:3~15.

[0053] Here, by selecting the height of the third cavity 306 to be 3 to 15 parts, the powder filled in the third cavity 306 can isolate the static pressure penetration of the molten steel in the ladle and protect the sealing alloy powder in the first cavity 304. At the same time, by selecting the height of the third cavity 306 to be 3 to 15 parts, it can be ensured that its thickness is not too high, thus preventing excessive powder from being carried into the downwardly poured molten steel to form inclusions.

[0054] By selecting the height of the first cavity 304 located in the middle of the cylinder 301 to be 15 to 80 parts, the graphite cylinder 302 and the core rod 303 can form an inner and outer double-layer graphite heating structure, which occupies most of the axial height of the sealing alloy structure 3 for steel ladle tapping, making it the core area for induction heating and melting pouring.

[0055] By selecting the height of the second cavity 305 located at the bottom of the cylinder 301 to be 2 to 15 parts, the second cavity 305 is a small cavity located below the graphite cylinder 302. Thus, when it is filled with only a small amount of sealing alloy powder, it can serve as a simple buffer seal at the bottom of the cylinder 301 and an auxiliary deoxidation thin layer at the end.

[0056] In some possible embodiments, the induction coil 2 is a spiral hollow structure, the diameter of the induction coil 2 is 3 to 8 times the inner diameter of the steel discharge port 101; the height of the induction coil 2 is 50% to 70% of the height of the brick body 1; and the outer wall of the induction coil 2 is provided with an insulating layer and a heat insulation layer in sequence.

[0057] Here, by selecting a spiral hollow structure for the induction coil 2, it can be manufactured by winding a hollow copper tube into a spiral shape. The hollow channel in the induction coil 2 can circulate a cooling medium (inert gas cooling), thereby achieving continuous internal cooling of the induction coil 2 when it is energized.

[0058] The diameter of the induction coil 2 is selected to be 3 to 8 times the inner diameter of the steel discharge port 101. This allows the induction coil 2 to be completely surrounded by the outside of the steel discharge port 101, and the magnetic induction lines generated by it can cover the steel discharge port 101 and the entire steel ladle steel discharge sealing alloy structure 3 inside. At the same time, the magnetic field can completely surround the first cavity 304 located in the middle of the cylinder 301 and heat the sealing alloy powder located therein.

[0059] Furthermore, the height of the induction coil 2 is selected to be 50% to 70% of the height of the brick 1. This allows the axial height of the induction coil 2 to cover the middle section of the tool holder brick, corresponding to the filling powder of the first cavity 304 in the middle of the steel ladle sealing alloy structure 3, without extensively covering the top third cavity 306 and the bottom second cavity 305. Here, the transverse axis of the induction coil 2 is on the same straight line as the transverse axis of the graphite cylinder 302.

[0060] At the same time, the outer wall of the induction coil 2 is covered with an insulating layer and a heat insulation layer from the inside to the outside, so that the induction coil 2 is first insulated to prevent conductivity, and then covered with a heat insulation layer on the outside of the insulating layer, so as to form a double-layer protective structure for the induction coil 2, thereby isolating the induction coil 2 from the brick body 1 and the high-temperature molten steel heat source.

[0061] In some possible embodiments, the brick body 1 is cast from a high-alumina or spinel castable.

[0062] Here, by selecting brick body 1 as a brick body integrally cast from high-alumina or spinel castable, brick body 1 can have the advantages of high temperature resistance, thermal shock resistance, molten steel corrosion resistance, and strong structural integrity. At the same time, it can stably wrap the induction coil 2 located inside it, isolate the steel ladle shell from conductivity, and provide a regular coaxial installation reference for the steel discharge port 101 and the steel ladle steel discharge sealing alloy structure 3. This ensures that the coaxiality of the induction coil 2 and the steel ladle steel discharge sealing alloy structure 3 does not deform during long-term hot service, and ensures the stability of the induction heating magnetic field and the reliability of the sealing.

[0063] In some possible embodiments, the metal powder is aluminum powder.

[0064] Here, aluminum powder with a melting point much lower than that of iron-carbon alloys is selected as the metal powder. When the induction coil 2 generates an alternating magnetic field, the aluminum powder can be heated by the internal and external heating system formed by the graphite cylinder 302 and the core rod 303, so as to realize the rapid melting of the aluminum powder and open the flow channel of the steel discharge port 101. At the same time, the molten aluminum powder flows into the molten steel. Since aluminum is a common deoxidation alloy raw material for ordinary carbon steel, alloy steel and special clean steel, the aluminum flowing into the molten steel will not introduce impurities that are restricted by the steel type.

[0065] In some possible embodiments, the cylindrical portion 301 includes a cylindrical body 3011, a cover plate 3012, and an encapsulation layer 3013. Both ends of the cylindrical body 3011 are open. The cover plate 3012 covers the open portion at the top of the cylindrical body 3011. The cover plate 3012 is made of iron, aluminum, or zirconium. The encapsulation layer 3013 is located at the open portion at the bottom of the cylindrical body 3011 and is used to encapsulate the sealing alloy powder within the cavity formed by the cylindrical cavity of the cylindrical portion 301 and the graphite assembly. The encapsulation layer 3013 is made of a flammable material.

[0066] Here, when filling the sealing alloy powder, the sealing alloy powder can be loaded from the lower opening at the bottom of the cylinder 3011. That is, the powder for filling the third cavity 306 is first loaded from the lower opening. After this part is filled, the graphite cylinder 302 is placed into the cylinder cavity of the cylinder 3011 from the lower opening. Then, the mandrel 303 is placed in a position coaxial with the graphite cylinder 302 so that the graphite cylinder 302 and the mandrel 303 form the first cavity 304. Then, the sealing alloy powder for filling the first cavity 304 is filled into the first cavity 304 to complete the filling of the first cavity 304. Subsequently, the sealing alloy powder for filling the second cavity 305 is filled into the second cavity 305 to complete the filling of the cavity formed by the cylinder cavity of the cylinder 301 and the graphite assembly. Finally, the lower opening is sealed with flammable material to complete the assembly of the sealing alloy structure 3 for steel ladle tapping.

[0067] Among them, by selecting the encapsulation layer 3013 to be made of flammable material, the encapsulation layer 3013 located at the bottom of the cylinder 3011 can be ignited by high temperature, so that the opening at the bottom of the cylinder 3011 is opened, thereby allowing molten aluminum and graphite particles to flow out with the molten steel; in addition, the cover plate 3012 used to cover the opening located at the top of the cylinder 3011 is made of metallic iron, metallic aluminum or metallic zirconium, which can melt under the high temperature of the molten steel, without hindering the steel flow, and realizing smooth and continuous steel tapping.

[0068] The present invention provides a method for tapping steel from a ladle, comprising the following steps: (1) Install the above-mentioned steel ladle steel discharge sealing alloy structure on the steel discharge port to seal the steel discharge port, and then close the sliding plate located at the bottom of the steel ladle; (2) When the steel is poured into the ladle, the slide plate at the bottom of the ladle is opened and an alternating current is applied to the induction coil on the ladle seat brick so that the metal powder in the sealing alloy powder melts under the electromagnetic induction heating of the induction coil, so as to realize the steel tapping of the ladle.

[0069] It should be noted that before closing the slide plate located at the bottom of the ladle, ensure that the outer portion of the induction coil does not come into contact with the ladle shell; then insulate the outer portion of the induction coil before connecting it to the gas quick-connect adapter. At the same time, the gas quick-connect adapter must be fixed to the lower part of the ladle shell to enable the rapid introduction of cooling gas under production conditions, thereby ensuring the low-temperature environment of the induction heating system constructed by the induction coil, improving the convenience of technical operation and reducing the complexity of on-site operation.

[0070] Before the ladle is filled with molten steel, the bottom slide plate of the ladle is closed to fix the ladle seat bricks on the ladle. Before the ladle is cast, the wires of the induction heating power supply are connected to the induction coil extending from the bottom of the ladle. The gas cooling system is connected to the gas quick converter at the bottom of the ladle and inert gas is introduced for cooling. Then, the electromagnetic induction heating and melting of the sealing alloy powder is carried out and the ladle is automatically tapped.

[0071] The steel tapping method provided by this invention involves installing a sealing alloy structure for steel tapping on the tapping spout. By applying alternating current to an induction coil located on the ladle seat brick, the metal powder in the sealing alloy powder melts under the electromagnetic induction heating effect of the induction coil, thereby releasing the sealing alloy structure from blocking the tapping spout. Therefore, this method can solve the technical problem of achieving clean steel pouring in the prior art, and also meets the urgent need for secondary alloying of molten steel. Furthermore, it completely eliminates the secondary pollution problem of the poured molten steel caused by the use of diversion sand in existing steel tapping technologies.

[0072] The following examples and comparative examples provide a detailed description of the ladle tapping method provided by the present invention. It should be noted that, unless otherwise specified, the methods and materials described in the following examples are commercially available; and the experimental methods described are conventional methods unless otherwise specified.

[0073] Example 1 This embodiment provides a ladle tapping method, which is verified in the process of casting low-carbon, low-alloy steel using a 120-ton ladle in the continuous casting of slabs at a steel plant. The method specifically includes the following steps: (1) The induction coil was fabricated based on the dimensions of the steel ladle and the original bottom seat bricks and the inner diameter of the steel outlet used by the steel plant. Among them: since the inner diameter of the steel outlet is 5cm, the inner diameter of the fabricated induction coil is 12cm; the height is 25cm; the specifications of the coil used for the induction coil are copper hollow square tubes with a diameter of 2.0cm, a wall thickness of 0.3cm, and a turn spacing of 0.8cm; the coil is wrapped with quartz insulating tape and mullite heat insulation fiber, wherein the thickness of the quartz insulating tape is 0.05cm and the thickness of the mullite heat insulation fiber is 0.5cm.

[0074] (2) During the steel ladle casting process, the prefabricated induction coil is placed inside the brick body and at the center of the steel outlet, and then cured, dried and shaped. Among them, the curing time of the brick body is not less than 12 hours, the curing temperature is 180℃, and the curing time is 7 days.

[0075] (3) Place the prepared bricks at the bottom of the ladle, ensuring that the outer portion of the induction coil does not contact the ladle shell. In addition, insulate the outer copper tube of the induction coil before connecting it to the gas quick adapter. The gas quick adapter must be fixed to the lower part of the ladle shell.

[0076] (4) Before the ladle is filled with molten steel, the pre-filled ladle tapping sealing alloy structure is installed from the top of the ladle at the bottom of the ladle, and then the bottom slide plate of the ladle is closed. The sealing alloy powder is pre-filled into the interior of the cylinder, with the cylinder diameter and height consistent with the steel outlet of the brick body. The cylinder wall thickness is 2mm, and the cylinder material is iron. The upper part of the cylinder is sealed with aluminum metal discs, and the lower part is an open structure, sealed with flammable sealing tape after filling. The sealing alloy powder is filled in the cylinder from top to bottom, with the top layer filled with a mixture of zirconium oxide and graphite powder. The middle layer is filled with a mixture of aluminum powder and graphite powder, and a high-density graphite cylinder is installed on the inner wall of the middle area of ​​the cylinder, with a core rod made of high-density graphite. The bottom is completely filled with a mixture of aluminum powder and graphite powder. The thickness of the top layer of filling material is 3cm. The middle filling consists of aluminum powder and graphite powder in a mass ratio of 100:2, with aluminum powder having a particle size of 1mm and graphite powder having a particle size of 0.05mm. The high-density graphite cylinder is 3mm thick, and the core rod has a diameter of 4cm. The bottom filling material is 5cm thick, and the bottom filling consists of aluminum powder and graphite powder in a mass ratio of 100:3, with aluminum powder having a particle size of 1mm and graphite powder having a particle size not exceeding 0.05mm.

[0077] (5) Before casting the ladle, connect the wire of the induction heating power supply to the induction coil extending from the bottom of the ladle, and connect the gas cooling system to the gas quick converter at the bottom of the ladle and introduce inert gas for cooling.

[0078] (6) When casting molten steel in the ladle, open the slide plate located at the bottom of the ladle and apply alternating current to the induction coil located on the ladle seat brick using an induction heating power supply, so that the metal powder in the sealing alloy powder melts under the electromagnetic induction heating effect of the induction coil. The ladle can automatically discharge steel within an average of 2 minutes.

[0079] Testing revealed that, compared to the original sand tapping technology, the total oxygen content and the number of inclusions inside the billet were significantly reduced in this embodiment, with an average reduction of over 25%, and there were no longer any inclusions of chromium oxide or silicon oxide.

[0080] Example 2 The ladle tapping method provided in this embodiment is verified using a 130-ton ladle for casting low-carbon, low-alloy steel in the continuous casting process of slabs at a steel plant. The method specifically includes the following steps: (1) Based on the dimensions of the steel ladle and the original bottom seat bricks used by the steel plant, and the inner diameter of the steel outlet, the induction coil was manufactured. Among them: since the inner diameter of the steel outlet is 6cm, the inner diameter of the manufactured induction coil is 12cm; the height is 20cm; the specifications of the coil used for the induction coil are copper hollow square tubes with a diameter of 2.0cm, a wall thickness of 0.3cm, and a turn spacing of 0.8cm; the coil is wrapped with quartz insulating tape and mullite heat insulation fiber, wherein the thickness of the quartz insulating tape is 0.05cm and the thickness of the mullite heat insulation fiber is 0.5cm.

[0081] (2) During the steel ladle casting process, the prefabricated induction coil is placed inside the brick body and at the center of the steel outlet, and then cured, dried and shaped. Among them, the curing time of the brick body is 24 hours, the curing temperature is 180℃, and the curing time is 6 days.

[0082] (3) Place the prepared bricks at the bottom of the ladle, ensuring that the outer portion of the induction coil does not contact the ladle shell. In addition, insulate the outer copper tube of the induction coil before connecting it to the gas quick adapter. The gas quick adapter must be fixed to the lower part of the ladle shell.

[0083] (4) Before the ladle is filled with molten steel, the pre-filled ladle tapping sealing alloy structure is installed from the top of the ladle at the bottom of the ladle, and then the bottom slide plate of the ladle is closed. The sealing alloy powder is pre-filled into the interior of the cylinder, the cylinder diameter and height are consistent with the steel outlet of the brick body, the cylinder wall thickness is 2mm, and the cylinder material is iron. The upper part of the cylinder is sealed with aluminum metal discs, and the lower part is an open structure, sealed with flammable sealing tape after filling. The sealing alloy powder is filled in the cylinder from top to bottom, with the top layer filled with a mixture of zirconium oxide and graphite powder. The middle layer is filled with a mixture of aluminum powder and graphite powder, and a high-density graphite cylinder is installed on the inner wall of the middle area of ​​the cylinder, with a core rod made of high-density graphite. The bottom is completely filled with a mixture of aluminum powder and graphite powder. The thickness of the top layer of filling material is 2cm. The middle filling consists of aluminum powder and graphite powder in a mass ratio of 100:2, with aluminum powder having a particle size of 1mm and graphite powder having a particle size of 0.02mm. The high-density graphite cylinder is 5mm thick, and the core rod has a diameter of 3.5cm. The bottom filling material is 3cm thick, and the bottom filling consists of aluminum powder and graphite powder in a mass ratio of 100:2, with aluminum powder having a particle size of 1mm and graphite powder having a particle size not exceeding 0.02mm.

[0084] (5) Before casting the ladle, connect the wire of the induction heating power supply to the induction coil extending from the bottom of the ladle, and connect the gas cooling system to the gas quick converter at the bottom of the ladle and introduce inert gas for cooling.

[0085] (6) When casting molten steel in the ladle, open the slide plate located at the bottom of the ladle and apply alternating current to the induction coil located on the ladle seat brick using an induction heating power supply, so that the metal powder in the sealing alloy powder melts under the electromagnetic induction heating effect of the induction coil. The ladle can automatically discharge steel within an average of 2 minutes.

[0086] Testing revealed that, compared to the original sand tapping technology, the total oxygen content and the number of inclusions inside the billet were significantly reduced in this embodiment, with an average reduction of over 30%, and there were no longer any inclusions of chromium oxide or silicon oxide.

[0087] Example 3 The ladle tapping method provided in this embodiment is verified using a 300-ton ladle for casting low-carbon, low-alloy steel in the continuous casting process of slabs at a steel plant. The method specifically includes the following steps: (1) The induction coil was fabricated based on the dimensions of the steel ladle and the original bottom seat bricks and the inner diameter of the steel outlet used by the steel plant. Among them: since the inner diameter of the steel outlet is 6cm, the inner diameter of the fabricated induction coil is 14cm; the height is 28cm; the specifications of the coil used for the induction coil are copper hollow square tubes with a diameter of 2.0cm, a wall thickness of 0.3cm, and a turn spacing of 0.8cm; the coil is wrapped with quartz insulating tape and mullite heat insulation fiber, wherein the thickness of the quartz insulating tape is 0.05cm and the thickness of the mullite heat insulation fiber is 0.5cm.

[0088] (2) During the steel ladle casting process, the prefabricated induction coil is placed inside the brick body and at the center of the steel outlet, and then cured, dried and shaped. Among them, the curing time of the brick body is 24 hours, the curing temperature is 180℃, and the curing time is 9 days.

[0089] (3) Place the prepared bricks at the bottom of the ladle, ensuring that the outer portion of the induction coil does not contact the ladle shell. In addition, insulate the outer copper tube of the induction coil before connecting it to the gas quick adapter. The gas quick adapter must be fixed to the lower part of the ladle shell.

[0090] (4) Before the ladle is filled with molten steel, the pre-filled ladle tapping sealing alloy structure is filled from the top water inlet at the bottom of the ladle, and then the bottom slide plate of the ladle is closed. The sealing alloy powder is pre-filled into the interior of the cylinder, the cylinder diameter and height are consistent with the steel outlet of the brick body, the cylinder wall thickness is 2mm, and the cylinder material is iron. The upper part of the cylinder is sealed with aluminum metal discs, and the lower part is an open structure, sealed with flammable sealing tape after filling. The sealing alloy powder is filled in the cylinder from top to bottom, with the uppermost part filled with a mixture of zirconium oxide and graphite powder. The middle part is filled with a mixture of aluminum powder and graphite powder, and a high-density graphite cylinder is installed on the inner wall of the middle area of ​​the cylinder, with a core rod made of high-density graphite. The bottom is completely filled with a mixture of aluminum powder and graphite powder. The thickness of the uppermost filling material is 3cm. The middle filling consists of aluminum powder and graphite powder in a mass ratio of 100:2, with aluminum powder having a particle size of 1mm and graphite powder having a particle size of 0.02mm. The high-density graphite cylinder is 3mm thick, and the core rod has a diameter of 2.5cm. The bottom filling material is 3cm thick, and the bottom filling consists of aluminum powder and graphite powder in a mass ratio of 100:2, with aluminum powder having a particle size of 1mm and graphite powder having a particle size not exceeding 0.02mm.

[0091] (5) Before casting the ladle, connect the wire of the induction heating power supply to the induction coil extending from the bottom of the ladle, and connect the gas cooling system to the gas quick converter at the bottom of the ladle and introduce inert gas for cooling.

[0092] (6) When casting molten steel in the ladle, open the slide plate located at the bottom of the ladle and apply alternating current to the induction coil located on the ladle seat brick using an induction heating power supply, so that the metal powder in the sealing alloy powder melts under the electromagnetic induction heating effect of the induction coil. The ladle can automatically discharge steel within an average of 2 minutes.

[0093] Testing revealed that, compared to the original sand tapping technology, the total oxygen content and the number of inclusions inside the billet were significantly reduced in this embodiment, with an average reduction of over 30%, and there were no longer any inclusions of chromium oxide or silicon oxide.

[0094] Therefore, it can be seen that, compared with the prior art, the advantages and benefits of the present invention are as follows: (1) The technical solution provided by the present invention no longer uses the diversion sand used in the traditional steel tapping technology, which can effectively suppress the problem of secondary pollution of molten steel caused by diversion sand, and can ensure the clean casting and production of molten steel.

[0095] (2) The technical method provided by the present invention is simple and easy to implement in industry, and does not affect the production rhythm and safety of existing processes. Moreover, the steel ladle plugging alloy structure used in the present invention can be prefabricated and only needs to be filled before the steel ladle is filled with molten steel. This greatly reduces the problem of a large amount of sand leakage at the top of the plugging layer caused by conventional diversion sand filling, as well as the cumbersome filling of other non-diversion sand technologies.

[0096] (3) The central core sealing and induction-heated structure in this invention will not contaminate the molten steel during ladle casting. Furthermore, by utilizing aluminum, a commonly used deoxidizer and alloying material in steel metallurgy, secondary deoxidation and alloying of the molten steel inside the ladle can be achieved during ladle casting, further improving the cleanliness of the molten steel and ensuring the yield and stability of alloy components. Meanwhile, the added graphite, as an antioxidant, can prevent premature sintering of aluminum before induction heating and prevent oxidation of aluminum during ladle casting. On the other hand, carbon, an indispensable solute component in steel, will not cause any contamination of the molten steel due to the introduction of graphite during casting.

[0097] (4) The sealing alloy structure for ladle tapping in this invention is selected as having a graphite cylinder and a core rod in the middle, which can provide strong electromagnetic coupling during induction heating, thereby solving the material bottleneck of metal powder (aluminum) itself being a weak magnetic material requiring higher induction intensity and slow heating rate. In addition, graphite itself can also act as an induction heating element, effectively improving the induction heating melting effect of aluminum, achieving rapid and uniform induction heating of aluminum, and ensuring smooth tapping and casting of steel under short-term and low-power conditions. At the same time, due to the reduction in the required heating intensity, the cycle life of the induction coil can also be further improved.

[0098] (5) The filling material and filling method of the uppermost part of the sealing in this invention can help prevent the molten steel inside the ladle from penetrating into the interior of the sealing alloy structure for ladle steel discharge under static pressure, thereby causing changes in the alloy composition inside the sealing alloy structure for ladle steel discharge, which in turn causes an increase in the heating power and time required for induction heating, and even the problem that the ladle cannot be successfully opened for pouring.

[0099] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0100] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0101] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," or "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0102] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "exemplary embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0103] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A sealing alloy structure for steel ladle tapping, characterized in that, The device includes a cylindrical section, a graphite assembly, and sealing alloy powder. The cylindrical section is coaxially and detachably installed inside the steel ladle seat brick's discharge port. The graphite assembly is located inside the cylindrical cavity of the cylindrical section, and the sealing alloy powder fills the cavity formed by the cylindrical cavity of the cylindrical section and the graphite assembly. The sealing alloy powder is a mixed powder comprising graphite powder and metal powder, wherein the metal powder is a powder that can melt under the action of induced heat generated by an induction coil located on the steel ladle seat brick.

2. The sealing alloy structure for steel ladle tapping according to claim 1, characterized in that, The cylindrical portion is made of metal; the graphite assembly is made of high-density graphite, and the graphite assembly includes: A graphite cylinder is coaxially mounted inside the cylinder portion, and the outer wall of the graphite cylinder is in contact with the inner wall of the cylinder portion; A mandrel is located inside the graphite cylinder and coaxially arranged with the graphite cylinder, and the length of the mandrel is the same as the length of the graphite cylinder; the graphite cylinder and the mandrel form a first cavity, which is used to fill the sealing alloy powder.

3. The sealing alloy structure for steel ladle tapping according to claim 2, characterized in that, The mass ratio of the metal powder to the graphite powder in the sealing alloy powder in the first cavity is 100:1~5; the particle size of the metal powder in the sealing alloy powder in the first cavity is not higher than 2 mm, and the particle size of the graphite powder in the sealing alloy powder in the first cavity is not higher than 0.2 mm.

4. The sealing alloy structure for steel ladle tapping according to claim 2, characterized in that, The wall thickness of the graphite cylinder does not exceed 5 mm, and the diameter of the core rod does not exceed 5 cm.

5. The sealing alloy structure for steel ladle tapping according to claim 2, characterized in that, The first end of the graphite tube is disposed near the first end of the cylindrical portion, and the second end of the graphite tube is disposed near the second end of the cylindrical portion; the second end of the graphite tube is higher than the second end of the cylindrical portion; the cylindrical cavity region in the cylindrical portion from the second end of the graphite tube to the second end of the cylindrical portion is a second cavity, and the second cavity is used to fill the sealing alloy powder.

6. The sealing alloy structure for steel ladle tapping according to claim 5, characterized in that, The mass ratio of the metal powder to the graphite powder in the sealing alloy powder in the second cavity is 100:2~10; the particle size of the metal powder in the sealing alloy powder in the second cavity is not higher than 5 mm, and the particle size of the graphite powder in the sealing alloy powder in the second cavity is not higher than 0.2 mm.

7. The sealing alloy structure for steel ladle tapping according to claim 5, characterized in that, The first end of the graphite tube is lower than the first end of the tube portion; the cavity region in the tube portion between the first end of the graphite tube and the first end of the tube portion is a third cavity, and the third cavity is used to fill one or more powders of zirconium oxide, aluminum oxide, chromium oxide, magnesium oxide, silicon dioxide, ferrosilicon and graphite.

8. The sealing alloy structure for steel ladle tapping according to claim 7, characterized in that, The height ratio between the first cavity, the second cavity, and the third cavity is 15~80:2~15:3~15.

9. The sealing alloy structure for ladle tapping according to any one of claims 1 to 8, characterized in that, The metal powder is aluminum powder.

10. The sealing alloy structure for steel ladle tapping according to any one of claims 1 to 8, characterized in that, The cylindrical portion includes: A cylindrical body, both ends of which are open; A cover plate is affixed to the opening at the top of the cylinder; the cover plate is made of iron, aluminum, or zirconium. An encapsulation layer, located on the opening at the bottom of the cylinder, is used to encapsulate the sealing alloy powder within a cavity formed by the cylindrical cavity of the cylinder and the graphite assembly; the encapsulation layer is made of a flammable material.

11. A method for tapping steel from a ladle, characterized in that, Includes the following steps: (1) Install the steel ladle discharge sealing alloy structure according to any one of claims 1 to 10 on the discharge port to seal the discharge port, and then close the sliding plate located at the bottom of the ladle; (2) When the steel ladle is casting molten steel, the slide plate located at the bottom of the steel ladle is opened, and alternating current is applied to the induction coil located on the steel ladle seat brick, so that the metal powder in the sealing alloy powder melts under the electromagnetic induction heating effect of the induction coil, so as to realize the steel ladle tapping.

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