Safety stopper for continuous steel casting

Abstract

The utility model discloses a safe intercepting stopper for continuous steel casting, relates to the technical field of refractory material for continuous steel casting, and comprises a stopper body and a stopper head arranged at the end of the stopper body, and the stopper head is in the shape of a round bullet; a ceramic ball is embedded in the stopper head; a connecting hole is arranged in the stopper body and extends into the stopper head; and the connecting hole and the ceramic ball are coaxially arranged. The connecting hole corresponds to the fastening screw rod during the installation of the product, is vertically distributed, and the stopper is installed on the tundish stopper mechanism through the fastening screw rod during use. In the later use stage, the stopper head is abraded, the embedded ceramic ball is discharged from the stopper head, and the ceramic ball falls to the throat of the upper nozzle bowl along with the steel flow, blocks the steel flow channel, and thus the technical problem that the stopper cannot effectively block the steel flow hole of the upper nozzle in the later use stage is solved, and the tundish can be quickly and safely replaced.

Description

Technical Field

[0001] This utility model relates to the field of refractory materials for continuous casting, specifically a safety shut-off plug rod for continuous steel casting. Background Technology

[0002] The stopper rod is one of the most important control components in the continuous casting process. Working in conjunction with the top nozzle, it controls the flow rate of molten steel from the tundish to the crystallizer. The stopper rod operates under demanding conditions: it must withstand high-temperature baking without oxidation, prevent cracking during the initial casting stage, and endure prolonged immersion in molten steel to withstand its scouring and erosion. The stopper rod undergoes reciprocating motion during operation to ensure a stable casting speed.

[0003] The stopper head is a critical part of the stopper rod, and its resistance to erosion and spalling directly affects whether the stopper rod can control the flow normally and the length of continuous casting time.

[0004] The tundish is a refractory container used in short-process steelmaking. It first receives molten steel poured from the ladle, and then distributes it to the various crystallizers through the tundish nozzle. The tundish top nozzle is located at the bottom of the tundish, and a stopper rod is installed on the upper inside.

[0005] The existing technology CN202022290589.7 describes a stopper rod with a long service life that is resistant to molten steel corrosion and scouring, which is an existing stopper rod structure. However, it cannot solve the problem that in the later stages of use, the rod head gradually becomes thinner due to scouring and erosion by molten steel, and even scouring grooves are formed on the surface of the rod head, resulting in a decrease in flow control accuracy, inability to stop the steel flow when pouring is stopped, and thus prolonging the time for stopping pouring and changing ladles and reducing safety.

[0006] To address these issues, we provide a safety shut-off plug rod and prefabrication mold for continuous cast steel. Utility Model Content

[0007] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a safety stopper rod for continuous steel casting to solve the technical problem that the stopper rod cannot effectively block the steel flow hole at the water inlet in the later stage of use, resulting in the inability to stop the steel flow when casting is stopped.

[0008] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0009] A safety shut-off plug rod for continuous cast steel includes a plug rod body and a plug head at the end of the plug rod body. The plug head is shaped like a round bullet. A ceramic ball is filled inside the plug head. A connecting hole is provided inside the plug rod body and extends into the plug head. The connecting hole and the ceramic ball are arranged coaxially. The connecting hole corresponds to the bolts installed during actual installation, and the plug is vertically distributed and connected within the tundish.

[0010] The material of the rod head is one or more of aluminum carbon, zircon carbon, magnesium carbon, aluminum zircon carbon, magnesium zircon carbon, or magnesium spinel.

[0011] The rod body is made of corundum, bauxite, graphite and other materials combined with liquid phenolic resin.

[0012] Ceramic balls are pre-fired corundum or zirconia ceramic products that are embedded inside the stopper head during stopper rod forming. They are pressed together with the stopper rod, and then shaped and fired.

[0013] As continuous casting production progresses, the bar tip gradually becomes thinner due to the erosion caused by the molten steel, and even erosion grooves may appear on the surface of the bar tip. When the tundish is stopped and replaced, the ceramic ball falls off from the bar tip and flows with the steel flow towards the nozzle of the tundish until it blocks the steel flow hole of the tundish nozzle, thus stopping the outflow of molten steel from the tundish and facilitating the relocation and replacement of the tundish.

[0014] In a further technical solution, depending on the erosion rate and service life requirements of the rod head, the ceramic ball is a corundum ball or a zirconia ball fired at high temperature.

[0015] The material mass percentage of the corundum sphere is Al2O3 ≥ 95%, and the bulk density is ≥ 3.7 g / cm³. 3 ;

[0016] The material mass percentage of the zirconia spheres is: ZrO2 ≥ 93%, and the bulk density is ≥ 5.8 g / cm³. 3 .

[0017] In a further technical solution, the position of the ceramic ball at the tip of the stopper rod is determined by a comprehensive calculation based on the stopper rod's service life requirements and the erosion rate of the rod tip. The distance between the tip of the rod, which is away from the body of the stopper rod, and the ceramic ball is 15-20 mm.

[0018] In a further technical solution, the diameter of the ceramic ball is adapted to the diameter of the steel flow hole of the tundish top nozzle, which is suitable for blocking the steel flow hole of the tundish top nozzle.

[0019] A prefabrication mold for a safety shut-off plug rod for continuous casting includes a plug rod sleeve, a pressure cap installed at one end of the plug rod sleeve, and a base installed at the other end; a core rod is detachably installed on the base.

[0020] A molding cavity is provided inside the stopper rod sleeve, and a ceramic ball is pre-embedded in the molding cavity; the mandrel is located inside the molding cavity; the ceramic ball and the mandrel are arranged coaxially and are located on the central axis of the stopper rod sleeve;

[0021] A cap cup is also installed between the stopper rod sleeve and the pressure cap. The cap cup 11 is fixed in position by an annular platform inside the sleeve, and an arc-shaped surface is provided on the side opposite to the mandrel. The arc-shaped surface is adapted to the surface of the rod head.

[0022] In a further technical solution, a small hole is provided at the center of the lid bowl, which is suitable for use as a feeding port during production.

[0023] In a further technical solution, the rod body and the rod head are made of different materials; the ceramic ball has 1 to 5 grooves on its surface and is fitted into the rod head.

[0024] The rod body, rod head, and the ceramic balls embedded in the rod head are all components of the stopper rod. They are made of different raw materials in the same mold, depending on the performance and service life requirements. Ceramic balls are placed inside the rod head material, and the surface of the ceramic balls has 1-5 grooves. They fit together with the rod head material. During production, the mold is hammered while feeding materials to make the internal materials as dense as possible. Then the mold cover is closed and the material is sent to an isostatic press for one-time pressure pressing to form the stopper rod.

[0025] Compared with existing technologies, it has the following advantages:

[0026] This invention features a ceramic ball installed inside the rod head. The diameter of the ceramic ball is not less than the inner diameter of the upper water inlet. This allows the stopper rod to fall into the tundish and flow with the molten steel to the upper water inlet during the later stages of its use, effectively blocking the upper water inlet and reducing the downward flow of molten steel when the continuous casting system is stopped.

[0027] The high proportion of alumina or zirconium oxide in the ceramic spheres of this invention results in a melting point temperature much higher than that of molten steel. During continuous casting, the molten steel is approximately 1500-1600℃, allowing it to remain in the tundish for a relatively long time. High purity reduces the presence of low-melting-point impurity phases, improving the material's strength, hardness, and creep resistance at high temperatures.

[0028] The prefabricated mold used in this invention has a simple and clear structure, which ensures the molding effect under static pressure.

[0029] This invention has a simple structure, is safe to operate, shortens the tundish replacement time, and improves the safety of continuous casting operations. Attached Figure Description

[0030] Figure 1 This is a cross-sectional view of the stopper rod of this utility model;

[0031] Figure 2 This is a cross-sectional structural diagram of the prefabricated mold of this utility model;

[0032] Figure 3 This is a schematic diagram of the stopper rod, tundish, and tundish inlet of the present invention. Figure 1 ;

[0033] Figure 4 This is a schematic diagram of the stopper rod, tundish, and tundish inlet of the present invention. Figure 2 ;

[0034] Figure 5 This is a schematic diagram of the ceramic ball in this utility model. Figure 1 ;

[0035] Figure 6 This is a schematic diagram of the ceramic ball in this utility model. Figure 2 ;

[0036] In the picture:

[0037] 1. Stopper rod body; 2. Rod head; 3. Ceramic ball; 4. Connecting hole; 5. Inlet of tundish; 6. Flow hole; 7. Stopper rod rubber sleeve; 8. Pressure cap; 9. Base; 10. Core rod; 11. Cover cup; 12. Groove; 13. Molding cavity. Detailed Implementation

[0038] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0039] Example 1

[0040] Please see Figure 1 The present invention provides a technical solution: a safety stopper rod for continuous casting steel, comprising a rod body 1, a rod head 2 at the end of the rod body 1, the rod head 2 being in the shape of a round bullet; a ceramic ball 3 pre-embedded in the rod head 2; the rod body 1 having a channel 4 left by the core rod during forming, the channel 4 and the ceramic ball 3 being arranged coaxially.

[0041] Ceramic ball 3 is a corundum ball or zirconium oxide ball fired at high temperature;

[0042] The material mass percentage of the corundum sphere is Al2O3 ≥ 95%, and the bulk density is ≥ 3.7 g / cm³. 3 ;

[0043] The material mass percentage of the zirconia spheres is: ZrO2 ≥ 93%, and the bulk density is ≥ 5.8 g / cm³. 3 The high-quality proportions of alumina and zirconium oxide result in a melting point temperature exceeding 2000℃, while conventional molten steel typically melts at around 1500-1600℃, allowing it to remain in the tundish for a relatively long time. The high purity reduces the presence of low-melting-point impurity phases, improving the material's strength, hardness, and creep resistance at high temperatures.

[0044] The position of the ceramic ball at the tip of the stopper rod is determined by a comprehensive calculation based on the stopper rod's service life requirements and the erosion rate of the rod tip. The distance between the tip of the rod 2, which is away from the tip of the stopper rod body 1, and the ceramic ball 3 is 15-20 mm.

[0045] The diameter of the ceramic ball is selected according to the diameter of the steel flow hole at the water inlet, and is generally 20-60mm.

[0046] The material of the bar stock is one or more of aluminum carbon, zircon carbon, magnesium carbon, aluminum zircon carbon, magnesium zircon carbon, or magnesium spinel.

[0047] The rod body is made of a combination of bauxite and liquid phenolic resin.

[0048] The diameter of the ceramic ball 3 is matched with the diameter of the steel flow hole 6 of the tundish sprue 5, which is suitable for blocking the steel flow hole 6 of the tundish sprue 5.

[0049] Example 2

[0050] like Figure 2 As shown, another embodiment of the present invention is provided. Based on embodiment 1, a prefabrication mold for a safety shut-off plug rod for continuous casting steel includes a plug rod sleeve 7, a pressure cap 8 is provided at one end of the plug rod sleeve 7, and a base 9 is provided at the other end; a core rod 10 is detachably installed on the base 9.

[0051] A molding cavity 13 is provided inside the stopper rod sleeve 7, and the core rod 10 is located inside the molding cavity 13. When the stopper rod is fed to the appropriate height during production, the ceramic ball 3 is placed in, and the rod head material is continued to be added to the design height. The ceramic ball 3 and the core rod 10 are arranged coaxially and are located on the central axis of the stopper rod sleeve 7.

[0052] A cap cup 11 is also provided between the stopper sleeve 7 and the pressure cap 8. The cap cup 11 is fixed in position by the annular platform inside the sleeve, and has an arc-shaped surface on the side opposite to the core rod 10. The arc-shaped surface is adapted to the surface of the rod head 2.

[0053] A gap is provided between the cap 8 and the molding cavity 4, and it is suitable to be used as an injection port.

[0054] Ceramic balls are pre-fired corundum or zirconia ceramic products, embedded inside the stopper head during stopper rod forming. They are pressed together with the stopper rod, and then shaped and fired. The mold assembly, raw material feeding, isostatic pressing, shaping, glazing, and firing processes are the same as for ordinary stopper rods.

[0055] Example 3

[0056] like Figure 3-6 As shown, this is another embodiment of the present invention, based on embodiment 2.

[0057] The stopper rod body 1 and rod head 2 are made of different materials; combined Figure 2 As shown, after setting position control lines on the mandrel, different materials are filled in, and static pressure molding is used. During production, the mold is hammered while feeding materials to make the internal materials as dense as possible. Then, the mold cover is tightened, and the material is sent into an isostatic press for one-time pressure molding.

[0058] like Figure 3 and 4 As shown, Figure 3 This is a schematic diagram of the initial use of the stopper rod; Figure 4 During the later stages of continuous casting production, when the tundish is stopped and replaced, the ceramic ball falls off the rod head and flows with the steel flow towards the tundish nozzle bowl until it blocks the steel flow hole on the tundish, thus stopping the outflow of molten steel from the tundish and facilitating the relocation and replacement of the tundish.

[0059] refer to Figure 5 and 6 As shown, the ceramic ball 3 has 1 to 5 grooves 12 on its surface, and the ceramic ball 3 is embedded in the rod head 2.

[0060] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention.

Claims

1. A safety shut-off plug rod for continuous cast steel, characterized in that, It includes a stopper rod body (1), and a rod head (2) is provided at the end of the stopper rod body (1). The rod head (2) is in the shape of a round bullet. A ceramic ball (3) is pre-embedded in the rod head (2). A connecting hole (4) is provided in the stopper rod body (1) and extends into the rod head (2). The connecting hole (4) and the ceramic ball (3) are arranged on the same axis.

2. The safety shut-off plug rod for continuous casting steel according to claim 1, characterized in that: The ceramic sphere (3) is a corundum or zirconia ceramic sphere fired at high temperature; The material mass percentage of the corundum sphere is Al2O3 ≥ 95%, and the bulk density is ≥ 3.7 g / cm³. 3 ; The zirconium oxide spheres have the following material mass percentages: ZrO2 ≥ 93%, and a bulk density ≥ 5.8 g / cm³. 3 .

3. A safety shut-off plug rod for continuous casting steel according to claim 1, characterized in that: The distance between the tip of the rod head (2) away from the rod body (1) and the ceramic ball (3) is 15-20 mm.

4. A safety shut-off plug rod for continuous casting steel according to claim 1, characterized in that: The diameter of the ceramic ball (3) is matched with the diameter of the steel flow hole (6) of the tundish top water outlet (5), which is suitable for blocking the steel flow hole (6) of the tundish top water outlet (5).

5. A safety shut-off plug rod for continuous casting steel according to claim 4, characterized in that, The ceramic ball (3) has 1 to 5 grooves (12) on its surface and is fitted into the rod head (2).

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