Electrode for electroslag remelting

Abstract

The application discloses an electroslag remelting dummy electrode, which comprises a cylindrical dummy electrode body (2) and an O-shaped hanger (4) fixed at one end of the dummy electrode body (2), an air inlet hole (3) for ventilating into the cylinder is arranged at the top of the cylindrical dummy electrode body (2), and an air outlet hole (1) is arranged on the lower part of the side wall of the cylindrical dummy electrode body (2); a plurality of vertical heat dissipation grooves (6) are arranged on the inner wall of the cylinder body of the dummy electrode body (2). The connection between the dummy electrode body (2) and the O-shaped hanger (4) is integrated through a top plate (7) welded at the top end of the dummy electrode body (2) and used for plugging the upper part of the inner cylinder of the dummy electrode body (2); and the air inlet hole (3) is arranged on the top plate (7). The application solves the problems of large weight and high temperature rise of the dummy electrode for electroslag remelting, guarantees that the dummy electrode does not obviously deform in the using process, and reduces the dead weight of the dummy electrode.

Description

Technical Field

[0001] This invention relates to dummy electrodes used in electroslag remelting steelmaking equipment and their preparation methods. Background Technology

[0002] Electroslag remelting (ESR) and its equipment are frequently used methods, processes, and equipment in the production of high-quality steel. ESR involves forming ESR ingots from pre-smelted steel. In the ESR process, these ingots serve as electrodes in the ESR equipment, remelting the steel. Therefore, the ESR ingot acts as both an electrode and the raw material being remelted, hence it is also called a consumable electrode. The steel used as a consumable electrode needs to be clamped onto an electrode holder. This electrode holder, acting as a conductive terminal, serves two purposes: holding the electrode and acting as a conductive element, while also connecting to the power supply. Therefore, in the industry, the electrode holder is also referred to as a dummy electrode.

[0003] The dummy electrodes used in current electroslag remelting equipment are solid cylinders made of stainless steel. These solid dummy electrodes act as conductors, with one end connected to a consumable electrode and the other end connected to the furnace head. The dimensions of the solid cylindrical dummy electrodes currently used in a certain electroslag remelting equipment are... Weighing approximately 1.87 tons per piece, this solid dummy electrode is welded to the consumable electrode at its lower end. Current flows through the solid stainless steel column and the consumable electrode, forming an electroslag remelting process. During production, the solid stainless steel column is not cooled. This solid dummy electrode accounts for over 15% of the furnace head's total load-bearing capacity, making it not only heavy and difficult to lift on-site, but also costly to manufacture. Furthermore, this solid dummy electrode relies solely on its outer circumference for heat dissipation, resulting in poor heat dissipation. During use, due to conductivity (high current in steelmaking) and the steelmaking environment, it experiences significant temperature rises, leading to deformation, corrosion, or other thermal damage after a period of use. The joints connecting the dummy electrode to the consumable electrode or other components reach extremely high temperatures, causing these areas to glow red-hot and deform severely. This affects the connection with the consumable electrode and conductivity, shortening the lifespan of the solid dummy electrode. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a dummy electrode for electroslag remelting and its manufacturing method, which solves the problems of large weight, lack of cooling and excessive temperature rise of the dummy electrode for electroslag remelting in the prior art, ensures that the dummy electrode does not undergo significant thermal deformation during use, and reduces the weight of the dummy electrode.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: An electroslag remelting dummy electrode includes a dummy electrode body and an O-shaped lifting lug fixed to one end of the dummy electrode body. The dummy electrode body is cylindrical, with an air inlet at the top for air to pass into the cylinder and an air outlet on the lower side wall of the cylindrical dummy electrode body.

[0006] A further improvement of the technical solution of the present invention is that a number of vertical heat dissipation grooves are provided on the inner wall of the dummy electrode body cylinder.

[0007] A further improvement of the technical solution of the present invention is that: the connection between the dummy electrode body and the O-shaped lifting lug is achieved by a top plate welded to the top of the dummy electrode body for sealing the upper part of the inner cylinder of the dummy electrode body; the air inlet is provided on the top plate.

[0008] A further improvement of the technical solution of the present invention is that: the O-shaped lifting lug is a steel plate with lifting holes, the lower end of the steel plate is welded to the center line of the top plate, the middle part of the O-shaped lifting lug steel plate is bent to one side at 20°-25°, and stiffening plates for reinforcing the steel plate are welded on both sides below the bend and below the lifting holes, and a triangular support plate is welded at the part where the O-shaped lifting lug contacts the top plate; the air inlet is opened on one side of the O-shaped lifting lug steel plate.

[0009] A further improvement of the technical solution of the present invention is that: the top plate is a hollow structure with an internal cavity, an air inlet quick connector communicating with the cavity is provided on the upper surface of the top plate, and a number of air inlet holes for air to be introduced into the cylinder of the dummy electrode are provided in the inner layer of the top plate.

[0010] A further improvement of the technical solution of the present invention is that: at least six air inlet holes are provided in a uniformly distributed manner.

[0011] A further improvement to the technical solution of this invention is as follows: the manufacturing method of the electroslag remelting dummy electrode includes: the dummy electrode body is made by rolling and welding a stainless steel plate with the same length and width as the length and circumference of the dummy electrode body; specifically, firstly, several heat dissipation grooves are processed on one side of the stainless steel plate along the vertical direction of the dummy electrode body, then the stainless steel plate is rolled into a cylindrical shape using a plate rolling machine with the side with heat dissipation grooves as the inner surface, and the joints are tightly welded, and an air outlet is processed on the side wall of one end of the cylinder; thirdly, the top plate with an air inlet and the O-ring are sequentially welded to the other end of the cylinder; before use, the consumable electrode is welded to the end of the cylinder with the air outlet, and during use, the air inlet connector and the air outlet connector are respectively installed on the air inlet and the air outlet.

[0012] A further improvement of the technical solution of the present invention is that the heat dissipation groove is a rectangular groove, a C-shaped groove, or an open trapezoidal groove.

[0013] A further improvement of the technical solution of the present invention is that the welding described herein is all done by continuous full welding.

[0014] The technological advancements achieved by this invention due to the adoption of the above technical solutions are as follows: This invention uses stainless steel sheet rolled into a hollow dummy electrode, and adds heat dissipation grooves to the inner cavity sidewall. This allows dry air or inert gas to be introduced into the dummy electrode for air cooling, preventing excessive temperature rise and thus avoiding deformation, corrosion, or other thermal damage, significantly extending the dummy electrode's service life. Using this invention, the weight of the dummy electrode can also be reduced by 60%, greatly reducing the load on the furnace head.

[0015] The air inlet, air outlet, and vertical heat dissipation grooves of this invention allow the heat exchange gas to flow smoothly inside the dummy electrode and effectively remove heat from the electrode. The O-shaped lifting lugs enhance the strength of the lugs, reducing material usage and weight, and facilitating the lifting and installation of the dummy electrode. The top plate of this invention is constructed with an air inlet, several distributed internal air inlets, and cavities between them, allowing cooling gas to enter the dummy electrode cylinder evenly for uniform and rapid cooling. As a component connecting the conductive end of the electroslag furnace, the top plate can also be made of copper plate to meet conductivity requirements. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the dummy electrode of the present invention; Figure 2 This is a plan view of the stainless steel plate used to make the dummy electrode. Figure 3 This is a schematic diagram of the O-type lifting lug of the present invention. Figure 4 This is a schematic diagram of the top plate structure of the present invention; wherein, 1, air outlet, 2, dummy electrode, 3, air inlet, 4, O-ring, 5, stainless steel plate, 6, heat dissipation groove, 7, top plate, 8, stiffening plate, 9, support plate, 10, quick connector for air inlet, 11, cavity, 12, air inlet inner hole, 13, lifting hole. Detailed Implementation

[0017] An electroslag remelting dummy electrode of the present invention includes a dummy electrode body 2 and an O-shaped lifting lug 4 fixed to one end of the dummy electrode body 2. In use, the O-shaped lifting lug 4 is positioned at the upper end of the dummy electrode, and an electroslag ingot serving as a consumable electrode is tightly welded to the lower end of the dummy electrode body 2. The dummy electrode body 2 is cylindrical, and several vertical heat dissipation grooves 6 are provided on the inner wall of the cylindrical body. A top plate 7 is welded to the top of the dummy electrode body 2, and the O-shaped lifting lug 4 is welded to the top of the top plate 7; that is, the dummy electrode body 2 and the O-shaped lifting lug 4 are connected as a single unit through a top plate 7 welded to the top of the dummy electrode body 2. The O-type lifting lug 4 described in this invention is a steel plate with lifting holes 13. The lower end of the steel plate is welded to the diameter line on the upper surface of the top plate 7. The middle part of the steel plate of the O-type lifting lug 4 is bent to one side at 20°-25°, which facilitates the use of an overhead crane to lift the dummy electrode. Reinforcing ribs 8 are welded to the lower part of the bending point and on both sides of the lower part of the lifting holes 13. A triangular support plate 9 is welded to the part where the O-type lifting lug 4 contacts the top plate 7, which can enhance the strength of the O-type lifting lug 4 itself and the connection strength with the top plate 7.

[0018] An air inlet 3 for ventilation into the cylinder is provided at the top of the cylindrical dummy electrode body 2, and an air outlet 1 is provided on the lower side wall of the cylindrical dummy electrode body 2. That is, the air inlet 3 is provided on the top plate 7, and the air outlet 1 is provided on the side of the cylinder. The top plate 7 of the present invention is a hollow structure with an internal cavity 11. An air inlet quick connector 10 communicating with the cavity 11 is provided on the outer surface (upper surface) of the top plate 7, and a plurality of air inlet holes 12 are provided in the inner layer of the top plate 7. When manufacturing the top plate 7, it can be divided into a three-layer structure. The first layer (outer layer) has an air inlet hole, which should be located in the middle away from the center of the circular top plate 7. The air inlet hole is equipped with an air inlet quick connector 10 for introducing cooling gas. Between the outer layer and the inner layer (third layer) is the middle layer (second layer), and a cavity 11 is formed in the middle layer. The cavity 11 can be formed by sandwiching a steel plate circle between the steel plates of the first layer and the third layer. Several air outlet holes 12 are evenly arranged on the third layer of the top plate 7. There are at least six air outlet holes 12, which are used to evenly introduce the gas entering the cavity 11 into the cylinder of the dummy electrode body 2.

[0019] The dummy electrode body 2 of the electroslag remelted dummy electrode of the present invention is made of rolled stainless steel plate. The length and width of the rolled steel plate are equal to the length and circumference of the dummy electrode body 2. After being rolled into a cylinder, the joints are completely welded to form a cylinder. The manufacturing method of the electroslag remelted dummy electrode includes: First, several heat dissipation grooves 6 are processed on one side of the stainless steel plate 5 along the vertical direction of the dummy electrode body 2 (generally the length direction of the steel plate). The heat dissipation grooves 6 can be one or more of the following shapes: rectangular grooves, C-shaped grooves, or open trapezoidal grooves.

[0020] Second, using the side with the heat dissipation groove 6 as the inner surface, the stainless steel plate 5 is rolled into a cylindrical shape using a plate rolling machine, and the vertical joints are tightly welded. All welding described in this invention employs continuous full welding. An vent hole 1 is then machined on the side wall at one end of the cylinder. Third, the top plate 7 with the air inlet 3 and the O-ring 4 are then welded sequentially to the other end of the cylinder. In this invention, both the air inlet 3 and the air outlet 1 can be threaded holes to facilitate the installation of the air inlet connector and the air outlet connector via threads. 4. Before use, weld the consumable electrode to the end of the cylinder where the air outlet 1 is located; when using, install the air inlet connector and the air outlet connector on the air inlet 3 and the air outlet 1 respectively, and then air can be supplied for remelting production.

[0021] The present invention will be further described in detail below, taking as an example a specific implementation method for producing a dummy electrode for an electroslag remelting equipment.

[0022] Step A: Take a stainless steel plate 5 with a length of 1420mm, a width of 1500mm, and a thickness of 40-50mm, and machine rectangular grooves (3-5mm deep and 30mm wide) every 100mm along the width direction. These grooves can also be C-shaped grooves or open trapezoidal grooves, etc., to serve as heat dissipation grooves 6.

[0023] Step B: Roll the stainless steel plate 5 with the heat dissipation groove 6 inward (on the side with the heat dissipation groove 6) using a plate rolling machine to form a cylinder with an outer diameter of Φ450mm and a height of 1500mm, with the side with the heat dissipation groove facing inward.

[0024] Step C: Securely weld the joint of the cylinder using a full, continuous welding method. Then, machine an vent hole 1 on the side of one end of the cylinder, with the vent hole 1 approximately 50mm from the end face of the cylinder.

[0025] Step D: Weld the top plate 7 and O-rings to the other end of the cylinder. The top plate 7 has an air inlet 3 pre-machined on it. In this embodiment, the air inlet 3 and the air outlet 1 can be threaded holes of Φ20-30mm to facilitate the installation of pipeline interfaces that provide dry air, argon or other inert gases.

[0026] Step E: Before use, weld the consumable electrode to the end face of the dummy electrode 2 where the vent hole 1 is located, so that the consumable electrode and the dummy electrode 2 form a whole. Then, hoist it to the furnace head of the electroslag furnace, connect the argon gas interface reserved in the furnace head to the gas inlet of the dummy electrode, and after assembly, electroslag remelting production can begin. During the production process, argon gas can cool the dummy electrode 2 from the inside.

Claims

1. An electroslag remelted dummy electrode, characterized in that: It includes a dummy electrode body (2) and an O-shaped lug (4) fixed to one end of the dummy electrode body (2). The dummy electrode body (2) is cylindrical. An air inlet (3) is provided at the top of the cylindrical dummy electrode body (2) to allow air to pass into the cylinder, and an air outlet (1) is provided on the lower side wall of the cylindrical dummy electrode body (2).

2. The electroslag remelted dummy electrode according to claim 1, characterized in that: Several vertical heat dissipation grooves (6) are provided on the inner wall of the dummy electrode body (2).

3. The electroslag remelted dummy electrode according to claim 1, characterized in that: The connection between the dummy electrode (2) and the O-type lug (4) is achieved by a top plate (7) welded to the top of the dummy electrode (2) to seal the upper part of the inner cylinder of the dummy electrode (2); the air inlet (3) is provided on the top plate (7).

4. The electroslag remelted dummy electrode according to claim 3, characterized in that: The O-shaped lifting lug (4) is a steel plate with a lifting hole (13). The lower end of the steel plate is welded to the center line of the top plate (7). The middle part of the O-shaped lifting lug (4) steel plate is bent to one side at 20°-25°. Reinforcing ribs (8) are welded on both sides of the lower part of the lifting hole (13) below the bend. A triangular support plate (9) is welded at the part where the O-shaped lifting lug (4) contacts the top plate (7). The air inlet (3) is opened on one side of the O-shaped lifting lug (4) steel plate.

5. The electroslag remelted dummy electrode according to claim 3, characterized in that: The top plate (7) is a hollow structure with an internal cavity (11). A quick connector (10) for an air inlet that communicates with the cavity (11) is provided on the upper surface of the top plate (7). Several air inlet holes (12) for air to pass into the cylinder of the dummy electrode (2) are provided in the inner layer of the top plate (7).

6. The electroslag remelted dummy electrode according to claim 5, characterized in that: The air inlet (12) has at least six evenly distributed holes.

7. An electroslag remelted dummy electrode according to claims 1-6, characterized in that: The manufacturing method of the electroslag remelting dummy electrode includes: the dummy electrode body (2) is made by rolling and welding a stainless steel plate (5) with the same length and width as the length and circumference of the dummy electrode body (2); specifically, firstly, several heat dissipation grooves (6) are processed on one side of the stainless steel plate (5) along the vertical direction of the dummy electrode body (2), then the stainless steel plate (5) is rolled into a cylinder by a plate rolling machine with the side with heat dissipation grooves (6) as the inner surface, and the joint is tightly welded, and an air outlet (1) is processed on the side wall of one end of the cylinder; thirdly, the top plate (7) with an air inlet (3) and the O-type lifting lug (4) are sequentially welded to the other end of the cylinder; before use, the consumable electrode is welded to the end of the cylinder with the air outlet (1), and during use, the air inlet connector and the air outlet connector are installed on the air inlet (3) and the air outlet (1) respectively.

8. The electroslag remelted dummy electrode according to claim 7, characterized in that: The heat dissipation groove (6) is a rectangular groove, a C-shaped groove, or an open trapezoidal groove.

9. The electroslag remelted dummy electrode according to claim 7, characterized in that: All of the aforementioned welding is performed using continuous full-scale welding.

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