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CN-119702988-B - Tundish electromagnetic cyclone and cyclone stopper combined control continuous casting device and method

CN119702988BCN 119702988 BCN119702988 BCN 119702988BCN-119702988-B

Abstract

The invention belongs to the technical field of continuous casting, and discloses a tundish electromagnetic cyclone and cyclone stopper rod combined control continuous casting device and method. Before the molten steel flows out of the tundish, a rotating speed is provided for the molten steel, so that the molten steel in the water gap can obtain a stronger rotating effect under the condition of smaller electromagnetic rotational flow intensity. The electromagnetic cyclone device is embedded into the bottom of the tundish, so that the occupation of the device to the space of the continuous casting working platform is avoided, and the smooth operation of slag pushing work is facilitated. The rotating effect of the molten steel in the water gap and the crystallizer is increased, and the streamline of the molten steel in the crystallizer is increased, so that the floating removal of inclusions is facilitated. The flow field in the crystallizer is improved through the combined action of the swirl blades at the bottom of the tundish and the electromagnetic swirl, the bias flow problem is improved, the solidification temperature is uniform, the solidification structure of a continuous casting billet is optimized, the adaptability of a continuous casting machine to different continuous casting process parameters is improved, and the process stability and economic benefit of continuous casting are improved.

Inventors

  • WANG QIANG
  • SUN YANWEN
  • LIU XIAOMING
  • ZHANG SIYUAN
  • LIU ZEYI

Assignees

  • 东北大学

Dates

Publication Date
20260505
Application Date
20241224

Claims (6)

  1. 1. A tundish electromagnetic cyclone and cyclone stopper rod combined control continuous casting device is characterized by comprising a cyclone stopper rod (1), a tundish (2), a tundish cyclone blade (3), a tundish electromagnetic cyclone device (4), a sliding gate (5), a submerged gate (6) and a crystallizer (7), wherein the tundish electromagnetic cyclone blade (3) and the tundish electromagnetic cyclone device (4) are arranged in the bottom of the tundish on the basis of not changing the internal cavity structure of the tundish, one end of the sliding gate (5) is connected with the submerged gate (6), the other end of the sliding gate is connected with the tundish cyclone blade (3), the other end of the sliding gate is connected with the crystallizer (7), the tundish (2), a tundish outlet, the sliding gate (5), the submerged gate (6) and the crystallizer (7) form an integral molten steel runner (8), molten steel in the tundish (2) flows out of the tundish (2) through the tundish outlet with the tundish blade (3), flows into the crystallizer (7) through the sliding gate (5) and the submerged gate (6) in sequence, one end of the sliding gate is communicated with the tundish cyclone blade (3), the other end of the sliding gate is communicated with the tundish electromagnetic cyclone blade (4) and the bottom of the tundish is arranged in the tundish electromagnetic cyclone device (4), the tundish rotational flow blade (3) is positioned in the outlet of the tundish (2), and the outer diameter of the tundish rotational flow blade (3) is smaller than the inner diameter of the tundish electromagnetic rotational flow device (4); The shape of the tundish swirl vane (3) is a fan blade or a triangular prism, the cross section of the swirl vane is semicircular, circular arc or polygonal, the tundish swirl vane (3) is positioned at the molten steel outlet position at the bottom of the tundish, the vertical height of the tundish swirl vane (3) is 20-500 mm, and the cross section area of the tundish swirl vane (3) is 5-1000 mm 2 ; The continuous casting blank pulling speed is controlled by controlling the distance between the rotational flow stopper rod (1) and the rotational flow blade (3) of the tundish, and molten steel flows into the submerged nozzle (6) from the space between the rotational flow stopper rod (1) and the rotational flow blade (3) of the tundish in the tundish (2); the shape and the size of the end part of the rotational flow stopper rod (1) are completely the same as those of the rotational flow blade (3) of the tundish, the rotational flow stopper rod and the tundish are in interference fit, and when the rotational flow stopper rod (1) reaches the lowest point, the rotational flow blade (3) of the tundish is embedded into a groove of the stopper rod (1), and the continuous casting speed is 0 m/s.
  2. 2. The tundish electromagnetic cyclone and cyclone stopper combined control continuous casting device according to claim 1, wherein the number of the tundish cyclone blades (3) is 1-15, and the included angle between the tundish cyclone blades (3) and the vertical direction is more than 20 degrees and less than 75 degrees.
  3. 3. The tundish electromagnetic cyclone and cyclone stopper combined control continuous casting device according to claim 2 is characterized in that when the pulling speed of a casting blank is 0.2-0.6 m/min, the angles of the tundish cyclone blades (3) are 20-45 degrees, the number of the tundish electromagnetic cyclone devices (4) is 3-6, when the pulling speed is 0.6-1.0 m/min, the angles of the tundish cyclone blades (3) are 30-60 degrees, the number of the tundish electromagnetic cyclone devices (4) is 4-8, when the pulling speed is 1.0-1.4 m/min, the angles of the tundish cyclone blades (3) are 45-60 degrees, the number of the tundish electromagnetic cyclone devices (4) is 4-12, when the pulling speed is above 1.4 m/min, the input currents of the tundish electromagnetic cyclone devices (4) are 45-75 degrees, the number of the tundish electromagnetic cyclone blades (3) is 4-12, and when the pulling speed is above 400-A.
  4. 4. The tundish electromagnetic cyclone and cyclone stopper combined control continuous casting device according to claim 1 is characterized in that the tundish electromagnetic cyclone device (4) mainly comprises iron cores (9) and winding coils (10), the winding coils (10) are wound on the surfaces of each iron core (9), a rotating magnetic field is formed in the iron cores (9) after the winding coils (10) are electrified, and the rotating magnetic field acts on molten steel flowing through the tundish electromagnetic cyclone device (4) and drives the molten steel to rotate under the action of lorentz force.
  5. 5. The tundish electromagnetic cyclone and cyclone stopper combined control continuous casting device according to claim 1 is characterized in that the thickness of the tundish electromagnetic cyclone device (4) is 5-50 cm, the volume of the tundish electromagnetic cyclone device is 35640-356400 cm 3 , and air cooling, water cooling or oil cooling is adopted at the outer side of the tundish electromagnetic cyclone device (4).
  6. 6. A continuous casting method of a tundish electromagnetic cyclone and cyclone stopper combined control continuous casting device according to any one of claims 1 to 5, characterized by comprising the following steps: Step 1, obtaining continuous casting process parameters including steel grade, blank drawing speed and casting blank section size; Step 2, current with corresponding intensity is introduced into the tundish electromagnetic cyclone device (4) according to the continuous casting process parameter requirements; step 3, connecting the tundish (2) with the ladle through a long nozzle, and enabling molten steel in the ladle to flow into the tundish (2); Step 4, connecting the immersed nozzle (6) with the bottom of the tundish (2), and opening the sliding nozzle (5); Step 5, lifting a rotational flow stopper rod (1), wherein molten steel in a tundish (2) passes through a tundish rotational flow blade (3) and enters a sliding water gap (5) and a submerged water gap (6) in sequence through an outlet at the bottom of the tundish and an action area of a tundish electromagnetic rotational flow device (4); Step 6, the molten steel generates tangential velocity in the immersed nozzle (6) under the combined control of the tundish electromagnetic cyclone device (4) and the tundish cyclone blade (3), and starts to flow in a rotating way; And 7, flowing molten steel with a rotating tangential speed into the crystallizer (7) through the submerged nozzle (6), and improving a molten steel flow field in the crystallizer (7).

Description

Tundish electromagnetic cyclone and cyclone stopper combined control continuous casting device and method Technical Field The invention relates to the technical field of continuous casting, in particular to a tundish electromagnetic cyclone and cyclone stopper rod combined control continuous casting device and method. Background Continuous casting (continuous casting) technology has become a revolutionary technology in the steel industry since the mid-20 th century. By pouring, condensing and cutting molten steel in the continuous casting machine, the steel enterprises can directly obtain casting blanks with higher dimensional accuracy and surface quality, and the production efficiency and the product quality are greatly improved. With the continuous development of continuous casting technology, the production capacity of steel enterprises is rapidly improved, and the modernization process of the steel industry is greatly promoted. However, as global energy and resource crisis increases, competitive pressures facing iron and steel enterprises continue to increase. In order to improve the market competitiveness of enterprises, the quality of steel becomes one of the key factors. In the steel production process, the cleanliness of molten steel directly affects the mechanical properties and surface quality of the finished steel. Reducing the content of impurity elements in steel, particularly nonmetallic inclusions, has become an important task for iron and steel enterprises. Nonmetallic inclusions not only affect the mechanical properties of the steel, resulting in a decrease in the strength of the material, but also may initiate cracks or surface defects during processing. Therefore, how to effectively control the quantity, shape, size and distribution of the inclusions becomes a key task in the continuous casting process. In modern steel production, the crystallizer plays a key role. The crystallizer not only determines the cooling rate of molten steel, but also directly influences the surface quality of casting blanks and the generation of internal defects. The surface and internal defects of the continuous casting billet are closely related to the flow state of molten steel in the crystallizer. If the flow of molten steel in the crystallizer is unstable, a series of problems may be caused, and the quality of the continuous casting billet is further affected. The molten steel flow in the crystallizer controls the floating and separation of inclusions and bubbles. If the flow pattern is unstable, inclusions and bubbles may not be effectively removed, forming internal defects in the steel. In addition, the flow of molten steel near the meniscus also affects the melting, spreading and entrainment behavior of the mold flux. If the flow of the molten steel is unstable, the covering slag may not be uniformly distributed, and even the phenomenon that the slag is involved in the molten steel may occur, thereby affecting the quality of the molten steel and the surface quality of the casting blank. The fluctuation of the liquid level of the crystallizer is also a key factor, and the fluctuation of the liquid level can cause problems of shearing slag inclusion or vortex slag inclusion, and the problems can cause defects on the surface of a casting blank or internal quality degradation. Common flow control methods in the crystallizer comprise electromagnetic stirring, electromagnetic braking, mechanical rotor water gap technology, electromagnetic rotational flow water gap technology and the like of the crystallizer. The mechanical rotor nozzle technology makes molten steel in a nozzle generate rotational flow by arranging a rotary blade in a submerged nozzle, but in actual production, a mechanical rotor is damaged by erosion of high-temperature high-speed molten steel, and the mechanical rotor is a main source of large-size inclusions in molten steel. The Chinese patent with the patent application number 200510047290.6 discloses an electromagnetic rotational flow nozzle, and the Chinese patent with the patent application number 201410254236.8 discloses an electromagnetic rotational flow continuous casting method. The electromagnetic cyclone nozzle technology drives molten steel to rotate through electromagnetic force, is beneficial to improving the flowing state of the molten steel in a crystallizer, can particularly effectively reduce the phenomenon of uneven outflow of a nozzle outlet, and can also improve the equiaxial crystal rate, thereby reducing macrosegregation of casting blanks. Meanwhile, the electromagnetic cyclone water gap technology can obviously improve the removal rate of inclusions in the crystallizer and avoid the occurrence of slag rolling, thereby improving the cleanliness of continuous casting blanks. In the implementation link of the electromagnetic cyclone nozzle technology, in order to optimize the rotation efficiency of molten steel in the nozzle, a common method is to enhance the current of a