WO2018088753A1

WO2018088753A1 - Casting equipment and casting method using same

Info

Publication number: WO2018088753A1
Application number: PCT/KR2017/012308
Authority: WO
Inventors: 한승민; 최주한; 한상우; 김장훈; 조현진
Original assignee: 주식회사 포스코
Priority date: 2016-11-09
Filing date: 2017-11-02
Publication date: 2018-05-17
Also published as: KR101881971B1; US20190262895A1; CN109922905A; EP3539689A4; JP2019535524A; EP3539689A1; KR20180051917A

Abstract

The present invention relates to casting equipment and a casting method using the same, the casting method comprising the steps of: providing a tundish; pouring molten steel into the tundish; installing, in the upper portion of the tundish, a vacuum forming member for producing a vacuum in at least a part of the region above the molten steel meniscus received in the tundish; blowing gas into the molten steel to form a swirling flow; and producing a vacuum in at least a part of the region above the molten steel meniscus. More specifically, therefore, the present invention can efficiently remove inclusions in molten steel and suppress reoxidation of the molten steel.

Description

Casting facility and casting method using the same

The present invention relates to a casting facility and a casting method using the same, and more particularly, to a casting facility and a casting method using the same that can effectively remove the inclusions in the molten steel, the reoxidation of the molten steel.

Continuous casting equipment is a facility for manufacturing cast steel by receiving refined molten steel from steelmaking equipment. Continuous casting equipment includes ladles that carry molten steel, tundish for temporary storage of molten steel from ladles, and primary solidification of slats with continuous molten steel from tundish. The mold consists of a mold and a cooling stand that performs a series of molding operations while secondarily cooling the castings continuously drawn from the mold.

Molten steel is taken in a tundish and stays for a predetermined time, the inclusions are separated, the slag is stabilized, and reoxidation is prevented. The molten steel is then fed into the mold to form an initial solidification layer in the shape of the cast, wherein the surface quality of the cast is determined.

The quality of the slab surface in the mold is determined by the cleanliness of the inclusions in the molten steel. For example, when the cleanliness of molten steel for inclusions is not good, defects may occur on the surface of the cast steel due to the inclusion itself, the immersion nozzle may be blocked by the inclusions, and abnormality may occur in the molten steel flow, thereby lowering the surface quality of the cast steel.

Molten steel has a substantial degree of cleanliness of the inclusion depending on the degree of separation of the inclusions while the molten steel stays in the tundish for a predetermined time, and the degree of separation of the inclusions is proportional to the time spent in the molten steel tundish.

Therefore, in the related art, a dam or weir was built in the tundish to control the flow of the molten steel to adjust the dwell time of the molten steel in order to increase the molten steel residence time in the tundish. However, when the size of inclusions mixed in the molten steel is 30 μm or less, the time taken for the inclusions to be separated and separated is longer than the residence time of the molten steel. For this reason, the inclusions having a size of 30 μm or less are removed by using a dam and weir. There is a problem that is difficult to do.

(Prior art document)

Japanese Patent No.4096635

Japanese Patent No. 3654181

The present invention provides a casting facility and a casting method using the same that can effectively remove the inclusions in the molten steel to suppress the clogging of the nozzle during casting.

The present invention provides a casting facility and a casting method using the same to suppress the reoxidation of molten steel to secure cleanliness.

Casting equipment according to an embodiment of the present invention, the casting equipment, the cover member is installed on the tundish to form a space on at least a portion of the upper surface of the molten steel accommodated in the tundish; A vacuum pump connected to the cover member to form a vacuum in the space part; And a control unit controlling an operation of the vacuum pump.

The cover member may include a vertical portion formed in a hollow shape in which upper and lower portions are opened, and provided in a vertical direction such that at least a portion thereof is immersed in the molten steel; And a horizontal portion connected to an upper portion of the vertical portion to form a space portion between the vertical portion and an exhaust port formed at the horizontal portion to be connected to the vacuum pump.

The horizontal portion may be formed to cover only the upper portion of the vertical portion.

The horizontal portion may be formed to be seated on the tundish.

The tundish is provided with a structure crossing the inside of the tundish spaced apart from the bottom surface of the tundish to form a flow of molten steel, spaced apart from the bottom surface of the tundish the structure on both sides of the structure It may be provided with an induction member disposed in parallel with the.

The upper surface of the guide member may be provided at a position higher than the height of the upper surface of the structure.

A nozzle is provided to supply gas to the tundish, and the nozzle may be provided at one side of the structure between the guide members.

In the space portion may include a detection means for measuring the water level of the molten steel.

The detecting means may include at least one of a distance sensor and a temperature sensor.

Casting method according to an embodiment of the present invention, the casting method, the process of preparing a tundish; Injecting molten steel into the tundish; Installing a vacuum forming member on the upper portion of the tundish to form a vacuum in at least a portion of the upper portion of the molten steel bath surface accommodated in the tundish; Blowing gas into the molten steel to form a rotary flow; And forming a vacuum in at least a portion of the upper surface of the molten steel.

In the preparing of the tundish, an induction member defining a region for forming a vacuum is formed, and the induction member is spaced apart from the bottom of the tundish and traverses the inside of the tundish. It can be formed alongside the structure.

The process of installing the vacuum forming member may include installing a cover member between the induction members; Immersing at least a portion of the cover member in the molten steel to form a space portion spaced apart from the molten steel surface of the cover member; And connecting a vacuum pump to the cover member.

The process of forming the rotary flow may include a process of blowing a gas to one side of the structure.

The forming of the vacuum may include sucking the space part by operating the vacuum pump.

The process of forming the vacuum may be performed when at least a portion of the cover member is immersed in the molten steel.

The forming of the vacuum may include measuring fluctuations in the surface level of molten steel in the space part, and adjusting the degree of vacuum in the space part according to fluctuations in the level of the molten steel.

According to the casting facility and the casting method using the same according to an embodiment of the present invention, by forming a continuous rotational flow in the molten steel irrespective of the change in the water surface of the molten steel can remove the inclusions in the molten steel efficiently. That is, by forming a space in at least a part of the upper surface of the molten steel accommodated in the tundish, and sucking the inside of the space to form a vacuum, the molten steel may be kept constant at all times. Therefore, by forming a vacuum in the space regardless of the change in the surface of the molten steel outside the space portion to maintain a constant level of the molten steel can increase the residence time of the molten steel in the tundish to efficiently remove the inclusions in the molten steel.

In addition, since the gas injected to form the rotational flow is discharged to the outside through the space in which the vacuum is formed, it is possible to prevent the molten steel generated by the gas discharge from contacting the atmosphere, thereby suppressing or preventing the reoxidation of molten steel.

In addition, the cleanliness of the molten steel can be maintained to suppress or prevent nozzle clogging or cast defects that may occur during casting.

1 is a view schematically showing a casting facility according to an embodiment of the present invention.

2 is a view showing a main configuration of a casting facility according to an embodiment of the present invention.

3 is a view showing an example of a vacuum forming member applied to a casting facility according to an embodiment of the present invention.

Figure 4 is a view showing a modification of the vacuum forming member applied to the casting facility according to an embodiment of the present invention.

5 is a view showing an example in which a detection means for measuring the molten steel water level is installed in the casting facility according to an embodiment of the present invention.

6 is a view showing a state of forming a rotary flow in the molten steel when casting using a casting facility according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms, and only the embodiments of the present invention make the disclosure of the present invention complete and the scope of the invention to those skilled in the art. It is provided to inform you completely. Like numbers refer to like elements in the figures.

1 is a view schematically showing a casting facility according to an embodiment of the present invention, Figure 2 is a view showing the main configuration of the casting facility according to an embodiment of the present invention, Figure 3 is a casting according to an embodiment of the present invention 4 is a view showing an example of a vacuum forming member applied to the installation, Figure 4 is a view showing a modification of the vacuum forming member applied to the casting installation according to an embodiment of the present invention, Figure 5 is an embodiment of the present invention The drawing shows an example in which a detection means for measuring the molten steel water level is installed in the casting facility according to the present invention.

Referring to FIG. 1, a casting facility 1, for example, a continuous casting facility includes a tundish, which serves to store and distribute molten steel M supplied from a ladle 10, which is a vessel containing refined molten steel. 20), a stopper (not shown) or sliding plate (not shown) for controlling the flow rate of the molten steel (M), the immersion nozzle 32 and molten steel for supplying the molten steel (M) in the tundish (20) to the mold (30) It may include a mold 30 to solidify (M) to make a cast (S). In addition, a cooling line 50 for cooling the slab S may be provided below the mold 30.

Referring to FIG. 2, the tundish 20 may be formed in a hollow shape in which an upper portion of the tundish 20 is opened and a tap hole 21 through which molten steel is discharged. Various structures may be provided inside the tundish 20 to form a flow of molten steel. Such a structure may include a dam 23, a weir 24, and an eddy current prevention dam (not shown). In this case, the dam 23 may be formed to protrude upward from the bottom of the tundish 20. The weir 24 is provided spaced apart from the bottom of the tundish 20 and at a position higher than the level of the molten steel and higher than the height of the dam 23, across the inside of the tundish 20 on the side wall of the tundish 20. It can be formed to be. And the vortex prevention dam is provided on the outlet 21 side in the lower portion of the tundish 20 can suppress the generation of vortex in order to prevent the slag from flowing into the mold (30). The dam 23 and the weir 24 may be spaced apart from each other, and may form a passage used by the molten steel between the dam 23 and the weir 24.

One tap 21 may be provided at each side in the longitudinal direction of the tundish 20, and a shroud nozzle 12 is disposed at the center in the longitudinal direction of the tundish 20 and accommodated in the ladle 10. Molten steel may be injected into the tundish 20.

Through such a configuration, the molten steel injected from the shroud nozzle 12 may be discharged to the tap hole 21 while moving the passage formed by the weir 24 and the dam 23 in the tundish 20. Thus, by forming the flow of molten steel in the tundish 20 to increase the residence time of the molten steel in the tundish 20 it is possible to capture the inclusions in the molten steel to the slag (S) of the upper molten steel.

However, in such a tundish 20 structure, the molten steel injected from the shroud nozzle 12 forms a flow simply passing through the passage formed by the weir 24 and the dam 23, so that the inclusions in the molten steel are sufficiently filled. There is a problem that is difficult to remove. Therefore, the nozzle 26 may be installed below the tundish 20, and gas, for example, an inert gas, may be blown into the tundish 20 to form a rotary flow of molten steel in the tundish 20. In this case, the nozzle 26 may be formed at one side of the weir 24, for example, adjacent to the shroud nozzle 12. The molten steel can further increase the residence time of the molten steel in the tundish 20 by forming a rotary flow to move around the weir 24 by the gas supplied from the nozzle 26.

However, in this case, since the gas injected into the tundish 20 is discharged to the outside of the molten steel to form slag by moving the slag, the molten steel is in contact with the atmosphere and re-produced. In addition, since the surface of the molten steel in the tundish 20 is reduced when the ladle is replaced, there is also a problem in that rotational flow of the molten steel is not generated smoothly in the tundish 20.

Accordingly, in the present invention, by installing a vacuum forming member 100 capable of forming a vacuum in at least a portion of the tundish 20 to continuously generate a rotational flow irrespective of fluctuations in the water level of the molten steel to efficiently generate inclusions in the molten steel. It can be removed, and the reoxidation that can occur by molten steel in contact with the atmosphere can be suppressed.

In order to install the vacuum forming member 100, the tundish 20 may be provided with an induction member 25 defining a region for maintaining a constant level of the molten steel, that is, a region in which rotational flow is formed. When the vacuum is formed in a predetermined region in the tundish 20 using the vacuum forming member 100, the tundish 20 may be difficult to maintain the vacuum state when the molten steel level is lower than the upper portion of the weir 24. By forming the induction member 25 in the region for installing the vacuum forming member 100, that is, the region in which the rotational flow is formed can be prepared in advance. For example, when the level of the molten steel is higher than the upper portion of the weir 24, the vacuum may be formed using the vacuum forming member 100, but when the level of the molten steel is lower than the upper portion of the weir 24, the vacuum forming member may be formed. A space may be formed between the 100 and the molten steel bath surface to release the vacuum.

Induction member 25 is provided to traverse the inside of the tundish 20 is spaced from the bottom of the tundish 20, may be provided to be spaced apart from the weir 24 on both sides of the weir 24. have. At this time, the guide member 25 may be formed on the upper side where the nozzle 26 is formed so that the rotational flow of molten steel can be formed therebetween. The weir 24 may be disposed between the induction members 25, and the molten steel moves along the weirs 26 between the induction members 25 by the gas supplied through the nozzle 26, thereby forming a rotational flow. Can be. At this time, the guide member 25a may be formed on at least one side of the guide member 25 so that the rotational flow of molten steel can be smoothly generated. The guide member 25a may form an inclined surface on one side of the guide member 25 to control the moving direction of the molten steel. In the drawing, although the inclined surface 25a is formed on the induction member 25 provided on one side of the weir 24 in which the downflow is formed, the induction member 25 provided on the other side of the weir 24 in which the upflow is formed. An inclined surface may also be formed. However, the direction of the inclined surface formed on the side on which the upflow is formed and the side on which the downflow is formed may be different.

The lower portion of the guide member 25 may be disposed at a lower position than the upper portion of the weir 24, and the upper portion of the guide member 25 may be disposed at a position higher than the upper portion of the weir 24. Accordingly, even when the molten steel level of the molten steel decreases as in the ladle replacement, the molten steel can smoothly generate the rotational flow while maintaining the higher surface level than the upper portion of the weir 24 between the guide members 25.

Referring to FIG. 3, the vacuum forming member 100 includes a cover member 110 that forms a space portion a in at least a portion of the tundish 20, and a cover member so as to suck the inside of the cover member 110. It may include a vacuum pump 120 connected to 110. In addition, the control unit 130 for controlling the operation of the vacuum pump 120 according to the detection means 130 for measuring the molten metal level of the molten steel in the cover member 110 and the molten steel level measured by the detection means 130 ( Not shown).

The cover member 110 may be disposed along the width direction of the tundish 20, and may be formed in a hollow shape in which the lower part is open and the exhaust port 114 is formed in the upper part. The cover member 110 may include a vertical portion 111 extending in the vertical direction and a horizontal portion 112 connected to an upper portion of the vertical portion 111. At this time, the exhaust port 114 may be formed in the horizontal portion 112, it may be connected to the vacuum pump 120 is connected to a separate exhaust pipe.

The vertical portion 111 may be inserted between the guide members 25 so that the lower portion thereof may be immersed in the molten steel, and the space portion a is formed at the upper side of the molten steel in the cover member 110 in the state immersed in the molten steel. It can be formed to a length that can be. Through this configuration, the cover member 110 may form at least a portion, for example, a lower portion of the tundish 20 in the molten steel to form a space a therein.

In addition, the horizontal portion 112 may connect the upper portion of the vertical portion 111 to form a space portion (a) between the horizontal portion 112 and the vertical portion 111. The horizontal part 112 may be formed to have an area corresponding to the area size formed inside the vertical part 111 to cover only the upper part of the vertical part 111, but as shown in FIG. 4, the cover member 110a. ) May be formed to cover the top of the tundish 20. In this case, the horizontal portion 112a is formed to be seated on the top of the tundish 20, that is, to cover the top of the tundish 20, and the vertical portion 111a extends in a vertical direction to a lower portion of the horizontal portion 112a. It may be provided to be.

And the cover member 110 may be provided with a detection means 130 for measuring the level of the molten steel in the space (a). The detection means 130 may be provided in the horizontal portion 112, as shown in Figure 5 (a) may be used a distance sensor 130a for measuring the distance from the horizontal portion to the molten steel. In addition, the detection means 130 may be provided in the vertical portion 111 immersed in the molten steel as shown in (b) of FIG. 5 may be used a temperature sensor 130b for measuring the temperature of the molten steel.

The vacuum pump 120 may be connected to the cover member 110 to suck the space a inside the cover member 110 to form a vacuum in the space a. Accordingly, the pressure inside the cover member 110, that is, the space portion a, is lower than the ambient pressure, so that the molten steel level of the molten steel inside the cover member 110 becomes higher than the molten steel surface level of the periphery, that is, the outside of the cover member 110.

The controller may control the operation of the vacuum pump 120 according to the molten steel level of the molten steel by receiving the result measured by the detecting unit 130, thereby uniformly adjusting the molten steel level in the space part a. For example, when molten steel is continuously injected from the ladle 10 to the tundish 20, the rotational flow is smoothly formed by the gas blown through the nozzle 26, but the supply of molten steel for the ladle 10 replacement is If temporarily stopped, the molten steel level of the molten steel in the tundish 20 may be lowered. Accordingly, by controlling the operation of the vacuum pump 120 according to the fluctuation of the molten steel level inside the cover member 110, the pressure of the space part a is adjusted appropriately to increase the molten steel level inside the cover member 110. You can keep it constant.

Hereinafter, a casting method according to an embodiment of the present invention will be described.

First, the molten steel that has been refined is charged into the ladle 10, and the ladle 10 is moved to a continuous casting facility and seated on the ladle turret. When the ladle is seated on the ladle turret, the nozzle unit (not shown) including the shroud nozzle 12 is connected to the tap hole under the ladle 10.

When the nozzle unit is connected to the ladle 10, the vacuum forming member 100 is installed on the tundish 20 and the molten steel is injected into the tundish 20 by opening the outlet of the lower part of the ladle 10.

When molten steel is injected into the tundish 20, and the molten steel level of the molten steel injected into the tundish 20 reaches a degree of rotational flow, for example, the upper portion of the weir 24, gas is injected into the molten steel through the nozzle 26. I can blow it. In this case, the gas blown into the tundish 20 may include an inert gas such as argon (Ar). When the gas is supplied to the tundish 20, a rotary flow of molten steel may be formed in the tundish 20 as illustrated in FIG. 6A. Rotating flow of the molten steel may be formed between the guide member 25, the upstream is formed on one side of the weir 24, the nozzle 26 is provided, and the downstream may be formed on the other side of the weir 24. . Then, the molten steel exits to the space formed between the induction member 25 and the dam 23 on the other side of the weir 24 and moves to the tap hole 21 side of the tundish 20.

When the molten steel is injected into the tundish 20 and the molten steel level rises, the lower part of the cover member 110 installed in the tundish 20, that is, a part of the vertical part 111 is immersed in the molten steel, thereby covering the cover member ( 110, the space portion (a) may be formed on the upper surface of the molten steel.

When the vertical portion 111 is immersed in the molten steel and the space portion a is formed inside the cover member 110, the controller may operate the vacuum pump 120 to suck the inside of the cover member 110 to form a vacuum. have. At this time, if the cover member 110 is sucked into the cover member 110 by the vacuum pump 120 before the vertical portion 111 is immersed, the air may flow into the tundish 20, so that the vertical portion 111 of the cover member 110 is formed. After being immersed in the molten steel, the inside of the cover member 110 may be sucked to form a vacuum.

Whether the vertical portion 111 is immersed in the molten steel can be measured through the detection means 130. When the distance sensor 130a is used as the detecting means 130 as shown in FIG. 5A, the vertical part is measured by measuring the distance from the distance sensor 130a to the molten steel bath surface inside the cover member 110. It is possible to determine whether or not 111 is immersed. That is, when the result measured by the distance sensor 130a is transmitted to the controller, the controller compares the distance to the molten steel surface measured by the distance sensor 130a and the predetermined distance measured distance to each other to determine whether the vertical part 111 is immersed. Can be determined.

And when using the temperature sensor 130b as the detecting means 130 as shown in Figure 5 (b), a plurality of temperature sensors 130b installed in the longitudinal direction of the vertical portion 111 to the vertical portion 111 It is possible to determine whether the vertical portion 111 is immersed by detecting the temperature change of the vertical portion 111 immersed in the molten steel using the ().

The cast steel can be cast by injecting molten steel into the mold 30 through the immersion nozzle 32 connected to communicate with the tap hole 21 at the lower portion of the tundish 20 by opening the tap hole 21.

While casting the cast steel, the gas is continuously injected into the tundish 20 to form a rotary flow of molten steel, and the vacuum may be sucked into the cover member 110 through the vacuum pump 120 to maintain a vacuum state. Rotational flow may be continuously formed in the tundish 20 during casting thereto. In addition, since the gas generating the rotational flow is discharged to the region where the vacuum is formed, the molten steel can be prevented from contacting the atmosphere.

Meanwhile, when ladle is replaced, the molten steel supply to the tundish 20 may be temporarily stopped while the ladle is replaced. In this case, since molten steel in the tundish 20 is continuously injected into the mold 30 as shown in FIG. 6B, the molten steel level of the molten steel in the tundish 20 is reduced. When the molten steel level is reduced in this way, the inside of the cover member 110 may be more strongly sucked using the vacuum pump 120 to adjust the degree of internal vacuum formation. That is, when the molten steel level of the molten steel in the tundish 20 is lowered, the molten steel molten metal level in the cover member 110 may be lowered correspondingly. Therefore, by controlling the operation of the vacuum pump 120 according to the change in the level of the molten steel measured by the detection means 130, the degree of vacuum formation is stronger than before the level of the molten steel is lowered. As a result, the molten steel level of the molten steel in the cover member 110 can be kept constant. At this time, if the inside of the cover member 110 is excessively strong suction molten steel may flow out through the exhaust port 114, it is preferable to control the operation of the vacuum pump 120 according to the amount of fluctuation of the water level. In addition, since the level of the molten steel can be kept constant between the guide members 25, it is possible to continuously form the rotational flow of the molten steel regardless of the level of fluctuations in the level of the molten steel.

In this way, regardless of the level of melt level of the molten steel in the tundish 20, it is possible to continuously maintain the rotational flow of the molten steel formed between the induction members 25, that is, the lower cover member 110. In this way, by continuously forming the rotational flow of the molten steel in the tundish 20 during the casting of the cast can increase the residence time of the molten steel in the tundish 20 to efficiently remove the inclusions in the molten steel. In addition, reoxidation of molten steel can be prevented by preventing molten steel from coming into contact with the atmosphere in the region where the rotational flow of molten steel is formed.

In the above, while the preferred embodiment of the present invention has been described and illustrated using specific terms, such terms are only for clearly describing the present invention, and the embodiments of the present invention and the described terms are used in the technical spirit of the following claims. It is obvious that various changes and modifications can be made without departing from the scope of the present invention. Such modified embodiments should not be understood individually from the spirit and scope of the present invention, but should fall within the claims of the present invention.

Casting facilities according to the present invention and the casting method using the same, it is possible to effectively remove the inclusions in the molten steel to maintain the cleanliness of the molten steel can suppress or prevent nozzle clogging or cast defects that may occur during casting, through which process efficiency And productivity can be improved.

Claims

As a casting facility,

A cover member installed in the tundish to form a space in at least a portion of the upper surface of the molten steel accommodated in the tundish;

A vacuum pump connected to the cover member to form a vacuum in the space part; And

And a control unit for controlling the operation of the vacuum pump.
The method according to claim 1,

The cover member,

A vertical part formed in a hollow shape in which an upper part and a lower part are opened, and provided in a vertical direction so that at least a part thereof is immersed in the molten steel; And

And a horizontal portion connected to an upper portion of the vertical portion to form a space portion with the vertical portion.

Casting unit is formed in the horizontal portion exhaust port to be connected to the vacuum pump.
The method according to claim 2,

Casting unit is formed so that the horizontal portion covers only the upper portion of the vertical portion.
The method according to claim 3,

The horizontal portion is cast equipment formed to be seated on the top of the tundish.
The method according to claim 4,

The interior of the tundish is provided with a structure crossing the interior of the tundish spaced apart from the bottom surface of the tundish to form a flow of molten steel,

Casting equipment provided with a guide member spaced apart from the bottom surface of the tundish parallel to the structure on both sides of the structure.
The method according to claim 5,

The upper surface of the guide member,

Casting facility provided at a position higher than the height of the upper surface of the structure.
The method according to claim 6,

A nozzle is provided to supply gas to the tundish,

The nozzle is provided on one side of the structure between the guide member casting equipment.
The method according to claim 7,

Casting equipment comprising a detection means for measuring the level of the molten steel of the molten steel in the space.
The method according to claim 8,

The detection means is a casting facility comprising at least one of a distance sensor and a temperature sensor.
As the casting method,

Preparing a tundish;

Injecting molten steel into the tundish;

Installing a vacuum forming member on the upper portion of the tundish to form a vacuum in at least a portion of the upper portion of the molten steel bath surface accommodated in the tundish;

Blowing gas into the molten steel to form a rotary flow;

Forming a vacuum in at least a portion of an upper portion of the molten steel surface;

Casting method comprising a.
The method according to claim 10,

In the process of preparing the tundish,

Forming an induction member defining a region for forming a vacuum,

The guide member is formed in parallel with the structure on both sides of the structure provided across the inside of the tundish spaced apart from the bottom of the tundish.
The method according to claim 11,

The process of installing the vacuum forming member,

Installing a cover member between the guide members;

Immersing at least a portion of the cover member in the molten steel to form a space portion spaced apart from the molten steel surface of the cover member; And connecting a vacuum pump to the cover member.
The method according to claim 12,

The process of forming the rotary flow,

Casting method comprising the step of blowing a gas to one side of the structure.
The method according to claim 13,

The process of forming the vacuum includes the process of sucking the space portion by operating the vacuum pump.
The method according to claim 14,

The process of forming the vacuum is performed when at least a portion of the cover member is immersed in the molten steel.
The method according to claim 15,

The process of forming the vacuum,

Measuring a fluctuation level of molten steel in the space part;

Casting method for adjusting the degree of vacuum of the space portion in accordance with the fluctuation of the level of the molten steel.