KR102441318B1 - Casting apparutus and method thereof - Google Patents

Abstract

The present invention relates to a casting equipment and a casting method, comprising: injecting molten steel into a mold; solidifying the molten steel and drawing a slab; And transforming the non-solidified portion, which is a region other than the solidified portion solidified to the inside in the thickness direction of the cast slab drawn from the lower part of the mold; including, and it is possible to suppress damage to the equipment during the production of the cast slab.

Description

Casting equipment and casting method {Casting apparutus and method thereof}

The present invention relates to a casting equipment and a casting method, and more particularly, to a casting equipment and a casting method capable of suppressing damage to the equipment during the production of cast slabs.

In general, continuous casting is a process of continuously injecting molten steel into a mold, and continuously drawing molten steel having a surface solidified in the mold to the lower side of the mold to manufacture slabs of various shapes such as slabs, blooms and billets.

In this continuous casting process, the slab is cooled first in the mold, and after passing through the mold, water is sprayed on the slab and then solidified through the process of secondary cooling. After the slab drawn from the mold is drawn out in the vertical direction for a predetermined section, it goes through a bending section (bending process), and then is converted to the horizontal direction (correction, unbending process), and the drawing proceeds in the horizontal direction. At this time, when bending and straightening while the moving direction of the slab is changed, the segments installed in the lower part of the mold should be designed to withstand an additional load for deforming the slab, for example, a deformation load.

On the other hand, in the initial and final stages of the continuous casting process, in order to prevent the molten steel from leaking from the mold or the slab drawn from the mold bursting, the initial and final ends of the slab are sufficiently cooled in the mold and then drawn out from the mold. . The initial end and the end end of the slab cooled in this way are almost in a solidified state, and the temperature is lower than that of the middle portion including the unsolidified molten steel therein, so that the deformation resistance is greatly increased. Accordingly, when bending the initial end and the end end of the cast steel, a very large load is applied to the guide roll. In addition, in order to maintain the gap between the guide rolls during bending of the cast slab, a gap adjusting device such as a hydraulic cylinder that adjusts the gap of the guide rolls generates a reaction force corresponding to the deformation resistance of the cast slab. In this case, parts such as a bearing and a girder supporting the guide roll as well as the guide roll may be deformed or damaged by the reaction force generated by the spacer adjusting device. If the guide rolls or parts are damaged in this way, since defects occur in the slab, the operation must be stopped for repair of the casting equipment, thereby reducing productivity and increasing production costs due to repair costs.

US 10-1323292 B US 10-2009-0021219 A

The present invention provides a casting equipment and a casting method capable of stably casting a cast slab and suppressing equipment damage.

The present invention provides a casting equipment and a casting method that can improve the productivity of the cast and reduce the production cost.

A casting facility according to an embodiment of the present invention is a casting facility for manufacturing a slab by being disposed below a mold and the mold and a plurality of segments are continuously arranged, wherein the segments are a plurality of segments installed to face each other so that the slab passes. It includes a guide roll, and may include a regulator for adjusting the guide interval in the thickness direction of the slab according to the load applied to the guide roll.

The adjuster may include: a tie rod connecting the plurality of guide rolls to be spaced apart from an upper frame and a lower frame disposed to face each other; and a hydraulic cylinder connected to the tie rod and installed on one of the upper frame and the lower frame to adjust the guide interval.

a measuring device for measuring the load applied to the guide roll; and a control unit capable of controlling the operation of the hydraulic cylinder to adjust the guide interval according to the load measured by the measuring device.

The measuring device may be installed in a region where the casting direction is changed under the mold.

The adjuster may include: a tie rod connecting the plurality of guide rolls to be spaced apart from an upper frame and a lower frame disposed to face each other; and an elastic member that is telescopically installed on the tie rod so as to adjust the guide interval by a load applied to the guide roll.

The elastic member may include a pre-compressed spring.

Casting method according to an embodiment of the present invention, as a casting method for manufacturing a slab, comprising the steps of adjusting the interval between the rolls, which is the interval between the guide rolls installed to face each other at the bottom of the mold, as a reference interval; injecting molten steel into the mold; solidifying the molten steel and drawing a slab; and adjusting the distance between the rolls according to the load applied to the guide rolls.

The gap between the rolls can be adjusted in the area in which the traveling direction of the cast slab is switched from the vertical direction to the horizontal direction.

A casting method according to an embodiment of the present invention is a casting method for manufacturing a slab, comprising: injecting molten steel into a mold; solidifying the molten steel and drawing a slab; and transforming the non-solidified portion, which is an area other than the solidified portion that has been solidified to the inside in the thickness direction of the cast slab drawn from the lower portion of the mold.

The step of deforming the non-solidified portion may include bending and unfolding the non-solidified portion while drawing the slab.

The step of deforming the non-solidified portion may include adjusting a gap between the rolls, which is a gap between guide rolls installed to face each other at the bottom of the mold.

The step of drawing the slab further includes measuring a load applied to the guide roll, and the step of measuring the load is at least one point in the area in which the traveling direction of the slab is switched from the vertical direction to the horizontal direction. can be measured in

Further comprising the step of setting a reference load range that can be applied to the guide roll, the step of adjusting the distance between the rolls, when the measured load is included in the reference load range, adjusting the distance between the rolls larger than the reference distance And, when the measured load is less than the minimum value of the reference load range, the distance between the rolls may be maintained to be the same as the reference distance.

In the measuring the load applied to the guide roll, the pressure generated in at least one of a tie rod and a hydraulic cylinder for adjusting the distance between the rolls may be measured.

The step of adjusting the interval between the rolls larger than the reference interval may include forming a space between at least one surface of the cast slab and the guide roll facing the guide roll in the thickness direction of the slab.

The step of adjusting the gap between the rolls to be greater than the reference gap may include adjusting the gap between the rolls to be greater than the thickness of the solidified part solidified to the inside in the thickness direction among the cast slabs drawn from the lower part of the mold.

In the step of adjusting the interval between the rolls to be greater than the reference interval, the interval between the rolls may be adjusted in sequence along the direction in which the cast slabs advance.

In the step of adjusting the interval between the rolls larger than the reference interval, the interval between the rolls can be sequentially adjusted from the point where the load is measured along the direction in which the cast steel proceeds.

After adjusting the gap between the rolls to be greater than the reference gap, the method may include returning the gap between the rolls to the reference gap.

The step of restoring the interval between rolls may include returning the interval between rolls to the reference interval in the order of increasing the interval between rolls.

The returning step may be returned from the gap between the rolls of the guide rolls through which the solidified part to the inside in the thickness direction of the cast slab drawn from the lower part of the mold has passed.

The step of adjusting the gap between the rolls may include, when a load greater than a preset load is applied to the guide roll, adjusting the gap between the rolls without an external force applied from the outside.

The step of adjusting the gap between the rolls without the external force includes pushing the guide roll outward by a load applied to the guide roll, and the step of pushing the guide roll outward may be performed using elasticity. .

When the load applied to the guide roll is smaller than a load preset to the guide roll, the method may include returning the guide roll by using elasticity.

The step of adjusting the gap between the rolls may be performed when the traveling direction of at least one of the initial end and the final end of the slab is switched.

ADVANTAGE OF THE INVENTION According to embodiment of this invention, it can suppress or prevent that a casting equipment is damaged in the process of drawing a slab. That is, it is possible to reduce the load acting on the guide roll by adjusting the roll interval of the guide roll provided in the lower part of the mold in the process of drawing the slab, by adjusting the bending and straightening position in the slab. Accordingly, it is possible to suppress or prevent the guide roll and various parts supporting the guide roll from being deformed or damaged. In particular, it is possible to suppress or prevent damage to the casting equipment by the initial end or the end end of the slab that is supercooled and drawn in the mold at the beginning and the end of casting. Therefore, since the casting equipment can be managed stably, it is possible to suppress the interruption of operation due to damage to the casting equipment, and it is possible to improve process efficiency and productivity. In addition, it is possible to reduce the maintenance cost of the casting equipment.

1 is a view schematically showing the configuration of a casting facility according to an embodiment of the present invention.
Figure 2 schematically shows the casting process;
Figure 3 is a view showing an example of measuring the load acting on any one of the guide rolls forming the bending portion when casting a cast slab.
Figure 4 is a view showing a process of adjusting the interval between the guide rolls and bending the cast steel in the casting method according to an embodiment of the present invention.
5 is a flowchart showing a casting method according to an embodiment of the present invention.
Figure 6 is a view showing a state of adjusting the interval of the guide roll when the cast steel proceeds in the vertical direction.
7 and 8 are views showing a state of adjusting the interval of the guide roll when the traveling direction of the cast slab is changed.
Figure 9 is a view showing a state of adjusting the interval of the guide roll when the cast slab proceeds in the horizontal direction.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only these embodiments allow the disclosure of the present invention to be complete, and the scope of the invention to those of ordinary skill in the art completely It is provided to inform you. During the description, the same reference numerals are assigned to the same components, and the drawings may be partially exaggerated in size to accurately describe the embodiments of the present invention, and the same reference numerals refer to the same elements in the drawings.

1 is a view schematically showing the configuration of a casting equipment according to an embodiment of the present invention, Figure 2 is a view schematically showing a casting process.

Referring to FIG. 1 , the casting equipment according to an embodiment of the present invention includes a mold 30 and a cooling line 40 disposed below the mold 30 and having a plurality of segments 50 continuously disposed therein. And, some of the plurality of segments 50 may adjust the distance between the upper frame 51 and the lower frame 52 in which the guide roll 100 is installed according to the load applied by the cast slab 1 during casting. can be formed.

A casting facility according to an embodiment of the present invention will be described in more detail as follows. A casting facility, for example, a continuous casting facility, is a ladle (10) containing molten steel refined in a steelmaking process, and a tundish (tundish; 20) that receives molten steel through an injection nozzle connected to the ladle 10 and temporarily stores it. ) and a mold (mold) 30 for receiving the molten steel stored in the tundish 20 and initially solidifying it in a predetermined shape. In addition, a plurality of segments (segment; 50) are provided in the lower part of the mold 30 to perform a series of molding operations while cooling the cast slab 1 drawn from the mold 30, for example, the unsolidified slab 1 is successively. It includes a cooling line 40 that is arranged as

The segment 50 includes an upper frame 51 and a lower frame 52 that are vertically spaced apart from each other, and the upper frame 51 and the lower frame 52 have a plurality of guide roll assemblies 53 and 54 arranged to face each other. are placed In addition, the segment 50 includes a tie rod 56 for vertically connecting the upper frame 51 and the lower frame 52 in a spaced apart state, and is installed on the upper frame 51 , the tie rod 56 . by adjusting the separation distance between the upper frame 51 and the lower frame 52 by replacing the piston with a plurality of hydraulic cylinders 55 for applying a pressing force to the cast slab (1). The tie rod 56 and the hydraulic cylinder 55 may be used as a gap adjusting device for adjusting the gap between the rolls, which is the distance between the guide rolls 100 facing each other. At this time, one end of the tie rod 56 may be fixed to the lower frame 52 , and the other end of the tie rod 56 may pass through the upper frame 51 and be connected to the piston of the hydraulic cylinder 55 . And the hydraulic cylinder 55 is fixedly installed on the upper frame 51, and when the hydraulic cylinder 55 is driven to adjust the gap between the rolls, the tie rod 56 connects the upper frame 51 and the lower frame 52. While maintaining the connected state and moving the piston of the hydraulic cylinder 55 in the vertical direction, the distance between the upper frame 51 and the lower frame 52 is adjusted, and through this, the distance between the rolls can be adjusted. The distance between the rolls is a distance between the guide roll 100 installed on the upper frame 51 and the guide roll 100 installed on the lower frame 52, and may mean the distance between the guide rolls 100 facing each other. have. In addition, the gap between the rolls is a guiding interval for guiding until the moving direction of the cast slab 1 drawn from the mold 30 is converted from the vertical to the horizontal direction, and the rolling down gap when the cast slab 1 proceeds in the horizontal direction. can mean Here, an example will be described in which the interval between rolls is a guide interval for guiding before the moving direction of the cast slab 1 drawn from the mold 30 is switched from the vertical direction to the horizontal direction. The cast slab 1 drawn from the mold 30 passes through the separation space between the upper frame 51 and the lower frame 52 and includes a guide roll 100 and a bearing housing for rotatably supporting the guide roll. It is guided and reduced by a plurality of guide roll assemblies 53 and 54 to be formed into a predetermined shape. That is, a plurality of segments 50 are aligned and installed in a direction intersecting the direction in which the cast slab 1 moves, and the slab 1 passes between the plurality of guide rolls 100 facing each other, at this time the cast slab ( 1) The guide rolls 100 on both sides press down the cast steel.

A measuring device 60 capable of measuring a load applied to the guide roll 100 may be installed in some segments 50 of the plurality of segments 50 . At this time, the measuring device 60 is installed in the segment 50 that forms a section in which the direction in which the cast slab proceeds is changed in the lower portion of the mold 30 , and can measure the load applied to the guide roll 100 . That is, the cast slab 1 is bent and deformed when the traveling direction is changed, and the load applied to the guide roll 100 is gradually increased until the slab 1 is bent the most. Accordingly, the measuring device 60 is installed between the first point or the first point at which the cast slab 1 starts to deform and the second point where the slab 1 is most deformed, and the load applied to the guide roll 100 can be measured. This is to prevent in advance that the guide roll 100 or other parts are damaged by overload. The measuring device 60 is installed in at least one of the hydraulic cylinder 55 , the tie rod 56 , and the bearing housing to measure the load applied to the guide roll 100 . The measuring device 60 may include at least one of a pressure gauge capable of measuring the pressure of the fluid injected into the hydraulic cylinder 55, and a load cell capable of measuring the load applied to the tie rod 56 or the bearing housing. have.

In addition, the casting facility may include a control unit 70 capable of controlling the operation of the hydraulic cylinder 55 according to the load measured by the measuring device 60, for example, the measured load. The control unit 70 can control the overall operation of the casting equipment, and according to the load measured by the measuring device 60 during casting, the distance between the rolls, that is, the distance between the upper frame 51 and the lower frame 52 , is hydraulically controlled. The operation of the cylinder 55 may be controlled.

Through this configuration, by measuring the load applied to the guide roll 100 during casting, and adjusting the distance between the rolls according to the measurement result, it is possible to prevent damage to the equipment due to overload in advance.

On the other hand, the segment may not include a hydraulic cylinder for adjusting the interval between the rolls of the guide roll (100). That is, the upper frame and the lower frame may be connected by a tie rod to be spaced apart by a predetermined distance. In this case, when a load of a preset size, for example, a load included in the reference load range is applied to the guide roll, an elastic member may be installed on the tie rod to increase the distance between the rolls or the distance between the upper frame and the lower frame. In this case, the elastic member may include a compression spring (pre-compressed spring), and is installed in at least one of at least between the tie rod and the upper frame and between the tie rod and the lower frame, so that the distance between the rolls can be adjusted. For example, when a load smaller than the reference load range is applied to the guide roll during casting, the elastic member may maintain its state to maintain a constant distance between the rolls. On the other hand, when a load included in the reference load range is applied to the guide roll, the elastic member may contract in a direction in which the tie rod extends to increase the gap between the rolls. In addition, in this configuration, when the load applied to the guide roll is reduced, the elastic member may automatically return (extend) to return to the interval before the increase in the interval between the rolls.

When the load applied to the guide rolls increases through this configuration, the gap between the rolls can be automatically increased and returned, thereby preventing the guide rolls from being damaged by overload. In addition, when the load applied to the guide roll is reduced, since the gap between the rolls is automatically returned, it is possible to reduce the section in which the thickness defect occurs in the cast slab, thereby suppressing the decrease in productivity.

In addition, the segment may further include a measuring device capable of measuring a load applied to the guide roll, and an alarm capable of generating an alarm according to the load measured by the measuring device. At this time, the measuring device may measure the load applied to the tie rod, and the alarm may generate an alarm and inform the operator when the measured load measured by the measuring device is included in the reference load range.

Referring to FIG. 2 , a plurality of segments 50 have a vertical portion R1 extending in the vertical direction in the region directly under the mold 30 , and a constant curvature to the cast slab 1 under the vertical portion R1 . A horizontal portion (R3) extending in the horizontal direction is formed at the lower portion of the bending portion (R2) and the bending portion (R2), which is an area to be corrected by bending and converting to the horizontal direction.

First cooled in the mold 30, the cast slab 1 drawn from the mold 30 is secondary cooled while passing through the cooling line (40). The cast slab 1 passes through the vertical portion R1 extending in the vertical direction just below the mold 30, and then the area where the slab 1 is bent, for example, the cast slab 1 is bent and converted to the horizontal direction to correct Through the bent portion (R2), it proceeds along the horizontal portion (R3) drawn out horizontally. At this time, the bending portion (R2) is a first section (R11) for deforming the cast slab (1), and a second section (R22) to maintain the deformed state of the cast slab (1) and to correct the deformed cast (1), That is, it may include a third section (R23) for spreading the bent slab (1).

When passing through the cooling line 40, the slab 1 is subjected to pressure from both sides of the slab 1 or from the top and bottom of the slab 1 by the guide roll 100 of the segment 50, and a coolant injector (not shown), the cooling water is injected to the cast steel (1). Referring to Figure 2, one surface (right) in contact with the guide roll 100 in the cast is called an inner surface (inside, 1a), and the other surface (left) is called an outer surface (outside, 1b). That is, when the cast steel is bent while passing through the bending portion R2, the right side with a small radius of curvature is called the inner surface (1a), and the left side with a large radius of curvature is called the outer surface (1b). And in the bending portion R2, the right side having a small radius of curvature is called the inner side, and the left side having a large radius of curvature is called the outside side.

Referring to FIG. 2 , the slab drawn from the mold 30 is the initial slab 1 by the width of the mold 30 , that is, the interval T0 between both sides of the mold 30 , for example, the width of the mold 30 . ) is determined, the distance between the rolls of the guide rolls 100 opposing each other, for example, the reference gap G0, is controlled according to the thickness T1 of the cast slab 1, and the cast slab 1 is pressed down . Typically, the reference interval G0 is adjusted to be equal to the mold width T0 (GO=T0). By the way, the guide roll 100 is when the cast slab 1 proceeds from the vertical portion R1 to the bent portion R2, and from the bent portion R2 to the horizontal portion R3, when the cast slab 1 is bent and unfolded load, such as a deformation load, is additionally received. In particular, the initial end of the cast slab 1 formed at the beginning of casting, and the final end of the cast slab 1 formed at the end of casting are supercooled in the mold 30 and solidified to the inside in the thickness direction or in the thickness direction and the width direction. It is drawn from the mold 30 in a state including the solidification part (S1, see FIG. 4). Accordingly, when the initial end and the end end of the cast steel 1 pass through the bending portion R2, the guide roll 100 installed in the bending portion R2 must deform the solidified portion, so the vertical portion R1 and the horizontal portion ( R3) is subjected to a greater load than the guide roll (100) installed.

3 is a view showing an example of measuring the load applied to the guide roll, when casting a cast slab, shows an example of measuring the load applied to any one of the guide rolls forming the bending portion. Although it is described here as a load applied to the guide roll, it may be a load measured from parts such as a tie rod, a bearing housing, a hydraulic cylinder, etc. constituting the segment.

Referring to FIG. 3 , it can be seen that a very large load is applied to the guide roll of the bent portion at the beginning of casting and at the end of casting during casting. This includes the solidified portion (S1) completely solidified to the inside of the initial end and the end end of the cast steel (1) (see Fig. 4), the solidified portion (S1) is a temperature higher than that of the non-solidified portion (S2) that is other areas This is because a larger load is applied to the guide roll 100 because the relatively low deformation resistance is large. Here, the non-solidified portion S2 may mean a state in which the outside is solidified and the inside contains unsolidified molten steel. The solidified portion S1 may be formed to have a length shorter than the vertical length of the mold 30 , for example, to have a length of about 200 to 400 mm. 3 shows that a very large load is rapidly applied to the guide roll 100 when the initial end and the end end of the cast slab 1 pass through the bent portion R2. Compared to the total casting time, it is seen that the load is rapidly applied to the guide roll 100 because the time for the initial end and the end end of the cast slab 1 to pass through the bending portion R2 is short, and the guide roll 100 The load applied to it may have a shape that gradually increases and gradually decreases after reaching a maximum value.

Accordingly, in an embodiment of the present invention, when the initial end and the final end of the cast slab, that is, the solidified portion S1 of the cast slab passes through the bending portion R2, the guide roll 100 so as not to apply a deformation load to the guide roll 100. By increasing the interval of , a load applied to the guide roll 100 by the solidification unit S1, for example, a deformation load can be reduced.

Figure 4 is a view showing the process of adjusting the gap between the rolls in the bending portion in the casting method according to an embodiment of the present invention, and bending the slab. Figure 4 (a) is a view showing the state before increasing the gap between the rolls, Figure 4 (b) is a view showing the state after increasing the gap between the rolls, and is exaggerated for explanation.

Referring to Figure 4 (a), the slab (1) is drawn from the mold 30, when passing through the vertical portion (R1) the inner surface (1a) and the outer surface (1b) of the slab is a vertical portion (R1) It proceeds in a state in contact with all the guide rolls 100 forming the. At this time, the interval between the rolls of the guide roll 100 installed under the mold 30 may be in a state of being adjusted to the same size as the thickness T1 of the slab 1 . The slab 1 passing through the vertical portion R1 enters the bending portion R2 from the initial end portion, and may be bent by the guide roll 100 installed in the bending portion R2. When the cast slab 1 is bent in the bending portion R2, the load may be distributed to several guide rolls 100 in contact with the cast slab 1 .

Among the guide rolls 100 forming the bending portion R2, the guide rolls installed on the outside of the bending portion R2 are referred to as RO1 to RO7 in the advancing direction of the slab, and the guide installed on the inside of the bending portion R2 Assume that the roll is RI1 ~ RI7 in the direction of movement of the cast iron. For example, the four guide rolls RO1 to RO4 are in contact with the outer surface 1b of the cast slab 1 that has entered the bending portion R2, and the four guide rolls RI1 to RI4 are also in contact with the inner surface 1a of the cast slab 1 . ) can be in contact. And while the cast steel 1 proceeds between these guide rolls (RO1 ~ RO4, RI1 ~ RI4), it is bent by each guide roll (RO1 ~ RO4, RI1 ~ RI4), and the guide rolls (RO1 ~ RO4, RI1 ~ RI4) will be loaded. At this time, the cast steel 1 is supported in at least two places by a guide roll disposed on the outside of the bending portion R2, and is pressed in one place by a guide roll disposed on the inside of the bending portion R2. will be bent For example, the outer surface 1b of the cast slab 1 is supported by two guide rolls RO2 and RO4, and the inner surface 1a of the cast slab 1 has one guide roll RI3 applying pressure to the cast slab 1 . and bend it. In this case, the loads L11, L12, L13 are applied to the guide rolls RO2, RO4, RI3, and the hydraulic cylinder 55 is formed between the guide rolls facing each other and the guide rolls of the respective guide rolls RO2, RO4, RI3. The load (L11, L12, L13) to maintain the distance can generate the reaction force (F11, F12, F13) toward the cast steel (1) in the opposite direction to the applied.

As such, when the cast slab 1 passes through the bending portion R2, the inner surface 1a and the outer surface 1b of the cast slab 1 are in contact with both guide rolls RO1 to RO7, RI1 to RI7. will do Accordingly, when the initial end formed with the solid region S1 passes through the bending portion R2, an overload occurs for each guide roll installed in the traveling direction of the cast slab 1 in order to bend the initial end. In particular, when the guide rolls RO2 , RO4 , and RI3 contact only the solid region S1 to bend the solidified portion S1 , a greater load may be applied to the guide rolls RO2 , RO4 , RI3 .

Accordingly, as shown in Figure 4 (b), when the initial end of the cast steel (1) passes through the bending portion (R2), the guide installed on the bending portion (R2) so as not to deform the solidified portion (S1) of the initial end portion (R2) It is possible to increase the spacing of the rolls (RO1 to RO7, RI1 to RI7). When the casting is completed, the initial end is cut off and treated with scrap, etc., and it is irrelevant even if the thickness between the rolls is increased due to the increase in the gap between the rolls. Therefore, when the initial end of the cast steel passes through the bending portion (R2), the initial end, for example, the solidified portion (S1) can increase the interval of the guide roll so as not to be bent. When increasing the distance between the guide rolls, the guide rolls RO1 to RO7 installed on the outside of the bending portion R2 maintain a fixed state, and the guide rolls RI1 to RI7 installed on the inside of the bending portion R2 are By moving it, the interval of the guide roll can be adjusted. Alternatively, all of the guide rolls RO1 to RO7 and RI1 to RI7 installed outside and inside the bent portion R2 may be moved.

When the interval between the rolls of the guide roll 100 installed in the bending portion R2 is increased by a predetermined length D from the reference interval G0 and adjusted to G1 (G0 + D), the cast steel 1 and the bending portion R2 ), a space can be formed between the guide rolls (RI1 to RI7) installed on the inside. At this time, the reference interval (G0) may be the same as the width (T0) of the mold 30, it may be the same as the thickness (T1) or the thickness of the solidified portion (S1) of the target slab. Thus, when a space is formed between the cast slab 1 and the guide rolls RO1 to RO7, RI1 to RI7, the gap between the rolls increases than the thickness of the solidified portion S1, and the initial end of the cast 1, especially the solidified portion (S1) may pass through the bending portion (R2) as it is, without applying a load to the guide rolls (RO1 ~ RO7, RI1 ~ RI7). In addition, when the interval between the guide rolls RO1 to RO7 and RI1 to RI7 is increased, the non-solidified portion S2 other than the solidified portion S1 expands by the iron static pressure to increase the thickness. Accordingly, deformation may be made by contacting the guide rolls RO1 to RO7 and RI1 to RI7 from the non-solidified portion S2 . Therefore, since the deformation is made from the non-solidified portion S2 having less deformation resistance than the solidified portion S1, the loads L21, L22, and L23 applied to the guide rolls RO1 to RO7 and RI1 to RI7 can be reduced. In addition, the reaction forces F21 , F22 , and F23 generated in the hydraulic cylinder 55 in order to maintain the distance between the guide rolls RO1 to RO7 and RI1 to RI7 can also be reduced.

As such, by increasing the interval of the guide roll 100 when the solidified portion S1 of the cast slab 1 passes through the bent portion R2, a space can be formed between the cast slab 1 and the guide roll 100 . Accordingly, the solidified portion S1 may pass through the bent portion R2 without being deformed, and may be deformed from the non-solidified portion S2 other than the solidified portion S1. Therefore, the load applied to the guide roll 100 can be reduced. In addition, when the end end of the cast steel 1 passes through the bending portion R2, by increasing the interval between the rolls of the guide roll 100 installed in the bending portion R2 in the same principle as the non-solidified portion S2, it is deformed until the end The solidified portion S1 of the end passes through the bent portion R2 without being deformed, thereby reducing the load applied to the guide roll 100 .

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

5 is a flowchart showing a casting method according to an embodiment of the present invention, FIG. 6 is a view showing a state in which the distance between the rolls is adjusted when the cast slab proceeds in the vertical direction, and FIGS. 7 and 8 are the moving direction of the cast slab is changed It is a view showing the state in which the gap between the rolls is adjusted when it becomes, and FIG. 9 is a view showing the state in which the gap between the rolls is adjusted when the cast slab proceeds in the horizontal direction.

The casting method according to an embodiment of the present invention comprises the steps of adjusting the interval between the rolls of the guide rolls 100 installed to face each other at the bottom of the mold 30 to the reference interval G0, and adding molten steel to the mold 30. It may include the step of injecting, solidifying the molten steel, drawing the slab 1, and adjusting the gap between the rolls according to the load applied to the guide roll 100 . Here, the reference interval (G0) means the interval of the guide roll 100 that can be formed to a target thickness of the cast slab 1, and may be the same as the width T0 of the mold 30, It may be the same as the thickness (T1) of the cast steel (1).

In addition, the casting method according to an embodiment of the present invention includes the steps of injecting molten steel into the mold 30 , solidifying the molten steel and drawing the cast slab 1 , and the cast slab 1 drawn from the lower portion of the mold 30 . ) may include a step of the non-solidified portion that is a region other than the solidified portion to the inside in the thickness direction.

With reference to Figure 5, a casting method according to an embodiment of the present invention will be described in detail.

First, a casting facility for manufacturing a slab may be prepared (S102).

The interval between the rolls of the guide roll 100 installed under the mold 30 may be adjusted according to the thickness of the cast slab to be cast. For example, the interval between the rolls of the guide roll 100 forming the vertical portion R1, the bending portion R2, and the horizontal portion R3 may be adjusted to a reference interval G0 equal to the width T0 of the mold 30. have. In addition, a measuring device 60 for measuring the load applied to the guide roll 100 on the segment 50 may be installed. The measuring device 60 may be installed in the segment 50 forming the bent portion R2 , and installed in at least one of a bearing housing constituting the segment 50 , a tie rod 56 , and a hydraulic cylinder 55 . can be The measuring device 60 may be installed in at least one of the plurality of segments 50 installed in the first section (R21, see FIG. 2 ) where the cast slab 1 is deformed in the bending portion R2, that is, bent (R21, see FIG. 2). In addition, the measuring device 60 may be formed in the segment 50 that is installed before the slab 1 is bent the most even in the first section R21. This is because the load applied to the guide roll 100 is the highest when the cast steel 1 is deformed the most, so the load applied to the guide roll 100 is measured before the load is applied to the guide roll 100 to the maximum. This is to prevent the guide roll 100 from being damaged by increasing the gap between the rolls of the guide roll 100 .

And it is possible to set a reference load range used as a reference for adjusting the interval of the guide roll (100). The reference load range is smaller than the maximum load that can damage the guide roll 100 when deforming the cast slab 1, and larger than the general load normally applied to the guide roll 100 when deforming the cast slab (1). can For example, when the maximum load is 1 and the normal load is 0.3, the reference load range may be set to about 0.4 to 0.9 or 0.6 to 0.8. In this way, the reference load range is set, the load applied to the guide roll 100 during casting is measured, and when the measured load is included in the reference load range, the interval between the guide rolls 100 may be increased. Here, the reference load range may vary depending on the casting conditions such as the steel type, the width of the cast steel, cooling conditions, and the like. In addition, even if the load applied to the guide roll 100 is greater than the general load, the guide roll 100 is not easily damaged, and there is a risk of operation accidents such as slab bursting in the process of adjusting the gap between the rolls. Therefore, the interval between rolls can be adjusted by appropriately setting the reference load range.

Then, a dummy bar (not shown) is put into the mold 30 to place the tail of the dummy bar on the cooling line 40 , and the head of the dummy bar is placed inside the mold 30 , and then the mold 30 and the dummy It is possible to seal between the heads of the bars. In this way, the order of each process or step of preparing the casting equipment is not limited thereto, and may be variously changed.

Thereafter, molten steel that has been refined may be injected into the mold 30 ( S104 ). The molten steel injected into the mold 30 may be first cooled in the mold 30 , and may be fused with the head of the dummy bar to form the initial end of the cast steel 1 . Molten steel is injected into the mold 30, and when the molten steel is cooled to some extent, the dummy bar is moved using a pinch roller (not shown) installed in the cooling line 40 to continuously draw the cast steel from the mold 30 (S106) can do.

In the lower part of the mold 30 , the guide roll 100 maintains a pre-adjusted gap between the rolls, for example, the guide gap, and can draw the slab 1 drawn out from the mold 30 . When the initial end of the cast slab 1 drawn out from the mold 30 enters the bent portion R2 through the vertical portion R1, the guide roll 100 is The load may be measured (S108). When casting starts, the measuring device 60 may continuously measure the load applied to the guide roll 100 , and may continuously transmit the measured load of the guide roll 100 , for example, a measured load to the control unit 70 . have.

The control unit 70 may determine whether the measured load is included in the reference load range ( S110 ), and may adjust the interval between rolls according to the determination result.

If the measured load does not reach the preset reference load range (measured load < reference load range), that is, if the measured load is less than the minimum value of the reference load range, keep the distance between rolls intact (D0) and leave the cast steel as it is. can be drawn Even when the initial end of the slab 1 passes through the bending portion R2, the measured load may be smaller than the reference load range.

On the other hand, when the measured load is included in the preset reference load range, the operation of the hydraulic cylinder 55 may be controlled to increase the distance between rolls to be larger (D1) than the reference gap (G0) (S112). The control unit 70 may control the operation of the hydraulic cylinder 55 to increase the interval between the guide rolls 100 forming the bent portion R2 . In addition, the control unit 70 is a hydraulic cylinder ( 55) can be controlled. That is, the control unit 70 can control the operation of the hydraulic cylinder 55 installed in each of the segments 50 forming the bent portion R2 so as to increase the spacing between the rolls along the moving direction of the cast slab 1 . . At this time, a space is formed between the cast slab 1 and the guide roll 100 , and the solidified portion S1 can pass between the guide rolls 100 . That is, the gap between the rolls is increased than the thickness of the solidified portion S1 , so that the solidified portion S1 is not deformed by the guide roll 100 and can proceed between the guide rolls 100 . The control unit 70 may increase the spacing between the rolls sequentially along the traveling direction of the cast slab 1 so that the initial end of the cast slab 1, for example, the solidified part S1 does not receive deformation resistance by the guide roll 100. have. In this case, as shown in FIG. 7 , the distance between the rolls of the guide roll 100 forming the vertical part R1 and the horizontal part R3 maintains the reference distance G0 and forms the bent part R2. The interval between the rolls of the guide roll 100 may be adjusted to G1 (G0+D) greater than the reference interval G0. For example, the increase amount D of the gap between the rolls may be 1 to 10 mm, or 3 to 7 mm, and may be changed according to casting conditions such as steel type and casting speed. If the increase amount (D) of the gap between the rolls is too small, the load applied to the guide rolls 100 is sufficiently reduced because the solidified portion S1 of the cast slab 1 does not pass smoothly between the guide rolls 100 and is deformed. cannot be reduced On the other hand, if the increase amount (D) of the gap between the rolls is too large, the solidified portion (S1) may pass smoothly between the guide rolls (100). However, the reduction force applied to the cast slab 1 by the guide roll 100 is rapidly reduced, and the non-solidified part S2 other than the solidified part S1 expands, and operation accidents such as slab burst may occur. Therefore, by appropriately increasing the gap between the rolls, the load applied to the guide roll 100 can be reduced, and the operation can be stably performed.

And when increasing the gap between the rolls of the guide roll 100, if the speed at which the gap between the rolls increases is too slow, the space between the cast slab 1 and the guide roll 100 is not sufficiently secured. It is not possible to sufficiently reduce the load applied to the In addition, while the gap between the rolls of the guide roll 100 increases, the cast 1 continues to progress, so the increased gap between the rolls is reflected in the cast as it is. Accordingly, the length of the region thicker than the target thickness in the slab increases, and the length cut off from the slab after casting increases, so there is a problem in that productivity is lowered. On the other hand, if the speed at which the gap between the rolls increases is too fast, the thickness of the cast steel increases rapidly in the region where the gap between the rolls increases. Accordingly, as the molten steel escapes from the mold 30 and flows into the slab 1, the molten steel molten steel surface inside the mold 30 becomes unstable, thereby affecting the quality of the slab.

In this way, in a state in which the distance between the rolls is increased, the load applied to the guide roll 100 can be continuously measured. Then, it is determined again whether the measured load is included in the reference load range (S114), and the interval between rolls can be adjusted according to the determination result.

When the measured load is included in the preset reference load range, the slab can be drawn as it is, while maintaining the interval between the rolls in an increased state (S118). This means that the solidified portion (S1) of the cast slab (1) applying an excessive load to the guide roll (100) has not yet passed the segment (50) in which the measuring device (60) is installed, and the solidified portion (S1) is the corresponding segment Until passing (50), the gap between the rolls can be maintained in the increased state (D1).

On the other hand, when the measured load exceeds the preset reference load range and becomes smaller than the minimum value of the reference load range, the roll-to-roll gap may be reduced to return to the reference gap G0 ( S116 ). This means that the solidified part (S1) of the cast slab (1) applying an excessive load to the guide roll (100) has passed through the segment (50) in which the measuring device (60) is installed, and the solidified part (S1) is the corresponding segment (50) If passed, the gap between the rolls can be returned to the reference gap G0. This is because if the gap between the rolls is larger than the target thickness T1 of the cast slab 1, the thickness defect of the cast slab 1 occurs, so the solidified part It is good to quickly restore the interval between the rolls of the guide roll 100 installed in the segment 50 through which (S1) has passed, thus reducing the length cut from the cast slab after casting to prevent a decrease in production. At this time, the gap between the rolls can be returned in order along the direction in which the solidified portion (S1) of the cast slab 1 proceeds, as shown in FIG. 8 .

After returning the interval between the rolls of the bent portion R2 in this way, the cast steel can be continuously drawn out. That is, as shown in FIG. 9 , the slab can be drawn out in a state in which the distance between the rolls in the horizontal portion R1, the bent portion R2, and the horizontal portion R3 are all the reference intervals G. Here, the length of the solidified portion S1 formed in the cast slab 1 according to casting conditions such as steel type, casting rate, cooling rate, etc. has been described as restoring the gap between the rolls by measuring the load applied to the guide roll 100 . It is also possible to return the interval between rolls to the reference interval (G0) by using and casting speed.

After returning the interval between the rolls to the reference interval G0, it may be checked whether casting is complete (S120). Here, an example in which a load greater than or equal to the reference load range was applied to the guide roll 100 when the initial end of the cast slab 1 passes through the bent portion R2 has been described. However, a load smaller than the reference load range is applied to the guide roll 100 when the initial end passes through the bending portion R2, and when the terminal end of the cast steel passes through the bending portion R2, the guide roll 100 is referenced A load included in the load range may be applied. Therefore, after returning the interval between the rolls of the guide roll 100 to the reference interval G0, it is checked whether casting is completed, and accordingly, the drawing of the cast slab can be continued or the casting can be completed. At this time, whether the casting is completed can be confirmed through the casting time or the number of times of adjusting the interval of the guide roll 100 .

Then, when the injection of the molten steel into the mold 30 is completed, the terminal end of the slab 1 can be formed by reducing the drawing speed of the slab and cooling the molten steel injected into the mold 30 . And by drawing the slab again, the terminal end of the slab 1 can be withdrawn from the mold 30 .

The distal end of the cast slab 1 drawn from the mold 30 passes through the vertical portion R1, and may enter the bent portion R2. The measuring instrument 60 installed on the segment 50 forming the bent portion R2 continuously measures the load of the guide roll 100 during casting, and the solidified portion of the end end of the cast slab 1 is at the bent portion R2. When entering, the measurement load increases rapidly. In this case, the distance between the rolls may be adjusted according to the measured load, and the distance between the rolls may be adjusted in the same manner as the method described above.

That is, it may be determined whether the measured load is included in the reference load range, and the interval between rolls may be adjusted according to the determination result.

When the measured load does not reach the preset reference load range (measured load < reference load range), that is, when the measured load is less than the minimum value of the reference load range, the distance between the rolls of the guide roll 100 is set as the reference gap (G0). In the state held, the terminal end of the cast steel can be drawn out.

On the other hand, when the measured load is included in the preset reference load range, the operation of the hydraulic cylinder 55 may be controlled to increase the interval between rolls. In this case, the distance between the rolls of the guide roll 100 forming the vertical portion R1 and the horizontal portion R3 maintains the reference interval G0, and between the rolls of the guide roll 100 forming the bent portion R2. The interval may be adjusted to be larger than the reference interval G0. And when the end end of the cast steel 1 passes through the bent portion R2, the interval between the rolls may be returned to the reference interval G0, or it may be maintained in an increased state.

And when the distal end of the slab 1 completely exits the cooling line 40, the casting is completed.

In the above, the present invention has been described with reference to the above-described embodiments and the accompanying drawings, but the present invention is not limited thereto and is defined by the claims to be described later. Therefore, those of ordinary skill in the art will appreciate that the present invention can be variously modified and modified within the scope that does not depart from the spirit of the claims to be described later.

10: ladle 20: tundish
30: mold 40: cooling line
50: segment 51: top plate
52: lower plate 53, 54: guide roll assembly
55: hydraulic cylinder 56: tie rod
60: measuring instrument 70: control unit
100: guide roll

Claims (25)

As a casting equipment for manufacturing a slab by a mold and a plurality of segments disposed below the mold and continuously disposed,
The segment includes a plurality of guide rolls installed to face each other so that the slab passes,
Guide between guide rolls in the thickness direction of the cast slab so as not to apply a deformation load to the solidified part solidified to the inside in the thickness direction among the cast slabs drawn from the lower part of the mold, and to apply a deformation load to the non-solidified part, which is an area other than the solidified part. A casting plant comprising an adjuster for adjusting the spacing. The method according to claim 1,
The regulator is
a tie rod connecting the upper frame and the lower frame on which the plurality of guide rolls are disposed to face each other so as to be spaced apart; and
and a hydraulic cylinder connected to the tie rod and installed in one of the upper frame and the lower frame to adjust the guide interval. 3. The method according to claim 2,
a measuring device for measuring the load applied to the guide roll; and
Casting equipment further comprising a; control unit capable of controlling the operation of the hydraulic cylinder to adjust the guide interval according to the load measured by the measuring device. 4. The method of claim 3,
The measuring device is a casting facility installed in a region where the casting direction is changed in the lower part of the mold. The method according to claim 1,
The regulator is
a tie rod connecting the upper frame and the lower frame on which the plurality of guide rolls are disposed to face each other so as to be spaced apart; and
Casting equipment comprising a; elastic member that is telescopically installed on the tie rod so as to adjust the guide interval by the load applied to the guide roll. 6. The method of claim 5,
The elastic member is a casting equipment comprising a compression spring (pre-compressed spring). A casting method for manufacturing a slab, comprising:
adjusting the interval between the rolls, which is the interval between the guide rolls installed to face each other at the bottom of the mold, as a reference interval;
injecting molten steel into the mold;
solidifying the molten steel and drawing a slab; and
Including; adjusting the distance between the rolls according to the load applied to the guide roll;
The step of adjusting the gap between the rolls does not apply a deformation load to the solidified portion solidified to the inside in the thickness direction among the cast slabs drawn from the lower part of the mold, and to apply a deformation load to the non-solidified portion, which is a region other than the solidified portion, A casting method performed before the moving direction of at least one of the initial end and the end end of the cast is switched from the vertical direction to the horizontal direction. delete A casting method for manufacturing a slab, comprising:
injecting molten steel into the mold;
solidifying the molten steel and drawing a slab; and
Transforming the non-solidified portion, which is an area other than the solidified portion that has been solidified to the inside in the thickness direction among the cast slabs drawn from the lower part of the mold;
In the step of deforming the non-solidified part, the moving direction of at least one of the initial end and the final end of the cast slab is switched from the vertical direction to the horizontal direction so as not to apply a deformation load to the solidified portion, and to apply a deformation load to the unsolidified portion Casting method comprising the step of adjusting the gap between the rolls, which is the gap between the guide rolls installed to face each other at the bottom of the mold before being cast. 10. The method of claim 9,
The step of transforming the non-solidified part,
Casting method comprising the step of bending the unsolidified portion while drawing the slab, and unfolding. delete 11. The method of claim 7 or 10,
The step of drawing the slab further comprises measuring a load applied to the guide roll,
The step of measuring the load is a casting method of measuring at least one point in the region in which the traveling direction of the slab is switched from the vertical direction to the horizontal direction. 13. The method of claim 12,
Further comprising the step of setting a reference load range that can be applied to the guide roll,
The step of adjusting the gap between the rolls,
When the measured load is included in the reference load range, the interval between the rolls is adjusted to be larger than the reference interval,
If the measured load is less than the minimum value of the reference load range, the casting method for maintaining the distance between the rolls equal to the reference distance. 14. The method of claim 13,
Measuring the load applied to the guide roll,
A casting method for measuring the pressure generated in at least one of a tie rod and a hydraulic cylinder for adjusting the gap between the rolls. 14. The method of claim 13,
The step of adjusting the interval between the rolls to be larger than the reference interval,
A casting method comprising the step of forming a space between the guide roll and at least one surface of the cast iron facing the guide roll in the thickness direction of the cast steel. 14. The method of claim 13,
The step of adjusting the interval between the rolls to be larger than the reference interval,
A casting method comprising the step of adjusting the gap between the rolls to be greater than the thickness of the solidified part solidified to the inside in the thickness direction among the cast slabs drawn from the lower part of the mold. 14. The method of claim 13,
The step of adjusting the interval between the rolls to be larger than the reference interval,
A casting method for sequentially adjusting the spacing between the rolls along the direction in which the cast slabs advance. 14. The method of claim 13,
The step of adjusting the interval between the rolls to be larger than the reference interval,
A casting method for sequentially adjusting the spacing between the rolls along the direction in which the cast steel advances from the point at which the load is measured. 14. The method of claim 13,
After adjusting the interval between the rolls to be larger than the reference interval,
and returning the roll-to-roll spacing to the reference spacing. 20. The method of claim 19,
The step of restoring the gap between the rolls,
A casting method comprising the step of returning the distance between the rolls to the reference gap in the order of increasing the gap between the rolls. 20. The method of claim 19,
The returning step is
A casting method of returning from the gap between the rolls of the guide rolls through which the solidified part has passed to the inside in the thickness direction among the cast slabs drawn from the lower part of the mold. 11. The method of claim 7 or 10,
The step of adjusting the gap between the rolls,
When a load greater than a preset load is applied to the guide roll, the casting method comprising the step of adjusting the distance between the rolls without an external force applied from the outside. 23. The method of claim 22,
The step of adjusting the gap between the rolls without the external force,
A load applied to the guide roll comprises pushing the guide roll outward,
The step of pushing the guide roll to the outside is a casting method performed using elasticity. 24. The method of claim 23,
and when the load applied to the guide roll is smaller than a load preset to the guide roll, returning the guide roll by using elasticity. delete

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