KR20230031527A - Slab, dummy bar and casting method - Google Patents

Abstract

The present invention provides a slab, a dummy bar and a casting method using the same, wherein a load applied to a device can be reduced effectively when an initial slab portion is bent at the initial stage of casting. The slab includes: a normal slab portion extending in a longitudinal direction to have width and thickness constant within an error range and having width greater than thickness; and an initial slab portion extending in a longitudinal direction from the normal slab portion part, wherein the initial slab portion includes at least one inclined surface to become narrower toward an end. The dummy bar includes: a body part extending in a longitudinal direction and formed to be able to be bent in a thickness direction; a head part including an upper surface having width greater than thickness and connected to the body part; and an adjustment part arranged on both sides of the head part to be able to form a slope or a plurality of steps on both sides in the widthwise direction of the upper surface of the head part, and protruding upward from the upper surface of the head part.

Description

Cast steel, dummy bar and casting method {SLAB, DUMMY BAR AND CASTING METHOD}

The present invention relates to a cast slab, a dummy bar, and a casting method, and more particularly, to a cast slab, a dummy bar, and a casting method capable of effectively reducing a load applied to an apparatus at an early stage of casting.

The casting device is a facility that casts slabs of various sizes. The casting device includes a mold that receives refined molten steel, solidifies it into a slab shape and discharges it downward, a cooling table that cools and presses down the slab discharged from the mold while drawing it in the casting direction, and is inserted into the mold before the molten steel to the bottom of the mold. When the surface is formed and the molten steel is injected into the mold to form the initial cast steel portion, a dummy bar is provided to guide the drawing of the initial cast steel portion and the normal cast steel portion by pulling the initial cast steel portion in the casting direction.

On the other hand, if the initial cast steel portion is not properly solidified inside the mold, the shape of the initial cast steel portion may be deformed when the initial cast steel portion is pulled into the dummy bar. From this, the coupling between the initial cast piece and the dummy bar is released so that they can be separated from each other, and casting can be stopped.

Therefore, before pulling the initial cast steel portion with the dummy bar, the initial cast steel portion must be appropriately solidified inside the mold. However, it is difficult to control casting conditions to appropriately solidify the initial cast steel. Therefore, during the appropriate solidification of the initial cast steel portion to prevent separation between the initial cast steel portion and the dummy bar, excessive solidification of the initial cast steel portion often occurs.

If the initial cast steel is excessively solidified inside the mold, the initial cast steel is not smoothly bent in the bending section of the cooling zone. That is, the initial cast steel portion is not smoothly bent and deformed. At this time, the roller in the bending section may be permanently deformed while the bending deformation of the initial cast piece is difficult or delayed. In addition, if the initial cast steel portion is not smoothly bent and deformed, the rate at which the cast steel is drawn may be slow. From this, an operation accident such as overflow of the molten steel molten steel surface in the mold may occur.

The background technology of the present invention is published in the following patent documents.

KR 10-2020-0143915 A KR 10-2018-0087360 A

The present invention provides a cast steel, a dummy bar, and a casting method capable of effectively reducing the load applied to the device in the initial stage of casting.

A cast steel according to an embodiment of the present invention is a cast steel cast by drawing a melt injected into a mold into a dummy bar, and is extended in the longitudinal direction so that the width and thickness are constant within the error range, and the length in the width direction is the length in the thickness direction. a larger normal cast portion; and an initial cast piece portion extending in the longitudinal direction from the normal cast piece portion, and the initial cast piece portion includes at least one inclined surface so that the width becomes narrower towards the end.

The initial cast steel portion may include both side surfaces in the width direction, both side surfaces in the thickness direction, and front surfaces connecting both side surfaces in the width direction and both sides in the thickness direction, and the front surface may include the inclined surface.

The front surface may be divided into a center area in the width direction and edge areas on both sides of the center area, and the inclined surfaces may be formed on the edge areas, respectively.

A dummy bar according to an embodiment of the present invention is a dummy bar for drawing a cast steel from a mold, and includes a body portion extending in a longitudinal direction and capable of being bent in a thickness direction; a head portion having an upper surface having a length in the width direction greater than a length in the thickness direction and connected to the body portion; and an adjusting unit disposed on both sides of the head unit and protruding upward from the upper surface of the head unit so as to form an inclination or a plurality of steps on both sides of the upper surface of the head unit in the width direction.

The control unit may include a plurality of pads detachably mounted on both side surfaces of the head unit.

Each of the plurality of pads may protrude from the upper surface of the head unit in stages as the distance from the side surface of the head unit to which each pad is mounted increases.

The plurality of pads may continuously protrude from the upper surface of the head unit as the distance from the side surface of the head unit to which each pad is mounted increases.

The plurality of pads may have the same length in a width direction within an error range.

Each of the plurality of pads may have a smaller length in a width direction as the distance from the side surface of the head unit to which each pad is mounted increases.

Each of the plurality of pads may have a length in a width direction that is farther away from a side surface of the head unit to which each pad is mounted.

The pad may be formed in a range of 20 mm to 80 mm in length in the width direction.

The control unit further includes a plurality of bolts formed to pass through the plurality of pads in the width direction, and the head portion has installation grooves on both side surfaces to which the bolts can be coupled, and each of the plurality of pads , It may be provided with an insertion hole into which the bolt can be inserted and an installation hole into which the bolt can be coupled.

A casting method according to an embodiment of the present invention is a casting method for casting a cast steel having a length in the width direction greater than a length in the thickness direction, comprising: forming a bottom surface at the bottom of a mold whose upper and lower parts are open in the casting direction; Step of injecting the molten material into the mold and solidifying it into the slab; Including, the process of moving the bottom surface in the casting direction and drawing the cast steel; including, and the solidifying process into the cast steel is, in the casting direction, in some areas of the lower surface of the cast steel so that the width of the initial cast steel portion is narrowed. It includes; the process of forming an inclined surface.

The process of forming an inclined surface on a partial region of the lower surface of the cast steel may include a process of forming inclined surfaces on edge regions on both sides of the lower surface of the cast steel in the width direction using the shape of the bottom surface.

In the process of drawing the cast steel, the initial cast steel portion and the normal cast steel portion excluding the initial cast steel portion pass through the vertical section, the inflection section and the curved section of the drawing path of the cast in order, and contact with a plurality of rollers in the thickness direction. Including, the bending and deforming process; the length of the inclined surface extending in the casting direction may be greater than the distance at which the plurality of rollers disposed in the inflection section are spaced apart from each other in the casting direction.

The process of bending and deforming in the thickness direction by contacting the plurality of rollers may include a process of increasing the pressure by concentrating the pressing force provided to the roller in contact with the initial slab portion at the end of the initial slab portion. .

According to an embodiment of the present invention, when casting a cast steel having a width greater than the thickness, the initial cast steel portion may be cast so that the width becomes narrower toward the front in the casting direction. From this, it is possible to smoothly bend the initial cast steel portion in the thickness direction while drawing it in the casting direction without increasing the strength of the roller in contact with the initial cast steel portion and the pressing force applied from the roller to the initial cast steel portion.

Accordingly, since the bending deformation of the initial cast steel section is smoothly performed, it is possible to prevent a decrease in casting speed and roller damage caused by difficulty in bending deformation, and the initial cast steel section and subsequent normal cast steel sections smoothly progress in the casting direction. can make it Therefore, it is possible to prevent cast steel congestion and roller damage that may occur because the initial cast steel portion is not easily bent and deformed. From this, it is possible to prevent instability of the molten steel molten steel surface in the mold that may occur due to stagnation of the cast steel, and to prevent surface defects of the normal cast steel portion that may occur due to roller damage.

1 is a schematic view showing an initial cast steel portion and a normal cast steel portion of a cast steel according to an embodiment of the present invention.
2 is a schematic diagram of a casting device and a dummy bar according to an embodiment of the present invention.
Figure 3 is a schematic view showing the appearance of casting the initial cast piece in the mold after forming the bottom surface of the mold with another dummy bar according to an embodiment of the present invention.
4 is a schematic view showing how a cast steel is drawn while moving a dummy bar according to an embodiment of the present invention.
5 is a schematic diagram showing a partially disassembled dummy bar according to an embodiment of the present invention.
6 is a schematic view showing a state in which a dummy bar is inserted into a mold according to an embodiment of the present invention.
7 is a schematic view showing a state in which a dummy bar is inserted into a mold according to a modified example of an embodiment of the present invention.

Hereinafter, 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, and will be implemented in a variety of different forms. Only the embodiments of the present invention are provided to complete the disclosure of the present invention and to fully inform those skilled in the art of the scope of the invention. In order to explain an embodiment of the present invention, the drawings may be exaggerated, and the same reference numerals in the drawings refer to the same elements.

Cast steel, dummy bar and casting method according to an embodiment of the present invention can effectively reduce the load applied to the casting device by the initial cast steel portion when bending the initial cast steel portion of the cast steel at the beginning of casting. Cast steel, dummy bar and casting method according to an embodiment of the present invention can be applied to a casting apparatus for continuously casting cast steel from refined molten steel.

However, the cast steel according to the embodiment of the present invention is not limited to the cast steel cast in the casting apparatus of the steel mill and can be changed in various ways. In addition, the dummy bar and the casting method according to the embodiment of the present invention can be variously applied to an apparatus for drawing various treated objects into the dummy bar.

1 is a schematic view showing an initial cast steel portion and a normal cast steel portion of a cast steel according to an embodiment of the present invention.

Referring to FIG. 1, a cast steel 10 according to an embodiment of the present invention will be described.

First, the melt is explained. Typically cast steel 10 can be produced from a melt. The melt may include molten steel. The molten material may be injected into the mold 300 with the upper and lower portions open and solidified into the slab 10. In addition, the slab 10 is continuously discharged downward from the mold 300 and can be reduced and cooled while being drawn along the drawing path. At this time, while the cast steel 10 is drawn along the drawing path R, it can be bent and deformed with a predetermined curvature while passing through the inflection section R2 in which the curvature increases as it moves away from the mold 300, and the curvature is After passing through a certain curvature section R3 and maintaining the curvature, then, it can be corrected while passing through a calibration section in which the curvature decreases as the distance from the mold 300 increases. Here, the above-described sections of the drawing path R will be described again below (see FIG. 4).

On the other hand, the error range may be a predetermined error range reflecting the change in width and thickness due to the rolling of the cast steel 10.

The initial cast steel portion 11 may be a portion of the cast steel 10 first cast inside the mold (see FIG. 3). The normal slab portion 12 may be the remaining portion of the cast slab 10 cast inside the mold after the initial cast slab portion 11 exits the mold (see FIG. 4).

The initial cast steel portion 11 may have a lower temperature and higher strength than the normal cast steel portion 12. Therefore, it may be difficult to bend the initial cast steel portion 11 compared to the normal cast steel portion 12. In addition, when the cast steel 11 is cooled in the mold, compared to the normal cast steel portion 12 being cooled by the mold, the initial cast steel portion 11 is also cooled by the dummy bar, so the initial cast steel portion 11 Cooling efficiency may vary, and it is difficult to control the cooling of the initial cast steel portion 11 compared to the normal cast steel portion 12. Therefore, there are cases in which the initial cast steel portion 11 is supercooled than the desired temperature in the mold. From this, the strength of the initial cast piece portion 11 may be increased. Therefore, the initial cast steel portion 11 may be more difficult to bend than the normal cast steel portion 12.

Therefore, in the embodiment of the present invention, the initial cast steel portion 11 may be formed to have a shape in which the width becomes narrower toward the end so that the initial cast steel portion 11 can be smoothly bent and deformed.

Hereinafter, with reference to FIG. 1, the shape of the initial cast piece portion 11 will be described in detail.

The cast steel 10 is cast by drawing the melt injected into the mold into a dummy bar, and is extended in the longitudinal direction such that the width and thickness are constant within the error range, and the normal cast piece portion having a length in the width direction greater than a length in the thickness direction ( 12), and an initial cast piece portion 11 extending in the longitudinal direction from the normal cast piece portion 12. At this time, the initial cast piece portion 11 includes at least one inclined surface so that the width becomes narrower toward the end. Here, the longitudinal direction, the width direction, and the thickness direction will be described in detail again while explaining the casting apparatus below.

The initial cast piece portion 11 has width-direction both side surfaces 11a extending in the width direction and opposing in the thickness direction, thickness-direction both side surfaces 11b extending in the thickness direction and facing in the width direction, and both width-direction side surfaces 11a ) and a front surface 11c connecting both side surfaces 11b in the thickness direction. At this time, the normal cast piece portion 12 may be located behind the initial cast piece portion 11 facing the front surface 11c.

The initial cast piece portion 11 may include at least one inclined surface 11c-2 in a predetermined region of the front surface 11c so that the length in the width direction decreases from the rear to the front surface 11c. In this case, when the number of inclined surfaces 11c-2 is one, the inclined surface 11c-2 may be provided on one edge area or the other edge area of the front surface 11c. In addition, when the number of inclined surfaces 11c-2 is two, the inclined surfaces 11c-2 may be provided at one edge area and the other edge area of the front surface 11c, respectively.

Specifically, the front surface 11c of the initial cast piece portion 11 is divided into a center area in the width direction and an edge area on both sides of the center area, and the inclined surface 11c-2 may be formed on the edge area, respectively, and the center area A plane 11c-1 may be formed in the region.

In this way, in the initial cast piece portion 11, the front surface 11c has the inclined surface 11c-2, so that the length of the both side surfaces 11a in the width direction decreases from the rear toward the front surface 11c. there is.

When the cast steel 10 passes through the inflection section R2 of the drawing path R, the inclined surface 11c-2 so that both sides 11a of the initial cast steel portion 11 in the width direction come into contact with two rollers, respectively. ) may be longer than twice the roller pitch P of the inflection section and less than twice the roller pitch P of the inflection section. Here, the roller pitch P of the inflection section may be a distance at which rollers disposed in the inflection section are spaced apart in the longitudinal direction (see FIG. 4).

An inclination angle θ of the inclined surface 11c-2 with respect to the flat surface 11c-1 may be, for example, 45°. Of course, the inclination angle θ may be variously changed according to the length H of the inclined surface 11c-2 extending in the longitudinal direction and the length of the flat surface 11c-1 in the width direction.

The length of the plane (11c-1) extending in the width direction may be a predetermined length for the dummy bar to stably support the cast steel (11) in the mold.

The portion where the inclined surface 11c of the initial cast piece 11 is located is referred to as the front end. While passing through the inflection section R2, the initial cast piece portion 11 may be bent and deformed while the front end portion of each side surface 11a in the width direction contacts two rollers spaced apart in the longitudinal direction in the width direction. At this time, the front end of the initial cast steel portion 11 on the front face 11c side is in contact with the roller in a narrow width, and the rear end of the front end of the initial cast steel portion 11 is in contact with the roller in a wide width. can be contacted with Due to this difference in contact width, the front end of the initial cast piece portion 11 on the side of the front surface 11c can be strongly pushed down in the thickness direction.

From this, the initial cast piece portion 11 can be smoothly bent in the thickness direction, and the normal cast piece portion 12 continuously passing through the inflection section from immediately after the initial cast piece portion 11 passes through the inflection section smoothly. Can be bent and deformed.

On the other hand, when the rollers spaced apart from each other in the longitudinal direction bend and deform the initial cast steel portion 11, the difference in contact area between two adjacent rollers in the longitudinal direction and the initial cast steel portion 11 in the width direction must be large to prevent bending deformation. can be smooth Therefore, when the length H of the inclined surface 11c-2 extending in the longitudinal direction is more than twice the roller pitch of the inflection section, the front end of the initial cast piece 11 at which the inclined surface 11c-2 is located is the length. It comes into contact with three rollers in the direction. In this case, when the rollers spaced apart in the longitudinal direction come into contact with the front end of the initial cast piece portion 11, the difference in contact area between the adjacent rollers and the initial cast piece portion 11 in the width direction becomes small, so that the initial cast piece portion 11 becomes smaller. It may be difficult to smoothly bend and deform the piece 11 .

In addition, from the viewpoint of the roller, since the front end of the initial cast piece portion 11 has a shape in which the width gradually widens, each roller contacting the initial cast piece portion 11 has a narrow area in the width direction with the initial cast piece portion 11. After contact, the contact area is gradually enlarged.

Therefore, the load applied from the initial cast steel portion 11 to the roller is not a large load applied at once, and a small load due to the narrow width of the initial cast steel portion 11 to a large load due to the wide width of the initial cast steel portion 11 The load acts step by step until the load, and thus, the peak value of the load applied to the roller when passing through the initial cast piece 11 can be reduced. Therefore, damage to the roller by the initial cast piece 11 can be prevented.

Here, the peak value may mean the largest value of the value recorded when recording the value of the load applied to the roller from the cast piece over time with respect to the selected one roller. That is, the peak value may be the maximum value of the load. On the other hand, from the viewpoint of the roller, the load value at the moment when the roller first contacts the cast steel may be the maximum value, that is, the peak value.

On the other hand, the initial cast piece portion 11 may include a protruding portion 11d. The protrusion 11d may be formed by solidifying the melt flowing into the groove 524 for connecting the cast steel of the dummy bar 500 when the initial cast steel portion 11 is formed in the mold (see FIG. 5). The protruding portion 11d may be, for example, an annular shape, and may protrude forward from the front surface 11c of the initial cast piece portion 11.

2 is a schematic diagram of a casting device and a dummy bar according to an embodiment of the present invention. In addition, Figure 3 is a schematic view showing the state of casting the initial cast piece in the mold after forming the bottom surface of the mold with another dummy bar according to an embodiment of the present invention, Figure 4 is a moving dummy bar according to an embodiment of the present invention It is a schematic diagram showing how to draw a cast piece while doing it. 5 is a schematic diagram showing a partially disassembled dummy bar according to an embodiment of the present invention.

2 to 4, the casting apparatus according to the embodiment of the present invention, the mold 300, the top and bottom of which are open in the longitudinal direction, the cast steel 10 is drawn from the mold 300 and pressed and cooled The cooling table 400 installed on the lower side of the mold 300 can be inserted into the mold 300 to form a bottom surface at the lower part of the mold 300, and it can be inserted in the longitudinal direction along the cooling table 400. It is formed to be movable and includes a dummy bar 500 having an adjusting part so that a part of the bottom surface is inclined in the width direction.

In addition, the casting apparatus according to the embodiment of the present invention is disposed on the upper side of the mold 300, and the tundish 200 capable of injecting a molten material, for example, molten steel, into the mold 300 is disposed on the upper side of the tundish 200. and may include a ladle 100 supplying molten steel to the tundish 200.

Using the casting apparatus according to the embodiment of the present invention, it is possible to cast the cast steel 10 according to the embodiment of the present invention described above.

The longitudinal direction may be defined based on the cast piece 10. For example, at the position of the mold 300, since the cast 10 extends in the vertical direction, the longitudinal direction may mean the vertical direction. However, as the cast piece 10 moves away from the mold 300, it is bent and extended with a predetermined curvature, then it is corrected with a predetermined curvature and extended in the horizontal direction. Therefore, the longitudinal direction from the position where the slab 10 is bent to the position where it is straightened means a direction bent with a predetermined curvature along the slab 10, and thereafter the longitudinal direction may mean the horizontal direction. This longitudinal direction may also be referred to as the traveling direction of the cast piece 10. This may be more simply referred to as the casting direction.

Hereinafter, when the longitudinal direction needs to be described in detail, it is separately expressed as a vertical direction, a direction bent with a predetermined curvature, and a horizontal direction. On the other hand, if not, it is collectively expressed in the longitudinal direction.

On the other hand, the width direction and thickness direction may also be defined based on the cast steel (10). For example, the cast steel 10 may be a rectangular cast steel 10. At this time, the width direction may mean a direction parallel to the long side of the cast steel 10, and the thickness direction may mean a direction parallel to the short side of the cast steel 10. On the other hand, the cast piece 10 can be bent and straightened in the thickness direction.

In an embodiment of the present invention, the ladle 100 and the tundish 200 may have various configurations. Therefore, descriptions thereof are omitted.

The mold 300 serves to receive molten steel from the tundish 200 and solidify it into a cast steel 10. The inside of the mold 300 may be open in the longitudinal direction so as to continuously solidify the cast piece 10. That is, the mold 300 does not have a bottom surface. Therefore, before starting casting, the dummy bar 500 can be inserted into the lower part of the mold 300 to form a bottom surface so that the molten steel can be accommodated in the mold 300 for a predetermined period of time and solidified into a cast 10. there is.

Referring to FIG. 5 , the mold 300 includes a plurality of long side plates 310 extending in the width direction and spaced apart from each other in the thickness direction, and a plurality of long side plates 310 extending in the thickness direction and spaced apart from each other in the width direction. ) It may include a plurality of short side plates 320 arranged to connect surfaces facing each other. In this case, the mold 300 may be a rectangular mold 300 having a length in the width direction greater than a length in the thickness direction.

Referring to Figures 2 to 4, the cooling table 400 serves to cool and press down while drawing the slab 10 continuously discharged from the mold 300 from the lower side of the mold 300 in the casting direction. The cooling table 400 is disposed on the lower side of the mold 300, and is continuously disposed on the lower side of the bender 410 and the bender 410 having a passage extending in the longitudinal direction to allow the slab 10 to pass therethrough. And, a plurality of segments 420 each having a passage extending in the longitudinal direction so as to pass the cast steel 10, each extending in the width direction, spaced apart from each other in the longitudinal and thickness directions, and the cast steel 10 It may include a plurality of rollers 430 respectively installed inside the passage of the bender 410 and inside the passage of the plurality of segments 420 so as to contact each other.

The cooling table 400 may form a drawing path R having a predetermined length on the lower side of the mold 300 . The drawing path (R) is a vertical section (R1) extending vertically directly below the mold 300, extending obliquely downward from the vertical section (R1), and an inflection section in which the curvature increases as the distance from the vertical section (R1) increases. (R2), extending obliquely downward from the inflection section (R2), may include a curved section (R3) having a constant curvature.

In addition, the drawing path (R) extends obliquely downward from the curved section (R3), and the curvature decreases as the distance from the curved section (R3) decreases, and may include a horizontal section extending horizontally from the correction section. .

4 and 5, the dummy bar 500 is a dummy bar 500 for drawing the cast steel 10 from the mold 300, extending in the longitudinal direction and formed to be bendable in the thickness direction. The body portion 510, the head portion 520 having an upper surface 521 whose length in the width direction is greater than the length in the thickness direction, and connected to the body portion, the width of the upper surface 521 of the head portion 520 It includes an adjusting unit 530 disposed on both sides of the head unit 520 and protruding upward from the top surface of the head unit 520 so as to form an inclination or a plurality of steps on both sides of the direction.

The dummy bar 500 may be inserted into the lower part of the mold 300 to form a bottom surface. The dummy bar 500 is a part of the mold 300 so that the melt can be accommodated in the mold 300 for a predetermined time during which the melt is solidified into the initial cast part 11 in the mold 300 at the beginning of casting. It serves to form the bottom surface.

The body part 510 serves to move the head part 520 inserted into the lower part of the mold 300 along the drawing path R. To this end, the body portion 510 may include a plurality of links and a plurality of connection shafts. A plurality of links may be arranged in a longitudinal direction, and respective ends may overlap each other. In addition, a connecting shaft may be mounted at each end of the plurality of links. Accordingly, the plurality of links may be rotatably coupled with neighboring links in the longitudinal direction by respective connecting shafts. The body part 510 can move along the drawing path R and can be rotated in the thickness direction. Of course, the structure of the body part 510 may vary within a range that satisfies the role of moving the head part 520 .

The head portion 520 is connected to the body portion 510, can be inserted into the lower portion of the mold 300, and moves along the drawing path R by the body portion 510 to draw the cast steel 10. can The head part 520 may be formed in a block shape having a plurality of faces. The head part 520 may be coupled to and supported by the body part 510 . At this time, the head part 520 and the body part 510 may be rotatably coupled in the thickness direction.

When the head part 520 is inserted into the lower part of the mold 300, the surface facing the upper part of the mold 300 is referred to as the upper surface 521, and the short side plate 320 of the mold 300 is formed. The facing side is referred to as side 522 . At this time, the upper surface 521 of the head part 520 may extend in the width direction and the thickness direction. The side surface 522 of the head portion 520 may extend in the thickness and length directions.

When the head part 520 is inserted into the lower part of the mold 300, it can be spaced apart from the short side plate 320 of the mold 300 and come into contact with the long side plate 310, the upper surface 521 ) The length in the width direction and the length in the thickness direction of each may be formed to a predetermined length. At this time, the control unit 530 may be disposed between the upper surface 521 of the head unit 520 and the short side plate 320 of the mold 300. On the other hand, the upper surface 521 of the head portion 520 may be formed with a groove 524 for connecting the cast piece. The groove for connecting the slab may be connected to the protrusion 11d of the slab 11.

The control unit 530 expands the area of the bottom surface of the mold 300 including the top surface of the head part 520 in the width direction, and the edge areas on both sides of the bottom surface of the mold 300 in the width direction. It serves to raise the slant in the width direction.

The control unit 530 may include a plurality of pads 531 detachably mounted on both side surfaces 522 of the head unit 520 . In this case, the plurality of pads 531 may be mounted on the head part 520 in various ways. For example, the plurality of pads 531 may be mounted on the head part 520 in a bolting manner.

In this case, the adjusting unit 530 may further include a plurality of bolts 532 formed to pass through the plurality of pads 531 in the width direction. In addition, the head portion 520 may have installation grooves 523 into which bolts 532 may be coupled to both side surfaces 522 . In addition, each of the plurality of pads 531 may include an insertion hole 533 into which a bolt 532 may be inserted and an installation hole 534 into which the bolt 532 may be coupled. The insertion hole 533 and the installation hole 534 may be vertically spaced apart from the pad 531 on which each is formed. At this time, the insertion hole 533 is located at a relatively lower side and the installation hole 534 is located at a relatively upper side. can be located in

The plurality of pads 531 may each have a rectangular plate shape, and each widthwise length is between both side surfaces 522 of the head portion 520 and the short side plates 320 of the mold 300 facing each other. It may be smaller than the separation distance. Also, each of the plurality of pads 531 may have a length equal to or smaller than the length of the head portion 520 in the thickness direction.

The top surface 521 of the head part 520 and the top surface of the plurality of pads 531 may form a bottom surface capable of temporarily accommodating the molten material inside the mold 300 .

6 is a schematic view showing a state in which a dummy bar is inserted into a mold according to an embodiment of the present invention.

Referring to FIG. 6 , the plurality of pads 531 may have a structure symmetrical in the width direction around the head part 520 . Therefore, hereinafter, an embodiment will be described based on one side, for example, the right side of both sides in the width direction. Of course, the contents of the embodiment described below may be equally applied to the pad located on the other side in the width direction, for example, the left side.

Each of the plurality of pads 531 may protrude from the top surface 521 of the head part 520 in stages as the distance from the side surface of the head part 520 is mounted thereon. Thus, the upper end of the plurality of pads 531 may form a stepped step that increases in height as the distance from the side surface of the head part 520 increases.

Among the plurality of pads 531, the height of the upper end of the inner pad contacting the side surface of the head part 520 may be the same as the height of the top surface 521 of the head part 520, and the upper end of the pad goes outward from the inner pad 531. The height of may gradually increase with respect to the upper surface 521 of the head portion 520. The height difference between the upper end of the outer pad in contact with the short side plate of the mold 300 and the upper end of the inner pad described above is such that the inclined surface 11c-2 of the initial cast part 11 of the cast steel 10 extends in the longitudinal direction. It may be the same as the length H (see FIGS. 1 and 6).

Meanwhile, the plurality of pads 531 may have the same length in the width direction within an error range. Here, the error range may be an error range due to tolerance and measurement error. In addition, the length of the plurality of pads 531 in the width direction may decrease as the distance from the side surface 522 of the head part 520 increases. In addition, the length of the plurality of pads 531 in the width direction may increase as the distance from the side surface 522 of the head part 520 increases. As such, the length of the plurality of pads 531 in the width direction can be variously deformed, and from this, the inclined shape of the inclined surface of the cast piece 10 can be variously deformed. Meanwhile, the length of the above-described pad 531 in the width direction may be formed in a range of 20 mm to 80 mm.

If the length of the pad 531 in the width direction is less than 20 mm, the strength of the pad 531 is reduced, and it may be difficult for the pad 531 to smoothly support the initial cast piece within the mold 300. For example, when the length of the pad 531 in the width direction is greater than 80 mm, the length of the upper surface 521 of the head portion 520 in the width direction becomes small, so that the head portion 520 has an initial circumference in the mold 300. It may be difficult to smoothly support the piece 11 .

On the other hand, in the embodiment of the present invention, four pads 531 are provided between one side surface 522 of the head part 520 and one side short side plate 320 of the mold 300, but the number thereof varies. Corresponding to the change in number, the length of the pad 531 in the width direction may also be variously changed.

7 is a schematic view showing a state in which a dummy bar is inserted into a mold according to a modified example of an embodiment of the present invention.

Referring to FIG. 7 , according to a modified example of the present invention, the plurality of pads 531 may continuously protrude from the top surface of the head part 520 as they are farther from the side surface of the head part 520 to which each is mounted. there is. That is, each of the plurality of pads 531 may be formed with an inclined upper end, and the inclined upper ends may be connected to form an inclined surface.

1 to 7, the casting method according to an embodiment of the present invention is a casting method for casting a cast steel having a length in the width direction greater than a length in the thickness direction, a mold with upper and lower parts open in the casting direction ( 300) process of forming a bottom surface, a process of injecting a molten material such as molten steel into the mold 300 and solidifying it into a slab 10, moving the bottom surface in a casting direction such as a longitudinal direction and forming a slab 10 Including the extraction process.

At this time, the process of solidifying into the cast steel 10 is such that the width of the initial cast steel portion 11 of the cast steel 10 narrows in the casting direction, that is, from the upper part of the mold 300 to the lower part of the mold 300, the cast steel ( 10) includes a process of forming an inclined surface in a partial region of the lower surface of the cast steel 10 so that the width of the initial cast steel portion 11 is narrowed.

First, a bottom surface is formed on the lower part of the mold 300, the upper and lower portions of which are open in the casting direction. That is, the dummy bar 500 is passed from the top to the bottom of the mold 300 in the order of the body part 510 to the head part 520, and the head part of the dummy bar 500 ( 520) is placed. At this time, the control unit 530 may be mounted on both sides of the head unit 520 in the width direction, and the control unit 530 moves away from the head unit 520 to the upper surface 521 of the head unit 520. It may protrude from the surface to form a stepped or inclined surface. Accordingly, the lower part of the mold 300 may be covered by forming a bottom surface with the top surface of the head part 520 and the top of the adjusting part 530 . At this time, it is possible to seal the gap by inserting a sealing member such as wire, chip, or coil into the gap between the bottom surface and the inner surface of the mold 300 .

Thereafter, a molten material, such as molten steel, is injected into the mold and solidified into the cast steel. That is, in a state where the bottom surface is formed at the bottom of the mold 300, molten steel, for example, initial molten steel is injected into the mold 300. The initial cast steel portion 11 may be formed by the initial molten steel injected into the mold 300 (see FIG. 3).

At this time, in the process of solidifying into a cast steel, an inclined surface is formed in some area of the lower surface of the cast steel 10 using the shape of the bottom surface so that the width of the initial cast steel portion 11 of the cast steel 10 narrows toward the bottom surface. can Specifically, it is possible to form inclined surfaces on the edge regions of both sides of the lower surface of the cast steel 10 in the width direction by using the adjusting unit 530 (see FIG. 1).

Thereafter, the cast steel 10 is drawn by moving the bottom surface disposed in the mold 300 formed by the dummy bar 500 in the casting direction. At this time, molten steel, for example, subsequent molten steel may be continuously injected into the mold 300, and the normal cast piece portion 12 may be continuously solidified inside the mold 300 with the subsequent molten steel. The normal slab portion 12 may be drawn along the initial cast slab portion 11 (see FIG. 3).

In this process, the initial cast steel portion 11 and the normal cast steel portion 12 pass in the order of the vertical section (R1), inflection section (R2) and curved section (R3) of the drawing path (R) of the cast steel (10). and can be bent and deformed in the thickness direction by contacting with a plurality of rollers.

At this time, the length H of the inclined surface 1c of the initial cast piece 11 extending in the casting direction may be greater than the distance at which the plurality of rollers disposed in the inflection section are spaced apart from each other in the casting direction. Therefore, when the initial cast piece 11 is bent and deformed in the thickness direction by contacting the initial cast piece 11 with a plurality of rollers in the inflection section, the front end of the initial cast piece 11 on the front surface 1c side and the rear end Each roller can be brought into contact with, and the pressing force provided to the roller in contact with the initial cast piece portion 11 is concentrated on the narrow width of the end of the front surface 1c side of the front end of the initial cast piece portion 11 to provide pressure. can increase At this time, by contacting and supporting the rear end of the front end of the initial cast steel portion 11 with a roller in a wide width, the initial cast steel portion 11 can be smoothly bent and deformed. Subsequently, the normal cast piece portion 12 can be smoothly bent and deformed.

Thereafter, the initial cast steel portion 11 and the normal cast steel portion 12 passing through the curved section R3 are passed through the straightening section to straighten the cast steel in the horizontal direction, and the straightened cast steel is discharged from the casting device by passing through the horizontal section. can make it

The above embodiments of the present invention are for explanation of the present invention and are not intended to limit the present invention. It should be noted that the configurations and methods disclosed in the above embodiments of the present invention may be combined and modified in various forms by combining or crossing each other, and variations thereof may also be considered within the scope of the present invention. That is, the present invention will be implemented in a variety of different forms within the scope of the claims and equivalent technical ideas, and various embodiments are possible within the scope of the technical idea of the present invention by those skilled in the art to which the present invention pertains. will be able to understand

10: cast piece 11: initial cast piece
11c: slope 12: normal slab portion
100: Ladle 200: Tundish
300: mold 400: cooling table
500: dummy bar 510: body part
520: head unit 530: control unit

Claims (16)

A cast steel cast by drawing the melt injected into the mold into a dummy bar,
a normal slab portion extending in the longitudinal direction so that the width and thickness are constant within an error range, and the length in the width direction is greater than the length in the thickness direction;
Including; an initial cast member extending in the longitudinal direction from the normal cast member;
The initial cast steel portion includes at least one inclined surface so that the width becomes narrower toward the end portion. The method of claim 1,
The initial cast piece portion includes both sides in the width direction, both sides in the thickness direction, and a front surface connecting both sides in the width direction and both sides in the thickness direction,
The front surface is a cast steel comprising the inclined surface. The method of claim 2,
The front surface is divided into a central region in the width direction and an edge region on both sides of the central region,
The inclined surface is formed in each of the edge regions of the cast steel. As a dummy bar for drawing a cast steel from a mold,
a body portion extending in the longitudinal direction and being bendable in the thickness direction;
a head portion having an upper surface having a length in the width direction greater than a length in the thickness direction and connected to the body portion;
and adjusting units disposed on both sides of the head unit and protruding upward from the upper surface of the head unit so as to form an inclination or a plurality of steps on both sides of the upper surface of the head unit in a width direction. The method of claim 4,
The control unit includes a plurality of pads detachably mounted on both side surfaces of the head unit. The method of claim 5,
The plurality of pads protrude in stages from the upper surface of the head unit as the distance from the side surface of the head unit to which each pad is mounted increases. The method of claim 5,
The plurality of pads continuously protrude from the upper surface of the head unit as they are further away from the side surface of the head unit on which each pad is mounted. The method of claim 5,
The plurality of pads have the same length in the width direction within an error range. The method of claim 5,
The plurality of pads have a smaller length in the width direction as they are farther away from the side surface of the head part on which each is mounted. The method of claim 5,
A dummy bar in which the plurality of pads have a length in the width direction as they are farther away from the side surface of the head part on which each pad is mounted. The method of any one of claims 8 to 10,
The pad is a dummy bar formed in a range of 20 mm to 80 mm in length in the width direction. The method of claim 5,
The control unit further includes a plurality of bolts formed to penetrate the plurality of pads in the width direction,
The head portion has installation grooves on both side surfaces into which the bolts can be coupled,
Each of the plurality of pads has an insertion hole into which the bolt can be inserted and an installation hole into which the bolt can be coupled. A casting method for casting a cast steel having a length in the width direction greater than a length in the thickness direction,
Forming a bottom surface in the lower part of the mold, the upper and lower parts of which are open in the casting direction;
Step of injecting the molten material into the mold and solidifying it into the slab;
Including; moving the bottom surface in the casting direction and drawing the cast steel;
The process of solidifying into the cast,
Forming an inclined surface in a partial region of the lower surface of the cast steel so that the width of the initial cast steel portion of the cast steel is narrowed in the casting direction; Casting method comprising a. The method of claim 13,
The process of forming an inclined surface on a part of the lower surface of the cast steel,
Using the shape of the bottom surface, forming an inclined surface in the edge region on both sides of the lower surface of the cast steel in the width direction, respectively; Casting method comprising a. The method of claim 13,
The process of drawing the cast piece,
A process of bending and deforming in the thickness direction by contacting with a plurality of rollers while passing the initial cast steel portion and the normal cast steel portion except for the initial cast steel portion in the order of the vertical section, the inflection section and the curved section of the drawing path of the cast steel; ,
The length of the inclined surface extending in the casting direction is greater than the distance at which the plurality of rollers disposed in the inflection section are spaced apart from each other in the casting direction. The method of claim 15
The process of bending and deforming in the thickness direction by contacting the plurality of rollers,
Casting method comprising a; step of increasing the pressure by concentrating the pressing force provided to the roller in contact with the initial slab portion to the end of the initial slab portion.

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