Mold, mold manufacturing method, and slab

Abstract

An embodiment of the present invention is a mold provided with an internal space into which molten steel can be injected, the mold including a body having the internal space, and a convex member protruding from the body toward the internal space and formed to extend in a width direction of the body. The convex member includes a pair of side regions respectively located on one side and the other side of the center in the width direction, and each of the pair of side regions has a shape in which the protruding length thereof decreases as the distance from the center increases. In addition, the inner surface of each of the pair of side regions has a curved surface having a shape of 1 / 2 of a cosine curve having a cycle of 360 DEG. Therefore, according to an embodiment of the present invention, when manufacturing a slab rolled to form a steel plate, it is possible to manufacture a slab in which edge defects of the steel plate caused by an extended width of the slab can be suppressed.

Description

Technical Field

[0001] The present invention relates to a mold and a method for manufacturing the mold, and more particularly to a mold capable of effectively controlling the shape of a slab and preventing leakage of molten steel, and a method for manufacturing the mold.

[0002] The present invention relates to a slab, and more particularly to a slab capable of suppressing the occurrence of edge defects in a steel plate manufactured by rolling the slab due to an expanded width of the slab during rolling. Background Art

[0003] The slab manufactured by cooling the molten steel in the mold is pulled out to the lower side of the mold. The pulled slab moves along the cooling zone and undergoes secondary solidification by the cooling water injected at this time. The solidified slab is cut into a specified length and then rolled in a rolling device, and the rolled slab is called a steel plate.

[0004] In the rolling device, the slab is disposed between the upper rolling roller and the lower rolling roller, and the slab is rolled by the downward pressing force of the upper rolling roller and the upward pressing force of the lower rolling roller. Here, each of the upper rolling roller and the lower rolling roller extends in the width direction of the slab. In addition, a plurality of upper rolling rollers are arranged in the longitudinal direction on the upper side of the slab, and a plurality of lower rolling rollers are arranged in the longitudinal direction on the lower side of the slab.

[0005] When the upper rolling roll and the lower rolling roll press the slab, a phenomenon of expanding width occurs in which both edges of the slab in the width direction are twisted and expanded outward. This expansion of the slab causes wrinkle-shaped edge defects at both edges of the steel plate in the width direction. Therefore, the steel plate with edge defects is delivered to the customer after cutting both edges in the width direction. However, when both edges of the steel plate in the width direction are cut in this way, there is a problem of reduced actual yield.

[0006] In order to solve the problem of edge defects occurring due to the expansion width of the slab during rolling, a convex member has been provided on the inner surface of the mold. That is, among the long side members and the short side members forming the mold, a convex member protruding toward the inner space of the mold is provided on the inner surface of each of the short side members. Here, the longer the length of the convex member protruding toward the inner space, the more the expansion width of the slab during rolling is suppressed to reduce the occurrence of edge defects in the steel plate.

[0007] As the protruding length of the convex member increases, the angle between the edge of the inner surface of the convex member facing the inner space and the inner surface of each of the long side members decreases. Therefore, as the protruding length of the convex member increases, the size of the gap between the inner edge of the convex member and the inner surface of the long side member, that is, the size of the space between the inner edge of the convex member and the inner surface of the long side member becomes narrower, and a shape roughly similar to a triangle can be formed. In addition, the smaller the space between the inner edge of the convex member and the inner surface of the long side member, the easier it is for molten steel or a solidified shell to become stuck in the space between the inner edge of the convex member and the inner surface of the long side member. In addition, an operating accident in which the slab is torn in the mold due to the jamming of the molten steel or the solidified shell causes the molten steel to flow out of the mold.

[0008] (Prior Art Document) (Patent Document 1) Japanese Patent Registration No. 2586769 Summary of the invention

[0009] Technical issues

[0010] The present invention provides a mold capable of effectively controlling the shape of a slab and preventing leakage of molten steel, and a method for manufacturing the mold.

[0011] The present invention provides a slab capable of suppressing the occurrence of edge defects in a steel plate in the slab that becomes a steel plate through a rolling process.

[0012] Technical Solution

[0013] An embodiment of the present invention provides a mold having an internal space, into which molten steel is injected, the mold comprising: a body having an internal space; and a convex member protruding from the body toward the internal space and extending along the width direction of the body, wherein the convex member comprises a pair of side regions arranged on one side and the other side of the convex member in the width direction, each of the pair of side regions has a shape in which the protruding length decreases as it moves away from the center, and the inner surface of each of the pair of side regions has a surface in the shape of half a cosine curve whose cycle is 360°.

[0014] The male member may include a central region disposed between the pair of side regions, wherein a protruding length of the central region may be the same in a width direction, and

[0015] The inner surface, which is a surface of the central area facing the inner space, may have a flat surface.

[0016] The pair of side regions may be symmetrical in shape with respect to the central region.

[0017] One of the pair of side regions may have an inner surface shaped as a segment of 0° to 180° of one period of a cosine curve, and the other side region may have an inner surface shaped as a segment of 180° to 360° of one period of a cosine curve.

[0018] The body may include: a pair of long side members, each of which is formed to extend in one direction, and the pair of long side members are installed to face each other in a direction intersecting the extending direction; and a pair of short side members, each of which is formed to extend to intersect with the long side members, and the pair of short side members are installed to face each other to seal between the pair of long side members, wherein the convex member can be formed to protrude from the short side member toward the internal space.

[0019] The angle between the inner surface of the long side member and the edge of the inner surface of the side region may be 90°.

[0020] The protruding length of the central region of the male member may exceed 5 mm.

[0021] The width of the male member may be the same as the width of the short side members, and the width of the central region of the male member may be 10% to 15% of the width of the short side members.

[0022] The width of each of the short side members and the male member may decrease as it goes downward, and the width of the central area of ​​the male member may be the same in the vertical direction.

[0023] The width of each of the short side members and the male member may decrease as it goes downward, and the width of the central area of ​​the male member may decrease as it goes downward.

[0024] The length of the male member in the vertical direction may be the same as the length of the short side member in the vertical direction.

[0025] An embodiment of the present invention provides a method for manufacturing a mold, which includes a body having an internal space and a convex member protruding from the body toward the internal space, the method including: formulating a design scheme so that the convex member includes a first side area and a second side area, on which the protrusion length decreases toward two end portions in the center in the width direction, and the inner surface of each of the first side area and the second side area has a surface in the shape of half a cosine curve with a period of 360°; and processing a base material into a shape having the convex member included in the design scheme.

[0026] Formulating a design plan may include: determining the width (W m) and vertical length (H m ); and developing a design for an inner surface of the male member having a shape of an inner surface of each of the first side region and the second side region.

[0027] Formulating a design for the inner surface of the male member may include determining a protruding length (T c ) and width (W c ); and by using the determined width (W m ), the determined protrusion length (T c ) and width (W c ) is used to formulate a design for the first side region so that the shape of the inner surface of the first side region becomes the shape of half a periodic cosine curve.

[0028] Formulating a design for the first side region may include using the determined width (W m ) and the determined width of the central region (W c ) to determine the width (W) of the first side region to be manufactured s ); providing a cosine curve equation including the determined width (W of the first side region s ), the determined protrusion length of the central area (T c ), the width direction position (X) of the convex member and the thickness direction position (Y) of the convex member; and calculating the thickness direction position (Y) according to the width direction position (X) using a cosine curve equation, wherein the value of the width direction position (X) applied to the cosine curve equation can be the determined width (W) of the body. m ) to the determined width (W s ) is a value for a segment of points spaced apart, where multiple values ​​can be applied in a segment.

[0029] Formulating a design for the first side region may include connecting the plurality of thickness-direction locations (Y) calculated for each width-direction location (X) to create a design line for the first side region in the shape of half a periodic cosine curve.

[0030] Formulating a design for the inner surface of the male member may include formulating a design for a central region, which is a design for the inner surface of the central region disposed between the first side region and the second side region, and formulating the design for the central region may include extending a line from an end of the design line for the first side region to the determined width (W) of the central region. c ) to create the design line for the central area.

[0031] The method may further include formulating a design for the second side region such that the shape of an inner surface of the second side region is in the shape of half a periodic cosine curve, wherein formulating the design for the second side region may include forming a design line for the second side region symmetrically relative to a design line for the first side region using the central region as a center.

[0032] The method may further include preparing a base material having a widthwise length that is the determined width (W) of the body. m ) and the length in the thickness direction intersecting the width direction exceeds the protruding length (T c ), wherein the processing of the base material may include processing one of the two surfaces of the base material in the thickness direction so that from each of the two end portions in the width direction to the determined width (W of the side region) of the base material s ) is a design line for each of the first side region and the second side region.

[0033] An embodiment of the present invention provides a slab manufactured by solidifying molten steel, wherein each of two surfaces of the slab has a convex shape concave inward, and a portion of each of the two surfaces has a curved surface in the shape of half a cosine curve with 360° as one cycle.

[0034] Each of the two surfaces may include a central surface and a pair of side surfaces respectively arranged on one side and the other side of the central surface, and each of the pair of side surfaces may have a curved surface in the shape of half a cosine curve with a period of 360°, wherein the central surface has a plane.

[0035] A pair of side surfaces may have a symmetrical shape relative to the central surface, and one of the pair of side surfaces may have a shape within the range of 0° to 180° in a periodic cosine curve, and the other side surface may have a shape that is a segment of 180° to 360° as one periodic cosine curve.

[0036] Beneficial Effects

[0037] The mold according to an embodiment of the present invention can manufacture a slab that can suppress edge defects of a steel plate due to the expanded width of the slab in the manufacture of a slab that is rolled into a steel plate. In addition, when a slab is manufactured by solidifying molten steel inside a mold or when the width of the mold varies, it is possible to suppress or prevent steel or a solidified shell from getting stuck in the space between the inner surface of the edge of the convex member and the inner surface of the long side member. Therefore, it is possible to prevent the occurrence of an operational accident in which molten steel flows out of the mold due to tearing of the mold. That is, the mold according to an embodiment of the present invention can manufacture a slab that can suppress edge defects in a steel plate while preventing operational accidents due to leakage of molten steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a view of a casting apparatus including a mold according to an embodiment of the present invention.

[0039] Figure 2 is a three-dimensional view of a mold according to an embodiment of the present invention.

[0040] Figure 3 When from Figure 2 A front view when viewed from the "A" side in FIG. 1 is used to illustrate the installation state of the first short side member and the second short side member.

[0041] Figure 4 When from Figure 2 The "B" side view is a front view for explaining the shape of the short side member.

[0042] Figure 5 : is a conceptual diagram illustrating a state in which a defect occurs in an edge in the width direction of a steel plate manufactured by rolling a slab.

[0043] Figure 6 (a) is a three-dimensional view of a short side portion according to an embodiment of the present invention.

[0044] Figure 6 (b) is when at different heights and When observing Figure 6 A plan view of the short side portion illustrated in (a).

[0045] Figure 6 (c) is when viewed from the "C" side Figure 6 (a) is a front view of the convex component.

[0046] Figure 7 is a plan view of a short side portion according to an embodiment of the present invention when viewed from an upper side.

[0047] Figure 8(a) is a three-dimensional view of a short side portion according to a modified example of the embodiment.

[0048] Figure 8 (b) is when at different heights and When observing Figure 8 A plan view of the short side portion illustrated in (a).

[0049] Figure 8 (c) is when viewed from the "C" side Figure 8 (a) is a front view of the convex component.

[0050] Fig. 9 (a) to (c) are flow charts illustrating a method for preparing a design for an inner surface of a male member to manufacture a short side portion provided with the male member according to an embodiment of the present invention.

[0051] Fig.10 is a view illustrating a slab manufactured using a mold according to an embodiment of the present invention. DETAILED DESCRIPTION

[0052] Hereinafter, specific embodiments will be described in more detail with reference to the accompanying drawings. However, the present invention can be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. In the drawings, for clarity of illustration, the sizes of layers and regions are enlarged. The same reference numerals always refer to the same elements.

[0053] Figure 1 is a view of a casting apparatus including a mold according to an embodiment of the present invention.

[0054] Reference Figure 1 The casting device includes: a tundish 20, which supplies molten steel from a ladle 10 for storing molten steel; a mold 3000, which receives the molten steel from the tundish 20 to allow the molten steel to initially solidify into a specific shape; and a nozzle 22, which supplies the molten steel from the tundish 20 to the mold 3000.

[0055] In addition, the casting device is installed at the lower side of the mold 3000, and includes a cooling part 40 that injects cooling water onto the slab 1 pulled out of the mold 3000 to completely solidify the slab 1. Here, the cooling part 40 may be a device including a plurality of sections 41. In addition, each of the plurality of sections 41 may be a device having a plurality of rollers that can be rotated by a force by which the slab 1 moves, and a nozzle disposed between the plurality of rollers to inject cooling water onto the slab 1.

[0056] The slab 1 manufactured in the casting device is transferred to a rolling device to be rolled, thereby manufacturing a steel plate.

[0057] In the following, reference will be made to Figures 2 to 4 Another mold according to an embodiment of the present invention is described.

[0058] Figure 2 is a three-dimensional view of a mold according to an embodiment of the present invention. Figure 3 When from Figure 2 ”A” is a front view when viewed from the side, which is used to illustrate the installation state of the first short side member and the second short side member. Figure 4 When from Figure 2 The "B" side view is a front view for explaining the shape of the short side member.

[0059] Reference Figure 2 , the mold 3000 may include a body 3100 and a convex member CV protruding from an inner surface of the body 3100 toward the inner space. In addition, the mold 3000 may include a cooling water passage (not shown) installed to be embedded in the body 3100 to circulate cooling water.

[0060] Reference Figure 2 The body 3100 includes: a first short side member 3121 and a second short side member 3121, each of which extends in one direction (X-axis direction), and the first short side member 3121 and the second short side member 3121 are arranged to be spaced apart from each other in a direction (Y-axis direction) intersecting the extending direction; and a first long side member 3111 and a second long side member 3111, each of which extends in a direction intersecting or orthogonal to the extending direction (X-axis direction) of the first short side member 3121 and the second short side member 3121, and the first long side member 3111 and the second long side member 3111 are arranged to be spaced apart from each other in the extending direction of the first short side member 3121 and the second short side member 3121.

[0061] Each of the first short side member 3121 and the second short side member 3121 may have a shorter extension length than each of the first long side member 3111 and the second long side member 3111. That is, the length of each of the first long side member 3111 and the second long side member 3111 extending in the Y-axis direction may be shorter than the length of each of the first short side member 3121 and the second short side member 3121 extending in the X-axis direction.

[0062] The body 3100 is provided in the form of a tube having an internal space IS, wherein the first long side member 3111 and the second long side member 3111 and the first short side member 3121 and the second short side member 3121 are interconnected or coupled to each other. For example, one end of each of the first short side member 3121 and the second short side member 3121 is connected to the inner surface of the first long side member 3111 in the X-axis direction, and the other end is connected to the inner surface of the second long side member 3111. In addition, the first short side member 3121 and the second short side member 3121 are provided to be spaced apart from each other in the Y-axis direction. Here, the distance between the first short side member 3121 and the second short side member 3121 is provided to be greater than the distance between the first long side member 3111 and the second long side member 3111. Therefore, the body 3100 having the internal space IS with a rectangular shape is provided. More specifically, a body 3100 having a rectangular internal space IS is provided, the body 3100 having a length in the Y-axis direction longer than a length in the X-axis direction.

[0063] Hereinafter, the extension direction of each of the long side member 3111 and the short side member 3121 is defined as the width direction. Therefore, the length of each of the long side member 3111 and the short side member 3121 in the extension direction can be defined as "width". Therefore, the width of the long side member 3111 is the length in the Y-axis direction, and the width of the short side member 3121 is the length in the X-axis direction. In addition, in each of the long side member 3111 and the short side member 3121, the direction intersecting with the extension direction is defined as the thickness direction. Therefore, the length of each of the long side member 3111 and the short side member 3121 in the direction intersecting with the extension direction can be defined as "thickness". Therefore, the thickness of the long side member 3111 is the length in the X-axis direction, and the thickness of the short side member 3121 is the length in the Y-axis direction.

[0064] The first short side member 3121 and the second short side member 3121 are installed to face each other, and as Figure 3 As shown in FIG. 1 , the spacing distance G between the first short side member 3121 and the second short side member 3121 decreases as it goes downward. Therefore, the first short side member 3121 and the second short side member 3121 may be installed to be skewed or inclined.

[0065] Therefore, the length of the internal space IS of the mold 3000 in the longitudinal direction (the length in the Y-axis direction) decreases as it goes downward. As described above, the spacing distance G between the first short side member 3121 and the second short side member 3121 decreases as it goes downward, and therefore, the contraction of the solidified shell in the long side direction can be compensated. To explain more specifically, the solidified shell (long side solidified shell) formed by solidifying the molten steel along the first long side member 3111 and the second long side member 3111 can compensate for the contraction in the extension direction of the first long side member 3111 and the second long side member 3111. This can suppress the occurrence of a gap between the inner surface of the body 3100 and the solidified shell due to the contraction of the solidified shell in the long side direction, thereby suppressing the occurrence of solidification delay and defects caused thereby.

[0066] In addition, each of the first short side member 3121 and the second short side member 3121 is configured such that its extended length, that is, width W m As it decreases downward, Figure 4 In other words, each of the first short side member 3121 and the second short side member 3121 is arranged so that the extension length W in the X-axis direction which is the short side direction of the mold 3000 is m As it goes downward, it decreases. Therefore, one surface and the other surface of each of the first short side member 3121 and the second short side member 3121 are inclined relative to the X-axis direction. That is, the side surface of each of the first short side member 3121 and the second short side member 3121 is inclined to be closer to the center in the width direction as it goes downward. In addition, the first long side member 3111 and the second long side member 3111 are respectively connected to the side surface of the first short side member 3121 and the side surface of the second short side member 3121. Therefore, the first side member 3111 and the second side member 3111 are installed so that the spacing distance between the first side member 3111 and the second side member 3111 decreases as it goes downward.

[0067] As described above, the side surface of the short side member 3121 is formed to be inclined, and the first long side member 3111 and the second long side member 3111 installed to contact the short side member 3121 are installed to become closer to each other as they go downward, so as to compensate for the contraction of the solidified shell in the short side direction. That is, this is to compensate for the contraction of the solidified shell (short side solidified shell) formed by solidifying the molten steel formed along the first short side member 3121 and the second short side member 3121 in the extension direction of the first short side member 3121 and the second short side member 3121. This can suppress the occurrence of a gap between the inner surface of the body 3100 and the solidified shell due to the contraction of the solidified shell in the short side direction, thereby suppressing the occurrence of solidification delay and defects caused thereby.

[0068] The convex member CV may be provided on the inner surface of each of the first short side member 3121 and the second short side member 3121 of the body 3100. Hereinafter, a configuration including the short side member 3121 and the convex member CV mounted on the short side member 3121 is defined as the short side member 3120. Therefore, the mold 3000 may be described as including the first short side portion 3120 and the second short side portion 3120 and the first long side portion 3111 and the second long side portion 3111 each having the convex member CV.

[0069] The body 3100 includes an inner surface IF and an outer surface OF, the inner surface IF being a surface facing the internal space IS and in direct contact with the molten steel or the solidified shell, and the outer surface OF being the opposite surface of the inner surface IF and exposed to the outside. Here, the outer surface OF of the body 3100 may refer to the outer surface OF of each of the first long side member 3111 and the second long side member 3111 and the outer surface OF of each of the first short side member 3120 and the second short side member 3120. In addition, the outer surface OF of each of the first short side member 3120 and the second short side member 3120 refers to the surface of the two surfaces of the first short side member 3121 and the second short side member 3121 that is arranged on the side opposite to the convex member CV in the Y-axis direction. Therefore, the outer surface OF of the short side portion 3120 may refer to the surface of each of the first short side member 3121 and the second short side member 3121 that is opposite to the convex member CV.

[0070] In addition, the inner surface IF of the body 3100 may refer to the inner surface IF of each of the first long side member 3111 and the second long side member 3111 and the inner surface IF of each of the first short side member 3120 and the second short side member 3120. Here, the inner surface IF of each of the first short side 3120 and the second short side 3120 refers to the surface of the convex member CV facing the internal space IS. To explain more specifically, the convex member CV protrudes from the inner surface of the short side member 3121 toward the internal space IS. Therefore, it can be defined that the surface of the two surfaces of the convex member CV facing the short side member 3121 in the Y-axis direction is the outer surface and the surface opposite to the short side member 3121 is the inner surface IF. Therefore, the inner surface IF of the short side portion 3120 may refer to the surface of the convex member CV opposite to the short side portion 3121 or the surface facing the internal space IS.

[0071] Figure 5 : is a conceptual diagram illustrating a state in which edge defects occur in edges in the width direction of a steel plate manufactured by rolling a slab.

[0072] The manufactured slab 1 is cut into a predetermined length and then loaded into a rolling device for rolling. The slab 1 loaded into the rolling device is pressed and rolled in the thickness direction by the upper rolling roll and the lower rolling roll. Thus, a steel plate 2 is prepared by rolling the slab 1. However, when the slab 1 is rolled, the edge of the slab 1 in the width direction is twisted to cause an expanded width. The expanded width causes defects such as wrinkles on the edge of the steel plate 2 in the width direction, such as Figure 5 As shown in the figure.

[0073] In order to suppress or prevent the occurrence of wrinkle defects, a convex member is usually provided on the inner surface of the short side member. The convex member protrudes from the inner surface of the short side member toward the internal space, and is provided in a shape in which the protruding length decreases as it moves toward the edge in the width direction. The shape of the convex member is a roughly fan-shaped arc (circular arc shape). When molten steel solidifies using a mold in which the convex member is formed on the short side member, the short side of the slab becomes a concave shape.

[0074] In addition, when rolling a slab having a short side with a concave shape, the amount of expansion width can be reduced compared to when rolling a slab having a short side with a non-concave shape. Therefore, the occurrence of edge defects of the steel plate in the width direction can be suppressed.

[0075] As the protruding length of the convex member increases, the expansion width during rolling can be suppressed, and therefore, the edge defects such as wrinkles on the edge of the steel plate in the width direction can be suppressed. However, as the protruding length of the convex member increases, the angle between the edge of the inner surface of the convex member facing the inner space and the inner surface of the long side member decreases, and the angle can be an acute angle. Therefore, as the protruding length of the convex member increases, the size of the gap between the inner edge of the convex member and the inner surface of the long side member, that is, the size of the interval, narrows. In addition, the shape of the interval can be sharpened into a roughly triangular shape. In addition, the smaller the space between the inner edge of the convex member and the inner surface of the long side member, the easier it is for the molten steel or solidified shell to be stuck in the space between the inner edge of the convex member and the inner surface of the long side member. In addition, the slab may be torn inside the mold due to the stuckness of the molten steel or solidified shell, thereby causing an operational accident in which the molten steel flows out of the mold.

[0076] Therefore, it is necessary to manufacture a slab 1 that can suppress the occurrence of defects in the steel plate 2, and at the same time provide a mold that can prevent the occurrence of operational accidents in which molten steel flows out. To this end, in an embodiment of the present invention, a convex member CV is arranged on the inner surface of the short side member 3121, and when manufacturing a slab 1 that can suppress the occurrence of defects, the convex member CV is arranged to prevent the occurrence of operational accidents in which molten steel flows out. To this end, the convex member CV is arranged so that the angle between the inner surface IF of the edge of the convex member CV in the width direction (X-axis direction) and the inner surface IF of the edge of the long side member 3111 in the width direction (Y-axis direction) is 90° or a right angle. In addition, in order to make the angle between the inner surface IF of the long side member 3111 and the inner surface IF of the long side member 3112 be 90° or a right angle, the shape of the inner surface IF of the convex member CV is arranged in the form of a cosine curve in the width direction.

[0077] In the following, reference will be made to Figure 6 (a) to (c) and Figure 7 A short side portion according to an embodiment of the present invention is described. Here, the first short side portion and the second short side portion that are arranged to face each other have the same configuration, shape and size, and therefore, one short side portion will be described as an example. In addition, for ease of explanation, the first short side portion and the second short side portion are not simply referred to as the first short side portion and the second short side portion and the first short side member and the second short side member, but are instead referred to as "short side portion" and "short side member".

[0078] Figure 6 (a) is a three-dimensional view of a short side portion according to an embodiment of the present invention. Figure 6 (b) is when at different heights and When observing Figure 6 A plan view of the short side portion illustrated in (a). Figure 6 (c) is when viewed from the "C" side Figure 6 (a) is a front view of the convex component. Figure 7 is a plan view of a short side portion according to an embodiment of the present invention when viewed from an upper side.

[0079] The convex member CV protrudes from the inner surface of the short side member 3121 toward the internal space IS, as shown in FIG. Figure 2 as well as Figure 6 In other words, the convex member CV is configured to protrude from the inner surface of the short side member 3121 in the Y-axis direction. In addition, the convex member CV extends in the width direction of the short side member 3121, that is, in the X-axis direction. Here, the convex member CV is formed so that the extension length in the X-axis direction, that is, the width W cvThe width W of the short side member 3121 m Same, such as Figure 6 As shown in (b) of FIG.

[0080] In addition, when the convex member CV is formed on the inner surface of the short side member 3121, it is formed to extend from the upper end portion to the lower end portion of the inner surface of the short side member 3121, as shown in FIG. Figure 6 That is, the convex member CV is arranged so that its height H cv Equal to the height H of the short side member 3121 m In other words, the convex member CV is provided with an extension length H in the vertical direction (Z-axis direction) which is the same as the extension length of the short side member 3121. cv Therefore, the height of the upper end of the convex member CV may be the same as the height of the upper end of the short side member 3121, and the height of the lower end of the convex member CV may be the same as the height of the lower end of the short side member 3121. In addition, the protruding lengths of the convex members CV may be the same in the vertical direction.

[0081] Reference Figure 6 (a) and (b), the convex member CV is arranged so that the protruding length is from the central area A in the width direction (X-axis direction) c The shape of the inner surface IF of the convex member CV that decreases toward the two edges. In addition, when the protruding length of the convex member CV decreases toward the two edges in the width direction, the rate of decrease is not constant and decreases unevenly. Therefore, the inner surface IF of the convex member CV facing the internal space IS is set to a shape including a curved surface. The shape of the inner surface IF of the convex member CV extending in the width direction may include a curve.

[0082] In the following, reference will be made to Figure 7 The male member CV is described in more detail.

[0083] In the width direction (X-axis direction), the convex member CV includes a central area A c , set in the central area A c The first side region A on one side s1 and set in the central area A c The second side region A on the other side s2 .

[0084] Central Area A c It may be an area including the center of the convex member CV in the width direction and a section from the center to a point spaced a predetermined distance in each of one direction and another direction. c The same protrusion length T is provided in the width direction. c Here, the central area Ac The protruding length T c In other words, the central area A of the convex member CV is set to be greater than 5 mm. c The spacing distance between the inner surface IF of the central region A and the inner surface of the short side member 3121 exceeds 5 mm. c The protruding length T c It is set to be larger than 5 mm and smaller than 20 mm.

[0085] As described above, the central area A of the male member CV c Has a constant protrusion length T in the width direction (X-axis direction) c Therefore, the central area A of the convex member CV c The inner surface IF of the convex member CV may have a shape with a plane. The central area A of the convex member CV c Set to have a predetermined width W c , the predetermined width W c The width W of the short side member 3121 is set m In other words, the central area A of the convex member CV c The length W in the Y direction c The length W of the short side member 3121 in the Y direction is set to m 10% to 15% (W c =0.1W to 0.15W).

[0086] Central Area A c Can be equally set to have the same protruding length T in the width direction c Here, the central area A c The inner surface IF is set as a plane for measuring the inclination of the short side portion 3120. To explain more specifically, the spacing distance between a pair of short side portions 3120 can be adjusted according to the steel type or size of the slab 1 to be manufactured before casting starts.

[0087] In addition, in order to adjust the inclination of each of the pair of short side portions 3120 so that the spacing distance between the pair of short side portions becomes smaller as they go downward, the installation inclination of the short side portions 3120 may be adjusted according to the steel type or size of the slab to be manufactured before the start of casting. Here, in order to install the short side portions 3120 to achieve the target inclination, the inclination of the short side portions 3120 needs to be measured.

[0088] To this end, the inclination measuring device is brought into contact with the inner surface of the short side portion 3120 to measure the inclination. c Prepared so that the protruding length T cThe same in the width direction, so that the central area A c The inner surface IF is made flat. In addition, the inclination measuring device is connected to the central area A having a flat shape. c The short side portion 3120 is contacted, thereby measuring the installation inclination of the short side portion 3120. In addition, the measured installation inclination is used to adjust the inclination of the short side portion 3120 to the target inclination.

[0089] In the central area A of the male member CV c Width W c Exceeds the width W of the short side member 3121 m In 15% of the cases, the angle θ between the edge of the inner surface IF of the convex member CV and the edge of the inner surface IF of the long side member 3111 may be reduced to an acute angle less than 90°. Therefore, molten steel or a solidified shell may be stuck in the space between the edge of the inner surface IF of the convex member CV and the edge of the inner surface IF of the long side member 3111, causing the slab 1 to burst, and this may cause an operation accident in which molten steel flows out of the mold 3000.

[0090] On the contrary, in the central area A of the male member CV c When the width is less than 10% of the width of the short side member, there is a problem that the area for measuring the installation angle of the short side member 3121, that is, the inclination is narrow, making measurement difficult. This may cause a measurement error of the inclination of the short side member 3121.

[0091] First side area A s1 One end of the convex member CV and the central area A c The area between one end and the second side area A s2 Central Area A c The area between the other end of the convex member CV and the other end of the convex member CV. s1 and the second side region A s2 Each side region is provided with a protruding length T s , the protruding length T s is not constant and is not uniform in the width direction. That is, the first side region A s1 and the second side region A s2 The protruding length T of each s As it moves away from the central area A c To explain more specifically, the first side region A s1 The protruding length T s From Central Area A c The second side region A decreases from one end of the convex member CV to one end of the convex member CV.s2 The protruding length T s From Central Area A c The other end of the convex member CV decreases to the other end of the convex member CV.

[0092] When the first side area A s1 and the second side region A s2 The protruding length T of each side area s When it decreases, the rate or amount of decrease is not constant and decreases unevenly. Therefore, in the convex member CV, the first side area A s1 and the second side region A s2 The inner surface of the first side region A is formed as a curved surface. s1 and the second side region A s2 The inner surface of each of the first side regions A is configured to have a surface in the shape of a cosine curve in the width direction. More specifically, the first side region A s1 and the second side region A s2 Each of the inner surfaces of the first side region A has a surface shaped like half of a cosine curve with a cycle of 360°. Here, “1 / 2 of a cosine curve” may mean “half a cycle of a cosine curve with a cycle of 360°”. Thus, the first side region A may be described as s1 and the second side region A s2 Each of the inner surfaces has a curved shape in the form of a half cycle of a cosine curve with 360° as one cycle. In addition, 1 / 2 of the cosine curve with 360° as one cycle (half cycle of the cosine curve) can represent a curve in a section from 0° to 180° and a curve in a section from 180° to 360° in the cosine curve.

[0093] As mentioned above, the first side region A s1 and the second side region A s2 Each of the inner surfaces of the first side region A is formed as a surface in the shape of half of a cosine curve, that is, a surface in the shape of a half period of a cosine curve. s1 The inner surface of the second side region A may be in the form of a 0° to 180° segment of a cosine curve as a cycle. s2 The inner surface may be in the shape of a segment of 180° to 360° as one period of a cosine curve.

[0094] In order to s1 and the second side region A s2 The inner surface IF of each side region is set to be in the shape of half of a cosine curve with 360° as one cycle, using the width W of the short side member 3121. m, the central area A of the convex component CV c Width W s and the central area A of the convex member CV c The protruding length T c This will be referenced later. Fig. 9 Describe again.

[0095] As described above, the central area A of the male member CV c The protruding length T c It is set to be more than 5 mm, and preferably more than 5 mm and not more than 20 mm. c The protruding length T c When it is 5 mm or less, the effect of suppressing the expanded width during the rolling of the slab 1 is minimal, and therefore, the effect of suppressing the occurrence of edge defects in the steel plate may be minimal.

[0096] Again, return to Figure 6 (a) to (c) of the present invention will now describe the convex member CV. As described above, the convex member CV is formed to have the same height as the short side member 3121. That is, the convex member CV is formed to extend from the upper end portion to the lower end portion of the short side member 3121. In addition, the width W of the short side member 3121 is m As it decreases downward, the width W of the convex member CV cv It is set to be the same as the width of the short side member 3121. Therefore, the width W of the male member CV is cv As it goes downward, it decreases. Here, the width W of the central area of ​​the convex member CV is c They can be arranged equally in the vertical direction, such as Figure 6 In addition, in the convex member CV, the side region A s Width W s It can be set to decrease as it goes downward. In addition, in the convex member CV, the central area A c The protruding length T c can be the same in the vertical direction, and the side area A s The protruding length T s Can be the same in the vertical direction.

[0097] Figure 8 (a) is a three-dimensional view of a short side portion according to a modified example of the embodiment. Figure 8 (b) is when from different heights and When observing, Figure 8 A plan view of the short side portion illustrated in (a). Figure 8 (c) is when viewed from the "C" side Figure 8(a) is a front view of the convex component.

[0098] In the above-mentioned embodiment, description has been made in which the central area A of the male member CV c Width W c The same situation in the vertical direction. However, not limited to this, the central area A of the convex member CV c Width W c It can be arranged to decrease toward the lower side, such as Figure 8 As shown in (a) to (c) of FIG. In addition, here, the side area A s Width W s It can be set to be the same in the vertical direction or to decrease as it goes down. c Width W c In the case where it is arranged to decrease toward the lower side as in the modified example, the solidification shrinkage of the solidified shell can be controlled more effectively than in the embodiment.

[0099] Fig. 9 (a) to (c) are flowcharts illustrating a method for developing a design plan according to an embodiment of the present invention, the design plan including a design for an inner surface of a convex member for manufacturing a short side portion provided with the convex member.

[0100] In the following, reference is made to Figure 7 as well as Fig. 9 (a) to (c) will describe a method for formulating a design scheme including a design for the inner surface of a convex member according to an embodiment of the present invention and a method for preparing a short side portion using the design scheme.

[0101] First side area A s1 and the second side region A s2 are identical in shape and size, only their positions are different. Therefore, in the following description, the first side region A s1 The width and the second side area A s2 The width is described as "W s "same.

[0102] First, determine the width W of the short side member 3121 to be manufactured. m In addition, the central area A for the male member CV to be manufactured is determined c The protruding length T c and Central Area A c Width W c .

[0103] Central area A of the convex member CV c The protruding length T cIt is determined to be within a range exceeding 5 mm, preferably within a range exceeding 5 mm and less than or equal to 20 mm. More preferably, the central area A of the convex member CV c The protruding length T c It was determined to be in the range of 10 mm to 20 mm.

[0104] In addition, the central area A of the convex member CV c Width W c Determined as the width W of the short side member 3121 m In other words, when the width W of the short side member 3121 is m When determining, the determined width W of the short side member 3121 is used. m To determine the central area A of the convex component CV c Width W c Here, the width W of the short side member 3121 is m Determined as the width W of the short side member 3121 m 10% to 15% of.

[0105] In addition, when the width W of the short side member 3121 m and the central area A of the convex member CV c Width W c When determining, the first side area A is determined using the determined width. s1 Width W s Here, the first side region A s1 Width W s can be determined by the width W of the short side member 3121 m Subtract the central area A of the convex component CV c Width W c and half the length obtained (see equation 1). s2 Width W s The first side region W s1 Width W s Therefore, when determining the first side area W s1 Width W s When the second side area A is automatically determined s2 Width W s .

[0106] [Equation 1]

[0107]

[0108] As described above, when the width W of the short side member 3121 is m , protruding length T c, the central area A of the convex component CV c Width W c and a first side region A of the male member CV s1 Width W s When the first side region A to be manufactured is determined, the determined value is used to formulate s1 That is, a design is made so that the first side area A of the inner surface IF of the convex member CV facing the internal space IS s1 The shape of the inner surface IF becomes the shape within the 0° to 180° segment of a periodic cosine curve.

[0109] Here, you can use Fig. 9 The design of the inner surface IF of the convex member CV is formulated by the XY coordinate plane illustrated in (a) to (c). In addition, the XY coordinate plane can be a coordinate plane on the base material used to manufacture the short side portion. On the XY coordinate plane, the X-axis direction can be a direction corresponding to the width direction of the short side member 3121 and the convex member CV in the mold 3000 to be manufactured, and the Y-axis direction can be a direction corresponding to the thickness direction of the short side member 3121 and the convex member CV.

[0110] Hereinafter, a point on the X-axis line of the XY coordinate plane where the X-axis value is "0" is referred to as a "reference point X". 0 In addition, the reference point X with an X-axis value of "0" 0 ” may be a point at one end of the short side portion 3120, the short side member 3121, or the convex member CV.

[0111] In addition, the reference symbol "X" indicated on the X-axis line on the XY coordinate plane ws ” refers to the position in the X-axis and represents the position relative to the reference point X 0 Spacing out the side area A s Width W s In the following, for the sake of convenience, the point X 0 Spacing out the side area A s Width W s The point is called the "boundary point X ws ”.

[0112] To formulate the side area A for the XY coordinate plane s In the design of the inner part IF, the value of the Y axis is determined according to the value of the X axis. 0 The value to the X axis is the first side area A s1 Width W s The boundary point X of the valuews The Y-axis value is determined by the different X values.

[0113] When determining the Y-axis value according to the X-value, the cosine curve equation is used. That is, the cosine curve equation (see equation 2) is used to calculate the Y-axis value according to the X-axis value, and the cosine curve equation applies the width W of the short side member 3121. m and the central area A in the convex member CV s The protruding length T c and width W c .

[0114] [Equation 2]

[0115]

[0116] W s : Width of the side area of ​​the male member

[0117] T c : The protruding length of the central area of ​​the convex member

[0118] x: x-axis value

[0119] y: y-axis value

[0120] In Equation 2, the central area A of the convex component CV is c The protruding length T c is a value that has been determined. In addition, in equation 2, the first side area A of the convex member CV is s1 Width W s The width W of the short side member 3121 is determined by m and the central area A of the convex member CV c Width W c The value determined (see Equation 1). In addition, in Equation 2, "X" is the value from the reference point X 0 To boundary point X ws That is, the value applied to X in Equation 2 is greater than or equal to 0 (zero) and less than or equal to the width W of the side region. s (See Equation 1).

[0121] [Relational expression 1]

[0122] 0≤x≤W s

[0123] When determining the Y-axis value from the X-value using Equation 2, as described above, when the value is greater than or equal to 0 (zero) and less than or equal to the first side area A s1 Width W sWhen the value of is applied to equation 2 to perform the operation, the Y value is calculated according to each X value. That is, when the reference point X 0 To boundary point X ws In the segment, the Y-axis value is calculated based on the X-axis value.

[0124] To explain with a specific example, if "0 (zero)" is applied to X in Equation 2 to perform the operation, the value of Y is calculated, that is, In addition, if the value is expressed as an XY coordinate value, it can be expressed as 0, Here, with 0, The point with coordinate values ​​is the point where the side area starts and therefore has 0, The point with the coordinate value is referred to as the starting point P in the following text. s .

[0125] As another example, if "W s " is applied to X to perform the operation, and the value of Y is produced, that is, In addition, if the value is expressed as an XY coordinate value, it can be expressed as 0, Here, with coordinate value 0, The point of is the boundary between the side area and the central area, and is the point where the side area ends. The point is called the end point P e .

[0126] In the same way, when 0 (zero) is connected to W s When the value between is applied to X in equation 2 to perform the operation, the Y value for each X is calculated. For a more specific explanation, the calculation for the value greater than 0 (zero) and less than W will be described. s In this case, 10 points P with different XY coordinate values ​​are created. 1 , P 2 ,……,P 9 and P 10 That is to say, at the starting point P s With the end point P e Create 10 different points between 1 , P 2 ,……,P 9 and P 10 .

[0127] Therefore, if Fig. 9 As shown in (a), a starting point P is created on the XY coordinates. s and the end point P e and the starting point P s With the end point P eMultiple points P between 1 , P 2 ,……,P 9 and P 10 .

[0128] Next, create the connection starting point P s , multiple points P 1 , P 2 ,……,P 9 and P 10 and the end point P e Therefore, we create a line like Fig. 9 The connection starting point P in (b) s and the end point P e The curve is in the form of a half of a cosine curve with 360° as one cycle. That is, the curve is in the form of a segment from 0° to 180° of a cosine curve with 360° as one cycle. In other words, the curve is in the form of a half cycle of a cosine curve with 360° as one cycle, and is in the form of a segment from 0° to 180°.

[0129] Connect starting point P s , end point P e and the starting point P s With the end point P e Multiple points P between 1 , P 2 ,……,P 9 and P 10 The cosine curve shaped line is used to make the first side area A s1 The design line of the first side region (hereinafter, referred to as the design line DL for the first side region) s1 ). In other words, it is the first side area A for the inner surface IF of the male member CV. s1 Design line DL s1 .

[0130] Next, the central area A of the convex component CV on the XY coordinate plane c The inner surface IF creates a design line (hereinafter referred to as the design line DL for the central area) c ). Here, it is created from the end point P e Start with a predetermined central area A c Width W c Therefore, a central area A is created. c Design line DL for the central area c , and the design line DL for the central area c It can be a straight line where the value of the Y axis does not change according to the value of the X axis, such as Fig. 9As shown in (c) of FIG.

[0131] Next, create a central area A for manufacturing settings c The second side region A on the other side s2 The design line of the second side region (hereinafter, referred to as the design line DL for the second side region) s2 ). When formulating the design line DL for the second side region s2 , relative to the design line DL for the central area c So, if Fig. 9 As shown in (d) of FIG. 1 , a design line DL for the second side region in the shape of a cosine curve is created. s2 .

[0132] As described above, the design line DL for the first side region is connected s1 , Design line DL for the central area c and a design line DL for the second side region s2 The line is the design for the inner surface IF of the convex member CV (hereinafter, referred to as the "inner surface design"). Therefore, the internal design can be described as including the design line DL for the first side area s1 , Design line DL for the central area c and the design line DL for the second design area s2 .

[0133] In addition, the central area A of the short side member 3121 and the convex member CV c is designed so that the width W m and W cv Each of them decreases as it goes downward. In addition, the central area A c The protruding length T c The same in the vertical direction. Therefore, when formulating the internal design of the male member CV, it is desirable to formulate for each height. To this end, the width of the short side member 3121 and the central area A of the male member CV c Width W m and W cv is determined for each height. In addition, the width W of the short side member 3121 for each determined height is used. m , the central area A of the convex component CV for each height c Width W cv and the determined central area A c The protruding length T c Develop interior designs for each height.

[0134] When the design line DL of the inner surface IF of the male member CV is formulated, the short side member 3121 and the short side member 3120 including the male member CV are formulated using the design line DL. Here, the short side member 3121 and the male member CV are formulated to have a predetermined width W of the short side member 3121. m , the central area A of the convex component CV c Width W c , the central area A of the convex component CV c The protruding length T c and the side area A of the male member CV s Width W s In addition, among the surfaces located on both sides of the convex member CV in the thickness direction (Y-axis direction), the inner surface IF opposite to the short side member 3121 is designed to have the same shape as the predetermined inner surface design.

[0135] A more specific example thereof is given below.

[0136] First, a base material for preparing the short side portion 3120 is prepared. Here, the base material may be a square plate made of copper (Cu). In addition, when preparing the base material, the length in one direction is the predetermined width W of the short side member 3121. m , and the length in another direction intersecting the one direction is formulated to exceed the central area A of the convex member CV c The predetermined protrusion length T c .

[0137] Here, one direction of the base material is a direction corresponding to the width direction of the short side member 3121, and the other direction of the base material is a direction corresponding to the thickness direction of the short side member 3121. Therefore, one direction of the base material is referred to as the width direction, and the other direction of the base material is referred to as the thickness direction.

[0138] Next, the base material is processed. Here, the device for processing the base material is not particularly limited, but for example, a ball cutter can be used for processing.

[0139] When processing the base material, one of the two surfaces in the thickness direction of the base material is processed. Here, from both ends in the width direction on one surface to the predetermined side area A s Width W s The shape of the dots spaced apart by the length is processed into the design line DL for the side area s1 and DL s2That is, a surface in the shape of a segment of 0° to 180° of a cosine curve as one cycle is created on one side of the central area in the width direction of the base material, and a surface in the shape of a segment of 180° to 360° of a cosine curve as one cycle is created on the other side. As described above, the curved surfaces provided at both sides of the central area on one surface of the base material correspond to the side area A of the convex member CV to be manufactured. s In addition, in one surface of the base material, the central area corresponds to the central area A of the convex member CV to be manufactured. c inner surface.

[0140] Therefore, a predetermined width W is set. m The short side member 3121 is formed to protrude from the short side member 3121 and has a predetermined protruding length T c and width W c Central area A c The short side member 3120, and the first side region A s1 and the second side region A s2 The inner surface of the first side region A is formed as a convex member CV of a cosine curve. s1 The inner surface of the second side area A is arranged in the form of a 0° to 180° segment of a cosine curve as a cycle, and the second side area A s2 The inner surface of is arranged in the form of a segment of 180° to 360° of a cosine curve as one cycle.

[0141] In addition, as described above, the width W of the short side member 3121 m and the central area A of the convex member CV c Width W c It must be designed to decrease toward the lower side. Therefore, it is manufactured with the width W of the short side member 3121 determined in advance for each height. m and the central area A of the convex member CV c Width W s In addition, due to the central area A of the short side member 3121 and the convex member CV c Width W s It is different for each height, so the internal design is made for each height. Therefore, when the inner surface IF of the male member CV is made, it is made so that it has the same shape as the inner surface design made for each height.

[0142] As described above, when preparing a pair of short side members 3120 and a short side member 3121 having a convex member CV, a mold is manufactured by coupling the pair of short side members 3120 to the long side member 3111. That is, as Figure 2 As illustrated in FIG. 1 , one end of each of the first short side member 3121 and the second short side member 3121 is connected to the inner surface of the first long side member 3111, and the other end of each of the first short side member 3121 and the second short side member 3121 is connected to the inner surface of the second long side member 3111. Therefore, a mold having an inner space IS surrounded by the inner surface IF of the convex member CV provided on the first and second short side members and the inner surfaces IF of the first and second long side members 3111 and 3111 is prepared.

[0143] Here, the two side areas A s The inner surface IF of the short side portion 3120, that is, the inner surface IF of the convex member CV, is in the shape of a cosine curve. s1 The inner surface of the second side area A is arranged in the form of a 0° to 180° segment of a cosine curve as a cycle, and the second side area A s2 The inner surface of is arranged in the form of a segment of 180° to 360° of a cosine curve as a cycle. Figure 7 As shown in the figure, the side area A s The angle θ between the edge of the long side member 3111 in the inner surface and the inner surface IF is 90° or a right angle. In other words, the angle θ between the inner surface IF of the edge of the convex member CV in the width direction and the inner surface IF of the edge of the long side member 3111 in the width direction is 90° or a right angle. As described above, the angle θ between the inner surface of the edge of the convex member CV in the width direction and the inner surface of the edge in the width direction is 90°, and this means that the space between the inner surface IF of the edge of the convex member CV in the width direction and the inner surface of the edge of the long side member 3111 in the width direction is wider than when the angle θ is an acute angle (less than 90°).

[0144] Therefore, when the slab 1 is cast by solidifying the molten steel inside the mold 3000, the molten steel or the solidified shell can be suppressed or prevented from being stuck in the space between the inner surface IF of the edge of the convex member CV in the width direction and the inner surface IF of the edge of the long side member 3111 in the width direction. Therefore, an operation accident in which the molten steel flows out of the mold 3000 due to the tearing of the slab 1 can be prevented. In addition, the convex member CV can be provided on the inner surface IF of the short side member 3121, and when the steel plate 2 is manufactured by rolling the slab 1, the occurrence of wrinkle defects or edge defects in the width direction on the edge of the steel plate 2 can be suppressed. In other words, the mold 3000 provided with the convex member CV prepared by the method according to the embodiment can be used to manufacture a slab that can suppress the occurrence of edge defects in the steel plate 2 while preventing operation accidents due to molten steel leakage.

[0145] Fig.10 is a view illustrating a slab manufactured using a mold according to an embodiment of the present invention.

[0146] Reference Fig.10 , the surfaces at the two side portions of the slab 1 in the width direction are set to a concave shape that is concave inward. Here, each surface at the two side portions has a curve in the shape of half of a cosine curve with a period of 360°. In other words, each of the two surfaces has a curve in the shape of a half period of a cosine curve with a period of 360°. More specifically, each of the two surfaces includes a central surface F c and are respectively arranged on the central surface F c A pair of side surfaces F on one side and the other side s1 and F s2 In addition, a pair of side surfaces F s1 and F s2 Each of the central surface F has a curve in the shape of half a cosine curve with a period of 360°. c The side surface F may be a plane shape, and the side surface F s Relative to the central surface F c That is, the pair of side surfaces F s One side surface has a shape of a segment of 0° to 180° of one period of a cosine curve, and the other side surface has a shape of a segment of 180° to 360° of one period of a cosine curve.

[0147] When rolling the slab 1 having a concave shape on each of the two surfaces as described above, the amount of expanded width due to rolling can be reduced compared to the conventional method. Therefore, the occurrence of edge defects in the steel plate 2 due to the expanded width of the slab 1 can be suppressed.

[0148] Table 1 shows results illustrating the width of a region where defects occur in a width direction on the edge of a steel plate when a slab is manufactured using a mold having a convex member according to the embodiment and the comparative example and when the manufactured slab is rolled to manufacture a steel plate.

[0149] Here, the convex member according to the embodiment is formed by Fig. 9 The convex member is manufactured by the method described in Figure 2 , Figure 6 and Figure 7. That is, the convex member has a central region whose protruding length in the width direction is the same and a side region whose shape is a cosine curve extending in the width direction. In addition, in the convex member, the protruding length of the central region has a specific length in the range of 10 mm to 20 mm, and the width of the central region is 10% to 15% of the width of the short side member. In addition, in the mold with the convex member according to the embodiment, the angle θ between the inner surface of the edge of the convex member in the width direction and the inner surface of the edge of the long side member in the width direction is 90°.

[0150] The convex member according to the comparative example has a fan-shaped arc shape (circular arc shape), and the protruding length of the center of the convex member in the width direction is 5 mm. In addition, the inner shape of the convex member is not a cosine curve. In addition, in the mold having the convex member according to the comparative example, the angle between the inner surface of the edge of the convex member in the width direction and the inner surface of the edge of the long side member in the width direction is an acute angle less than 90°.

[0151] In Table 1, the first to eleventh steel types represent different steel types having different components. In addition, all of the first to eleventh steel types are steel types for manufacturing stainless steel plates, but the first to eleventh steel types are steel types having some different components.

[0152] For the experiment, molten steel of each of the first to eleventh steel types was poured into each mold according to the comparative example and the embodiment to manufacture a slab. In addition, the slab manufactured in this way was rolled under the same conditions to manufacture a steel plate.

[0153] Next, the width of the area where the wrinkle defect occurs along the edge of the steep plate in the width direction is measured. Here, when starting from the outermost edge of the steel plate in the width direction, the wrinkle toward the center is searched, and the distance from the wrinkle closest to the outermost edge to the wrinkle farthest from the outermost edge is measured and defined as the "defect occurrence width".

[0154] [Table 1]

[0155]

[0156] Referring to Table 1, it is confirmed that the defect occurrence width is reduced in the embodiment when compared with the comparative example.

[0157] In addition, when molten steel was injected into the mold according to the comparative example to cast the slab, an accident occurred in which the molten steel flowed out of the mold. However, during the casting of the slab by injecting molten steel into the mold according to the embodiment, an accident in which the molten steel leaked from the mold did not occur.

[0158] As described above, in the mold 3000 provided with the convex member CV according to the embodiment, when the slab 1 is cast by solidifying the molten steel inside the mold 3000, the molten steel or the solidified shell can be suppressed or prevented from being caught in the space between the inner surface IF of the edge of the convex member CV in the width direction and the inner surface IF of the edge of the long side member 3111 in the width direction. Therefore, an operation accident in which the molten steel flows out of the mold 3000 due to the tearing of the slab 1 can be prevented. In addition, the slab 1 capable of suppressing the occurrence of wrinkle defects or edge defects in the edge of the steel plate 2 in the width direction can be manufactured. That is, a slab capable of suppressing the occurrence of edge defects in the steel plate 2 and also preventing the occurrence of an operation accident due to the leakage of molten steel can be manufactured.

[0159] Industrial Applicability

[0160] The mold according to the embodiment of the present invention can manufacture a slab capable of suppressing edge defects of a steel plate that occur due to the expanded width of the slab in the manufacture of a slab to be rolled into a steel plate. In addition, when manufacturing a slab by solidifying molten steel inside the mold or when changing the width of the mold, it is possible to suppress or prevent steel or a solidified shell from being stuck in the space between the inner surface of the edge of the convex member and the inner surface of the long side member. Therefore, it is possible to prevent the occurrence of an operation accident in which molten steel flows out of the mold due to tearing of the mold.

Claims

1. A mold having an internal space into which molten steel is injected, the mold comprising: A body, wherein the body has the internal space; as well as a convex member protruding from the body toward the inner space and extending in a width direction of the body, wherein the convex member includes a pair of side regions disposed on one side and the other side of the convex member in the width direction, Each of the pair of side regions has a shape in which a protruding length decreases as it moves away from the center, and The inner surface of each of the pair of side regions has a surface in the shape of a half of a cosine curve having 360° as one cycle.

2. The mold according to claim 1, wherein: The male member includes a central region disposed between the pair of side regions, wherein the protruding length of the central region is the same in the width direction, and An inner surface, which is a surface of the central region facing the inner space, has a flat surface.

3. The mold according to claim 2, wherein: The pair of side regions are symmetrical in shape with respect to the central region.

4. The mold according to claim 3, wherein: One of the pair of side regions has an inner surface shaped as a segment of 0° to 180° of one period of a cosine curve, and the other side region has an inner surface shaped as a segment of 180° to 360° of one period of a cosine curve.

5. The mold according to claim 4, wherein: The body comprises: a pair of long side members, each of the pair of long side members being formed to extend in one direction and the pair of long side members being installed to face each other in a direction intersecting the extending direction; and a pair of short side members, each of the pair of short side members being formed to extend to intersect with the long side members, and the pair of short side members being installed to face each other to seal between the pair of long side members, The convex member is formed to protrude from the short side member toward the inner space.

6. The mold according to claim 5, wherein: The angle between the inner surface of the long side member and the edge of the inner surface of the side region is 90°.

7. The mold according to claim 2, wherein: The protrusion length of the central area of ​​the male member exceeds 5 mm.

8. The mold according to claim 5, wherein: The width of the male member is the same as the width of the short side members, and The width of the central region of the male member is 10% to 15% of the width of the short side members.

9. The mold according to claim 8, wherein: The width of each of the short side members and the male member decreases as the short side members and the male member go downward, and The width of the central region of the male member is uniform in the vertical direction.

10. The mold according to claim 8, wherein: The width of each of the short side members and the male member decreases as the short side members and the male member go downward, and The width of the central region of the male member decreases as the male member moves downward.

11. The mold according to claim 5, wherein: The length of the male member in the vertical direction is the same as the length of the short side members in the vertical direction.

12. A method for manufacturing a mold, the mold comprising a body having an interior space and a convex member protruding from the body toward the interior space, the method comprising: A design is made so that the convex member includes a first side region and a second side region, on which the protrusion length decreases toward both ends in the center in the width direction, and the inner surface of each of the first side region and the second side region has a surface in the shape of half a cosine curve having a period of 360°; as well as A base material is processed to have the shape of the male component included in the design.

13. The method according to claim 12, wherein: Formulating the design plan includes: Determine the width (W) of the body to be manufactured m ) and vertical length (H m );as well as A design is formulated for an inner surface of the male member having a shape of an inner surface of each of the first and second side regions.

14. The method according to claim 13, wherein: The design formulated for the inner surface of the male member includes: Determine the protruding length (T c ) and width (W c );as well as By using the determined width (W m ), the determined protrusion length (T c ) and width (W c ) is used to formulate a design for the first side region so that the shape of the inner surface of the first side region becomes the shape of half a periodic cosine curve.

15. The method according to claim 14, wherein: The design developed for the first side region includes: Using the determined width (W m ) and the determined width (W c ) to determine the width (W) of the first side region to be manufactured s ); A cosine curve equation is provided, the cosine curve equation including the determined width (W) of the first side region s ), the determined protrusion length (T c ), a width direction position (X) of the convex member and a thickness direction position (Y) of the convex member; and Calculating the thickness direction position (Y) from the width direction position (X) using the cosine curve equation, Wherein the value of the widthwise position (X) applied to the cosine curve equation is the determined width (W) of the body m ) to the determined width (W s ) is a value for a segment of points spaced apart, wherein a plurality of values ​​are applied in the segment.

16. The method according to claim 15, wherein: Formulating a design for the first side region includes connecting a plurality of thickness-direction positions (Y) calculated for each width-direction position (X) to create a design line for the first side region in the shape of half of the one-cycle cosine curve.

17. The method according to claim 16, wherein: Formulating a design for the inner surface of the male member includes formulating a design for the central region, the design for the central region being a design for the inner surface of the central region disposed between the first side region and the second side region, and Formulating a design for the central region includes extending a line from an end of the design line for the first side region to the determined width (W) of the central region. c ) to create a design line for the central area.

18. The method of claim 17, further comprising formulating a design for the second side region such that an inner surface of the second side region has a shape of half a periodic cosine curve, in, Formulating a design for the second side region includes forming a design line for the second side region symmetrically with respect to a design line for the first side region using the central region as a center.

19. The method according to claim 18, further comprising preparing a base material whose width direction length is the determined width (W m ) and the length in the thickness direction intersecting the width direction exceeds the determined protrusion length (T c ), in, The processing of the base material includes processing one of the two surfaces of the base material in the thickness direction so that the base material has a width (W) from each of the two end portions in the width direction to the side region. s ) is a design line for each of the first side region and the second side region.

20. A slab produced by solidifying molten steel, wherein: Each of the two surfaces of the slab has a convex shape that is concave inward, and a portion of each of the two surfaces has a curved surface in the shape of a half of a cosine curve having 360° as one cycle.

21. The slab according to claim 20, wherein Each of the two surfaces includes a central surface and a pair of side surfaces respectively provided on one side and the other side of the central surface, and Each of the pair of side surfaces has a curved surface in the shape of a half of a cosine curve having a period of 360°, wherein the central surface has a plane.

22. The slab according to claim 21, wherein The pair of side surfaces have a symmetrical shape with respect to the central surface, and One of the pair of side surfaces has a shape within a range of 0° to 180° in one period of a cosine curve, and the other side surface has a shape of a segment of 180° to 360° of one period of the cosine curve.

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