JP5453329B2 - Continuous casting mold - Google Patents

Description

The present invention relates to a continuous casting mold corresponding to a change in slab shape based on solidification shrinkage.

As shown in FIG. 5, a continuous casting mold 103 having a rectangular cross section formed by combining a pair of short side cooling members 100 and a pair of long side cooling members 101 (for example, see Patent Document 1) is used. In the continuous casting of the molten steel, when the molten steel comes into contact with the mold wall 104 of the short side cooling member 100 and the mold wall 105 of the long side cooling member 101 and is cooled to form a slab shell (solidified shell) 106, When the volume of the molten steel before solidification is compared with the volume when the slab shell 106 is formed by solidification, the volume of the slab shell 106 is smaller than the volume of the molten steel due to solidification shrinkage of the molten steel. .

For this reason, the amount of solidification shrinkage of the slab shell 106 toward the mold wall 104 of the short side cooling member 100 and the mold wall 105 of the long side cooling member 101 facing each other from the inlet side to the outlet side (in the casting direction). The short-side inclined portion 107 and the long-side inclined portion 108 are formed so that the interval gradually decreases following the above, and the cross-sectional area of the continuous casting mold 103 is gradually reduced in the casting direction to The surface is always in contact with each mold wall 104,105. Thus, the slab shell 106 is cooled by the continuous casting mold 103 so that the molten steel 109 existing in the slab shell 106 is solidified to increase the thickness of the slab.

JP 2003-136204 A

Here, when the slab shell 106 is formed, the slab corners cooled at the four corner regions of the continuous casting mold 103 are cast at the flat portion excluding the corners of the continuous casting mold 103. Compared with the one-side flat portion, it contracts greatly due to the influence of cooling from the two surfaces of the short side cooling member 100 and the long side cooling member 101. For this reason, it is easy to produce the corner air gap 110 between a casting_mold | template corner | angular part and a slab corner | angular part. As a result, the cooling of the slab corner becomes insufficient, and the quality of the slab corner due to solidification delay and the spray water (secondary cooling water) entering from the corner air gap 110 corrode (galvanic current). (Corrosion) is likely to occur.
In addition, since the corner of the slab corner is not sufficiently cooled, the thickness of the slab corner is thin, and when the slab shell 106 moves in the continuous casting mold 103, stress concentration occurs in the slab corner. There is a problem that the quality of the corner of the slab deteriorates or, in the worst case, breakout occurs at the corner of the slab.

The present invention has been made in view of such circumstances, and the mold space is changed corresponding to the slab shape based on the solidification shrinkage to prevent the occurrence of a corner air gap, thereby causing abnormal quality of the slab corner and corrosion of the lower part of the mold. It is an object of the present invention to provide a continuous casting mold capable of preventing the above.

The continuous casting mold according to the present invention that meets the above object is injected into a mold space surrounded by a pair of short sides that can be adjusted in distance and a pair of long sides that sandwich the short sides from both sides in the width direction. In a continuous casting mold that cools molten steel and draws it as a slab,
The flat side of the slab shell is formed in the direction in which the slab is pulled out, respectively, on the opposing long side excluding the four corners of the mold wall and the long side of the mold wall that forms the mold space. A long side inclined portion and a short side inclined portion in which the interval gradually narrows following the amount of solidification shrinkage are formed,
The short side of the four corner regions of the mold wall expands outward and gradually decreases in the direction in which the slab is pulled out, following the amount of solidification shrinkage at the short side corner of the slab shell. In addition, at each height position from the lower end of the mold wall to the meniscus portion where solidification of the molten steel starts, an interval between the short sides facing each other along the surface of the short side corner portion of the slab shell is set. The average heat at each height position calculated based on the width W of the slab at the lower end of the mold wall and the shape of the short side corner of the slab shell at the lower end of the mold wall A short-side enlarged portion that is the sum (W + 2C) of the value 2C that is twice the expansion amount C is formed.

In the continuous casting mold according to the present invention, the solidification shrinkage amount of the flat portion of the slab shell and the solidification shrinkage amount of the short side corner of the slab shell are calculated in the mold space portion calculated based on casting conditions. It is preferable to calculate based on the solidification shrinkage analysis result of the slab shell.

In the continuous casting mold according to claims 1 to 3, the volume of the mold space can be changed in the casting direction based on the solidification shrinkage amount of the flat portion of the slab shell and the solidification shrinkage amount of the corner portion of the slab shell. It is possible to prevent the occurrence of a corner air gap. As a result, it is possible to prevent the solidification delay at the corner of the slab and prevent the quality abnormality at the corner of the slab, and to prevent corrosion by suppressing the entry of spray water into the lower part of the mold. It becomes possible.

In particular, in the continuous casting mold according to claim 2, it is possible to easily obtain the shapes of the short side inclined portion, the long side inclined portion, and the short side enlarged portion, and it is easy to produce a continuous casting mold. Can be performed.

It is a partial top view of the casting_mold | template wall of the casting mold for continuous casting which concerns on the 1st Embodiment of this invention. It is a sectional side view of the short side (long side) which forms the mold wall of the same casting mold. It is a horizontal sectional view of a model when calculating the solidification shrinkage amount of the slab shell formed in the mold wall of the continuous casting mold. It is a partial top view of the casting_mold | template wall of the casting mold for continuous casting which concerns on the 2nd Embodiment of this invention. It is explanatory drawing which shows the state of the slab formed in the casting mold for continuous casting which concerns on a prior art example.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
As shown in FIG. 1, the continuous casting mold 10 according to the first embodiment of the present invention has a pair of short sides 11 arranged at intervals and a pair of short sides 11 sandwiched from both sides in the width direction. Molten steel is poured from above into the mold space 13 surrounded by the long side 12, brought into contact with the inner surface of the mold wall 14 forming the mold space 13, cooled, and pulled out from the lower side of the mold space 13 as a slab. ing. Here, the slab refers to, for example, a bloom to which a casting cross-sectional area is fixed. Details will be described below.

The short side 11 (long side 12) is mainly formed of copper, which is an example of a metal having good thermal conductivity, and a flow path through which industrial water, which is an example of cooling water, is provided on the back side. A cooling unit (not shown) is provided. In addition, the coating layer by plating or thermal spraying is formed in the surface (surface which contacts molten steel) of the short side 11 (long side 12). Here, the length from the upper end (molten steel injection side) to the lower end (slab drawing side) of the short side 11 (long side 12) is, for example, 700 to 1000 mm, and the thickness thereof is, for example, 10 to 10 mm. 50 mm.
Further, as shown in FIG. 2, the opposing short side 11 and long side 12 excluding the four corner regions of the mold wall 14 respectively have a solidification shrinkage amount in the flat portion of the slab shell in the drawing direction of the slab. A short-side inclined portion 15 and a long-side inclined portion 16 that follow and gradually decrease in distance are formed. Here, the flat portion of the slab shell is mainly molten steel that is in contact with the short side 11 or the long side 12 of the mold wall 14 forming the mold space 13 in the slab shell formed in the mold space 13. The region that can be approximated by solidification only by the cooling action from the short side 11 or the long side 12.

Further, as shown in FIG. 1, the short side 11 and the long side 12 of the four corner regions of the mold wall 14 are respectively expanded toward the outside and solidified at the corners of the slab shell in the direction in which the slab is pulled out. A short-side enlarged portion 17 and a long-side enlarged portion 18 that are gradually reduced following the contraction amount are formed.
Here, the corner portion of the slab shell is the short side of the slab formed in the mold space 13, the molten steel contacting the short side 11 or the long side 12 of the mold wall 14 forming the mold space 13. 11 and a region that can be approximated by solidification by receiving the cooling action from the long side 12 at the same time. The distance between the opposing short sides 11 at the end (lower end) of the slab drawing side of the mold wall 14 substantially matches the wide width W of the slab to be cast, and the distance between the opposing long sides 12. Substantially matches the narrow width V of the slab to be cast.

As shown in FIG. 3, a method for calculating the amount of solidification shrinkage of the flat portion R of the slab shell 19 will be briefly described as follows.
First, casting conditions including molten steel temperature, slab outer shape size, thermal expansion coefficient and rigidity of slab (elastic-plastic data), slab pulling speed from mold space 13, and mold wall 14 cooling capacity Based on the above, the temperature distribution in the casting direction of the slab shell 19 formed in the mold space 13 is calculated by, for example, the finite element method.
In the temperature distribution in the casting direction of the slab shell 19, at the same position (for example, the same height position Z from the lower end of the mold wall 14) with respect to the casting direction of the slab shell 19, The point P on the surface of the slab shell 19 that contacts the center is cooled only from the short side 11, and the point P on the surface of the slab shell 19 that contacts the center of the long side 12 is cooled only from the long side 12. On the other hand, the protrusion points Q at the corners of the slab shell 19 formed in contact with the four corner regions of the mold wall 14 are cooled simultaneously from the short side 11 and the long side 12. The temperature at the point P is the highest, and the temperature at the protrusion point Q at the corner of the slab shell 19 is the lowest. For this reason, the surface area of the slab shell 19 where the temperature difference from the point P is 50 ° C. or less at the surface temperature of the slab shell 19 is defined as the flat portion R of the slab shell 19, and the average in that area The temperature T _R (Z) is set as the temperature of the flat portion R of the slab shell 19.

The surface temperature of the flat portion R of the slab shell 19 T _{R (Z),} in the casting direction of the cast slab shell 19, the surface of at the lower end E of the mold wall 14 from the molten steel temperature T _M of the meniscus near the solidification starts The temperature continuously changes up to the temperature T _R (E) (T _R (E) <T _R (Z) <T _M ), and from the surface temperature T _R (Z) in the thickness direction of the flat portion R of the slab shell 19. continuously changes to the back temperature (temperature of molten steel) T _M. For this reason, when the outer shape of the flat portion R of the slab shell 19 pulled out from the lower end E of the mold wall 14 is a predetermined shape (the narrow width is V and the wide width is W), the height position Z extends from the lower end of the mold wall 14. The outer size of the flat portion R of the slab shell 19 is the increase in surface temperature (T _R (Z) −T _R (E)) and the decrease in temperature in the thickness direction of the slab shell 19 (T _M −T _R ( Z)) is increased by the average thermal expansion amount B (Z) combined.
Actually, in order to obtain a solidification shrinkage analysis result using a three-dimensional finite element analysis model, the three-dimensional temperature distribution (casting direction, circumferential direction, and thickness direction of the slab shell 19) and the slab shell 19 The amount of solidification shrinkage deformation taking into consideration the linear expansion coefficient and rigidity (elastic-plastic data) depending on the temperature distribution can be obtained. The main points here are the outer size of the flat portion R and the outer shape of the corner portion S of the slab shell 19. Since the size changes in the drawing direction of the slab and the amount is different between the flat portion R and the corner portion S of the slab shell 19, the calculation factor is slightly omitted here. I will explain.
Therefore, based on the external size of the flat portion R of the slab shell 19 at the height position Z of the mold wall 14, the external size of the flat portion R of the slab shell 19 at the lower end of the mold wall 14 is the average heat. Shrinkage is caused by the amount of coagulation shrinkage corresponding to the expansion amount B (Z).

From the above, based on the predetermined shape of the flat portion R of the slab shell 19 at the lower end of the mold wall 14, the average thermal expansion amount B at each height position from the lower end of the mold wall 14 to the vicinity of the meniscus portion is determined. At each height position, the long side inclined portion 15 is formed on the short side 11 so that the distance between the opposed short sides 11 is W + 2B and the distance between the opposed long sides 12 is V + 2B. When the long side inclined portion 16 is formed on each side 12, the interval between the opposing short sides 11 (long side 12) is set by the short side inclined portion 15 (long side inclined portion 16) of the slab shell 19. It gradually narrows following the amount of solidification shrinkage corresponding to the average thermal expansion amount B of the flat portion R.
The short side 11 and the long side 12 in the range from the meniscus portion to the upper end of the mold wall 14 are inclined portions 15a (16a) obtained by extending the short side inclined portion 15 and the long side inclined portion 16 in the vicinity of the meniscus portion, respectively. ).

Similarly, calculation of the amount of solidification shrinkage of the corner S of the slab shell 19 is as follows.
The surface temperature T _S (Z) of the corner portion S of the slab shell 19 at the same height position Z of the mold wall 14 changes along the surface of the corner portion S of the slab shell 19, and the corner of the slab shell 19 is changed. The temperature at the connection point G, H between the surface of the part S and the surface of each flat part R on the short side 11 side and the long side 12 side is substantially equal to the surface temperature T _R (Z) of the flat part R. Further, in the casting direction of the slab shell 19, the surface temperature T _S (E) (T _S (E) <T _S (Z) at the lower end E of the mold wall 14 from the molten steel temperature T _M near the meniscus where solidification starts. <T _M ) continuously, and in the thickness direction of the corner portion S of the slab shell 19, it continuously changes from the surface temperature T _S (Z) to the back surface temperature (molten steel temperature) T _M.
Therefore, when the outer shape of the corner portion S of the slab shell 19 pulled out from the lower end E of the mold wall 14 is a predetermined shape (the narrow width is V and the wide width is W), the height position Z from the lower end of the mold wall 14 The outer size of the corner portion S of the slab shell 19 is an increase in surface temperature (T _S (Z) −T _S (E)) and a temperature decrease in the thickness direction of the corner portion S of the slab shell 19 (T _The average thermal expansion amount C (Z) combined with _M− T _S (Z)) increases along the surface of the corner portion S of the slab shell 19.
Therefore, with reference to the outer size of the corner portion S of the slab shell 19 at the height position Z from the lower end of the mold wall 14, the outer size of the corner portion S of the slab shell 19 at the lower end of the mold wall 14 is The portion S contracts along the surface of the portion S by the amount of coagulation contraction corresponding to the average thermal expansion amount C (Z).

From the above, the average thermal expansion amount C at each height position from the lower end of the mold wall 14 to the vicinity of the meniscus is calculated based on the predetermined shape of the corner S of the slab shell 19 at the lower end of the mold wall 14. At each height position, the interval between the short sides 11 facing along the surface of the corner portion S of the slab shell 19 is W + 2C, and the long side 12 facing along the surface of the corner portion S of the slab shell 19. When the short-side enlarged portion 17 and the long-side enlarged portion 18 are formed so that the distance between them is V + 2C, the short side 11 (long side 12) facing along the surface of the corner portion S of the slab shell 19 is formed. ) Is gradually narrowed by the short side enlarged portion 17 (long side side enlarged portion 18) following the amount of solidification shrinkage corresponding to the average thermal expansion amount C of the corner portion S of the slab shell 19. become.
It should be noted that the short side 11 and the long side 12 of the four corner regions in the range from the meniscus portion to the upper end of the mold wall 14 are enlarged by extending the short side enlarged portion 17 and the long side enlarged portion 18 in the vicinity of the meniscus portion, respectively. A portion (not shown) is provided.

Next, the operation of the continuous casting mold 10 according to the first embodiment of the present invention will be described.
When molten steel is injected from above into the mold space 13 formed inside the mold wall 14 of the continuous casting mold 10, the molten steel comes into contact with the inner surface of the mold wall 14 and is cooled, and the molten steel exists inside the solidified layer on the front side. A half shell 19 is formed.

The outer size of the flat portion R of the slab shell 19 formed by contacting and cooling the opposing short side 11 and long side 12 excluding the four corner regions of the mold wall 14 is the short side inclined portion 15 and the long side. It is gradually reduced in the direction in which the slab is pulled out by the side inclined portion 16. Further, the outer size of the corner portion S of the slab shell 19 formed by contacting the short side 11 and the long side 12 in the four corner regions of the mold wall 14 and simultaneously cooling from the short side 11 and the long side 12 is as follows: Due to the short side enlarged portion 17 and the long side enlarged portion 18, the corner portion S of the slab shell 19 is expanded outward from the flat portion R at the same height position of the mold wall 14.

On the other hand, when the slab is drawn, the slab shell 19 moves from the upper side to the lower side in the mold wall 14 according to the drawing speed, and the surface temperature of the slab shell 19 gradually decreases. At this time, the corner portion S of the slab shell 19 is simultaneously cooled from the short side 11 and the long side 12 of the mold wall 14, and the flat portion R of the slab shell 19 is cooled only from the short side 11 or the long side 12. Become. For this reason, at the surface temperature of the slab shell 19 at the same height position of the mold wall 14, the surface temperature of the corner portion S is lower than the surface temperature of the flat portion R of the slab shell 19, and the slab shell 19 Compared with the flat part R, the corner part S is greatly coagulated and contracted.

Here, the outer size of the flat portion R of the slab shell 19 gradually contracts in accordance with the solidification shrinkage amount B of the flat portion R in the pulling direction. On the other hand, the interval between the short sides 11 (long sides 12) facing the mold wall 14 is also the average of the flat portion R of the slab shell 19 by the short side inclined portion 15 (long side inclined portion 16). The flat portion R of the slab shell 19 changes so as to narrow gradually following the amount of solidification and shrinkage corresponding to the thermal expansion amount B. It is possible to move toward the lower end side while always contacting the surface of the flat portion R with the long side 12.
Further, the outer size of the corner portion S of the slab shell 19 is increased outwardly at the same height position of the mold wall 14 and the corner portion S of the slab shell 19 in the direction in which the slab shell 19 is pulled out. It shrinks gradually following the amount of coagulation shrinkage. And the space | interval between the short sides 11 (long side 12) which opposes along the surface of the corner | angular part S of the slab shell 19 is the slab shell 19 by the short side enlarged part 17 (long side enlarged part 18). Since the corner portion S of the slab shell 19 gradually narrows following the amount of solidification and shrinkage corresponding to the average thermal expansion amount C of the corner portion S, the corner portion S of the slab shell 19 is a short side facing the four corner regions of the mold wall 14. 11 and the long side 12 can be moved toward the lower end side while always contacting the surface of the corner S.

As shown in FIG. 4, the continuous casting mold 20 according to the second embodiment of the present invention has a pair of short sides 21 and a pair of long sides sandwiching the short sides 21 from both sides in the width direction. The molten steel is poured from above into the mold space 23 surrounded by 22, brought into contact with the inner surface of the mold wall 24 that forms the mold space 23, cooled, and pulled out from the lower side of the mold space 23 as a slab. . Here, the slab refers to, for example, a slab having a variable width.

The short side 21 (long side 22) is formed from copper which is an example of a metal having good thermal conductivity, and a cooling unit (not shown) is provided on the back side. In addition, the coating layer by plating or thermal spraying is formed in the surface (surface which contacts molten steel) of the short side 21 (long side 22). Here, the length from the upper end (molten steel injection side) to the lower end (slab drawing side) of the short side 21 (long side 22) is, for example, 700 to 1100 mm, and the thickness thereof is, for example, 10 to 10 mm. 60 mm.
Further, like the short side 11 and the long side 12 of the continuous casting mold 10 according to the first embodiment, the opposing short side 21 and the long side 22 excluding the four corner regions of the mold wall 24 are respectively In the drawing direction of the slab, a short side inclined portion 25 and a long side inclined portion 26 are formed in which the interval gradually decreases following the solidification shrinkage of the flat portion of the slab shell. Here, the flat part of the cast slab shell can be approximated as molten steel solidifies by only the cooling from the short side 21 or the long side 22 of the mold wall 24 in the slab shell formed in the mold space 23. Refers to an area.

Further, as shown in FIG. 4, the short side 21 of the four corner regions of the mold wall 24 is enlarged toward the outside of the short side 21 and the short side corner of the slab shell in the direction in which the slab is pulled out. A short side enlarged portion 27 is formed which gradually shrinks following the amount of solidification and shrinkage.
Here, the short side corner of the slab shell is the slab shell formed in the mold space 23 and contacts the short side 21 of the mold wall 24 to cool from the short side 21 and the long side 22. It refers to the area that can be approximated when molten steel solidifies by receiving the action simultaneously. And the inner width in the lower end of the opposing short side 21 which forms the mold wall 24 substantially corresponds to the set width size when the slab is discharged from the lower end of the continuous casting mold 10, and the opposing long side The inner width at the lower end of 22 substantially matches the set thickness size when the cast piece is discharged from the lower end of the continuous casting mold 10.

The solidification shrinkage amount of the flat portion of the slab shell and the solidification shrinkage amount of the corner portion are calculated by the solidification shrinkage of the flat portion R of the slab shell 19 calculated in the continuous casting mold 10 according to the first embodiment. The amount and the amount of coagulation shrinkage of the corner S are substantially the same, and thus detailed description is omitted.
Note that the short side 21 and the long side 22 in the range from the meniscus portion to the upper end of the mold wall 24 are inclined portions (not shown) obtained by extending the short side inclined portion 25 and the long side inclined portion 26 in the vicinity of the meniscus portion, respectively. Z). Further, an enlarged portion (not shown) is provided on the short side 21 of the four corner regions in the range from the meniscus portion to the upper end of the mold wall 24 by extending the short side enlarged portion 27 in the vicinity of the meniscus portion.
The outer size of the flat part of the slab shell formed by cooling the molten steel injected into the mold wall 24 of the continuous casting mold 20 is gradually followed by the solidification shrinkage amount of the flat part in the drawing direction. Since it changes so as to narrow, the surface of the flat part of the slab shell moves toward the lower end side while always contacting the opposing short side 21 and long side 22 excluding the four corner regions of the mold wall 24. can do.
Further, the outer size of the corner of the slab shell increases from the lower end of the mold wall 24 toward the outside of the short side 21 at the same height position, and the short side angle of the slab shell in the direction in which the slab is pulled out. Accordingly, the surface of the short side corner of the slab shell is always brought into contact with the opposing short sides 21 of the four corner regions of the mold wall 24. However, it can move toward the lower end side.

Therefore, a corner air gap is likely to occur between the long side 22 of the four corner regions of the mold wall 24 and the long side corner of the slab shell, but the short side 21 of the four corner regions of the mold wall 24 Since the short side corners of the slab shell are in contact, it is possible to prevent insufficient cooling of the long side corners of the slab shell. As a result, it is possible to prevent the occurrence of quality abnormalities at the corners of the slab due to delay in solidification, and to prevent the corners of the slab from being thinned. It is possible to prevent the quality deterioration of the corner. Furthermore, the short side 21 of the slab shell comes into contact with the short sides 21 of the four corner regions of the mold wall 24, so that the corner air gap can be reduced as compared with the conventional continuous casting mold. Ingress of water can be suppressed.
Moreover, since the short side enlarged portion 27 is provided only on the short side 21 of the four corner regions of the mold wall 24, cast pieces having different wide sizes can be easily cast by changing the distance between the short sides 21 of the cast piece. be able to.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this embodiment, The change in the range which does not change the summary of invention is possible, Each above-mentioned embodiment is possible. The case where the mold for continuous casting according to the present invention is configured by combining a part or all of forms and modifications is also included in the scope of the right of the present invention.
For example, in the first embodiment, the short side and the long side of the region excluding the four corners of the mold wall are inclined in the range from the meniscus portion to the upper end, and the short side and the long side of the four corner region of the mold wall. In the range from the meniscus portion to the upper end, an enlarged portion is provided, but only the range from the meniscus portion to the lower end is the short side inclined portion, the long side inclined portion, the short side enlarged portion, and the long side side. You may make it provide an enlarged part.
Also in the second embodiment, an inclined portion is provided in the range from the meniscus portion to the upper end on the short side and the long side, and an enlarged portion is provided in the range from the meniscus portion on the short side to the upper end. You may make it provide a short side inclination part, a long side inclination part, and a short side expansion part only in the range to a lower end.
Further, the surface temperature of the flat part of the slab shell is represented by the average temperature of the flat part, and the average thermal expansion amount was obtained based on the surface temperature of the flat part of the slab shell and the temperature distribution in the thickness direction of the slab shell. However, the average thermal expansion amount may be obtained based on the calculated surface temperature of the flat portion and the temperature distribution in the thickness direction of the slab shell.

10: Continuous casting mold, 11: Short side, 12: Long side, 13: Mold space, 14: Mold wall, 15: Short side inclined part, 15a: Inclined part, 16: Long side inclined part, 16a : Inclined part, 17: short side enlarged part, 18: long side enlarged part, 19: cast slab shell, 20: continuous casting mold, 21: short side, 22: long side, 23: mold space part, 24 : Mold wall, 25: Short side inclined part, 26: Long side inclined part, 27: Short side enlarged part

Claims (3)

In the continuous casting mold for cooling the molten steel injected into the mold space surrounded by the pair of short sides capable of adjusting the interval and the pair of long sides sandwiching the short sides from both sides in the width direction, and drawing it as a slab,
The flat side of the slab shell is formed in the direction in which the slab is pulled out, respectively, on the opposing long side excluding the four corners of the mold wall and the long side of the mold wall that forms the mold space. A long side inclined portion and a short side inclined portion in which the interval gradually narrows following the amount of solidification shrinkage are formed,
The short side of the four corner regions of the mold wall expands outward and gradually decreases in the direction in which the slab is pulled out, following the amount of solidification shrinkage at the short side corner of the slab shell. In addition, at each height position from the lower end of the mold wall to the meniscus portion where solidification of the molten steel starts, an interval between the short sides facing each other along the surface of the short side corner portion of the slab shell is set. The average heat at each height position calculated based on the width W of the slab at the lower end of the mold wall and the shape of the short side corner of the slab shell at the lower end of the mold wall A casting mold for continuous casting, characterized in that a short side enlarged portion having a sum (W + 2C) of a value 2C that is twice the expansion amount C is formed. 2. The continuous casting mold according to claim 1, wherein the solidification shrinkage amount of the flat portion of the slab shell and the solidification shrinkage amount of the short side corner portion of the slab shell are calculated based on casting conditions. A continuous casting mold characterized in that it is calculated based on a solidification shrinkage analysis result of the slab shell. The continuous casting mold according to claim 1 or 2, wherein the average thermal expansion amount C is:
The surface temperature T _S (Z) of the short side corner of the slab shell at the same height position Z from the lower end of the mold wall, and the short side corner of the slab shell at the lower end of the mold wall surface temperature _T S (E) and the difference between the surface temperature rise of the short side corner of the slab shell component which is the _{(T S (Z) -T S} (E)),
And the molten steel temperature T _M of the meniscus portion, the short side corner of the which is the difference between the surface temperature T _{S (Z)} of the short side corner of the slab shell in the same height position Z the slab shell temperature decrease amount of the thickness direction using a _{(T M -T S (Z)} ), the continuous casting mold, characterized in that it is calculated.

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