JP2003136203A - Mold for continuous casting under taking into consideration variation of casting radius of cast slab caused by shrinkage and continuous casting facility using the mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold for continuous casing under taking into consideration the variation of the casting radius of a cast slab caused by shrinkage and a continuous casting facility using the mold with which the cast slab having good quality can economically be manufactured. SOLUTION: In the mold 10 for continuous casting used for the continuous casting facility 12 manufacturing the cast slab 11 cooling molten steel and solidified in a curving state from the molten steel, one of inside facing surfaces 16 in a mold body 15 is curved from an upper end toward a lower end, and the radius of curvature in the vertical direction of the curved inside facing surface 16 is continuously or intermittently reduced corresponding to the linear expansion amount and the temperature of the cast slab 11 from the upper end to the lower end of the curved inside faced surface 16. Further, the continuous casting facility 12 using the mold 10 for continuous casting is provided with plurality of guide rolls 19 gradually reducing in radii of curvatures of facing abutting carrying surfaces accompanied with reduction in radii of curvatures of the inside facing surfaces 16 at the downstream of the mold body 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous casting mold and a continuous casting facility using the same, in consideration of a change in the casting radius of a cast piece that has been solidified in a curved state due to shrinkage.

[0002]

2. Description of the Related Art Conventionally, a continuous casting mold (hereinafter, simply referred to as a mold) 70 used in a continuous casting facility has a pair of narrow cooling members 71, 72 as shown in FIG.
And long sides 73 and 74 which are a pair of wide cooling members arranged so as to sandwich the short sides 71 and 72, and bolts 75 are provided at both ends of the facing long sides 73 and 74, respectively.
Is attached and fixed by a nut 76 via a spring (not shown). The short sides 71 and 72 are mirror-symmetrical and have the same configuration, and as shown in FIGS. 6A and 6B, a large number, for example, 10 water guiding grooves 77 are provided in the vertical direction on the back surface side. It has a copper plate 78 and a back plate 80 (also referred to as a cooling box) which is an example of a support member fixed to the back surface side of the copper plate 78 by bolts 79. Then, the copper plate 78 is cooled by flowing industrial water, which is an example of cooling water, into the water guiding groove 77 via the drainage portion 81 and the water supply portion 82 provided at the upper end portion and the lower end portion of the back plate 80, respectively. There is.

On the other hand, although the long sides 73 and 74 have substantially the same structure, the inner facing surface 84 of each copper plate 83 is curved to one side from the upper end portion to the lower end portion, and the curved inner facing surface 84 is The radius of curvature in the up-and-down direction is defined by a predetermined radius of curvature R ₁
(For example, about 10 m) is set. Also, long side 7
The width of the copper plate 83 of 3, 74 is longer than the width between the short sides 71, 72, and the width of the back plate 85 fixed to the back surface side of the copper plate 83 becomes longer than the width of the copper plate 83. The number of bolts for fixing the copper plate 83 is larger than that of the short sides 71, 72. For this reason,
Copper plate 7 with short sides 71 and 72 sandwiched between long sides 73 and 74
8 is such that the side surface of the copper plate 78 is the inner facing surface 84 so as to contact the curved inner facing surface 84 of the copper plate 83 on the long sides 73 and 74.
The radius of curvature R ₁ is set to the same value. The copper plate 78 having the short sides 71 and 72 and the copper plate 83 having the long sides 73 and 74 form a mold body 86.

During the continuous casting operation, above the continuous casting mold 70 (short sides 71, 72, long sides 73, 7).
Molten steel is poured from the upper side (4), the cast piece to be the product is initially solidified by this mold 70, and the solidified cast piece is continuously drawn from below the mold 70 to manufacture. The mold 70
The molten steel temperature poured into the mold and the surface temperature of the slab at the outlet of the mold 70 differ depending on the operating conditions, but the molten steel temperature is usually about 150
The surface temperature of the slab at the outlet of the mold 70 is about 0 ° C.
It is 0-1200 degreeC. The inside of the slab here is in a non-solidified state, that is, in a liquid state. In this way, when the molten steel becomes a semi-solidified state and becomes solid, and when the temperature drops to the temperature of the outlet of the mold 70, for example, solidification shrinkage,
Shrinkage such as solid shrinkage occurs. Therefore, due to this contraction, between the cooling surface (contact surface with the slab) formed by the inner facing surface 87 of the copper plate 78 and the inner facing surface 84 of the copper plate 83 and the solidified shell (solidified shell) of the slab. Gap (air gap)
Occurs. The generation of this gap significantly reduces the heat transfer between the cooling surface and the solidified shell, and makes the solidified shell non-uniformly cooled. A breakout etc. will be invited.

Therefore, various proposals have been made for changing the inner surface shapes of the copper plates 78 and 83 by the amount corresponding to (compensating for) the shrinkage of the slab and maintaining a good contact state between the cooling surface and the solidified shell. There is. For example, in Japanese Patent Laid-Open No. 6-297101, the inner peripheral length formed by the inner facing surfaces of the short-side copper plate and the long-side copper plate is increased on the upper end side of the copper plate and decreased on the lower end side of the copper plate. Moreover, a continuous casting mold is disclosed in which the reduction rate of the inner peripheral length is reduced from the upper end to the lower end of the copper plate. This allows the use of a mold with an inner peripheral length that is approximately equal to the contracted contour of the initial solidification of the slab, and can keep the contact state between the copper plate and the solidified shell optimal, thus promoting the formation of the solidified shell and solidifying. The shell thickness was made uniform so as not to cause vertical cracks, rhombus deformation, etc. that would cause deterioration of the quality of the cast slab. Further, in Japanese Unexamined Patent Publication No. 2000-42690, a reduced portion corresponding to the solidification shrinkage amount from the liquid phase to the solid phase of the molten steel injected into the mold is provided in the vertical cross-sectional shape of the upper part of the copper plate (from the meniscus position to the predetermined region). A formed continuous casting mold is disclosed. As a result, the solidified shell of the slab can be reliably brought into contact with the cooling surface from the initial generation stage until it leaves the cooling surface (pulled out from the mold), so that the cooling effect of the cooling surface can be sufficiently exerted. It is possible to prevent internal cracking of the slab.

[0006]

However, even when the above-mentioned technique is used, the shrinkage of the cast piece is not completely compensated, the cooling of the cast piece is not uniform, and the contact between the cooling surface and the cast piece is not achieved. The reality is that it is not perfect. For example, cooling molten steel,
After the continuous casting mold used in the continuous casting equipment (arc-shaped continuous casting equipment) for producing cast pieces solidified from molten steel in a curved state, when the inner facing surface of the copper plate was observed, the wear state of the copper plate was not observed. Uniform, especially casting radius (radius of curvature)
Wear is large on the inner facing surfaces in the direction (cast arc reference surface and its facing surface), and the occurrence of wear is different between the reference surface and the facing surface. As described above, a large amount of local wear is generated on the inner facing surface of the copper plate, and therefore the continuous casting mold must be replaced, which shortens the life and is not economical. Further, the occurrence of large local wear on the inner facing surface of the copper plate means that the contact state between the inner facing surface and the slab surface is uneven from the upper end to the lower end of the copper plate. Therefore, the slab cannot be cooled uniformly,
There is a possibility of causing internal cracking of the slab, which causes quality deterioration, and further causing breakout of the slab. The present invention has been made in view of such circumstances, a continuous casting mold and a continuous casting facility using the casting mold considering the change of the casting radius of the casting due to shrinkage can be produced economically and good quality slab The purpose is to provide.

[0007]

The casting mold for continuous casting in consideration of the change in the casting radius of the casting due to the shrinkage according to the present invention in accordance with the above-mentioned object is a casting obtained by cooling molten steel and solidifying the molten steel in a curved state. In the continuous casting mold used in the continuous casting equipment to be manufactured, one of the inner facing surfaces of the mold body is curved from the upper end portion to the lower end portion, and the radius of curvature in the vertical direction of the curved inner facing surface is equal to that of the inner facing surface. From the upper end portion to the lower end portion, the linear expansion amount and the temperature of the cast slab were made to decrease continuously or intermittently. With this configuration, the radius of curvature in the vertical direction of the inner facing surface of the mold body can be set to a value corresponding to the contracted outer shape of the contracting slab, so that even if the slab contracts, the surface of the slab The contact state between the inner facing surface and the inner facing surface can be optimized, and the slab can be easily pulled out from the continuous casting mold along the shape of the inner facing surface. Here, in the continuous casting mold in consideration of the change in the cast slab casting radius due to shrinkage according to the present invention, the radius of curvature of the inner facing surface is 100% to 99 from the upper end to the lower end of the inner facing surface.
It is preferable to gradually decrease the range to 97.5%. With such a configuration, the radius of curvature of each portion from the upper end to the lower end of the inner facing surface can be set to a value corresponding to the contracted outer shape of the contracting slab, so that the slab contracts, It becomes possible to easily manufacture a continuous casting mold capable of optimally maintaining the contact state between the surface of the slab and the inner facing surface.

The continuous casting equipment using a casting mold for continuous casting in consideration of the change in the casting radius of the casting due to the shrinkage according to the present invention, which meets the above-mentioned object, is a casting in which molten steel is cooled and solidified from the molten steel in a curved state. In a continuous casting facility for manufacturing, one inner facing surface of a mold body for solidifying molten steel is curved from the upper end to the lower end, and the vertical radius of curvature of the curved inner facing surface is the upper end of the inner facing surface. From the bottom to the lower end, it is continuously or intermittently reduced according to the linear expansion amount and temperature of the slab, and further, on the downstream side of the mold main body, faces the inner facing surface as the radius of curvature of the inner facing surface decreases. A plurality of guide rolls are provided in which the radius of curvature of the contact transport surface gradually decreases. With this configuration, the radius of curvature in the vertical direction of the inner facing surface of the mold body, and further, the radius of curvature of the opposing abutting and transporting surfaces constituted by the plurality of guide rolls provided on the downstream side of the mold body, Since it can be set to a value corresponding to the contracted outer shape of the shrinking slab, even if the slab contracts, the contact state between the surface of the slab and the inner facing surface and between the surface of the slab and the abutting and conveying surface can be further improved. It can be optimized, and the cast piece can be easily pulled out from the continuous casting mold along the inner facing surface and the shapes of the plurality of guide rolls.

The present inventors have completed the present invention by simulating and analyzing the solidification and cooling conditions of a cast piece by a computer. From this examination, it was found that not only the flat cross-sectional shape of the slab changes but also the casting radius of the slab greatly changes due to solidification shrinkage of the slab during cooling, and the change in the casting radius is compensated for. In order to
The amount of linear expansion of the slab during solidification was examined.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, referring to the attached drawings, an embodiment in which the present invention is embodied will be described to provide an understanding of the present invention. Here, FIG. 1 is an explanatory view of a mold body of a continuous casting mold in consideration of a change in a cast slab casting radius according to an embodiment of the present invention, and FIG. 2 is an oblique view of the mold body of the continuous casting mold. FIG. 3 is an explanatory diagram viewed from above, FIG. 3 is an explanatory diagram of linear expansion with respect to temperature of a slab solidified by the continuous casting mold, and FIG. 4 is an explanatory diagram of a continuous casting facility using the continuous casting mold.

As shown in FIGS. 1 to 4, a continuous casting mold (hereinafter also simply referred to as a continuous casting mold) in consideration of a change in a cast slab casting radius according to an embodiment of the present invention.
10 is used for a continuous casting facility 12 that cools molten steel and manufactures a slab 11 that is solidified from molten steel in a curved state.
As described above, it is manufactured by combining the short side which is the pair of narrow cooling members and the long side which is the pair of wide cooling members (see FIG. 5). Also, the continuous casting mold 1
The short side of 0 is made of copper, which is an example of a metal having good thermal conductivity, and the copper plate 13 having a water passage portion on the back surface side and the copper plate 1
A back plate (also referred to as a cooling box or a water box), which is an example of a support member fixed by a bolt, which is an example of an attaching means, on the back surface side of No. 3, and a water supply section and a drain section provided on the back plate are provided. The copper plate 13 is cooled by flowing industrial water, which is an example of cooling water, to the water passage (see FIGS. 6A and 6B). The long side of the continuous casting mold 10 has substantially the same configuration as the short side described above,
The copper plate 13 on the short side and the copper plate 14 on the long side form a mold body 15. The details will be described below.

As shown in FIGS. 1 and 2, the vertical length L from the upper end to the lower end of each of the short-side and long-side copper plates 13 and 14 constituting the mold body 15 is, for example, about 700 to 900 mm, One of the mold bodies 15, that is, the inner facing surface 16 of the long side copper plate 14 is curved in one direction from the upper end to the lower end. Therefore, the pair of long side copper plates 14 are
Since the pair of short side copper plates 13 are arranged so as to be sandwiched therebetween,
The side surface of the copper plate 13 on the short side is warped so as to correspond to the curved state of the inner facing surface 16 on the long side. The width W of the copper plate 13
Since the widths of the copper plates 14 are similar from the upper end to the lower end, the inner facing surfaces 17 of the pair of short side copper plates 13 and the inner facing surfaces 16 of the pair of long side copper plates 14 are short. The inner peripheral length constituted by and is shorter at the lower end portion than at the upper end portion of the mold body 15. This is determined, for example, in consideration of volumetric shrinkage of the slab, such as solidification shrinkage and solid shrinkage, and the numerical value is determined based on past performance data and the linear expansion amount and temperature of the slab. It is preferable.

The inner facing surface of the copper plate 14 curved in the front-rear direction
The radius of curvature of 16 in the vertical direction is at the upper part of the inner facing surface 16.
About the same as the inner facing surface 84 (see FIG. 5) of the conventional copper plate 83
Radius of curvature R₂ (For example, about 10 to 15 m)
(Dotted line in 1), and the radius of curvature R at the bottom of the inner facing surface 16
₂ Smaller radius of curvature R₃ I am trying. This radius of curvature R
₃ Is determined according to the linear expansion amount and temperature of the slab
The radius of curvature R₂ Is 100%, 99-
It is set to a numerical value in the range of 97.5%. This makes the bay
The radius of curvature of the curved inner facing surface 16 in the vertical direction is
The linear expansion of the slab from the upper end to the lower end of the facing surface 16
And gradually decreases continuously or intermittently according to the temperature
It becomes possible to do. Note that continuous means the inner facing surface.
The radius of curvature from the upper end to the lower end of
Or change it by a certain value (for example, 1 to 10).
It means to change little by little every
Intermittent means from the upper end to the lower end of the inner facing surface,
Divide the inner facing surface into predetermined intervals (depending on the length of the copper plate
For example, every 50 to 200 mm)
This means setting the rate radius.

Here, the radius of curvature R ₃ of the inner facing surface 16
The reason why is set to the above numerical value will be described. As shown in FIG. 3, pure iron, which is an example of the chemical composition of the slab,
In a liquid state, it is poured into the continuous casting mold 10 and begins to solidify,
The slab temperature at the upper part of the continuous casting mold 10 is, for example, 1500.
If the temperature is around ℃, the linear expansion is 2.5
%, And when the surface temperature of the slab at the outlet of the continuous casting mold 10 is, for example, about 800 ° C., the linear expansion amount is about 1.0%. During this period, it is found that the phase expansion occurs in pure iron, so that the linear expansion amount is partially reduced. Therefore, if the reduced linear expansion amount is taken into consideration (for example, the average is taken), shrinkage of about 1.7% occurs in the slab by lowering the temperature of the slab from 1500 ° C to 800 ° C. Will be done. Therefore, with respect to the casting radius of the upper portion of the continuous casting mold 10, at the casting radius of the outlet of the continuous casting mold 10,
Since shrinkage of 1.7% occurs, the casting radius at the outlet of the continuous casting mold 10 must be 1.7% smaller than the casting radius of the upper part of the continuous casting mold 10. That is, if the radius of curvature R ₂ of the upper portion of the inner facing surface 16 of the copper plate 14 is 100%, it means that the radius of curvature R ₃ of the lower portion of the inner facing surface 16 is 98.3%. Therefore,
When the radius of curvature R ₂ is, for example, 10 m, the radius of curvature R
₃ will be 9.83m.

Note that, for example, the chemical composition of the slab (for example,
0.25 mass% carbon steel, 0.80 mass% carbon steel, etc.), the surface temperature of the upper slab of the continuous casting mold 10 and the outlet slab of the continuous casting mold 10 When the surface temperature is changed, the above-mentioned linear expansion amount is changed, so that the radius of curvature R ₃ is set in the range of 99 to 97.5%. However, in order to optimize the contact state between the surface of the slab to be solidified in the continuous casting mold 10 and the inner facing surface 16 of the copper plate 14, the radius of curvature R ₃ is in the range of 99 to 98%, and further 98 It is preferably in the range of 0.5 to 98%.

Next, a continuous casting facility using a continuous casting mold in consideration of a change in the cast slab casting radius according to the embodiment of the present invention will be described. As shown in FIG. 4, the continuous casting facility 12 includes a tundish 18 arranged at an upstream end, the continuous casting mold 10 for solidifying molten steel supplied from the tundish 18, and a continuous casting facility. The cooling device 20 is provided on the downstream side of the mold body 15 of the mold 10 and includes a plurality of guide rolls 19 for further cooling the slab 11 solidified by the mold body 15. The slab 11 is provided downstream of the cooling device 20.
Is pulled out from the mold body 15, and a pull-out correction device 22 in which a plurality of rolls 21 for rectifying the slab 11 solidified in a curved state to a flat state is arranged is installed, and the slab 23 in the flat state is Further, it is cut into a predetermined length by a cutting device (not shown) arranged further downstream.

The plurality of guide rolls 19 constituting the cooling device 20 are opposed to each other in contact conveying surfaces, that is, the plurality of guide rolls 19 and the slab 11 as the radius of curvature of the inner facing surface 16 of the copper plate 14 decreases. The radius of curvature R _{4 of the} surface connecting a plurality of contact points with and is curved is gradually reduced. Therefore, the radius of curvature R ₄ of the contact transport surface is based on the radius of curvature R ₃ of the lower end of the inner facing surface 16 of the copper plate 14,
From the upstream end to the downstream end of the contact conveyance surface, the linear expansion amount and the temperature of the cast slab 11 are made to correspond to the continuous or intermittent reduction. With such a configuration, it is possible to prevent a local force from the guide roll 19 on the slab 11 caused by the solid contraction of the slab 11, so that damage to the guide roll 19 can be reduced and it is economical.

When the continuous casting mold 10 is arranged in the existing continuous casting equipment, that is, the continuous casting equipment in which the radius of curvature of the contact transfer surface formed by a plurality of guide rolls cannot be changed, It is preferable that the radius of curvature of the inner facing surface is gradually increased from the lower end to the upper end of the inner facing surface of the mold body based on the radius of curvature of the upstream end of the plurality of guide rolls. Therefore, when the radius of curvature R ₄ of the upstream end of the contact conveyance surface is set to, for example, 10 m, the radius of curvature R ₃ of the lower end of the inner facing surface of the mold body becomes 10 m, and the upper end of the inner facing surface. The radius of curvature R _{2 of} is preferably set to 10.17 m from the above range. At this time, it is preferable that the radius of curvature of the inner facing surface be continuously or intermittently increased from the lower end to the upper end of the inner facing surface.

Although the present invention has been described with reference to one embodiment, the present invention is not limited to the configuration described in the above embodiment, but is described in the scope of claims. Other embodiments and modifications that are conceivable within the scope of the matters described above are also included. For example, in the above-described embodiment, the case of using an assembly mold in which a pair of short sides and a pair of long sides provided with a large number of water guiding grooves is used as the continuous casting mold has been described, but for example, a copper tube The present invention is also applicable to a tubular mold in which the above is housed in a housing having a water guiding groove, a block mold in which a water guiding groove is bored in a cast or forged copper block, and the like. Then, by changing the type of the mold used as the continuous casting mold in this manner, for example, a slab (for example, a width of about 1000 to 2500 mm and a thickness of 200 to 300).
mm), bloom (for example, width and thickness of 200 ~
400 mm), billet (for example, width and thickness is 1
It is possible to manufacture slabs such as beam blanks (used for H-section steel), etc., respectively.

Further, in the above-mentioned embodiment, the plane section is
For continuous casting having a mold body with a rectangular opening
I explained the case of using a mold, but the plane cross section of the opening
Corresponding the shape of, to the cross-sectional shape of the slab to be manufactured,
For example, polygon (for example, convex, concave, hexagonal, octagonal)
Etc.), a circle, an ellipse, and the like. That
In the above-mentioned embodiment, one inside of the mold body
Radius of curvature R at the top of the facing surface₂ The conventional copper plate of the mold body
The radius of curvature of the inner facing surface of the
Radius of curvature R₃ Corresponding to the linear expansion amount and temperature of the slab
Radius of curvature R ₂ Making it smaller. At this time, mold book
The contact state between the inner facing surface of one side of the body and the surface of the slab is better
In order to perform properly, the upper end of one inner facing surface of the mold body
From the bottom to the lower end, the temperature of the slab is set at a predetermined interval (eg, 1
It is measured every 0 mm), and based on the temperature and the amount of linear expansion,
It is also possible to set the radius of curvature of the inner facing surface.
is there. Further, in the above embodiment, the curved inner side
The vertical radius of curvature of the facing surface is based on the linear expansion of the slab.
I explained the case of changing, the linear expansion coefficient of the slab and
It is also possible to change it based on the coefficient of thermal expansion.

[0021]

According to the first and second aspects of the present invention, in a continuous casting mold that takes into account the change in the casting radius of the casting due to the shrinkage, the vertical radius of curvature of the inner facing surface of the casting mold body shrinks. Even if the slab contracts, the contact state between the surface of the slab and the inner facing surface can be optimized so that the slab can be moved from the continuous casting mold to the shape of the inner facing surface. Can be easily pulled out. Therefore, since the shape of the contracted slab is different from the shape formed on the inner facing surface in the past, it is possible to prevent the occurrence of a large amount of local wear that has occurred inside the mold body. Can be long and economical. Further, since the contact state between the one inner facing surface of the mold body and the slab surface can be made uniform from the upper end portion to the lower end portion of the mold body, the slab can be uniformly cooled by the mold body, which is stable. A quality slab can be manufactured. Particularly, in the continuous casting mold in consideration of the change in the cast piece casting radius due to the shrinkage according to claim 2, the radius of curvature of each portion from the upper end portion to the lower end portion of the inner facing surface shrinks the shrinking outer shape of the cast piece. Since it can be set to a value corresponding to, it is possible to easily manufacture a continuous casting mold that can keep the contact state between the surface of the slab and the inner facing surface optimal even if the slab contracts. Become. Therefore,
Since it is possible to provide a continuous casting mold that can reduce the possibility that a large force is locally applied to the inner facing surface due to the shape change of the slab due to shrinkage, for example, the frequency of continuous casting mold replacement due to wear or damage is reduced. It is economical because it can be done.

According to a third aspect of the present invention, in a continuous casting facility using a continuous casting mold that takes into account the change in the casting radius of the slab due to shrinkage, the radius of curvature in the vertical direction of one of the inner facing surfaces of the mold body, and further the mold. Even if the slab contracts, the radius of curvature of the abutting and conveying surfaces facing each other formed by the plurality of guide rolls provided on the downstream side of the main body can be set to a value corresponding to the contracted outer shape of the contracting slab. It is possible to further optimize the contact state between the surface of the slab and the inner facing surface, and the surface of the slab and the contact conveying surface, and the slab is cast from the continuous casting mold along the inner facing surface and the shape of the plurality of guide rolls. Can be easily pulled out. Therefore, since the shape of the shrunk slab is different from the shape formed by the inner facing surface and the contact transport surface, it is possible to prevent the occurrence of large local wear that has occurred inside the mold body, and Since it is possible to prevent the generation of a large local force received from the rolls, the continuous casting equipment can be stably operated and the workability is improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a mold body of a continuous casting mold in consideration of a change in a cast slab casting radius according to an embodiment of the present invention.

FIG. 2 is an explanatory view of a mold body of the continuous casting mold as seen obliquely from above.

FIG. 3 is an explanatory view of linear expansion with respect to temperature of a slab solidified by the continuous casting mold.

FIG. 4 is an explanatory view of a continuous casting facility using the continuous casting mold.

FIG. 5 is a plan view of a continuous casting mold according to a conventional example.

6A and 6B are side views seen from the inside of a short side used in a continuous casting mold according to a conventional example, respectively.
FIG. 7 is a sectional view taken along line AA of FIG.

[Explanation of symbols]

10: continuous casting mold, 11: cast piece, 12: continuous casting equipment, 13: copper plate, 14: copper plate, 15: mold body, 16:
Inside facing surface, 17: Inside facing surface, 18: Tundish, 19: Guide roll, 20: Cooling device, 21: Roll, 22: Pull-out straightening device, 23: Cast slab

Continued front page    (72) Inventor Hideto Sugiyama             5-1 Shinsone, Kokuraminami-ku, Kitakyushu City, Fukuoka Prefecture             Mishima Kosan Co., Ltd. F term (reference) 4E004 AA06 LC10 NA01 NB01 NC01

Claims (3)

[Claims] 1. A continuous casting mold used in a continuous casting facility for cooling molten steel and producing cast pieces solidified from the molten steel in a curved state, wherein one inner facing surface of the mold body extends from the upper end to the lower end. A curved radius of curvature of the curved inner facing surface in the vertical direction is continuously or intermittently applied from the upper end to the lower end of the inner facing surface in accordance with the linear expansion amount and temperature of the slab. A continuous casting mold that takes into account the change in the casting radius of the slab, which is characterized by being made smaller. 2. The continuous casting mold according to claim 1, which takes into account the change in the cast slab casting radius due to shrinkage, wherein the radius of curvature of the inner facing surface is 100% from the upper end to the lower end of the inner facing surface. From 99 to 97.5%, the casting mold for continuous casting in consideration of the change in the casting radius of the slab due to shrinkage. 3. In a continuous casting facility for cooling molten steel and producing a cast piece solidified from the molten steel in a curved state, one inner facing surface of a mold body for solidifying the molten steel is curved from an upper end to a lower end. In addition, the radius of curvature in the vertical direction of the curved inner facing surface is reduced continuously or intermittently from the upper end to the lower end of the inner facing surface in accordance with the linear expansion amount and temperature of the slab. In addition, a plurality of guide rolls are provided on the downstream side of the mold body, the radius of curvature of the facing abutting and conveying surfaces gradually decreasing as the radius of curvature of the inner facing surface decreases. Continuous casting equipment using a continuous casting mold that takes into account changes in the casting radius of slab due to shrinkage.