JPH0459063B2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) This invention relates to a mold that cools and solidifies supplied molten metal to form a slab in order to continuously cast metal such as steel. This invention relates to a continuous casting mold that uniformly cools a slab and prevents molten metal from flowing out even if the slab breaks within the mold.

(Prior Art) A mold used in continuous casting is a device that forms a mold into a cylindrical body, and cools and solidifies molten metal supplied into the hollow part of the mold to form a slab. In a mold, the mold is made of a material with excellent thermal conductivity so as to have a hollow part according to the desired cross-sectional shape and dimensions of the mold, and a cooling water jacket is equipped on the outside of the mold to keep the mold cool. The cooling water is configured to flow along the outer peripheral wall. Therefore, the heat of the molten metal is absorbed by the cooling water flowing through the mold, and the molten metal is cooled and solidified to become a slab.

A mold in a continuous casting mold originally has a structure in which a cylindrical body is integrally formed. Integral cylindrical bodies include those that are integrally tube-shaped (tubular mold or block mold), and those that are assembled into a cylindrical body by fixing multiple mold elements divided in the circumferential direction (assembled cylindrical body). This is a so-called fixed mold in which the cross-sectional dimension of the hollow part does not change during casting. Such molds are still widely used because they are easy to mold. Since the slab contracts as it cools, the inner circumferential wall of the stationary mold is provided with an appropriate taper (the cross-sectional dimension of the inner circumferential wall is smaller on the downstream side) in order to maintain contact between the mold and the slab.
However, because the shrinkage of a slab depends on many factors such as the type of metal being cast, temperature, and casting speed, it is difficult to maintain uniform contact between the inner peripheral wall of the mold and the surface of the slab. Partial cooling of the slab may progress, resulting in deformation, cracking, or disturbance of the internal structure of the slab.

In order to eliminate these drawbacks, in recent years, the above-mentioned fixed mold has been shortened, and the cylindrical body has been divided into multiple elements on the downstream side, and some or all of the elements have been made movable in the radial direction. Increasingly, so-called movable molds, which are pressed against the surface of the slab, are installed coaxially. Each element of the movable mold is arranged in a frame outside the mold, and the movable element (moving element) is supported by the frame via biasing means such as a spring or a hydraulic cylinder, and is pressed against the surface. As mentioned above, the movable mold is installed downstream of the fixed mold, that is, after the solidified layer has formed on the surface of the molten metal, but since the movable element is pressed against the surface of the slab, the slab is always Contact with the surface can be ensured, and the slab can be cooled uniformly. Moreover, since the moving element resists the pressure of the molten metal that acts to bulge the slab, it also has the effect of preventing bulging compared to cooling by spray water. A mold with such a movable mold is also called a self-tapered mold or an adjustable mold.

FIG. 7 shows a cross-sectional view of a conventional movable mold in a plane perpendicular to its axis. The figure shows, as an example, a movable mold for obtaining a slab having a circular cross section, and the cooling water jacket and the like on the outer peripheral wall of the mold are omitted. The four elements a' forming the cylindrical body are all moving elements, but while the moving direction of each element a' is up and down or left and right in the figure, the boundary between each element and the adjacent element That is, the divided end faces of each element are oriented diagonally in the figure and are not parallel to the above-mentioned movement direction. Conventionally, even in movable molds for not only circular but rectangular cross-section slabs, the moving direction of the moving element and the dividing end surface of each element were not parallel to each other as described above. Therefore, since the movable element cannot move inward (in the direction of diameter reduction) from the position where the divided end surfaces contact, a gap d as shown in the figure is provided in advance for movement in the direction of diameter reduction. I needed to arrange the elements. For molds with such movable molds, please refer to “World Steel &
It is described in "Metelworking" Vol. 4, 1982h, p. 160, and Japanese Patent Application Laid-open No. 56-47246.

(Problems to be Solved by the Invention) In the conventional continuous casting mold having the movable mold described above, if a solidified layer is not sufficiently generated around the entire surface of the slab, the molten metal inside the slab will flow out. This poses operational inconveniences. In other words, while casting is being carried out smoothly, the solidified layer generated in the upstream stationary mold becomes an outer shell and holds the molten metal, so there is no gap between the split end faces of each element as described above. However, if the solidified layer is insufficiently formed or breaks for some reason, molten metal will flow out from the gap. If the molten metal inside flows out (breakout) from the missing part of the solidified layer, not only will it be impossible to continue continuous casting, but the high temperature of the molten metal may damage the mold and surrounding equipment. be.

Furthermore, when performing continuous casting, there is always a period during which the formation of the solidified layer becomes unstable during each operation.
For example, at the beginning or just before the end of casting, the temperature of the molten metal and casting equipment may be unstable.
Because slag and inclusions are often involved, a uniform solidified layer is often not produced. Also, during casting, if the temperature of the molten metal is too high or the drawing speed is too high, it may not be possible to generate a solidified layer sufficient to withstand the internal pressure (pressure of the molten metal), or the solidified layer may break. There is also.

If the broken part of the solidified layer is inside the fixed mold, the broken part of the slab can be repaired by temporarily stopping drawing, and the molten metal will not flow out. For example, it becomes impossible to solve the problem of deformation and cracking of the slab due to non-uniform cooling.

(Objective of the Invention) This invention was made to solve the above-mentioned problems, and it is possible to cool the slab uniformly, and also prevent the solidified layer on the surface of the slab from forming insufficiently or breaking. The object of the present invention is to provide a continuous casting mold that can continue continuous casting without causing molten metal to flow out even in such cases.

(Means for Solving the Problems) In order to achieve the above object, in the present invention, in a continuous casting mold in which a fixed mold and a movable mold are coaxially connected, the movable mold is configured as shown below. (a) a movable element, (b) a fixed element, and (c) an insulating element; Thus constructed, each element was closely aligned with respect to its adjacent elements and the fixed mold, respectively.

(a) Movable element: An element that is disposed on a frame so as to be movable in the diameter reduction or diameter expansion direction of the cylindrical body, and whose divided end surfaces are formed parallel to the movement direction.

(b) Fixed element: An element fixed to said frame.

(c) Pressure contact element: an element that is movably supported by the frame or the movable element and biased toward the adjacent element.

Furthermore, in the present invention, each element of the movable mold and an element adjacent thereto in the axial direction or the fixed mold are connected to each other so as to be slidable in the moving direction and cannot be separated in the axial direction. It is preferable.

(Function) According to the continuous casting mold of the present invention configured as described above, there is no gap between each element and the adjacent element and the fixed mold, and in addition, the movable element moves in this state. can adhere closely to the surface of the slab. Therefore, the slab is cooled uniformly, and even if the solidified layer on the surface of the slab is insufficiently formed or broken in the mold, the molten metal will not flow out.

(Example) Hereinafter, an example of the present invention will be described based on the drawings. FIG. 1 is an axial cross-sectional view of a mold for horizontal continuous casting of steel according to the first embodiment, FIG. 2 is a cross-sectional view taken along the - line in FIG. 1, and FIGS. FIG. 3 is a detailed view of the parts and parts.

As shown in FIG. 1, in horizontal continuous casting, a mold A is connected to a tundish K for storing molten steel M, and a drawing roll L is disposed downstream of this. Therefore, the molten steel M is supplied to the tundish K and temporarily stored there, and then flows into the mold A where it is cooled and turned into a slab N, which is continuously drawn out by the rolls L. The molten steel M flows into the mold A through the nozzle Ka of the tundish K and the connecting refractory Kb, but from the time it comes into contact with the inner peripheral wall of the mold A, a solidified layer Na is formed sequentially from the contact surface, that is, the outer periphery, and the slab is formed. Form N.

Mold A is fixed mold A in order from the upstream side.
0, a movable mold A1 and a movable mold A2 are arranged coaxially. The fixed mold A0 is a tubular mold made of an integral copper alloy, and the cross section of the hollow part thereof is formed into a circular shape with a diameter that allows for shrinkage of the slab due to cooling. A cooling water jacket F0 is attached to the outside of the mold A0 via an O-ring P0, and the supplied cooling water is connected to the mold A0.
It is designed to flow along the outer peripheral wall of 0.
Further, a thermocouple G0 is installed near the entrance of the mold A0 to measure the temperature of the mold A0 during casting to detect abnormalities such as broken slabs.

As shown in FIG. 2, the movable slab A1 is a cylindrical body formed from a total of eight divided elements made of copper alloy and surrounding a circular hollow part. These elements consist of two types: the four elements 1a on the top, bottom, left and right, which occupy most of the area of the inner circumferential wall, and the other four elements 1b adjacent to them, but on the outside of each element,
Cooling water jacket B1a via O-ring P1,
B1b is installed and the supplied cooling water is supplied to each element 1.
It is designed to flow along the outer peripheral walls of a and lb. The rod end of the air cylinder C1 is engaged with the outside of the cooling water jacket B1a by an engaging member B1x. The base end of this cylinder C1 is fixed to the fixed frame F1 extending from the cooling water jacket F0, so that the element 1a
The cooling water jacket B1a is supported by the frame F1 via the cylinder C1. Since the cylinder C1 applies air pressure in the direction of expansion, the element 1a and the cooling water jacket B1a
is urged by this cylinder C1 to move inward (in the direction of diameter reduction), and conversely moves outward (in the direction of diameter expansion) due to the reaction force from the slab N. It is fastened to the outside of the other cooling jacket B1b to the fixed frame F1 with bolts (not shown). That is, out of a total of eight elements 1a and 1b, four elements 1a are movable elements (movable elements), and the other four elements 1b are supported by the frame F1 as fixed elements. However, the insertion hole of the engaging member B1x into which the rod of the cylinder C1 is inserted and the insertion hole (not shown) of the bolt that fastens the frame F1 and the cooling jacket B1b are both in the axial direction of the mold A ( A slightly elongated hole is drilled in the casting direction), and the jacket B1a (moving element 1a)
and the jacket B1b (fixing element 1b) can be slid slightly in the axial direction.

In the cross section perpendicular to the axis shown in FIG.
The divided end faces of the moving elements 1a, that is, the interfaces between each element 1a and the adjacent fixed element 1b are as follows:
The elements 1a are formed parallel to the above-mentioned movement direction, and each element is arranged so that there is no space between adjacent elements. Since the boundary surface is parallel to the moving direction, the movement of the element 1a is not restricted even if there is no gap between the elements as a movement margin.

As shown in FIG. 1, a movable mold A2 is further provided in series on the coaxial downstream side of the fixed mold A0 and the movable mold A1. This movable mold A2 has an axis-perpendicular cross section (not shown) similar to that shown in FIG.
Four moving elements 2a that are movable in the radially expanding direction and four fixed elements 2b (2b
and 2b ₁ , 2b ₂ , and 2b ₃ described later are not shown). The difference from movable mold A1 is that
A total of eight elements 2a and 2b are copper alloy plates 2a ₂ and 2
Graphite liners 2a ₁ and 2b ₁ are attached to the inner surface of b ₂ . Copper alloy plates 2a ₂ , 2b ₂ and graphite liner 2
a ₁ and 2b ₁ are fastened together with bolts (not shown) in the thickness direction, but the keys 2a ₃ and 2b ₃ are fitted and engaged so that they do not shift in the axial direction (casting direction). There is. Graphite liners 2a ₁ and 2b ₁ have self-lubricating properties,
Because it has a lower thermal conductivity than copper alloys,
It has the effect of smoothing the drawing of the slab N and increasing the cooling strength. In the movable mold A2 as well, the end faces of the four moving elements 2a are formed to be parallel to the moving direction, and each element is arranged closely with respect to the adjacent element.

Even when mold A is viewed in the axial direction as shown in Fig. 1, the divided end surfaces of movable elements 1a and 2a (with respect to adjacent elements or molds) are In addition, all the elements are arranged closely with respect to the adjacent elements and the fixed mold A0.

Since mold A is long in the axial direction, molds A0, A1, and A2 will thermally expand and be slightly displaced in the axial direction during casting, so if mold A cools and contracts after casting, molds A0, A1, and A2 will There will be gaps between the molds A1 and A2, but the following measures have been taken to prevent this. That is,
Each element 1a (1b) of the fixed mold A0 and the movable mold A1
The same applies to elements 1a and 1b, as shown in Figure 3.
is screwed near the end of the movable mold A1, and the shaft part is connected by a bolt H inserted into the insertion hole A0x of the protruding part A0w of the fixed mold A0, and each element 1a, 1b of the movable mold A1
and each element 2a, _2b of the movable mold A2, as shown in _FIG . It is connected by interlocking with 2y. Bolt H is inserted into hole A0x so that it can slide through a small gap.
The elements 1a and 1
b cannot be separated from the fixed mold A0 in the axial direction of the mold A, and the movable element 1a has a reduced diameter.
Movement in the direction of diameter expansion cannot be prevented. In addition, the fitting portion 1y and the fitting portion 2y are slidably engaged with each other through a small gap in the axial direction, and spaces 1z and 2z are provided in advance in the direction perpendicular to the axis, so that the elements 2a, 2b cannot be separated from the elements 1a, 1b in the axial direction, and the movable element 1
a and 2a cannot prevent each other from moving in the direction of diameter contraction/diameter expansion.

According to the mold A of this embodiment configured as described above, continuous casting is performed as follows. Steel M flowing into mold A from tandate K
first comes into contact with the inner peripheral wall of the fixed mold A0 and is cooled, forming a solidified layer Na on the outer periphery. As the slab N is pulled out by the rolls L, the solidified layer Na moves downstream and eventually reaches the inside of the movable mold A1. coagulation layer
Na contracts as it cools, and the outer diameter of the slab N becomes smaller, but in the movable mold A1, the four moving elements 1a, which are urged in the diameter reduction direction by the air cylinder C1, are wide. Since the surface of the slab N is always in contact with the surface of the slab N, there is no chance of partial contact between the slab N and the mold A1. In other words, the slab N is uniformly cooled and deformation and cracking are prevented. Also in the movable slab A2, since the four moving elements 2a are always in contact with the slab N by the air cylinder C2, uniform cooling progresses in the same way. The moving element 2a is equipped with a graphite liner 2a ₁ on its inner surface, which reduces friction with the slab N and gently cools the slab N, which more reliably prevents cracking and is suitable for steel types with high crack susceptibility. It also makes it possible to cast.

Moreover, since the mold A configured as described above has no gaps on the inner circumferential wall over its entire length, even if a problem occurs in which part of the solidified layer Na on the surface of the slab N is missing, the inside The molten steel M will not flow out (breakout). In other words, the molds A0, A1, and A2 surrounding the slab N not only have no gaps at their axial joints, but also molds A1 and A2.
Since there is no space between the eight dividing elements 1a and 1b of the mold A2 and between the eight dividing elements 2a and 2b of the mold A2, the solidified layer Na is missing and the molten steel M is mixed into the slab N.
Even if it reaches the surface of mold A and contacts the inner circumferential wall surface of any of the molds (or elements) of mold A, it will not overflow to the outside. Moving elements 1a and 2a
If sufficient air pressure is applied to the biasing cylinders C1 and C2, the elements 1a and 2a will not move outward even when the pressure of the molten steel M is applied, so the molten steel M in contact with the inner peripheral wall will expand. It can be cooled and solidified without forming any part.

Note that the gap mentioned above refers to the gap in which the molten metal M flows out, for example, 0.1 mm.
Microscopic gaps below this level are not considered a problem.

In other words, since each element is water-cooled, even if molten steel M enters between these gaps, it will immediately solidify.
This is because the passage of any further molten steel M is stopped. Therefore, the gap between the contact surfaces due to the surface roughness of the end face of each element and the slight gap due to thermal expansion and contraction in the circumferential direction can be ignored.

The above-mentioned lack of the solidified layer Na occurs when the solidified layer Na is not generated all around the surface of the slab N, or when a part of the generated solidified layer Na breaks. Most of them are Molten M, Tandaishi K and Mold A.
At the beginning of casting when the temperature is unstable, such as immediately before the end of casting when a large amount of slag and inclusions are involved, or when the temperature of the molten metal becomes high or the drawing speed is increased, etc. Occurs in Therefore, at times like this,
If you pay attention to the temperature of the fixed mold A0 detected by the thermocouple G0, and if there is an abnormality, reduce the drawing speed slightly, the molten steel M that is about to overflow from the crack will solidify as described above, and the slab N will be repaired. breakout is avoided. Thereafter, the drawing speed can be gradually increased and casting can be continued.

Next, a second embodiment of the present invention will be described based on FIG. FIG. 5 shows a cross section in the direction perpendicular to the axis of a movable mold A3 in a horizontal continuous casting mold for obtaining a slab N' having a rectangular cross section.
On the upstream side of the movable mold A3 of this mold, there is a fixed mold (not shown) integrally formed with a rectangular cylindrical body.
are arranged in series in the same manner as in FIG. 1 (first embodiment), and the entrance portion thereof is connected to a tundish (not shown).

The movable mold A3 is a mold formed by dividing a cylindrical body having a rectangular hollow portion corresponding to the cross-sectional shape and dimensions of the slab N' into a total of eight elements. The eight elements include four elements 3a corresponding to almost the entire length excluding the four corners on the top, bottom, left and right sides, and four corners having a radius matching the cross section of the mold N' on the inner peripheral wall. Element 3 of
There is c. Elements 3a and 3c have graphite liners 3a ₁ and 3c ₁ inside copper alloy plates 3a ₂ and 3c ₂ , respectively.
It is made up of a. In addition, the elements 3a and 3c have cooling water jackets B3a and B3c on the outside, respectively.
are installed and cooled by water supplied here. The above configuration is the same as that of the movable mold A1 or A2 described above except for the shape of the hollow part.

Among the four elements 3a, the upper and lower two elements 3a are
This is a moving element supported by an air cylinder C3 disposed between an engaging member B3x attached to the upper end (or lower end) of the cooling water jacket B3a and a fixed frame F3. In other words, since the cylinder C3 applies air pressure in the direction of expansion, the element 3a and the cooling water jacket B3a are applied to the cylinder C3.
It moves inward (in the diameter-reducing direction) until it comes into contact with the mold N', and conversely moves outward (in the diameter-expanding direction) due to the reaction force from the mold N'.

In addition, the two elements 3a on the left and right are coil springs D between the cooling water jacket B3a and the frame F3.
3a is a moving element interposed therebetween. Spring B3
Since a is inserted in a pre-compressed state, the left and right elements 3a and the cooling water jacket B3
A is urged inward (in the direction of diameter reduction). Therefore,
The two left and right elements 3a, like the two upper and lower elements 3a described above, move in the diameter-reducing and diameter-expanding directions while their inner peripheral walls maintain contact with the slab surface.

The other four elements 3c of the movable mold A3 are arranged in the frame F3 as pressure contact elements that are pressed toward the adjacent movable elements 3a. That is, a coil spring D3c1 is interposed between the left side (or right side) of the cooling water jacket B3c and the frame F3 outside thereof, and the coil spring _D3c1 is interposed between the upper side (or lower side) of the cooling water jacket B3c and the moving element 3a. Cooling water jacket B3 is attached to cooling water jacket B3a.
A coil spring _B3c2 is interposed between the element 3c and the member B3y extending upwardly (or downwardly) to bias and press the element 3c toward the element 3a adjacent to the left and right or up and down, respectively. Note that the sliding contact surface of the pressure contact element 3c with the moving element 3a is made by cutting out a part of the outer side and making it a non-contact part.
This reduces the area of friction between the Also, frame F
A back-up member F3c is attached near the corner of the cooling water jacket B3c at a position slightly apart from the corner of the cooling water jacket B3c, thereby ensuring the support of the cooling water jacket B3c.

As shown in the figure, the divided end faces of the four moving elements 3a, that is, the boundary surfaces between the circumferentially adjacent pressing elements 3c, are formed parallel to the moving direction, and then the eight elements 3a and 3c are The elements are arranged so that there is no space between them. In addition, for the axially adjacent fixed mold (not shown), 8
The elements 3a and 3c are arranged closely, and the third
They are connected by the same engaging means as in the figure (first embodiment).

Regarding the movable mold A3 configured as described above, there is no gap between each element 3a, 3c and the adjacent element and the fixed mold, and in this state, the movable element 3a moves and comes into close contact with the surface of the slab. can do. In particular, in this mold A3, the pressure contact element 3c
The continuous casting mold having such a movable mold A3 actively prevents the occurrence of minute gaps due to thermal expansion and contraction. According to this method, the slab can be cooled uniformly, and even if the solidified layer on the surface of the slab is insufficiently formed or breaks in the mold, the molten metal will not flow out and the slab will be cooled. You can repair it and continue casting.

Next, a third embodiment of the present invention will be described based on FIG. 6. Fig. 6 relates to a horizontal continuous casting mold for obtaining a slab N'' with a rectangular cross section and a wide cross section, and shows a cross section perpendicular to the axis of the movable mold A4. Also, on the upstream side of the movable mold A4, there is a fixed mold (not shown) integrally formed with a rectangular cylindrical body.
are installed in succession.

The movable mold A4 is a mold formed by dividing a cylindrical body into a total of 12 elements. The 12 elements include a total of six elements 4a corresponding to the left and right long parts of the top and bottom two sides and the center part of the two left and right sides, two elements 4b in the center of the top and bottom two sides, and a corner part. 4 elements 4c
There is. all elements 4a, 4b and 4c
A graphite liner is installed on the inside of each copper alloy plate, and cooling water jackets B4a, B4b, and B4c are provided on the outside, respectively, for cooling with supplied water.

Among the six elements 4a, the four elements 4a arranged on the left and right long parts of the upper and lower sides are air cylinders C.
The two elements 4a arranged on the left and right sides are movable elements supported by the fixed frame F4 via 4.
This is a moving element with a coil spring B4a interposed between it and the frame F4. Both have the function of moving in the direction of diameter contraction and diameter expansion while the inner peripheral wall maintains contact with the surface of the slab N''.In addition, the two elements 4b arranged at the center of each of the two upper and lower sides are Fixed frame F
This is a fixing element fastened with a bolt to a support member F4b fixedly attached to F4. Furthermore, the four corner elements 4c are press-contact elements that are pressed toward the adjacent elements 4a, similar to the press-contact elements 3c of the second embodiment, but one end of the coil spring D4c as a biasing means is , all of which are fixed to the outer frame F4 of the element 4c.

As shown in the figure, the divided end faces of the six moving elements 4a, that is, the boundary surfaces between the circumferentially adjacent elements, are formed parallel to the moving direction, and then the 12 elements 4a, 4b, 4c are separated from the adjacent elements. The elements are arranged so that there is no space between them. In addition, for the axially adjacent stationary mold (not shown)
The elements 4a, 4b, 4c are arranged closely and connected in the same manner as in FIG. 3 (first embodiment).

As described above, this movable mold A4 combines the three types of elements (moving element, fixed element, and pressure contact element) explained in the first and second embodiments, and combines each element with the adjacent element and the fixed mold. 〓It was arranged immediately. Therefore, the detailed configuration is the same as the two embodiments described above, and the manner of use is also the same. However, the slab N'' cast by the mold of this embodiment has a large cross-sectional area and is prone to bulging, but this movable mold A4 has fixed elements 4b arranged at the center of each of the two long sides, top and bottom. Therefore, it is possible to reliably prevent the slab N'' from expanding due to internal pressure. Further, since the mounting positions of the two upper and lower movable elements 4a can be adjusted with reference to the fixed element 4b before use, the casting preparation work can be performed accurately.

Note that the arrangement of each element is not limited to the above. For example, in the case of a wider mold, a plurality of moving elements 4a may be arranged so as to be adjacent to each other on each of the upper and lower sides. In addition, regarding the connection in the axial direction, instead of connecting as described above, a movable mold is installed adjacent to the downstream side of the movable mold A4, and the movable mold is supported by the frame F4 and has an upstream direction. Even if a pressure contact element that is biased toward the movable mold A4 is arranged, all the elements and molds are prevented from being separated in the axial direction.

Although the above three embodiments have been shown for horizontal continuous casting molds, the continuous casting mold of the present invention can also be used for vertical (vertically oriented) or inclined continuous casting. Furthermore, the metal to be cast is not limited to steel. Furthermore, it is also possible to construct a mold to obtain slabs having a special cross-sectional shape, not limited to circular or rectangular shapes.

(Effects of the Invention) The continuous casting mold of the present invention described above provides the following effects.

(1) Each movable element of the movable mold is pressed against the mold surface and cools the slab uniformly, so there is no deformation, cracking, or bulging of the slab, and a symmetrical solidification structure is formed. Good quality slabs can be obtained.

(2) Since there is no time for molten metal to flow out onto the inner peripheral wall of the mold, continuous casting can continue without breakout even if the solidified layer on the surface of the slab is insufficiently formed and breaks. can do. Moreover, because of this, the fixed mold, which tends to lose contact with the surface of the slab, can be significantly shortened, which further increases the effect of (1) above.

(3) Since breakout occurs as described in (2) above, it is possible to increase the casting speed and improve productivity.

(4) As mentioned in (2) above, since there is no gap, the hot slab hardly comes into contact with the outside air until it leaves the mold, so oxidation on the surface of the slab is suppressed. Furthermore, since the slab and the inner circumferential wall of the mold come into contact without intervening oxide scale, the cooling effect of the mold is also improved.

[Brief explanation of the drawing]

The drawings all show a mold for horizontal continuous casting, and FIG. 1 is an axial sectional view of the mold related to the first embodiment, FIG. 2 is a sectional view taken along the line -- in FIG. 1, and FIG. 4 is a detailed view of the same part, FIG. 5 is a sectional view perpendicular to the axis of the movable mold for the mold of the second embodiment, and FIG. 6 is a sectional view of the axis of the movable mold for the mold of the third embodiment. FIG. Further, FIG. 7 is a cross-sectional view of a conventional mold in a direction perpendicular to the axis of the movable mold. A...Mold, A0...Fixed mold, A1,A
2, A3, A4...Movable mold, 1a, 2a, 3
a, 4a... moving element, 1b, 2b, 4b... fixed element, 3c, 4c... pressure contact element, 1y, 2y...
...Fitting part, F0, B1a, B1b, B2a, B3
a, B3c, B4a, B4b, B4c... Cooling water jacket, C1, C2, C3, C4... Air cylinder, D3a, D3c ₁ , D3c ₂ , D4a, D4
c...Coil spring, F1, F3, F4...
Fixed frame, H...bolt, K...tandate, L...roll for drawing, M...molten steel,
N, N′, N″... Slab, Na... Solidified layer.

Claims (1)

[Claims] 1. A fixed mold integrally formed with a cylindrical body having a hollow portion such as a circular or polygonal cross section, and a cylindrical body similar to the above-mentioned one divided into a plurality of elements and placed in a frame. and a movable mold supported by the frame so as to be movable in the direction of diameter reduction or diameter expansion of the cylindrical body, the movable mold being coaxially connected with the movable mold, wherein the movable mold The mold is composed of a movable element and a fixed element fixed to the frame, and the divided end faces of the movable element are formed parallel to the direction of movement thereof, and each of the elements is connected to the adjacent element and the fixed element. Continuous casting molds are arranged close to each other in relation to a fixed mold. 2. A fixed mold integrally formed with a cylindrical body having a hollow part such as a circular or polygonal cross section, and a cylindrical body similar to the above, divided into a plurality of elements and arranged in a frame. A continuous casting mold in which a movable mold, a part of which is supported by the frame so as to be movable in the direction of diameter reduction or diameter expansion of a cylindrical body, is coaxially connected, wherein the movable mold is movable. element and a pressure contact element that is supported by the frame or the movable element in a freely deflectable manner and is biased toward the adjacent element, and the divided end faces of the movable element are parallel to the direction of movement of the elements. A mold for continuous casting, in which each of the elements is closely arranged with respect to an adjacent element and the fixed mold. 3. A fixed mold integrally formed with a cylindrical body having a hollow part such as a circular or polygonal cross section, and a cylindrical body similar to the above, divided into a plurality of elements, arranged in a frame, and A continuous casting mold in which a movable mold, a part of which is supported by the frame so as to be movable in the direction of diameter reduction or diameter expansion of a cylindrical body, is coaxially connected, wherein the movable mold is movable. a fixed element fixed to the frame, and a pressure contact element that is movably supported by the frame or the movable element and is biased toward the adjacent element, and is divided into movable elements. A mold for continuous casting in which end faces are formed parallel to the direction of movement thereof, and each of the elements is arranged closely relative to the adjacent element and the fixed mold. 4. Claims 1 to 3, wherein each element of the movable mold and an element adjacent thereto in the axial direction or the fixed mold are connected so as to be slidable in the moving direction but cannot be separated in the axial direction. The continuous casting mold according to any one of the above.