JPH01218741A - Mold for continuous casting - Google Patents

Abstract

PURPOSE:To prevent deformation and crack of a mold and to produce a cast billet having good quality by constituting the mold with a fixed mold and plural movable molds, dividing the movable molds into shifting element and fixed element, arranging the movable molds without any gap to the fixed mold and paralleling the divided end face for the shifting element with shifting direction. CONSTITUTION:The mold A for continuous casting is constituted by continuously arranging the fixed mold A0 and the movable mold A1, A2 from upstream side and water cooling jackets F0, B1a, B2a, etc., are arranged. The movable mold A1 (and so on the A2) is constituted by dividing into the shifting element 1a and fixed element 1b, and the shifting element 1a and the cooling water jacket B1a are supported with fixed frame F1 through a cylinder C1. Further, the shifting element 1a and the fixed element 1b are made to a little slidably to axial direction and the boundary face of the shifting element 1a with the fixed element 1b side by side is parallel formed to shifting direction of the shifting element 1a and both elements 1a, 1b side by side and the fixed mold A0 are arranged by connecting with bolts so as not to develop any gap. By this method, the case billet is uniformly cooled and the cast billet having good quality is obtd.

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) The mold used for continuous casting is formed into a cylindrical body.
This is a device that cools and solidifies the molten metal supplied to the hollow part to form slabs. In the mold, the casting is made of a material with excellent thermal conductivity so as to have hollow parts that correspond to the desired cross-sectional shape and dimensions of the slab, and a cooling water jacket is equipped on the outside of the mold. , the cooling water is configured to flow along the outer peripheral wall of the mold. Therefore, the molten metal loses its heat to the cooling water passing through the mold, is cooled and solidified, and becomes a slab.

A mold in a continuous casting mold originally has a structure in which a cylindrical body is integrally formed. An integral cylindrical body is not only an integral tube-shaped body (dubra mold or block mold), but also a cylindrical body made by fixing multiple mold elements divided in the circumferential direction and combining them (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. As slabs shrink as they cool,
In order to maintain contact between the mold and the slab, the inner peripheral wall of the fixed mold is provided with a suitable taper (the cross-sectional dimension of the inner peripheral wall is smaller on the downstream side). 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 progresses,
This may cause 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. onto the surface of the slab.

Increasingly, so-called movable molds for pressing are installed coaxially. Each element of the movable mold is arranged in a frame outside the mold, and the movable elements (moving elements) are supported by the frame via biasing means such as springs or hydraulic cylinders, and are be forced to. As mentioned above, the movable mold is connected to the downstream side of the fixed mold, that is, after the solidified layer has been formed on the surface of the molten metal.
Since the moving element is pressed against the surface of the slab, constant contact with the surface of the slab can be ensured, and the slab can be cooled uniformly. Moreover, since the moving element resists the pressure of the molten metal acting on the bulge that causes the slab to bulge, it also has the effect of preventing bulging compared to cooling with spray water.

A mold with such a movable mold is called a self-contained mold.
Also called Cheebird mold or adjustable mold.

FIG. 7 shows a cross-sectional view of a conventional movable mold in a plane perpendicular to its axis. The figure shows, for 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 as described above. Therefore, since the movable elements cannot move inward (in the diameter reduction direction) from the position where the split end surfaces contact, each element is moved by providing a gap d as shown in the figure in advance to allow for movement in the diameter reduction direction. It needed to be arranged.

Regarding molds with movable molds like this,
World 5teel & Meta1workin
g''vol. 1.4, 1982, p., L8 (1), and JP-A-56-47246.

(Problems to be Solved by the Invention) The conventional continuous casting mold having the movable mold described above has the following problems:
If a solidified layer is not sufficiently formed around the entire surface of the slab, the molten metal inside the slab will flow out, which is an operational disadvantage.

In other words, while casting is being performed 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 temperatures of the molten metal and casting equipment are unstable, or there is a lot of slag and inclusions, so 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. Sometimes I end up doing it.

If the fracture in the solidified layer is located inside the fixed mold, the fracture in the slab can be repaired by temporarily stopping the drawing, and the molten metal will not flow out; In this case, the problem of deformation and cracking of the slab due to non-uniform cooling cannot be solved.

(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) and b) of a) movable element, b) fixed element and C) pressure contact element.
, constituted by a) and C) or a), b) and C),
Each element was arranged without gaps relative to the adjacent element and the fixed mold.

a) Movable element: An element that is disposed on a frame so as to be movable in the direction of diameter contraction or diameter expansion 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 this state, the movable element is moved. It 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 sectional view of a mold for horizontal continuous casting of steel according to the first embodiment, FIG. 2 is a sectional view taken along the line n-tt in FIG. 1, and FIGS. FIG. 3 is a detailed view of parts ■ and ■ in the figure.

As shown in FIG. 1, in horizontal continuous casting, a mold A is connected to a tundish K that stores molten steel M, and a drawing roll L is disposed downstream of the mold A. Therefore, the molten steel M is supplied to the tundish K and once stored there, and then flows into the mold A where it is cooled, becomes a slab N, and is rolled and continuously drawn out.

The molten steel M flows into the mold A through the nozzle Ka of the tundish 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, from the outer periphery, and the slab is formed. Form N.

Mold A is fixed mold AO in order from the upstream side.

A movable mold A1 and a movable mold A2 are arranged coaxially. The fixed mold AO 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 FO is attached to the outside of the mold AO via an O-ring PO to the main part, so that the supplied cooling water flows along the outer circumferential wall of the mold AO. In addition, a thermocouple GO is installed near the entrance of the mold AO,
Measures the temperature of the mold AO during casting to detect abnormalities such as breakage of slabs.

As shown in FIG. 2, the movable mold A1 is a cylindrical body formed from a total of eight divided elements made of prepared 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, A cooling water jacket old a1Blb is provided via an O-ring P1, and the supplied cooling water is supplied to each element 1a.
.

It is designed to flow along the outer peripheral wall of 1b.

Of these, the rod end of the air cylinder CI is engaged to the outside of the cooling water jacket Bla by an engaging member B I K. The base end of this cylinder CI is fixed to the fixed frame F1 extending from the cooling water jacket FO, so the element 1a and the cooling water jacket BLa are supported by the frame Pi via the cylinder C1. . Since the cylinder C1 applies air pressure in the direction of expansion, the element 1a and the cooling water jacket Bla are urged by this cylinder C1 and move inward (in the direction of diameter reduction), and conversely, due to the reaction force from the slab N Move outward (diameter expansion direction). The outside of the other cooling jacket Bib is fastened 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 Blx 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 Bib are both in the axial direction of the mold A ( The hole is slightly elongated in the casting direction (casting direction), and the jacket Bla (
Moving element 1a) and jacket Blb (fixed element Lb
) can slide slightly in the axial direction.

In the cross section perpendicular to the axis shown in FIG. 2, the divided end surfaces of the four moving elements 1a, that is, the boundary surfaces between each element 1a and the adjacent fixed element 1b are parallel to the above-mentioned moving direction of the element 1a. Each element is then arranged so that there are no gaps between adjacent elements. Since the boundary surface is parallel to the moving direction, the movement of the element 1a is not restricted even if a gap is not provided between the elements to allow movement.

On the downstream side coaxially with the fixed mold AO and the movable mold A1,
As shown in FIG. 1, a movable mold A2 is further provided. This movable mold A2 has an axis-perpendicular cross section (not shown) similar to that in FIG. 2, and like the movable mold AI, the air cylinder C2
Four moving elements 2 that can be moved in the direction of diameter contraction and diameter expansion by
a, and four fixed elements 2b fixed to the frame F1 (
2b and 2b, 2b, 2b3 described later are not shown). The difference from the movable mold A1 is that a total of eight elements 2a, 2b are made of copper alloy plates 2a, 2.2b,
The graphite liner 2a8.2bI is attached to the inner surface of the Copper alloy plates 2a, 2b and graphite liners 2a, .
2b is fastened with a bolt (not shown) in its thickness direction, and keys 2a3 and 2b3 are fitted to prevent displacement in the axial direction (casting direction). Since the graphite liners 2a, 2b have self-lubricating properties and lower thermal conductivity than copper alloys, they function to facilitate the drawing of the slab N and to reduce the cooling strength. In the movable mold A2 as well, the end faces of the four moving elements 2a are formed so as to be parallel to the moving direction, and each element is arranged with no gap from the adjacent element.

Even when mold A is viewed in the axial direction as shown in Fig. 1, at each connecting part of fixed mold AO1, movable mold AI, and movable mold A2, the divided end faces of movable elements 1a and 2a (boundary between adjacent elements or molds) In addition, all the elements are arranged without gaps with respect to the adjacent elements and the fixed mold AO.

Since mold A is long in the axial direction, mold AO1 is
Since A1 and A2 thermally expand and are slightly displaced in the axial direction, if mold A cools and contracts after casting, gaps will be created between mold AO and mold A1, and between mold A1 and mold A2, respectively. We are taking drastic measures against this. That is, each element 1a of the fixed mold AO and the movable mold A1
(The same applies to lb) means element 1a (l
b), and the shaft portion is connected by a bolt H inserted into the insertion hole AOx of the protrusion AOw of the fixed mold AO, and connects each element 1a (lb) of the movable mold AI with the movable mold. Each element 2a (2b) of A2 is as shown in Figure 4.
The U-shaped fitting portion ty at the end of the element 1a (lb) is connected by meshing with a similar fitting portion 2y of the copper alloy plate 2a2 (2bt). The bolt H is slidably inserted into the insertion hole AOx through a small gap, and the element 1a (l
b) and the protruding part AOw and between the protruding part AOw and the head of the bolt H, so that
Element La (lb) is mold A relative to fixed mold AO.
cannot be separated in the axial direction, and the movable element 1a is not prevented from moving in the direction of diameter contraction/diameter expansion. In addition, the fitting part 1
The element 2a (
2b) cannot be separated from the element 1a (lb) in the axial direction, and the movable elements 1a and 2a are not prevented from moving each other in the diameter contraction/diameter expansion directions.

According to the mold A of this embodiment configured as described above,
Continuous casting is performed as follows.

The molten steel M flowing into the mold A from the tandate K is
First, it comes into contact with the inner peripheral wall of the fixed mold AO and is cooled, forming a solidified layer Na on the outer periphery. As the slab N is pulled out by rolling, the solidified layer Na moves downstream and eventually reaches the inside of the movable mold AI. The solidified layer Na contracts as it cools, and the outer diameter of the slab N becomes smaller, but in the movable mold AI, 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 uneven contact between the slab N and the mold Al. In other words, the slab N is uniformly cooled and deformation and cracking are prevented. In the movable mold A2 as well, 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. Moving element 2a
is equipped with a graphite liner 2a+ on the inner surface, which reduces friction with the slab N and gently cools the slab N, which more reliably prevents cracking and allows casting of steel types with high crack susceptibility. enable.

Moreover, since the mold A configured as described above has no gaps in its 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 internal molten # 111M will not leak out (breakout). In other words, the molds AO1AI and A2 that surround the slab N have not only no gaps at their respective axial joints, but also gaps between the eight dividing elements 1a and lb of the mold A1. Since there is no gap between the dividing elements 2a and 2b, the solidified layer Na is missing and the molten steel M reaches the surface of the slab N and comes into contact with the inner peripheral wall surface of one of the molds (or elements) of the mold A. However, it will not overflow beyond this point. If sufficient air pressure is applied to the biasing cylinders C1 and C2 of the movable elements 1a and 2a, the elements la and 2a will not move outward even when the pressure of the molten steel M is applied, so that they will not come into contact with the inner peripheral wall surface. The molten steel M is cooled and solidified without forming any bulges.

Note that the above-mentioned gap refers to a gap that allows the molten steel M to flow out, and microscopic gaps of, for example, about 0.1 mm or less are not considered a problem.

In other words, since each element is water-cooled, even if molten steel M enters a gap of this size, it will immediately solidify and stop any further molten steel M from passing through.

Therefore, gaps between the contact surfaces due to the surface roughness of the end faces of each element, slight gaps due to thermal expansion and contraction in the circumferential direction, etc. can be ignored.

The above-mentioned lack of the solidified layer Na occurs because the solidified layer Na is not generated all around the surface of the slab N, or a part of the generated solidified layer Na breaks.
Most of these troubles occur at the beginning of casting when the temperature of molten steel M, tundish, and mold A is unstable, immediately before the end of casting when slag and inclusions are often involved, or when the temperature of the molten metal becomes high. This occurs in mold A when the drawing speed is increased. Therefore, at times like these, pay attention to the temperature of the stationary mold AO detected by the thermocouple GO, and if there is an abnormality, reduce the drawing speed slightly. The slab N is solidified and repaired, and 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. Figure 5 shows a slab N with a rectangular cross section.

It shows a cross section in the direction perpendicular to the axis of a movable mold A3 in a horizontal continuous casting mold for obtaining. On the upstream side of the movable mold 3 of this mold, a fixed mold (not shown) integrally formed with a rectangular cylindrical body is installed in series in the same manner as in FIG. 1 (first embodiment). The eye part is connected to the tongue (shown in the figure).

The movable mold A3 is a mold formed by dividing a cylindrical body having a rectangular hollow portion according 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 corners on the four sides, top, bottom, left and right, and slab N on the inner peripheral wall.

Four corner elements 3c with a radius corresponding to the cross section of
There is. Elements 3a and 3c are each copper alloy plate 3
Graphite liner 3a, 3c inside at, 3c2.

It is made up of a. Further, the elements 3a and 3c are provided with cooling water jackets B3a and B3c on the outside, respectively, and are cooled by water supplied thereto.

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.

Of the four elements 3a, the upper and lower two elements 3a are supported by an air cylinder C3 disposed between the engagement member B3x attached to the upper end (or lower end) of the cooling water jacket B3a and the fixed frame F3. It is a moving element. 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 urged by the cylinder C3 and move inward (in the direction of diameter reduction) until they come into contact with the slab N', and vice versa. Then, the slab moves outward (in the direction of diameter expansion) due to the reaction force from the slab N'.

The two left and right elements 3a are movable elements in which a coil spring I) 3g is interposed between the cooling water jacket B3a and the frame F3. Since the spring D3a is inserted in a pre-compressed state, it urges the left and right elements 3a and the cooling water jacket 83a inward (in the direction of diameter reduction). Therefore, like the two upper and lower elements 3a described above, the two left and right elements 3a 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 a frame F3 as a press-contact element pressed toward the adjacent movable element 3a.
It is located inside. That is, cooling water jacket B3c
A coil spring Dec is interposed between the left side (or right side) of the frame F3 and the outer frame F3, and a coil spring Dec is interposed between the upper side (or lower side) of the cooling water jacket B3c and the cooling water jacket B3a of the moving element 3a. A coil spring D3c2 is interposed between the element 3c and the attached member 83F that extends above (or below) the cooling water jacket B3c.
c are biased and pressed toward the elements 3a adjacent to each other in the left and right or top and bottom directions. Note that the sliding surface of the pressure contact element 3c with the moving element 3a is partially cut out on the outside to form a non-contact portion, thereby reducing the friction area with the element 3a.

In addition, there is a back-up member F near the corner of the frame F3.
3c is attached at a position slightly away from the corner of the cooling water jacket B3c, thereby ensuring 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, 3
'c are arranged so that there are no gaps between adjacent elements. Furthermore, the eight elements 3a and 3c are arranged without any gaps in the axially adjacent fixed molds (not shown) and connected by the same engaging means as in FIG. 3 (first embodiment). ing.

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. can do. In particular, in this mold A3, since the pressure contact element 3c is biased and pressed toward the adjacent element 3a, generation of minute gaps due to thermal expansion and contraction is actively prevented. Therefore, according to the continuous casting mold having such a movable mold A3, the slab can be cooled uniformly, and the solidified layer on the surface of the slab is not sufficiently formed or broken in the mold. Even in such cases, the slab can be repaired and casting can be continued without spilling the molten metal.

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, a fixed mold (not shown) integrally formed with a rectangular cylindrical body is connected upstream of the movable mold A4.

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 at the center of the top and bottom two sides, and a corner part. There are four elements 4c. all elements 4a,
4b and 4c each have a graphite liner attached to the inside of a copper alloy plate, and a cooling water jacket B4aSB4bSB4c is provided on the outside to cool them with supplied water.

Among the six elements 4a, the four elements 4a arranged on the left and right elongated parts of the two upper and lower sides are movable elements supported by the fixed frame F4 via the air cylinder C4. The two elements 4a are movable elements with a coil spring D4a interposed between them and the frame F4. In both cases, the inner peripheral wall maintains contact with the slab N'' surface while reducing the diameter and
It has the function of moving in the direction of diameter expansion. Furthermore, the two elements 4b disposed at the center of each of the two upper and lower sides are fixed elements fastened with bolts to a support member P4b fixed to the fixed frame 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 moving elements 4a, 4b, 4
c are arranged so that there are no gaps between adjacent elements. Additionally, an axially adjacent stationary mold (not shown)
Also, the 12 elements 4a, 4b, 4c are arranged without gaps 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. They are arranged without any gaps. 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 example
” has a wide cross-sectional width and is prone to bulging, but this movable mold A4 has a fixed element 4b at the center of each of the long upper and lower sides.
is provided, it is possible to reliably prevent the slab N''' from expanding due to internal pressure.Moreover, the movable elements 4a on the upper and lower sides are installed with reference to the fixed element 4b before use. The position can be adjusted, so 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 adjacent to each other on each of the upper and lower sides. In addition, regarding the connection in the axial direction, even if the connection is not made as described above, a movable mold is installed adjacent to the downstream side of the movable mold A4, and the movable mold has a frame F4.
Even if a pressure contact element is disposed that is supported by and urged upstream (toward the movable mold A4), 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.

=27- Furthermore, it is also possible to construct a mold to obtain a slab 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 surface of the slab and uniformly cools the slab, preventing deformation and cracking of the slab.
Alternatively, it is possible to obtain a high-quality slab in which no bulging occurs and the solidified structure is symmetrically formed.

2) Since there is no gap on the inner peripheral wall of the mold for molten metal to flow out, continuous casting can continue without breakout even if the solidified layer on the surface of the slab is insufficiently formed or breaks. Can be done. Moreover, because of this, the fixed mold, which tends to lose contact with the surface of the slab, can be significantly shortened, so that the effect of 1) above is increased.

3) Since breakout is less likely to occur as 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 outside air until it leaves the mold, so oxidation of 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 cross-sectional view of the mold related to the first embodiment, FIG. 2 is a cross-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 of the mold of the second embodiment, and FIG. 6 is a detailed view of the movable mold of the third embodiment. FIG. 3 is a cross-sectional view taken in a direction perpendicular to the axis of the mold. 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, AO...Fixed mold, A1', A2
．． A3. A4...Movable mold, la, 2.1.3a,
4a...-moving element, tb, 2b, 4b... fixed element, 3c, 4c... pressure contact element, ly, 2Y... fitting part, FO, Bla, Blb, B2a, B3a, B3c, B
4a, B4b, 84cm cooling water jacket, C1, C2
,C3,C4・,r,,Acylinda,D3a. D3c+, D3c, D4a, D4c=-Coil spring, Fl, P3°F4...Fixed frame, H...Bolt, K...Tandish, L...Drawing roll, M...molten steel, N. N', N''... Slab, Na... Solidified layer - 31 = Fig. 1 Throat/ Fig. 3 Fig. 4 Fig. 2 Fig. 5 Fig. 6 Fig. 7 Book

Claims (4)

[Claims] (1) A fixed mold in which a cylindrical body having a hollow portion such as a circular or polygonal cross section is integrally formed, and a cylindrical body similar to the above is divided into a plurality of elements and arranged in a frame, A continuous casting mold including a movable mold supported on the frame so as to be movable in the direction of diameter reduction or diameter expansion of a cylindrical body, the movable mold being coaxially connected to the movable mold, wherein the movable mold is movable. The movable element 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 their moving direction, and each of the movable elements is Continuous casting molds arranged without any gaps. (2) 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, divided into a plurality of elements and arranged in a frame, A continuous casting mold including a movable mold supported on the frame so as to be movable in the direction of diameter reduction or diameter expansion of a cylindrical body, the movable mold being coaxially connected to the movable mold, wherein the movable mold is movable. and a pressing element that is movably supported by the frame or the movable element and is biased toward the adjacent element, and the divided end faces of the movable elements are moved in the direction of their movement. A mold for continuous casting in which each of the elements is formed in parallel and arranged without gaps with respect to the adjacent elements and the fixed mold. (3) A fixed mold in which a cylindrical body having a hollow portion such as a circular or polygonal cross section is integrally formed, and a cylindrical body similar to the above is divided into a plurality of elements and arranged in a frame, A continuous casting mold including a movable mold supported on the frame so as to be movable in the direction of diameter reduction or diameter expansion of a cylindrical body, the movable mold being coaxially connected to the movable mold, wherein the movable mold is movable. a movable element, a fixed element fixed to the frame, and a pressure contact element that is movably supported by the frame or the movable element and biased toward the adjacent element; A mold for continuous casting in which divided end faces of the elements are formed parallel to the direction of movement of the elements, and each of the elements is arranged with no gaps between adjacent elements and the fixed mold. (4) 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.
3. The continuous casting mold according to any one of 3 to 3.