JPH02112853A - Sidewall of device conducting continuous casting between movable wall, device having said sidewall and continuous casting method of thin metallic product - Google Patents

Abstract

PURPOSE: To prevent a molten metal from penetration by constructing a lateral wall of an apparatus to continuously cast a thin metal between movable walls with a sealing plate/two insert members and making facing faces of insert members protruding into a casting space flat or concave as a solidified metal covers a joint between a movable wall and an insert member. CONSTITUTION: A vertical plate 61 facing an end face of a cylindrical surface of both rolls 1, 2 supports two insert members 7, 8 made of a high thermal conductivity material. Each insert member 7, 8 are protruded toward a casting space from a plate 61 and are aligned to edges 11 of cylindrical walls of both rolls 1, 2. A width, the insert members 7, 8 protrude from the plate 61, is evenly decreased from upper ends 72, 82 to lower ends 71, 81. A region of the same side two insert member 7, 8 is constructed with a refractory cover 9, a surface 91 is inclined to a vertical face, its connecting line parts to faces 73, 83 of the insert members 7, 8 are made a continuous surface not having raggedness.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an apparatus for continuous casting of thin metal products, in particular thin steel products, between movable walls, in particular between rolls, and in particular to a device for continuous casting of thin metal products, in particular thin steel products, between movable walls, in particular between rolls. This relates to a horizontal wall, generally called a "side wall", that defines a casting space near the side end.

BACKGROUND OF THE INVENTION A problem common to various types of apparatus for continuous casting between movable walls is how to liquid-tightly seal the side edges of the casting space between the movable walls.

Another problem is how to prevent the cast metal from sticking to the side walls. If the cast metal sticks to the side walls, there is a risk of leakage at the edges of the cast product.

Yet another problem is how to prevent the formation of a solidification wedge in contact with the movable walls above the neck or the narrowest part of the flow path between the movable walls.

To solve these problems, it has already been proposed to use insulating sidewalls to limit the initiation of solidification in contact with the sidewalls, thereby preventing the formation of a solidification wedge. A device of this type is described in detail in French patent application no. 8705234 in the name of the applicant.

It is also known from US Pat. No. 3,038,219 and European Patent Application No. 2,12,423 to use side walls with relief angles, ie side walls whose surfaces widen symmetrically towards the neck. This arrangement allows the product to spread laterally as it approaches the neck. This lateral expansion is caused by the solidification process or by the rolling action of the prematurely solidified solidified wedge.

However, the above structure cannot prevent molten metal from entering between the side wall and the movable wall, and cannot sufficiently control solidification in this region.

That is, insulating the sidewalls sufficiently to prevent solidification of molten metal in contact with the sidewalls allows molten metal to enter the area of the seam between the sidewalls and the movable wall. In addition, the mechanical strength of the materials used to form the highly insulating sidewalls is generally low, so friction between the metal and the roll ends can quickly lead to wear, resulting in accelerated penetration of molten metal. .

Conversely, if the insulation level of the sidewall is lowered, the cast metal will come into contact with the sidewall and solidify, so even if the sidewall has a relief angle,
A coagulation wedge forms and the problem of product edge sticking or product edge misalignment remains.

OBJECTS OF THE INVENTION It is an object of the present invention to overcome the above-mentioned drawbacks and to provide a method for covering the entire width of a cast product without premature solidification due to contact of the product with the side walls at the long ends of the cast product. The purpose is to allow cooling.

Means for Solving the Problem The side wall according to the invention consists of a sealing plate held in abutment against the end face of the movable wall and two inserts made of a material with high thermal conductivity. The insert protrudes into the casting space between the two movable walls and is close to the edge of the movable walls; furthermore, the insert has a surface facing towards the casting space and has a surface between the movable walls. The area extending close to the neck and defined between the two inserts is covered with a cover made of a heat insulating material, characterized in that the surface of this cover is flat or concave.

In the device according to the invention, the solidified metal shell adjoining the cooled movable wall extends onto the side of the insert facing towards the casting space. Therefore, the obtained continuous shell is
Cover the seam between the movable wall and the insert to prevent penetration of molten metal there.

Furthermore, due to the high thermal insulation in the area between the inserts, no skin is formed when the molten metal comes into contact with the sidewall areas between the inserts.

In a particular arrangement of the invention, a substantial clearance angle is provided between the surface of the side wall facing the casting space, the surface of the insert facing the casting space, and the surface of the heat-insulating cover. There is. In this arrangement, the relief angle of the side walls allows the ends of the cast product to expand laterally, while at the same time the ends of the skin formed in contact with the insert are gradually forced into the movable wall by the static pressure of the iron. is brought into contact with.

In another additional arrangement, the face of the insert facing the casting space is also inclined with respect to a vertical plane perpendicular to the movable wall. This angle of inclination gradually decreases from the upper end of the insert member to the lower end thereof, and the lower end of the insert member is substantially perpendicular to the movable wall.

In this case, the effect of the gradual abutment of the coagulated crust is further increased, and the width of the coagulated crust gradually widens and becomes thicker.
Near the vicinity of the neck, the thickness of the two solidified shells is approximately constant across the width of the product.

This particular arrangement makes it possible, in particular, to minimize the forces applied perpendicular to the roll wall.

That is, if solidification begins at the edge of the shell from the surface level of the molten metal and tongues perpendicular to the roll wall are formed, these tongues will become thicker as they approach the neck, and the static It becomes difficult to uniformly contact the tongues against the cooling wall of the roll using pressure alone, resulting in irregular solidification and at the same time a large force is generated near the neck where the tongues touch each other, causing the tongues to contact each other. part will be "rolled".

Furthermore, if these tongues do not properly abut the cooling wall surface, a seal between the roll and the side wall cannot be achieved, so there is a risk of molten metal penetrating between the tongues and the adjacent side wall. This risk is virtually eliminated in the case of the special arrangement described above.

Another object of the invention is a device for continuous casting of thin metal products between movable walls, in particular between rolls, characterized in that it is provided with side walls according to one of the above-mentioned configurations.

A further subject of the invention is a method for continuous casting of thin metal products, in particular thin-walled steel strip, using the above-mentioned device, characterized in that the casting space is supplied with molten metal, the inserts and the insulation are The movable walls are simultaneously driven in the same direction while keeping the bath surface of the molten metal below the upper end of the cover, so that the molten metal comes into contact with the cooled movable walls to form a solidified shell, and this solidification Each end of the shell is extended above the face of the insert facing towards the casting space, and the solidified shell is enlarged and thickened in proportion to the movement of the movable wall, movable in the vicinity of the area of the neck. The point is that they merge together between the walls and then the solidified thin metal product is continuously drawn downstream.

The features and advantages of the invention will become clearer from the following description of an exemplary embodiment, illustrating the case of continuous casting between two rolls, with reference to the accompanying drawings.

Embodiments The schematic diagrams shown in FIGS. 1 to 6 are for illustration purposes only, and the relative dimensions of each element are for ease of understanding the object and purpose of the present invention, and may not be actual. It is understandable that there is no such thing.

FIG. 1 conceptually shows one end of a device for continuous casting between two rolls 1.2, for example:
The second roll is represented simply by the line 21 at its wall end.

The axes of these two rolls are parallel to each other and in the same horizontal plane P
are arranged above and are driven to rotate in opposite directions in the directions of arrows 3 and 4. The areas of the necks 5 correspond to the level of the plane P passing through the axes of the two rolls and are spaced apart from each other by a distance corresponding to the thickness of the product to be cast.

Molten metal is fed into the casting space by any known method. This casting space is defined by wall surfaces of both rolls above the neck portion and side walls provided at the end edges of both rolls. This side wall is in liquid-tight contact with both roll edges. Since the side wall is stationary and the roll walls are movable, there is a minimum amount of functional space between the side wall and the roll edges to prevent large friction and wear. play must be maintained. Therefore, since it is not possible to make it completely liquid-tight, there is a risk that molten metal will enter between the two. One of the aims of the invention is, inter alia, to reduce the risk of molten metal entering between the two.

As already mentioned, if the side wall is made of a sufficiently insulating material that will not solidify even when molten metal comes into contact with it, the solidified metal shell will form in contact with the cooled roll wall surface. , it breaks off just at the seam between the side wall and the roll, where there is a high risk of ingress of molten metal.

In particular, the present invention provides for sealing the molten metal by extending the solidified shell to the point where the side wall immediately adjoins the roll, while at the same time allowing the edges of this shell to be easily formed. This prevents molten metal from contacting the sidewalls and solidifying. That is, the solidified skin covering the seam between the roll and the side wall acts as a sealing wall to prevent the ingress of molten metal.

FIG. 1 shows, via functional play, a transverse wall constituted by a vertical flat plate 61 facing the ends of both rolls 1.2, i.e. the end faces of the cylindrical surfaces of both rolls, i.e. A "side wall" 6 is shown. This plate 61
supports two insert members 7.8 made of a material with high thermal conductivity. Each insert 7.8 is a thin sheet metal, preferably about half the thickness of the product to be cast, bent along the curvature of the roll and plate 61
It projects towards the inside of the casting space and coincides with the edge 11 of the cylindrical wall of both rolls.

Preferably, the lower ends 71 , 81 of the insert join together slightly above the neck 5 . The width by which the insert member projects from the plate 6 is from the upper end 72.82 to the lower end 71.
．． It decreases uniformly towards 81. The face 73.83 of the insert facing the casting space is inclined at all heights with respect to the generatrix of the roll at that height, the angle of inclination being from the upper end of the insert. It gradually increases toward the lower end and reaches about 90° at the lower end. In other words, the surface 73.83 of each insert is a curved surface, the horizontal generatrix of which at the upper end 72.82 forms an obtuse angle of, for example, about 135° with the corresponding generatrix of each adjacent roll; It gradually decreases as you go to 90° at the lower end.
is equal to

The area between the two inserts of the side wall on the same side is constituted by a plate or cover 9 of heat-insulating refractory material, the surface 91 of which faces the casting space is preferably flat. This surface 91 is inclined with respect to the vertical plane and forms a clearance angle, as already mentioned and as can be seen in FIG. The surface is continuous with no irregularities. Advantageously, the refractory material 9 is surface hardened to prevent rapid wear by the cast metal.

Of course, it will be appreciated that the height of the molten metal during casting must be maintained below the upper limits of the insert and refractory material.

As shown in FIG. 2, the lower end of the insert member can be a step 62 that is steep relative to the plate 61, as shown in the aforementioned European Patent Application No. 212,423. This frees up the end of the casting in the area of the neck for expansion in the direction, but as will be explained in more detail later.
Preferably, the surface 73.83 of the insert and the surface 91 of the refractory material and the surface 63 of the part immediately below are continuous.

The surface 73.83 of the insert member is connected to the surface 91 of the insulating refractory material 9.
If the surface is the same as that, the production of the insertion member is simplified,
It also ensures the continuity of the solidified shell in the seam area between the roll and the insert. However, compared to the embodiments described below with reference to FIGS. 3-6, in this case the heat transfer is lower due to the formation of the crust and its favorable transformation.

3 to 6 show horizontal sections of the casting apparatus at various heights during the casting shown in FIG. 2.

FIG. 3 schematically shows a cross-section at a height of 2, which is close to the height N of the molten metal. Molten metal 10 solidifies against the cooled walls of rolls 1 and 2, forming a thin solidified crust 101, 102 on each roll. This shell extends as far as the tongues 103,104. This tongue portion 103.
104 is formed by solidifying the molten metal as it comes into contact with the thermally conductive insert member 7.8 which is cooled adjacent to the cooled wall surface of the roll, and is cooled by contacting with the large mass plate 61. be done. In contrast, cast metal in contact with the insulating refractory material 9 does not solidify. It can be seen that the area of points 105, 106 between the roll and the insert is sealed from above by a solidified shell.

FIG. 4 is a cross-sectional view at the intermediate height {circle around (2)}, showing that the shells 101, 102 have been conveyed to this height by the walls of the rotating rolls. This movement also causes the tongues 103.104 to slide over the surfaces 73.83 of the insert.

As the casting metal continues to cool, the thickness of the skin 101°, 102' and tongues 103', 104' increases. The width of the face 73.83 of each insert decreases as the angle of inclination relative to the roll wall increases. At the same time, the width of the solidified shell contact with the rolls increases as the sidewalls recede. Also,
The tongue exists in balance with the roll wall due to the static pressure of the molten iron. Furthermore, since the surface 91 of the refractory 9 has a clearance angle, the width of the casting space is expanded.

At the level of V at the lower end of the insert (Fig. 5), the skin G 10
1", 102'" thickness is further increased. two tongues formed on each insert member abut against the roll wall;
At the same time, they join each other at the 10゛8 part.

In the area of the neck (height ■, FIG. 6), the two shells are in complete contact and a product 109 of the desired cross-section is formed. A lateral widening of the ends caused by the rolling action is possible until the width of the casting space finally increases and contacts the wall surface 63.

As can be understood from the above description, the apparatus according to the present invention (1) can seal the casting space, (2) can expand the product in the horizontal direction, and (3) has a solidified skin on the side wall. It is possible to control the formation and deformation of the coagulated crust, especially its ends (tongues), while preventing the formation of a shell.

Figures 7-10 illustrate preferred embodiments of sidewalls according to the present invention.

In this embodiment, the plate 61 consists of several parts assembled by screwing so that it can hold the insert 7.8. This plate 61 has a flat support plate 64 in which two bearings positioned by centering pins 112 are mounted on the plate 6.
5.66 are fixed with screws 111. The bearings are arranged such that the flat surfaces of the plates 65, 66 are placed opposite the ends of the rolls and the edges 67.66 are curved with the same radius as the rolls.
68. This edge 67.
68 is exactly on the extension of the roll.

The metal insert 7.8 abuts the curved edges 67, 68 mentioned above and is in contact with the support plate 64.

This insert passes through an oval hole 75 formed in it and is fixed to the stand 7 on the bearing plate 65,66.
4, parallel to the edge of the bearing plate to prevent the insert from moving in a direction parallel to the axis of the roll, but allowing it to extend longitudinally. It can be moved slightly in any direction.

The thickness of the insert member is constant (eg 2 mm).

The width of the insert protrudes from the surface of the bearing plate by a few mm (for example 5-10 mm) at the upper end, but decreases towards the bottom;
At the lower end it is very small (eg 1-2 mm).

These values are given as examples only and will vary depending on the overall dimensions of the device. These values correspond to clearance angles of insert and refractory of approximately 1 to 3°.

The surface 73.83 of the insert 7.8 is shaped in the manner described above, with the angle of inclination of the surface varying uniformly with respect to the roll wall. The insert thus has a diameter of approximately 45 mm at its upper end.
It has an oblique cross-section at an angle of 100°, from which it increases downwardly and becomes square in cross-section at the lower end.

Both sides of the metal intermediate plate 69 are formed with the same curvature as that of each insert, so that both inserts are connected to the bearing plate 65.
．． It is inserted between the two inserts in abutment with the curved edges 67, 68 of 66. This intermediate plate 69
is fixed to the support plate 64 with screws 113.

The intermediate plate 69 is thinner than the bearing plates 65, 66, and when the refractory material 9 is placed between the inserts and rests against the intermediate plate 69, the surface 91 of the refractory material faces towards the casting space. is flush with the surface 73.83 of the insert. This refractory material is the intermediate plate 69
It can be a pre-assembled plate pre-bonded to the plate, or it can be made by depositing the material, for example by spraying.

The lower end of the insert of the intermediate plate 69 and the lower end of the insulating fireproof cover 9 are at the same level as the neck or slightly higher. At this height, the lower ends of the two inserts are slightly open from each other and have a constant width to prevent the "tips" of the insulating refractory material from becoming brittle.

Below this height (corresponding to height V in FIG. 2), the side walls extend into guide shoes 120. This guide shoe 120 is fixed to the support plate 64 with screws 114. The rear part 121 of the guide shoe 120 has a corresponding recess 122.12 formed in the bearing plate 65.66.
It is inserted in 3. The front part 124 of the guide shoe has its end face 125.126 in the enclosure 7. of the bearing plate 65.66.
It is processed to have the same curvature as that of 68.

The surface of this guide shoe facing the cast product has a relief area 127 which is an extension of the surface 91 of the fireproof cover 9 above the neck.
The bearing plate 6 is located below the neck portion (at the height of the plane P).
It has a vertical plane portion 128 coplanar with the surface of 5.66.

The guide shoe 120 is preferably made of a wear-resistant material, such as cast iron.

The advantage of the above-mentioned special shape of the guide shaft: L-120, in particular its relief area 127, compared to the step 62 shown in FIG. In addition, it is possible to prevent the insert member and the fireproof cover from being rapidly worn out or destroyed.

The invention is not limited to the embodiments described above, which are described by way of example only. Various technical modifications to the side wall elements and their assembly methods are possible.

For example, the insertion member may be made of a boron nitride compound other than metal,
For example, it can be made of materials consisting of BN and Sialon, S+3N4, AIN or SiC.

It is also possible for the surface 91 of the fireproof cover to be a concave surface instead of a flat surface.

Furthermore, it is also possible for the insert to project further forward between the rolls and for the guide shoe to likewise project between the rolls and, as a result, to protrude from the bearing plate.

In order to promote the formation of the tongue of the solidified shell, a device can be provided for local cooling of the bearing plate and/or the support plate and the guide shoe in the vicinity of the insert, or the insert can also be cooled directly.

[Brief explanation of the drawing]

Figure 1 is a partial schematic diagram of a device for continuous casting between rolls.
The arrangement of the side walls according to the present invention is shown, and FIG. 2 is a sectional view taken along plane ■-■ in FIG. 1, and FIGS. 3 to 6 are solidification states of the product at each height shown in FIG. FIG. 7 is a plan view of a side wall according to the present invention designed to fit a casting machine, and FIG. 8 is a longitudinal section of this side wall taken along the line X-X in FIG. FIG. 9 is a sectional view of this side wall taken along line XX in FIG. 7, and FIG. 10 is another horizontal sectional view of this side wall taken along line XX in FIG. 7. . IO・ ・ ・ 64・ ・ ・ 69・ ・ ・ 101.102 103.104 120・ ・ ・

Claims (8)

[Claims] (1) It has cooling movable walls facing each other that are simultaneously driven in the same direction (3, 4), and two stationary side walls (6) that partition a casting space together with the cooling movable walls.
A side wall used in an apparatus for continuous casting of thin metal products between movable walls includes a sealing plate held in contact with the end surfaces of the movable walls (1, 2), and a sealing plate made of a material with high thermal conductivity. two inserts (7, 8) projecting into the casting space between the two movable walls and close to the edges (11) of the movable walls; The part has a side facing towards the casting space (73,
83) and extends close to the neck (5) between the movable walls, the area demarcated between the two inserts (7, 8) being made of a heat insulating material; , characterized in that the surface (91) of this cover (9) is flat or concave. (2) The surface of the insert member facing the casting space (73, 83
2. Side wall according to claim 1, characterized in that the surface (91, 73, 83) facing the casting space formed by the surface (91) of the cover of insulating material is provided with a clearance angle. (3) Said side of the insert facing towards the casting space (7
3, 83) are inclined with respect to a vertical plane perpendicular to the movable wall, and this angle of inclination is the upper end of the insert member (72, 82).
gradually decreases from to its lower end (71, 81),
3. Side wall according to claim 1, characterized in that the lower end of the insert is substantially perpendicular to the movable wall. 4. The side wall of claim 2, wherein the relief angle is about 1 to 3 degrees. (5) Claim characterized in that the angle of inclination of said surface (73, 83) of the insert facing towards the casting space with respect to the generatrix of the adjacent movable wall is approximately 135° at the upper end of the insert. The side wall according to item 3. (6) on the underside of the insert member and the heat insulating cover there is a shoe (120) adjacent to their lower ends, the surface of this shoe facing the casting space being inserted above the neck part (5); The above surfaces (91, 73,
83), characterized in that it has a relief area (127) in the extension of the neck part (5) and a vertical plane part (128) below the neck part (5). side wall. (7) An apparatus for continuously casting thin metal products between movable walls, in particular between rolls, characterized by comprising the side wall according to any one of claims 1 to 6. (8) Supplying molten metal to the casting space, keeping the bath surface of the molten metal below the upper ends of the insertion member and the heat insulating cover, and simultaneously driving the movable walls in the same direction to cool the metal. contacting the movable wall with molten metal to form a solidified shell, extending each end of the solidified shell over the side of the insert facing the casting space, and placing the solidified shell against the movable wall. Claim 7, characterized in that the solidified thin metal product is enlarged and thickened in proportion to the movement of the movable walls so as to merge into each other between the movable walls in the vicinity of the region of the neck, and then the solidified thin metal product is continuously drawn downstream. A method for continuous casting of thin metal products using the apparatus described in .