JPH11291000A - Continuous casting, particularly, steel continuous casting equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a continuous casting equipment of a metal which has a means for pouring molten metal into a casting mold having cooling wall surface and continuously pulls out the obtd. product from the outlet opening part of the casting mold. SOLUTION: A member 1 having a receiving chamber 5 for introducing the metal into the casting mold 2 is provided and a connected chamber 8 portion with a tubular wall 81 is constituted at the lower extending position of the receiving chamber 5. The tubular wall 81 has the outlet opening part 82 positioned at lower part than the upper side level of the cooling wall surface 4 in the casting mold and is parted with the cooling wall by arranging an outer peripheral free space 10. The receiving chamber 5 is connected with the casting mold with a closed joining member J, and an annular chamber 9, in which the whole surface is shut off as the outer peripheral free space 10 and gas is trapped in the inner part thereof, is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a continuous casting facility, and more particularly to a continuous casting facility for producing steel slabs, blooms, billets and the like.

[0002]

2. Description of the Related Art Continuous casting equipment has been known for a long time.
It generally has a bottomless ingot mold into which molten metal is poured from a dispensing means, typically an intermediate container called a dispenser or "tundish". In general, ingot molds have cooled sidewalls, which are attached to a gantry and define a casting cavity having a cross section corresponding to the product cross section.
The metal poured from the dispenser into the ingot mold forms a solid skin along the cooled wall. The thickness of the skin gradually increases downward and can be extracted from the outlet opening as a product having a liquid or paste-like core. The product is then guided through the sheath and returned horizontally to complete coagulation.

[0003] In conventional continuous casting, the free surface (ie, upper level) of the liquid metal in the ingot mold is exposed to open space or in any case under air pressure.
This free surface is commonly called the "meniscus". The boundary area of the free surface, that is, the part in contact with the cooling wall surface of the ingot mold is instantaneously solidified, and contracts due to the temperature lowering effect and the phase change of the product from outside to inside. As a result, the edges of the solidified metal flake off inward against the walls of the ingot mold, forming hard particles called "solidification horns".

Further, in order to facilitate the downward movement of the metal, the ingot mold is generally subjected to a vertical vibration, and a lubricant (meltable powder or oil) is formed between the cooled wall surface and the solidified surface of the metal. ) Is introduced. Since the solidification angle follows the movement of the ingot mold, the liquid metal injected into the ingot mold later flows into the space between the wall surface and the solidification angle, and fills this space to produce surface defects (double skin). ) Or subepidermal defects. Furthermore, the lubricant easily enters the space between the cooled wall surface and the solidification angle due to the vibration of the ingot mold, and the solidification angle bends greatly to form a deep mark on the final product. Non-metallic inclusions can be introduced.

Therefore, attempts have been made to control the solidification phenomenon on the free surface of the metal as much as possible in order to prevent the formation of the solidification angle or at least suppress the degree of the generation. One of the proposed methods is to use a so-called "hot head" ingot mold to maintain the ductility of steel in the lower part of the ingot mold, and to set the solidification starting point below the free surface of the liquid metal. ing. To do so, the heat exchange in the upper part of the cooled wall can be reduced. For example, the applicant has filed French Patent No. 8
In 3.001949, inserts of different thickness are placed between the inner lining of the ingot mold and the cooled wall to change the thermal conductivity of the wall in the upper part of the cooling wall, whereby the metal is placed in the upper meniscus. Coagulation was started slightly below the surface.

Recently, a method has been proposed in which a filling frame made of a refractory material is provided on the top of the cooling wall so that the height of the free surface of the metal is higher than the upper edge of the cooling wall. In this method, the wall of the casting cavity at the junction between the upper refractory material section and the lower cooling wall section becomes a junction area called a "triple junction" where the liquid metal is present on one side And the other side has a completely different temperature 2
There is a wall in which two wall surfaces, that is, a high-temperature refractory wall surface above the joint portion and a cooling wall surface of the ingot mold below the joint portion are laminated. Therefore, no clear solidification is obtained at this joining level.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a novel arrangement which eliminates the problems caused by the presence of the triple point and reduces and suppresses vibration marks and other surface defects which appear at the start of the solidification process. To provide.

[0008]

SUMMARY OF THE INVENTION The present invention comprises an ingot mold having a generally vertical axis defined by a cooled wall having an upper edge and a lower edge defining an inlet opening and an outlet opening. A continuous metal casting facility having a bottomless mold to constitute and a means for continuously injecting liquid metal, wherein the liquid metal forms a metal bath having a substantially horizontal upper surface in an ingot mold. The liquid metal solidifies along the cooled wall to form a product bounded by the solidified outer surface, which is continuously discharged from the outlet opening of the ingot mold at a withdrawal rate corresponding to the liquid metal injection rate. In the metal continuous casting facility to be extracted, an intermediate member arranged between the ingot mold and the metal injection means for introducing liquid metal into the ingot mold is provided. The intermediate member is constituted by an upper receiving chamber disposed on the ingot mold and at least one connecting channel extending downward from the upper receiving chamber, and an outer cross-sectional dimension of a tubular wall defining the connecting channel is ingot mold. Smaller than the dimensions of the inlet opening of the ingot mold, such that the connecting channel is inserted inside the ingot mold so that its outlet opening is below the upper level of the cooling wall of the ingot mold, whereby the connecting channel The tubular wall is separated from the cooling wall of the ingot mold by a free outer free space, and the receiving chamber is connected to the ingot mold by an airtight partition to form an annular chamber with all surfaces closed in the outer free space. When the gas is trapped inside and the metal rises in the outer free space, Gas provides a continuous metal casting plant, characterized in that it is compressed.

[0009]

DETAILED DESCRIPTION OF THE INVENTION Lubricants are generally liquid at the temperature of the metal and are placed on the metal and run down the cooled walls of the ingot mold to lubricate the ingot mold. In a particularly advantageous embodiment, means can be provided for introducing lubricant into the annular chamber between the tubular wall of the connecting channel and the cooled wall of the ingot mold. The free space located between the tubular wall of the connecting channel and the cooled wall of the ingot mold has sufficient width over its periphery to prevent the upper surface of the metal from solidifying in the free space in the free space. ing.

Another particularly advantageous feature of the present invention is that the gas is closed in a closed annular chamber under pressure adjusted to the difference between the height of the metal surface in the receiving chamber and the height of the metal surface in the outer free space. Is provided. In particular, the connecting channel has an internal cross-section such that the flow rate of the liquid metal supplied to the ingot mold is kept at a low value, in particular 3-6 times the casting speed, thereby preventing turbulence in the ingot mold can do. Preferably, the inner cross section of the tubular extension is at least equal to 20% of the product cross section. In the case of slab casting, the casting cavity has a generally rectangular cross section composed of two large faces and two small faces.

Another feature of the present invention is that the tubular wall surface of the connecting channel is defined by two large surfaces substantially parallel to a larger surface of the ingot mold at a portion inserted into the ingot mold. It is in. In a preferred embodiment, the joining member J between the receiving chamber and the ingot mold is defined by a partition surrounding the connecting channel, which is rigidly connected to the receiving chamber and the cooled wall of the ingot mold. In a first embodiment, the joining member J is constituted by the lower edge of the receiving chamber surrounding the outside of the connecting channel and supported on the upper edge of the ingot mold via a gasket. In another embodiment, the connection chamber is held by a support member surrounding it, the support member being rigidly connected to the ingot mold to close the annular chamber.

The support member of the receiving chamber can be connected to the ingot mold by a bellows when the ingot mold is vibrating vertically. Another advantageous feature of the present invention is that the ingot mold is kept stationary and the closed annular chamber is changed to oscillate the free surface of the liquid metal in the free peripheral space between the ingot mold and the connecting channel. The provision of gas at pressure. In one embodiment of the present invention, the free surface of the liquid metal in the chamber can be oscillated by varying the raised filling level of the receiving chamber. Lubricant (meltable powder or liquid oil) is supplied by means for injecting into the annular chamber. The lubricant injection means consists of a storage container, in particular a hopper, the pressure of which is regulated such that the pressure difference is kept entirely zero.

In a preferred embodiment, particularly applicable to slab casting ingot molds having two large faces and two small faces, the connecting channel is below the liquid metal inlet, the large ingot mold in the face of the channel. A solid block disposed between the two surfaces parallel to the other surface, whereby the direction of the metal flow can be deflected towards the smaller surface of the ingot mold. The facility of the present invention may include means for cooling the tank wall made of a refractory material on one side so that a solid metal film is formed on the inner wall of the receiving chamber to prevent abrasion and erosion of the wall. it can.

In another embodiment of the invention, the space defined between the connection chamber and the distribution means is closed by a bellows, so that the liquid metal does not pass through a nozzle immersed between the distribution means and the connection chamber. Flows directly to The invention further provides
It has the advantage of facilitating the realization of a casting unit comprising a plurality of lines with each ingot mold being fed from the same dispenser. In this case, in practice, 1
A common inlet member on the set of ingot molds, the inlet member having a single receiving chamber, the bottom of the receiving chamber being formed with a plurality of openings located on the axis of each ingot mold; Each opening leads to a tubular extension that forms a connecting channel of the receiving chamber, the lower end of which is inserted into the corresponding ingot mold.

It should be noted that the present invention ultimately obviates the need for a liquid metal dispenser, in which case the liquid metal is introduced directly from the pocket into the receiving chamber of the introduction member. The present invention may have other configurations than those described above, which will be described using the following non-limiting examples with reference to the accompanying drawings.

[0016]

FIG. 1 shows a continuous casting plant 1, in particular a continuous casting plant for producing steel slabs, blooms or billets. The continuous casting plant 1 has a bottomless ingot mold 2, which has walls 4, generally made of copper, defining a casting cavity. The cross-section of the casting cavity corresponds to the cross-section of the product 3, such as a slab, bloom, billet, etc. that is extracted from the outlet of the ingot mold. The wall 4 is cooled from the outside by a jacket E (FIG. 5) in which water or a coolant is circulated. The wall 4 is substantially vertical, but may be curved to produce a bent product from the start, and the bent product can be straightened horizontally in the guide and secondary cooling seeds. All of the above configurations are conventional, and a detailed description thereof will be omitted. The molten metal flows down by gravity from the distribution means D shown in FIG. This distributing means D can be constituted by an intermediate container 7 called a dispenser or "tundish", the inside of which is covered with a fire-resistant wall 7a. Liquid metal carried by a casting ladle (not shown) is supplied from a steel making plant.

In the conventional method, the metal is directly injected into the ingot mold through an opening provided at the bottom of the dispenser and a nozzle connected to the opening and inserted into the ingot mold 2 to protect the metal from oxidation. It had been. According to the invention, the metal is first injected into the intermediate member 1 arranged on the ingot mold 2 between the ingot mold and the dispenser 7. This intermediate member 1 is composed of two vertically arranged parts, namely an upper receiving chamber 5 and a connecting channel 8 on its lower extension. The connecting channel 8 is delimited by a tubular wall, has an outer wall surface 81,
The cross-sectional dimension of this tubular wall is smaller than the inlet opening 6 of the ingot mold 2. The tubular wall is inserted into the ingot mold and its outlet opening 82 is provided at the upper edge 6 of the cooled wall 4.
Come below. Accordingly, the outlet opening 82 of the tubular wall is immersed in the liquid metal filling the ingot mold. The outer wall surface 81 of the connection channel 8 is separated from the inner wall surface of the cooled wall 4 of the ingot mold 2 by a free space (hereinafter, an outer free space) 10 surrounding the outer wall surface 81.

The receiving chamber 5 has a lining of refractory material inside, so that the upper level 11 of the liquid metal in the receiving chamber 5 is well above the upper edge 6 of the ingot mold 2. Is held in. The injected metal descends along the wall 4 of the ingot mold 2 and is extracted from the ingot mold as a solidified product 3. The injection speed is adjusted in relation to the product withdrawal speed. In the present invention, the iron static pressure (ferrostat) applied to the metal at the outlet opening 82 of the connecting channel 8
The metal rises in the outer free space by ic pressure). The receiving chamber 5 is connected to the wall 4 of the ingot mold 2 by a liquid-tight joining member J, so that a closed tubular chamber 9 is formed above the outer peripheral free space 10. The inside of the tubular chamber 9 is defined by an outer wall surface 81 of the connecting channel 8, and the outside and the upper side are defined by the inner wall 41 of the ingot mold 2, the joining member J, and the bottom of the receiving chamber 5, and the lower side thereof is It is defined by the surface 12 of the liquid metal that has risen in the outer free space 10.

The width d of the outer free space 10 can be substantially constant, but the two walls facing each other, namely the wall 41 of the ingot mold 2 and the wall 8 of the connecting channel 8
Between 1 and the width required for the metal to remain in the liquid state.
The liquid metal poured into the receiving chamber 5 is cast into the ingot mold 2 via the connecting channel 8 and rises inside the annular outer peripheral free space 10 so as to be substantially horizontal between the two walls 41, 81. A free surface 12 is formed. Since the joining means J is provided between the receiving chamber 5 and the ingot mold 2, the annular chamber 9 above the free surface 12 is sealed, so that the annular chamber 9 is pressurized by the raised liquid metal. Is done. Annular chamber 9 serves as a gas cushion that encloses air, argon, nitrogen, helium, and other gases within annular chamber 9.

The horizontal cross section of the ingot mold 2 when casting the slab is rectangular, and the two larger parallel sides of the ingot mold are perpendicular to the plane of FIG. In this case, the lateral profile of the connecting channel 8 is also rectangular, the two larger faces being perpendicular to the plane of FIG. 1 and parallel to the larger face of the ingot mold 4. As shown in FIG. 8, the smaller face of the connecting channel 8 may be semi-cylindrical, bulging outward. In the embodiment of FIG. 1, the receiving chamber 5 is supported on the ingot mold 5 via a lower edge 13. This lower edge 13 protrudes downward,
A flat seal 14 is formed by a joining member J made of a temperature-resistant material at this position, located between the lower end of the lower edge 13 and the upper end 6 of the ingot mold 2.

The lower surface of the receiving chamber 5 has a lower edge 13 for support.
1 extending transversely between the connecting channel 8 and
5 is formed. The lower surface 16 of this transverse crank 15 facing the ingot mold 2 is concave. The concave space located above the face of the seal 14 forms a closed chamber 9. In the configuration of the present invention, the ingot mold 2 is injected into the receiving chamber 5 and is connected through the connecting channel 8.
A part of the metal that has fallen inside rises in the outer free space 10, and the pressure of the gas confined in the annular chamber 9 is increased by the static pressure of iron (the upper level 11 of the liquid metal in the receiving chamber 5 and the outer free space). (Corresponding to the height between the free surface 12 of the metal in 10). If the density of the liquid metal is denoted by ρ and the gravitational acceleration is denoted by g, the pressure P generated in the annular chamber 9 by this liquid metal column at the level of the surface 12 is P = ρgh.

In general, the free surface 1 of the metal in the receiving chamber 5
1 is kept at a substantially constant level and the surface of the liquid 12 in the outer free space 10 is kept at a substantially constant level. Match. However, in the present invention, large fluctuations occurring at the level of the surface 11 in the receiving chamber 5 are mainly manifested as pressure changes inside the annular chamber 9 and fluctuations in the level of the annular surface 12 are small. This level depends on the compressibility of the trapped gas. For example, when the withdrawal speed suddenly decreases, the level 11 inside the receiving chamber 5 rises, and the pressure inside the chamber 9 rises. However, the metal surface 12
There is no noticeable variation in this level, which is maintained below the upper edge of the cooling wall 4. Conversely, when the metal supply speed from the dispenser 7 decreases, the level 11 in the receiving chamber 5 decreases and the pressure in the annular chamber 9 decreases, but the level of the surface 12 in the outer free space 10 changes greatly. do not do.

In practice, taking into account the volume of the trapped gas and its compressibility, the free surface 12 of the liquid metal rising in the outer free space 10 is kept at a lower level than the surface of the seal 14. As such, the dimensions of the annular chamber 9 are designed. The lower part of the connecting channel 8 is immersed in a liquid metal bath and is kept sufficiently far from the cooled wall 4 of the ingot mold. Since the surface 12 is kept in a liquid state, there is no contact between the cooled wall and the refractory material receiving chamber. If the intermediate member 1 is supported on an ingot mold, the joint is always kept above the level 12. In the case of FIG. 8, that is, when the introduction member 1 is connected to the ingot mold via the bellows, there is no joint.

In any case, the formation of the triple point and the problems occurring at this position can be avoided. A particular advantage is that, since the cross-sectional area Si of the internal passage of the connecting channel 8 is smaller than the internal cross-sectional area Sp (or cross-section of the product) of the ingot mold 2, the flow velocity Vi of the liquid metal inside the connecting channel 8 is reduced, It only needs to correspond to the extraction speed (cross-sectional ratio). That is, the problem of fast turbulence generally occurring at the nozzle outlet opening position, which is observed when the end of the nozzle directly opens into the ingot mold, is avoided. For example, the cross section Si of the outlet of the connecting channel 8 is the cross section Sp of the product.
About 20 to 30% of the above. In practice, this results in a lower steel flow rate, 3-6 times the casting speed, or 6-12 m / min. On the other hand, the flow rate of general metal reaches 60 to 100 m / min at the nozzle outlet.

The energy generated in the ingot mold 2 by the agitation of the jet and the bath when the metal penetrates rapidly decreases at a rate of approximately the square of the penetration speed. Therefore, in the present invention, the turbulence directly related to the kinetic energy found on the surface of a normal bath is suppressed and can be at least greatly reduced. Furthermore, because of the low impact, the metal jet at the outlet of the connecting channel 8 is immediately destroyed by the liquid mass, and the difference in density causes the outer free space 1 along the arrow in FIG.
It rises toward zero. This allows the free surface of metal 1
2 will always be reheated, making it easier to keep the metal in a liquid state.

The metal cast into the ingot mold 2 comes into contact with the cooling wall 4 of the ingot mold and solidifies from the surface to form a product 3. The product 3 withdrawn from the outlet opening 60 of the ingot mold is defined by a solidified outer layer 30 of increasing thickness from the level of the surface 12. Outer edge 31 of the surface having the shape of a meniscus
Solidifies immediately upon contact with the wall 4, but the surface of the molten metal is constantly replaced and the temperature rises resulting in a hardened edge 3
1 retains ductility. The solidified skin moving down along the ingot mold is brought into contact with the wall 4 by the pressure in the liquid metal (at the level of the surface 12 which is proportional to the height h of the iron). Thus, the risk of forming solidification angles inside the cast product is reduced.

In the embodiment shown, an intermediate member 1 consisting of a receiving chamber 5 and a connecting channel 8 is supported on an ingot mold 2 and can oscillate with the ingot mold 2 in a vertical direction at a predetermined amplitude. This vibration is generated by mechanical means (not shown) to prevent the adhesion phenomenon and facilitate the penetration of the lubricant between the solidified metal layer and the ingot mold. The depth a (FIG. 1) at which the connection channel 8 of the refractory material is immersed in the ingot mold 2 can be relatively shallow. This depth may be such that the outlet opening 82 of the connecting channel 8 is maintained below the metal surface 12 determined by the pressure in the annular chamber 9. From this point of view, in order to maintain a sufficient gas pressure in the annular chamber and particularly to compensate for any leakage occurring,
Is provided with means 19 for supplying a pressurized gas. FIG.
Here, this gas supply means is at the end of a duct 19 which opens through the upper part of the wall of the ingot mold 2 and opens above the free surface 12. This duct 19 is a gas source,
In particular, it is connected to argon, nitrogen, helium and other sources of pressurized gas. The gas source preferably has an adjustment mechanism as shown in FIG.

On the outer wall of the receiving chamber 5, for example, a cooling liquid
In particular, cooling means 1 composed of a jacket circulating water
7 are provided. The cooling means 17 prevents overheating of the liquid metal injected into the receiving chamber 5 and, in some cases, prevents wear and erosion of the refractory material of the chamber 5 by a thin layer of solidified metal formed on the inner wall of the receiving chamber 5. It can protect and reduce the risk of inclusions caused by entrapment of particles of the refractory material. Liquid metal level 11 is ingot mold 2
Above, so that the liquid metal can be clarified (sedimentation separated) in the receiving chamber 5, whereby the ingot mold 2
Metal inclusions and impurities incorporated into the metal are reduced.

Hereinafter, the method of operating the continuous casting equipment of the present invention will be described. At the start of the casting process, the lower opening 60 of the ingot mold 2 is sealed with a dummy bar or start bar (not shown). The liquid metal is poured into the receiving chamber 5 and gradually fills the ingot mold 2 via the connecting channel 8.
When the lower end of the connecting channel 8 is immersed in the liquid metal bath and the liquid surface rises to a height of 12, the gas contained in the sealed annular chamber 9 is compressed. The advancement movement of the starting bar is such that the advancement of the product 3 defined by the solidified skin 30 increasing in thickness from the head to the bottom formed at the point of contact with the cooling wall of the ingot mold 2 is ensured. , Is controlled using a drawing roll (not shown).

Conventionally, metal is directly supplied to the ingot mold 2 from the dispenser D via a nozzle.
The impact of the metal jet at the nozzle outlet caused the metal jet to penetrate quite deeply into the metal contained in the ingot mold, causing untimely remelting. In the present invention, this danger is eliminated because the flow rate of the metal at the outlet 81 of the connection channel 8 is relatively slow because the passage portion of the connection channel 8 is large. Accordingly, solidification at the outlet of the ingot mold is increased, and the risk of holes being formed in the solid skin is reduced. Furthermore, since the receiving chamber 5 is raised by applying a load to the steel, the replacement becomes regular,
The thickness of the solid at the outlet of the ingot mold is increased compared to the conventional configuration. Therefore, the thickness of the solidified metal in the ingot mold is increased, it becomes more regular, it is possible to perform casting at a safe or constant casting speed, and high security against opening is guaranteed. You. Furthermore, the impact of the jet at the outlet of the connecting channel 8 is relatively weak, so that the solidified skin 30 is not damaged and the annular space 1 is not damaged.
An opening 29 can be provided radially above the lower opening 81 to help the hot metal re-raise within zero.

Therefore, the height L of the wall of the ingot mold
Can be reduced at a certain casting speed or the casting speed can be increased for a given height L to find an optimal solution. As shown, the first fining takes place in the upper part of the receiving chamber 5 and thus outside the solidification zone, so that the steel solidifying inside the ingot mold 2 has already been clarified and the main inclusions have been removed. is there. That is, fining generally occurring in the ingot mold is performed in the receiving chamber 5 having a high ability to remove inclusions. Since the receiving chamber 5 has a large volume and the metal descending speed is very slow in the ingot mold, the ability to remove inclusions increases.

Surface 1 of liquid metal inside outer free space 10
No. 2 is maintained by an inert gas pressure and maintained at a substantially constant level due to a low metal penetration rate, so that no oxidation occurs here. Furthermore, since on its outer circumference the free surface 12 of the liquid metal only contacts the single cooling wall 4 of the ingot mold, there is no triple point and the conventional solidification problems associated therewith are avoided. You. The present invention has many more advantages. For example, it is known to apply an oscillating motion to the ingot mold to help introduce lubricant between the cooled walls of the ingot mold and the solidified layer. A lubricant can be introduced between the solidified layer of metal below the free surface 12 and the wall of the ingot mold. Therefore, it is possible not only to eliminate the mechanical vibration of the ingot mold, but also to eliminate fluctuations before and after the average height of the metal 12.

In any case, it is sufficient to change the gas pressure inside the annular chamber 9 to change the height of the free surface 12, so that the ingot is required to change the height of the free surface 12 periodically. There is no need to mechanically vibrate the mold 2. 2 and 3 show an annular chamber 9
6 is a graph showing an example of a pressure fluctuation in the inside. In these graphs, the time change is plotted on the horizontal axis, and the gas pressure (represented by the solid line graph C1) is plotted on the vertical axis. The dotted line graph C2 plots the height N (vertical axis) of the free surface 12. FIG. 2 shows a sinusoidal variation of the gas pressure inside the chamber 9. The increase or decrease in pressure determines the decrease or increase in the surface, and in FIG. 2 the phase shift between the curves C1 and C2 reflects a certain delay. FIG. 3 shows the pressure change as a triangular signal, with similar level fluctuations and similar phase shifts.

Thus, by changing the pressure in the annular chamber 9, the free surface 12 is vibrated without displacing the ingot mold 2, and one side of the average level is oscillated.
One area can be covered or exposed with liquid metal. When this region is exposed, the wall surface of the ingot mold 2 is covered with the lubricant introduced into the annular chamber 9, and when this region is covered with the liquid metal, the lubricant is applied between the solid steel skin and the wall surface of the ingot mold. Trap in between. This makes it possible to extract the product 3 smoothly without danger of sticking.

The fluid or powder lubricant is advantageously injected using the arrangement shown in FIG. For example, using a container 21 installed at a position higher than the ingot mold 2 composed of a sealed hopper and the receiving chamber 5, a lower portion of the container 21 is connected to a lubricant injection pipe 20 having a check valve.
Is connected to the annular chamber 9. The upper part of the container 21 and the annular chamber 9 are connected in parallel to a pressurized gas supply system 23 via conduits 19, 19 '. Therefore, the same pressure is applied to the inside of the container 21 and the inside of the annular chamber 9. as a result,
The lubricant is supplied to the ingot mold 2 only by the action of gravity. The container 21 is connected to a bracket 24 via a weighing device 25.
Advantageously, it is located above and tracks the weight change of the lubricant in the container 21 to initiate the filling process at the appropriate time.

As described above, the level fluctuation of the free surface 11 of the metal inside the receiving chamber 5 is mainly reflected in the pressure rise inside the annular chamber 9. It does not significantly affect the level of the free surface 12 of the metal in contact. Thus, while the conventional scheme in which metal is cast directly into the ingot mold requires a fairly precise control of the steel level, such a control is more secondary in the configuration of the present invention. However, if the ingot mold 2 is mechanically vibrated together with the intermediate member 1, the immersed portion of the connecting channel 8 is exposed to this movement, and the vibration may affect the free surface 12. It is preferable to use a thin-walled connecting channel 8 to eliminate this effect.

As described above, the hydrostatic change of the surface level 12 due to the pressure fluctuation in the annular chamber 9 makes it possible to eliminate the vibration of the ingot mold which has been conventionally performed. Thus, level fluctuations of the free surface 12 are achieved by changing the upper level of the tank 5, eliminating the disadvantages of moving large chunks. Note that the amplitude of the oscillating motion is secondary since the entire surface 12 of the product (slab, bloom or billet) in the outer free space 10 can be filled with filler. The oscillation frequency can be reduced to prevent uncontrolled movement of the free surface 12. As a result, the free surface 12 is hardly agitated and kept pressurized,
The conditions under the epidermis are very good thanks to the uniformity of the epidermis 30, so that the uniformity of the surface of the solid product is increased. Further, it is believed that segregation is also significantly reduced and that applying pressure to the free surface 21 allows for a casting process with less overheating in the ingot mold. As shown in FIG. 4, the dispenser 7 can be provided with a nozzle 26 for ejecting a jet of liquid metal. The lower end of this nozzle is below the surface 11 of the liquid metal filling the receiving chamber 5.

FIG. 5 shows another specific example of the joining member J. In this case, a bellows 18 surrounding the receiving chamber 5 is provided.
An opening 28 provided at the bottom of the dispenser 7. The upper part of the bellows 18 is airtightly fixed to the bottom of the dispenser 7. The lower part of the bellows 31 is airtightly fixed to the ingot mold 2 or its jacket E. Thus, the inner volume of the bellows 18 is protected from the atmosphere, so that liquid metal can flow directly through the opening 28 without the need for a submerged nozzle. As a result, casting can be performed more quickly without causing disturbance due to the intermediate member 1 at the level of the ingot mold 2. The bellows 18 can absorb the vertical vibration of the dispenser 7 generated in the ingot mold 2 and the receiving chamber 5. If no mechanical vibration is applied to the ingot mold 2, a bellows 18 can be replaced with a rigid skirt that seals the internal space. The interior space of bellows 18 can be placed under relatively reduced pressure to evacuate the liquid steel jet from opening 28. The pressure inside the bellows 18 can be adjusted.

FIGS. 6 and 7 show a plan view and a sectional view of a unit for casting a product having a rectangular section called a slab. The elements described above are represented by the same reference numbers or numbers obtained by adding 100, and descriptions thereof will be omitted except for the changed parts. In this example, the intermediate member 1 has an upper receiving chamber 105, which is supported on the ingot mold 2 via a lower edge and is extended by a connecting channel 108, which extension is Has penetrated into the upper part of. As shown in FIG. 7, the receiving chamber 105 is a container having an oblong cross section defined by two parallel wall surfaces corresponding to the longer side of the ingot mold and a rounded end connecting the two wall surfaces. Is configured.

A solid block 83 is provided at the center of the connecting channel 108 to help disperse the metal flowing through the nozzle 26 reaching the center of the receiving chamber 105. This block is shown in a plan view in the left half of FIG. 7 and in a horizontal sectional view in the right half. This block 83 is nozzle 2
6 lie across the connecting channel 8 and divide the metal into two streams, indicated by arrows F ′, and have two elongates that terminate above the lower opening 82 of the connecting channel 8. It leads to an opening 84 having a cross section. That is,
The metal cast via the nozzle 26 is evenly dispersed within the ingot mold 2 and the elongated cross section 84 is sufficient to allow the metal to descend at a relatively slow speed. As already mentioned, the radial openings 29 ensure a rapid diffusion of the metal in the annular space 10.

FIGS. 8 and 9 show a longitudinal section and a horizontal section, respectively, of another embodiment specifically designed as a unit for casting thin slabs. Elements that are the same as or similar to the elements described in FIGS. 1 to 6 are denoted by the same reference numerals or, in some cases, by numbers with 200 added, and description thereof will not be repeated except for those having changed. In this embodiment, the connection chamber 205 is not directly supported on the ingot mold, and the support frame 3 surrounding the upper part of the receiving chamber 205
5 and kept at a constant height,
Thereby, it is connected to the ingot mold 2 so that the ingot mold 2 can vibrate. The support frame 35 can be constituted by a metal base that is mechanically welded, and has a cooling jacket 117 that is in contact with the outer wall of the receiving chamber 105.

The upper part of the receiving chamber 205 and the connecting channel 2
08 is formed by a doubly curved portion to promote the descent of the metal into the ingot mold 2. The ingot mold 2 has a rhombic or spindle-shaped horizontal cross-section to facilitate the introduction of metal, and has a desired rectangular cross-section.
The central portion becomes gradually narrower toward the outlet opening 60 (which is narrower in width than the length). Similarly, the introduction member 1 whose at least lower part constitutes the connection channel 208
Has a rhombic cross-section, which is similar to the cross-section of the ingot mold 2 by a similar transformation,
An annular space having a substantially constant width is formed between the outer wall of the ingot mold and the inner surface of the ingot mold. As in FIG. 7, a solid block 283 is disposed in the connecting channel 208 and has two elongated openings 284, the width of which is away from the axis of the nozzle 26 and approaches the shorter side of the ingot mold. According to.

In the embodiment of FIG. 8, the annular chamber 9 is closed by a support frame 35 directly supported on the ingot mold, and the introduction member 1 oscillates with the ingot mold. As already mentioned, it is also possible to provide the introduction member 1 on a fixed bracket. In that case, the support frame 35 is connected to the ingot mold by bellows to enable the vibration of the ingot mold and the sealing of the annular chamber 9. However, in this case, the volume of the gas to be confined increases, and the fluctuation width of the metal surface 12 level in the annular space 10 with respect to the fluctuation of the metal surface 11 level in the receiving chamber 5 increases.

The present invention is not limited to the above specific examples, and other modifications do not depart from the scope of the present invention described in the claims. For example, FIGS.
When casting a slab in which the length of the casting cavity is much longer than the width, a receiving chamber 405 having a cross section similar to the cross section of the ingot mold and a plurality of longitudinally offset connecting channels, as shown in FIG. 408 (connection channel 408 receiving supply from an opening 438 arranged at the bottom of the receiving chamber 405). As shown in FIG. 12, each connecting channel 408 is constituted by a tubular wall, and the outer diameter of each tubular wall is equal to the wall 481 and the longitudinal side 404 of the ingot mold.
Is determined so that there is a minimum distance necessary to prevent the metal from solidifying in the narrowest part of the outer free space 410.

When casting a thin slab using an ingot mold having a rhombic or spindle-shaped cross-section as shown in FIG. 9, each connecting channel is given a different cross-section so that the centrally located channel 408b is formed. The width can be wider than the channel 408a located at the end. The introduction speed of the liquid steel into the ingot mold 402 can be made substantially uniform.

Another advantageous feature of the present invention is that the implementation of a multiple casting line unit that allows multiple products to be cast simultaneously in parallel is greatly simplified. FIG. 13 is a conceptual diagram of such a unit, which has a plurality of ingot molds 2 (four in this example) arranged in parallel with each other, and these ingot molds 2a, 2a,
are of sufficient length to cover the four ingot molds and are connected to a single receiving chamber 305 that supplies liquid metal to each ingot mold. The liquid metal is cast via a single nozzle 26 extending from the dispenser 7 to approximately the center of the receiving chamber 305. An opening 38 is formed at the bottom of the receiving chamber 305 on the axis of each ingot mold 2a, 2b,..., And a connection channel 308 is provided at the tip thereof. In the above embodiment, the receiving chamber 305
Have four extensions, which make up respective connection channels 308a, 308b,..., Which connection channels respectively correspond to the corresponding ingot molds 2a, 2a, 2b,.
b,...

The supply of the liquid metal to the receiving chamber 305 is performed by a single dispenser 7, and a common level adjustment is performed in the receiving chamber 305 for the four ingot molds 2a, 2b,. It will be appreciated that the rate of introduction of the metal into each ingot mold 2a, 2b... Is automatically matched to the withdrawal rate of the corresponding ingot mold. That is, individual variations in flow velocity at the outlet opening 38 are balanced by the common receiving chamber 305 and appear as slight variations in the metal level 311 in the receiving chamber 305 due to the large dimensions of the receiving chamber. In this way, the product extraction rate in each casting line can be adjusted independently of the others.

When one line is interrupted, four stoppers or closing plungers, not shown, provided at the four inlet openings 38 of each connecting channel 308 are closed. This multi-line structure can be advantageously used for casting round or square billets. The above examples show that the present invention is suitable for casting any kind of product, especially bloom, under the same conditions as billets and conventional slabs (thick or thin). In addition to the above advantages, the following advantages can be further obtained. Because the change in casting speed has little effect on the solidification process,
Adjustment of the casting speed from the dispenser 7 can be performed more easily than conventional casting. A tubular connecting channel 8, 1 located between the receiving chamber and the ingot mold without harming the steel contained in the ingot mold.
08, 208, 308 can be flushed with argon or nitrogen.

The receiving chambers 5, 105, 205 and 3 are intermittently overflowed into a discharge tub provided adjacent to the receiving chamber to receive the overflow.
The upper level of 05 can be purified. The components of the device are thus simplified. In some cases, it is also possible to supply the receiving chamber directly, for example under pressure, from a cast ladle, especially for slabs. The casting speed can be 8 to 10 m / min or more. In practice, it is advantageous to perform the casting quickly to reheat the free surface 12 inside the outer free space 10. At that time, the speed is maintained at a sufficiently low value in any case so that the metal bath is not disturbed due to the large cross section of the outlet opening 82.

Since there is no risk associated with automatic start, all fluctuations can be canceled by overflow. The potential offered by the present invention, i.e., the elimination of the need for vibrating means for each ingot mold, and the ability to adjust the rate of metal introduction into the ingot mold, makes billet, bloom, and sometimes twin slab casting much simpler. Be transformed into Reference numerals in the claims are merely for assistance in understanding and do not limit the scope.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view at the height of an ingot mold of a continuous casting facility.

FIG. 2 is a graph showing vibration of a free surface of a liquid metal due to a pressure change.

FIG. 3 is a graph corresponding to a change in vibration shown in FIG. 2;

FIG. 4 is a vertical sectional view showing a lubricant supply system to an ingot mold.

FIG. 5 is a view similar to FIG. 4 showing a deformation unit without a submerged nozzle;

FIG. 6 is a vertical vertical sectional view showing a modified example of a unit for casting a general intermediate size slab.

FIG. 7 is a sectional view taken along line VII-VII in FIG. 6;

FIG. 8 is a longitudinal vertical cross-sectional view of another embodiment having a separate support member for an elevated connection chamber.

9 is a sectional view taken along line IX-IX in FIG.

FIG. 10 is a vertical sectional view showing another embodiment for slab casting.

11 is a plan view of the unit shown in FIG.

FIG. 12 is a sectional view taken along line XII-XII in FIG. 10;

FIG. 13 is a vertical sectional view of a unit of the present invention having multiple lines.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Intermediate member 2 Ingot mold 3 Product 4 Cooled wall 5, 205, 305 Receiving room 8 Connecting chamber 9 Annular chamber 10 Free outer peripheral space 13, 31 Partition wall 15 Crank 21 Storage container 23 Pressurized gas supply system 37 Bellows 60 Exit opening 81 tubular wall 82 outlet opening M liquid metal

Claims (19)

[Claims] An ingot mold defined by a cooled side wall (4) having an upper edge (6) and a lower edge (60) defining an inlet opening and an outlet opening and having a substantially vertical axis. (2) having a bottomless mold and means (D) for continuously injecting the liquid metal (M),
The liquid metal constitutes a metal bath whose upper surface is substantially horizontal in the ingot mold (2) and the liquid metal solidifies along the cooled wall (4) and is defined by the solidified outer surface (30). (3), and this product is continuously extracted from the outlet opening (60) of the ingot mold (2) at a withdrawal speed corresponding to the liquid metal injection speed. An intermediate member (1) for introducing liquid metal into the ingot mold (2), which is disposed between the metal injection means (D) and the intermediate member (1) is provided on the ingot mold (2). An upper receiving chamber (5) arranged therein and at least one connecting channel (8) defined by a tubular wall extending downward therefrom, the outer surface (8) of the tubular wall defining the connecting channel. The cross-sectional dimension of 1) is the inlet opening of the ingot mold (2) (6)
And the connecting channel is inserted into the ingot mold such that its outlet opening (82) is located below the upper level of the cooling wall (4) of the ingot mold, whereby the connecting channel (8)
Is separated from the cooled wall surface (4) of the ingot mold by a free outer peripheral free space (10), and the receiving chamber (5) is connected to the ingot mold by a sealing joint member to form an outer peripheral free space. An annular chamber (9) is formed on (10) in which all surfaces in which gas is trapped are closed, and the metal is placed in an outer free space (10).
Metal continuous casting equipment characterized in that this gas is compressed when it rises inside. 2. The installation according to claim 1, comprising means (20) for introducing a liquid lubricant at the same temperature as the metal into the interior of the annular chamber (9). 3. An outer free space (1) located between the tubular wall (81) of the connecting channel (8) and the cooled wall (4).
The width of the entire perimeter of 0) is sufficient to prevent the upper surface (12) of the metal (M) from solidifying in the outer free space (10). Equipment described in. 4. The inner cross section of the connecting channel (8) is dimensioned such that the penetration rate of the liquid metal introduced into the ingot mold (2) is sufficiently low to ensure that the deep part of the liquid metal bath is not disturbed. The equipment according to any one of claims 1 to 3, comprising: 5. The connecting channel (8, 108, 208, 3).
08), the penetration speed (Vi) of the liquid metal (M) into the ingot mold (2) is about 3 to 3 times the casting speed.
5. The facility of claim 4 having dimensions that are six times as large. 6. The connecting channel (8, 108, 208, 3).
08) The inside section (Si) is at least the product section
5. The installation according to claim 4, which is equal to 20% of (Sp). 7. The casting cavity has a substantially rectangular cross section with two large faces and two small faces, and the tubular wall of the connecting channel (8, 108, 208, 308) has at least an ingot mold (2). 7. The installation according to any one of the preceding claims, wherein the part inserted therein is defined by two large surfaces substantially parallel to the larger surface of the ingot mold (2). 8. The connecting member (J) between the receiving chamber (5) and the ingot mold (2) comprises a connecting channel (8).
8. A partition according to any one of claims 1 to 7, surrounding the receiving chamber and being partitioned by a partition (13, 31) which is hermetically connected to the receiving chamber (5) and the cooled wall (4) of the ingot mold (2). Equipment. 9. The upper part of the outer wall of the connecting channel (8) is connected to the receiving chamber (5) by a transverse crank (15) arranged on the upper edge (6) of the ingot mold. The equipment according to 8. 10. A lower part of the receiving chamber (5) surrounding the connecting channel (8) and supported on the upper edge (6) of the ingot mold via a gasket (14). An installation according to claim 9, constituted by an edge (13). 11. The connecting chamber (205) is hermetically fixed to a support frame (35, 35a) connected to the ingot mold by a sealing joint member J.
The facility according to any one of claims 9 to 13. 12. The support frame (35) of the receiving chamber (5).
a) an ingot mold (2) by means of a bellow (37) allowing a vertical oscillation of the ingot mold (2);
12. The installation according to claim 11, wherein the receiving chamber (5) is fixed to the housing. 13. A closed annular chamber (9) with a gas supply means (19), the pressure of said annular chamber being adapted to the liquid metal surface (11) and the free space (9) in the receiving chamber (5). Level difference h from the free surface (12) of the liquid metal in the chamber
The installation according to any one of the preceding claims, wherein the installation is adjusted according to: 14. A connecting channel (8) and an ingot mold (2), wherein the gas supply means (19) of the closed annular chamber (9) controls the gas pressure fluctuation inside the annular chamber (9) near the average pressure. 14. An installation according to any one of the preceding claims, connected to means for oscillating the level of the free surface (12) of the liquid metal around an average level in the outer free space (10) between the first and second liquid metal. 15. A container (21) for storing lubricant disposed above the ingot mold (2), having one outlet connected to a supply duct open at the end into the annular chamber (9). ) And an annular chamber with a tip (9)
Duct (19) opened inside and storage container (21) at the tip
And a pressurized gas supply system (23) having a tap-off duct (19 ') opening therein, said pressurized gas supply system comprising a metal surface (1) in an outer free space (10).
2) The installation according to claim 13, wherein a gas is introduced at the same pressure on the top and the lubricant, so that the lubricant flows on the surface (12) of the liquid metal (M) only by gravity. 16. A solid block (32, 232) in the central part of the connecting channel, which block is connected to the lower side of the inflow point (26) when metal is injected into the receiving chamber (5). 16. A method as claimed in any of claims 1 to 15 wherein the metal flow is diverted laterally over a portion of the inner cross-section of the channel (8) towards walls located at both longitudinal ends of the ingot mold (2). Equipment according to any one of the preceding claims. 17. A cooling means (1) for cooling a wall surface of a receiving chamber (5).
The equipment according to any one of claims 1 to 16, comprising (7, 18). 18. The metal introduction member (1) is surrounded by a deformable partition (31), the upper part of which is airtightly connected to the distribution means (D), the lower part of which is ingot molded. 2. A metal casting by a free jet (metal flow without a nozzle), which is connected to (2) and forms a closed space around the receiving chamber (5).
The facility according to any one of claims 7 to 13. 19. Ingot mold (2a, 2b ...)
And comprises a common introduction member (1) extending over a set of ingot molds (2a, 2b...), The common introduction member comprising a single receiving chamber (3).
05), and a plurality of openings located on the axis of each ingot mold are provided at the bottom of the receiving chamber.
These openings respectively correspond to the connecting channels (3) of the receiving chamber (5).
08a, 308b), the lower end of this connecting channel being inserted into a corresponding ingot mold (2a, 2b,...). Equipment described in item.