CA1182617A - Metal inlet in continuous casters having moving mold walls - Google Patents
Metal inlet in continuous casters having moving mold wallsInfo
- Publication number
- CA1182617A CA1182617A CA000382933A CA382933A CA1182617A CA 1182617 A CA1182617 A CA 1182617A CA 000382933 A CA000382933 A CA 000382933A CA 382933 A CA382933 A CA 382933A CA 1182617 A CA1182617 A CA 1182617A
- Authority
- CA
- Canada
- Prior art keywords
- inlet
- pouring body
- mold walls
- gap
- mold
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
- B22D11/0637—Accessories therefor
- B22D11/064—Accessories therefor for supplying molten metal
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Continuous Casting (AREA)
- Molds, Cores, And Manufacturing Methods Thereof (AREA)
- Catching Or Destruction (AREA)
- Feeding And Watering For Cattle Raising And Animal Husbandry (AREA)
- Casting Support Devices, Ladles, And Melt Control Thereby (AREA)
- Dental Prosthetics (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An improvement in an inlet for liquid metal in a continuous caster, the inlet including a stationary refractory pouring body having a region from which the liquid metal exits, and a mold which partially encloses the pouring body and is equipped with mold walls which are movable in the casting direction. The improvement includes the following:
(1) In the exit region of the pouring body, the space between the pouring body and the facing surfaces of the mold walls defines a gap; and (2) The mold walls are coated in such a manner and are moved at such a speed that a liquid region filled with liquid metal is defined in the gap, between a solidification region starting at the walls, and the pouring body.
An improvement in an inlet for liquid metal in a continuous caster, the inlet including a stationary refractory pouring body having a region from which the liquid metal exits, and a mold which partially encloses the pouring body and is equipped with mold walls which are movable in the casting direction. The improvement includes the following:
(1) In the exit region of the pouring body, the space between the pouring body and the facing surfaces of the mold walls defines a gap; and (2) The mold walls are coated in such a manner and are moved at such a speed that a liquid region filled with liquid metal is defined in the gap, between a solidification region starting at the walls, and the pouring body.
Description
6~7 BACKGROUND OF THE INVENTION
The present invention relates to a metal inlet in continuous casters equipped with a stationary refractory pouring body, or tundish, and a mold which in part surrounds the pouring body and is provided with walls which are movable in the casting direction.
Such prior art continuous casters can be operated successfully, particularly when the metal inlet is closed -toward the outside, since access of air to the molten liquid metal can be prevented and the adjustment of the quantity of metal intro-duced~ particularly at high casting speeds, can be mastered.
Difficulties arise in the region of the stationary pouring body since that body must be sealed with respect to the mold wall.s which move in the casting direction, so as to prevent the escape of molten metal to the outside, and, for example, to insure good bar qualities.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an inlet for the liquid metal which, with a relatively simple structural design, provides sufficient tightness in the -transition region between the pouring body and the moving mold walls, the mold walls possibly being designed in the form of bands.
It is another object of the present invention to provide an inlet for use particularly with con-tinuous casters which process metals such as aluminum, copper, steel and zinc.
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It is a further object of the present in~ention to assure operational safety in the region of the metal inlet, especially at high casting temperatures and for materials having high chemical aggressivity.
The engineering problem on which the present invention is based is that the forces acting between metal melt and mold material or casting body material require very small gap dimensions to provide a purely mechanical seal and such dimensions cannot be maintained over the necessary periods of several hours at the high casting temperatures, particularly for copper and steel with their high aggressivity towards refractory materials. Although the molten metal entering the gap between the mold walls and the pour~
ing body could have a sealing effect once it is completely solidi-fied, this solidification process is undesirable and disadvan-tageous since the just solidified metal would be continuously pulled out of the gap or scrape on the moving mold walls and thus be damaged on its surface. This would result in destruction of the just produced metal skin, a poor surface of the cast produced, and possible damage to the continuous caster.
Accordingly, the present invention provides in an inlet for molten metal in a continuous caster, which inlet comprises a stationary refractory pouring body having an exit portion defining a passage from which molten metal e~its, and a mold which partially encloses said pouring body and is equipped with mold walls which are movable in the casting direction, the improvement wherein a) each said mold wall is spaced from said pouring body to define a gap with said pouring body in the region of said exit portion; b) each said mold wall is pro~ided, at the surface thereof facing said
The present invention relates to a metal inlet in continuous casters equipped with a stationary refractory pouring body, or tundish, and a mold which in part surrounds the pouring body and is provided with walls which are movable in the casting direction.
Such prior art continuous casters can be operated successfully, particularly when the metal inlet is closed -toward the outside, since access of air to the molten liquid metal can be prevented and the adjustment of the quantity of metal intro-duced~ particularly at high casting speeds, can be mastered.
Difficulties arise in the region of the stationary pouring body since that body must be sealed with respect to the mold wall.s which move in the casting direction, so as to prevent the escape of molten metal to the outside, and, for example, to insure good bar qualities.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an inlet for the liquid metal which, with a relatively simple structural design, provides sufficient tightness in the -transition region between the pouring body and the moving mold walls, the mold walls possibly being designed in the form of bands.
It is another object of the present invention to provide an inlet for use particularly with con-tinuous casters which process metals such as aluminum, copper, steel and zinc.
3L~8Z~
It is a further object of the present in~ention to assure operational safety in the region of the metal inlet, especially at high casting temperatures and for materials having high chemical aggressivity.
The engineering problem on which the present invention is based is that the forces acting between metal melt and mold material or casting body material require very small gap dimensions to provide a purely mechanical seal and such dimensions cannot be maintained over the necessary periods of several hours at the high casting temperatures, particularly for copper and steel with their high aggressivity towards refractory materials. Although the molten metal entering the gap between the mold walls and the pour~
ing body could have a sealing effect once it is completely solidi-fied, this solidification process is undesirable and disadvan-tageous since the just solidified metal would be continuously pulled out of the gap or scrape on the moving mold walls and thus be damaged on its surface. This would result in destruction of the just produced metal skin, a poor surface of the cast produced, and possible damage to the continuous caster.
Accordingly, the present invention provides in an inlet for molten metal in a continuous caster, which inlet comprises a stationary refractory pouring body having an exit portion defining a passage from which molten metal e~its, and a mold which partially encloses said pouring body and is equipped with mold walls which are movable in the casting direction, the improvement wherein a) each said mold wall is spaced from said pouring body to define a gap with said pouring body in the region of said exit portion; b) each said mold wall is pro~ided, at the surface thereof facing said
- 2 -6~'7 pouring body, with a coating selected to influence solidification of the metal; and c~ said coating is selected and said mold walls are arranged to move at such a speed during flow of molten metal out o said pouring body via sa.id passage to cause the molten metal to solidify at a location starting at said mold walls and to create a region filled with molten metal and located within each such gap and between said pouring body and said location of molten metal solidiication.
The present invention is thus based on the concept that a continuous casting process is possible under stationary con-ditions only if no bridge of solidified metal is formed in the gap between the facing surfaces of the mold walls and the pouring body. It is therefore important to prevent solidification of the metal at the pouring body, since otherwise the danger of hridge formation to the mold would exist. In order for the beginning solidification not to reach the pouring body~ i.e. to mai.ntain a liquid region filled with liquid metal between the pouring body and the mold walls, the mold walls are provided with a suitable heat insulating coating and move relative to the pouring body at such speed that only as much metal flows into the gap between the walls and the pouring body as is consumed by solidification and removed by the movement of the mold walls.
A two-phase region is thus always present between the mold walls and at least the exit region of the pouring body. In -this region the metal Elowing into the gap is just consumed by solidification in the solidification region.
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Thus, the gap set between the pouring body and the moving mold walls can be automatically sealed by solidifying metal if the material properties and geometric relationship of the components to be sealed against one another, and the velocity of movement of the mold walls are precisely adjusted to one another so that the quantity of metal flowing into the gap corresponds to the quantity of solidified metal removed from the gap by the mold walls.
Coating materials according to the present invention, are, in particular, powders and alcoholic suspensions based on glass, slag, graphite, or ceramic-graphite. The coating may also be produced with the use of suitable salts, fats and oils.
In preferred embodiments of -the invention, the gap is set in such a manner that its width is no greater than two millimeters and is preferably no more than 1.5 or 1 millimeter.
With appropriate mutual matching of the material properties and geometric relationships of the components to be sealed against one another, and taking into consideration the metal being cast, it is possible, however, to also set the gap larger than two millimeters. The facing walls of the mold and of the pouring body are therefore advantageously designed and arranged in such a manner that at least in the exit region of -the pouring body, they are parallel to one another.
Preferably, the gap between the pouring body and the moving mold walls is set to a value between 0.5 and 1 millimeter, with the mold walls moving at a rate of between 10 and 20 meters per mirlute. Sucn an embodiment is par-ticularly suitable for the casting of steel.
Due to the high thermal stresses on the mold walls, warping of the walls, which changes their distance from the pour-ing body, poses a particular problem. In order to keep this distance, i.e. the gap width, as constant as possible at the desired ~alue, it is advisable to provide guide rails which support the mold walls under a slight tension. The guide rails which are advantageously made of -the same material as the pouring body, particularly in the exit region, may be fixed to the pouring body, but are advisably movable therein in a manner such that either a desired distance between mold and pouring body remains in effect during the casting process or the distance between the mold and the pouring body can be varied to the desired extent.
The guide rails may be arranged to be movable in the pouring body, particularly with the use of spring elements. In a particularly preferred embodiment of the present invention, the position of the guide rails may be externally varied with respect to the mold walls. For this purpose, the guide rails may be made adjustable in height within the pouring body particularly by means of adjustment wedges or s milar remotely controllable lifting devices.
Advisably the guide rails are made relatively narrow on their side which faces the mold walls. Their width transverse to the longitudinal direction of the pouring body is preferably no more than five millimeters.
It has also been found to be advantageous to arrange the guide rails in such a manner that -their greatest distance from one another in the direction transverse to the longitudinal direction of the pouring body is -two hundred millimeters. In order to prevent bridge formation between -the mold walls and the pouring body, the guide rails should approach the exit edge of the pouring body no closer than thirty millimeters and prefer-ably no closer than fifty millimeters.
In a particularly preferred embodiment of the present invention, the exit portion of the pouring body is equipped with a bore which widens in the cas-tlng direction in the manner of a funnel. Advantageous:Ly, the bore walls have convex curvature, but under certain circumstances, they can also be linear or can have a concave curvature. The curvature of the exit portion, which is adjusted to the specific casting conditions, permits the optimum attainment of high mechanical stability of the spout region of the pouring body, sufficiently high heat capacity and heat dissipation to the outside, i.e. in the direction toward the mold, and substantial calming of the turbulent flow.
The exit portion and the remaining, or main, portion of the pouring body are preferably made of refractory materials having different thermal conductvities. Advantageously, the exit portion and remaining portion of the pouring body will be connected together in such a manner that thermally caused changes in the dimensions of each portion may take place. In particular, these two regions of the pouring body may be fastened together by means of plug-in connec-tions. This connection between the exit portion and the remaining portion is par-ticularly advantageous if the exit region is made of a material having good thermal conductivity, and the conductivity of -the exit portion is higher than tha-t of the remaining region.
6~
Suitable materials for construction of the exit portion arel in particular, Si3N4, BN and cermet. The remaining portion oE the pouring body may be constructed particularly of refractory ceramics containiny a large amount of alumina, such as sillimanite rock.
To prevent the molten metal from penetrating too far into the gap between the mold and the pouring body, the gap is advantageously filled with an inert gas, in the exit region of the pouring body. The pressure of this inert gas is selected to lie slightly below that of the metallostatic pressure of the melt in exit region. Since the inert gas pressure is always less than the metallostatic pressure of the melt, the inert gas cannot enter the liquid metal and the cast bar.
In one embodiment of the invention employing an inert gas seal! the pouring body, in its outer side facing the mold walls is provided with an annular channel which is connected outside of the mold to an inert gas source and which, on the side facing away from the exit region, is sealed against the mold walls.
~0 It is to be understood that both the foregoing general description and the following detailed description are exemplary, but are not restrictive of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
. .
Figure 1 is a longitudinal, partial sectional, schematic elevational view of one-halE of a metal inlet according to the invention, in -the exit region of the pouring body.
Figure 2 is a partial sec-tional view, to a smaller scale than that of Fi~ure 1, of a pouring body equipped with a ~:~8~
plurali-ty of juxtaposed gulde rails, the sectional view being transverse -to the longitudinal direction of the pouring body.
Figure 3 is a longitudinal sectional, schematic view of a metal inlet according to the invention, whose pouring body is equipped with an inert gas channel in its exit region.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The metal inlet according to the invention, as shown in Figure 1, includes, as its essential components, band-shaped mold walls 2 which are movable in the direction of arrow 1, and a stationary pouring body 3 which includes an exit portion 4 and a remaining portion 5. The portion 4 is constructecl of a material having good thermal conductivity and region 5 is con~
structed of a material having poor thermal conductivity. Portion 4 presents outer faces 4' and an exit edge 4". Each face 4' and each outer face 5' of main portion 5 are spaced from the associated mold wall 2 to define a gap 9.
The molten metal to be cast is introduced in the direction of arrow 6 through a bore 7 in pouring body 3 between moving mold walls 2. A region of solidification 8 begins at mold walls 2. When viewed in the casting direction, according to arrow 6, bore 7 having a longitudinal axis 7' widens in the exit portion 4 in the manner of a funnel which has an outer face 4' and an exit edge 4".
To seal gap ~ between each mold wall 2 and outer faces 4' and 5' of portions 4 and 5, respectively, of pouring body 3, the distance between each wall 2 and body 3 is always maintained at about 0.7 millimeters. Moreover, mold walls 2, which move at a rate of about 17 meters per minute, are coated in such a manner that the onset of solidlfication shown in solidification region 8 does not reach the pourlng body 3 or its exit portion ~. Rather, a gap-like liquid region 8' filled with molten metal remains between the walls and the pouring body. The maintenance of this liquid region 8' has the result that no bridge of solidifying metal forms in the gap 9 between the walls 2 and pouriny body 3. The operating conditions existing during the casting process, specifically gap width, coating of the mold walls and rate of movement of the mold walls, are selected such that exactly the same quantity of liquid me-tal always flows to the left through gap-like liquid region 8' as is removed after solidification at the mold walls 2 by their movement to the right in the direction of arrow 1.
In order to assure that the gap width always remains at the desired value amount, pouring body 3 is equipped at its side facing mold walls 2 i.e. in the region of outer faces 4' and 5', with guide rails 10, whown in Figure 2, against which the mold walls 2 are supported under a slight amount of tension. The width _ of these guide rails is preferably no more than Eive millimeters and the distance a between the rails, transverse to the longitudinal direction of pouring body 3 is no more than two hundred millimeters.
According to a modification oE the embodiment shown in Figure 2, in order to be able to vary the yuiding effect of guide rails 10, if required, the guide rails may be adjus-tably held in pouring body 3. It is also possible to arrange guide rails 10 to be movable within pouring body 3 through the intermediary oE spring elements.
26~
The center plane of pouring hody 3 transverse to longi-tudinal axis ~' is identified as 7" in Figure 2.
Advisably, guide rails 10 - when viewed in -the direction of the longitudinal axis 7' (or in the direction of the arrows 1 and 6~ - will lie as close as possible -to exit edge 4" of exit position 4. However, the distance of the rails from -this exi-t edge must be selected in such a way that the rails will in any case lie outside of solidification region 8 - which extends into gap 9 - as indicated in Figure 1. Therefore, the dis-tance c in Figure 1 of the leading edges of suide rails 10 from exit edge 4" is therefore no less than 30 millimeters.
In the embodiment shown in Figure 3, exi-t portion 4 of pouring body 3 is equipped with an annular channel 11 through which inert gas is introduced into the gap between walls 2 and exit position 4. This annular channel 11 is connected by conduit 12 to an inert gas source which is not shown.
The pressure of the inert gas is here selected to always lie slightly below the value of the metallostatic pressure in the melt in the region cf exit edge 4" of exit portion 4. The presence of the inert gas a-t this pressure prevents excessive penetration of the melt into the gap between walls 2 and exit portion 4 without the danger of inclusion of inert gas in the cast bar.
On the rear side of the annular channel facing away from exit edge 4", -the channel is closed off by a seal 13 which simultaneously con-tac-ts -the mold walls 2 and -the pouring body 3 While the described embodiment incorporates band-shaped mold walls, the presen-t invention is not limited thereto, but can be used in conjunction with differently designed mold walls.
It will be understood that the above description of the present invention is susceptible to vari.ous modifications, changes and adaptions, and the sa:me are intended to be comprehended within the meaning and range of equivalents of the appended claims.
The present invention is thus based on the concept that a continuous casting process is possible under stationary con-ditions only if no bridge of solidified metal is formed in the gap between the facing surfaces of the mold walls and the pouring body. It is therefore important to prevent solidification of the metal at the pouring body, since otherwise the danger of hridge formation to the mold would exist. In order for the beginning solidification not to reach the pouring body~ i.e. to mai.ntain a liquid region filled with liquid metal between the pouring body and the mold walls, the mold walls are provided with a suitable heat insulating coating and move relative to the pouring body at such speed that only as much metal flows into the gap between the walls and the pouring body as is consumed by solidification and removed by the movement of the mold walls.
A two-phase region is thus always present between the mold walls and at least the exit region of the pouring body. In -this region the metal Elowing into the gap is just consumed by solidification in the solidification region.
!~ 3 -6~L~
Thus, the gap set between the pouring body and the moving mold walls can be automatically sealed by solidifying metal if the material properties and geometric relationship of the components to be sealed against one another, and the velocity of movement of the mold walls are precisely adjusted to one another so that the quantity of metal flowing into the gap corresponds to the quantity of solidified metal removed from the gap by the mold walls.
Coating materials according to the present invention, are, in particular, powders and alcoholic suspensions based on glass, slag, graphite, or ceramic-graphite. The coating may also be produced with the use of suitable salts, fats and oils.
In preferred embodiments of -the invention, the gap is set in such a manner that its width is no greater than two millimeters and is preferably no more than 1.5 or 1 millimeter.
With appropriate mutual matching of the material properties and geometric relationships of the components to be sealed against one another, and taking into consideration the metal being cast, it is possible, however, to also set the gap larger than two millimeters. The facing walls of the mold and of the pouring body are therefore advantageously designed and arranged in such a manner that at least in the exit region of -the pouring body, they are parallel to one another.
Preferably, the gap between the pouring body and the moving mold walls is set to a value between 0.5 and 1 millimeter, with the mold walls moving at a rate of between 10 and 20 meters per mirlute. Sucn an embodiment is par-ticularly suitable for the casting of steel.
Due to the high thermal stresses on the mold walls, warping of the walls, which changes their distance from the pour-ing body, poses a particular problem. In order to keep this distance, i.e. the gap width, as constant as possible at the desired ~alue, it is advisable to provide guide rails which support the mold walls under a slight tension. The guide rails which are advantageously made of -the same material as the pouring body, particularly in the exit region, may be fixed to the pouring body, but are advisably movable therein in a manner such that either a desired distance between mold and pouring body remains in effect during the casting process or the distance between the mold and the pouring body can be varied to the desired extent.
The guide rails may be arranged to be movable in the pouring body, particularly with the use of spring elements. In a particularly preferred embodiment of the present invention, the position of the guide rails may be externally varied with respect to the mold walls. For this purpose, the guide rails may be made adjustable in height within the pouring body particularly by means of adjustment wedges or s milar remotely controllable lifting devices.
Advisably the guide rails are made relatively narrow on their side which faces the mold walls. Their width transverse to the longitudinal direction of the pouring body is preferably no more than five millimeters.
It has also been found to be advantageous to arrange the guide rails in such a manner that -their greatest distance from one another in the direction transverse to the longitudinal direction of the pouring body is -two hundred millimeters. In order to prevent bridge formation between -the mold walls and the pouring body, the guide rails should approach the exit edge of the pouring body no closer than thirty millimeters and prefer-ably no closer than fifty millimeters.
In a particularly preferred embodiment of the present invention, the exit portion of the pouring body is equipped with a bore which widens in the cas-tlng direction in the manner of a funnel. Advantageous:Ly, the bore walls have convex curvature, but under certain circumstances, they can also be linear or can have a concave curvature. The curvature of the exit portion, which is adjusted to the specific casting conditions, permits the optimum attainment of high mechanical stability of the spout region of the pouring body, sufficiently high heat capacity and heat dissipation to the outside, i.e. in the direction toward the mold, and substantial calming of the turbulent flow.
The exit portion and the remaining, or main, portion of the pouring body are preferably made of refractory materials having different thermal conductvities. Advantageously, the exit portion and remaining portion of the pouring body will be connected together in such a manner that thermally caused changes in the dimensions of each portion may take place. In particular, these two regions of the pouring body may be fastened together by means of plug-in connec-tions. This connection between the exit portion and the remaining portion is par-ticularly advantageous if the exit region is made of a material having good thermal conductivity, and the conductivity of -the exit portion is higher than tha-t of the remaining region.
6~
Suitable materials for construction of the exit portion arel in particular, Si3N4, BN and cermet. The remaining portion oE the pouring body may be constructed particularly of refractory ceramics containiny a large amount of alumina, such as sillimanite rock.
To prevent the molten metal from penetrating too far into the gap between the mold and the pouring body, the gap is advantageously filled with an inert gas, in the exit region of the pouring body. The pressure of this inert gas is selected to lie slightly below that of the metallostatic pressure of the melt in exit region. Since the inert gas pressure is always less than the metallostatic pressure of the melt, the inert gas cannot enter the liquid metal and the cast bar.
In one embodiment of the invention employing an inert gas seal! the pouring body, in its outer side facing the mold walls is provided with an annular channel which is connected outside of the mold to an inert gas source and which, on the side facing away from the exit region, is sealed against the mold walls.
~0 It is to be understood that both the foregoing general description and the following detailed description are exemplary, but are not restrictive of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
. .
Figure 1 is a longitudinal, partial sectional, schematic elevational view of one-halE of a metal inlet according to the invention, in -the exit region of the pouring body.
Figure 2 is a partial sec-tional view, to a smaller scale than that of Fi~ure 1, of a pouring body equipped with a ~:~8~
plurali-ty of juxtaposed gulde rails, the sectional view being transverse -to the longitudinal direction of the pouring body.
Figure 3 is a longitudinal sectional, schematic view of a metal inlet according to the invention, whose pouring body is equipped with an inert gas channel in its exit region.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The metal inlet according to the invention, as shown in Figure 1, includes, as its essential components, band-shaped mold walls 2 which are movable in the direction of arrow 1, and a stationary pouring body 3 which includes an exit portion 4 and a remaining portion 5. The portion 4 is constructecl of a material having good thermal conductivity and region 5 is con~
structed of a material having poor thermal conductivity. Portion 4 presents outer faces 4' and an exit edge 4". Each face 4' and each outer face 5' of main portion 5 are spaced from the associated mold wall 2 to define a gap 9.
The molten metal to be cast is introduced in the direction of arrow 6 through a bore 7 in pouring body 3 between moving mold walls 2. A region of solidification 8 begins at mold walls 2. When viewed in the casting direction, according to arrow 6, bore 7 having a longitudinal axis 7' widens in the exit portion 4 in the manner of a funnel which has an outer face 4' and an exit edge 4".
To seal gap ~ between each mold wall 2 and outer faces 4' and 5' of portions 4 and 5, respectively, of pouring body 3, the distance between each wall 2 and body 3 is always maintained at about 0.7 millimeters. Moreover, mold walls 2, which move at a rate of about 17 meters per minute, are coated in such a manner that the onset of solidlfication shown in solidification region 8 does not reach the pourlng body 3 or its exit portion ~. Rather, a gap-like liquid region 8' filled with molten metal remains between the walls and the pouring body. The maintenance of this liquid region 8' has the result that no bridge of solidifying metal forms in the gap 9 between the walls 2 and pouriny body 3. The operating conditions existing during the casting process, specifically gap width, coating of the mold walls and rate of movement of the mold walls, are selected such that exactly the same quantity of liquid me-tal always flows to the left through gap-like liquid region 8' as is removed after solidification at the mold walls 2 by their movement to the right in the direction of arrow 1.
In order to assure that the gap width always remains at the desired value amount, pouring body 3 is equipped at its side facing mold walls 2 i.e. in the region of outer faces 4' and 5', with guide rails 10, whown in Figure 2, against which the mold walls 2 are supported under a slight amount of tension. The width _ of these guide rails is preferably no more than Eive millimeters and the distance a between the rails, transverse to the longitudinal direction of pouring body 3 is no more than two hundred millimeters.
According to a modification oE the embodiment shown in Figure 2, in order to be able to vary the yuiding effect of guide rails 10, if required, the guide rails may be adjus-tably held in pouring body 3. It is also possible to arrange guide rails 10 to be movable within pouring body 3 through the intermediary oE spring elements.
26~
The center plane of pouring hody 3 transverse to longi-tudinal axis ~' is identified as 7" in Figure 2.
Advisably, guide rails 10 - when viewed in -the direction of the longitudinal axis 7' (or in the direction of the arrows 1 and 6~ - will lie as close as possible -to exit edge 4" of exit position 4. However, the distance of the rails from -this exi-t edge must be selected in such a way that the rails will in any case lie outside of solidification region 8 - which extends into gap 9 - as indicated in Figure 1. Therefore, the dis-tance c in Figure 1 of the leading edges of suide rails 10 from exit edge 4" is therefore no less than 30 millimeters.
In the embodiment shown in Figure 3, exi-t portion 4 of pouring body 3 is equipped with an annular channel 11 through which inert gas is introduced into the gap between walls 2 and exit position 4. This annular channel 11 is connected by conduit 12 to an inert gas source which is not shown.
The pressure of the inert gas is here selected to always lie slightly below the value of the metallostatic pressure in the melt in the region cf exit edge 4" of exit portion 4. The presence of the inert gas a-t this pressure prevents excessive penetration of the melt into the gap between walls 2 and exit portion 4 without the danger of inclusion of inert gas in the cast bar.
On the rear side of the annular channel facing away from exit edge 4", -the channel is closed off by a seal 13 which simultaneously con-tac-ts -the mold walls 2 and -the pouring body 3 While the described embodiment incorporates band-shaped mold walls, the presen-t invention is not limited thereto, but can be used in conjunction with differently designed mold walls.
It will be understood that the above description of the present invention is susceptible to vari.ous modifications, changes and adaptions, and the sa:me are intended to be comprehended within the meaning and range of equivalents of the appended claims.
Claims (17)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In an inlet for molten metal in a continuous caster, which inlet comprises a stationary refractory pouring body having an exit portion defining a passage from which molten metal exits, and a mold which partially encloses said pouring body and is equipped with mold walls which are movable in the casting direction, the improvement wherein a) each said mold wall is spaced from said pouring body to define a gap with said pouring body in the region of said exit portion;
b) each said mold wall is provided, at the surface thereof facing said pouring body, with a coating selected to influence solidification of the metal; and c) said coating is selected and said mold walls are arranged to move at such a speed during flow of molten metal out of said pouring body via said passage to cause the molten metal to solidify at a location starting at said mold walls and to create a region filled with molten metal and located within each such gap and between said pouring body and said location of molten metal solidification.
b) each said mold wall is provided, at the surface thereof facing said pouring body, with a coating selected to influence solidification of the metal; and c) said coating is selected and said mold walls are arranged to move at such a speed during flow of molten metal out of said pouring body via said passage to cause the molten metal to solidify at a location starting at said mold walls and to create a region filled with molten metal and located within each such gap and between said pouring body and said location of molten metal solidification.
2. Inlet as defined in claim 1, wherein each said gap has a width of no more than two millimeters.
3. Inlet as defined in claim 2, wherein each said gap has a width of no more than 1.5 millimeters.
4. Inlet as defined in claim 3, wherein each said gap has a width of no more than one millimeter.
5. Inlet as defined in claim 1, wherein the width of each said gap is between 0.5 and 1 millimeter, and said mold walls are arranged to be moved at a rate of between 10 and 20 meters per minute in the casting direction.
6. Inlet as defined in claim 1, additionally comprising guide rails provided at said pouring body which set the space defining each said gap, wherein said guide rails are supported at said mold walls under a slight tension.
7. Inlet as defined in claim 6 wherein there are two said guide rails for each said gap spaced apart by a maximum distance of two hundred millimeters, transverse to the direction of movement of said mold walls.
8. Inlet as defined in claim 6 or 7, wherein the width of each said guide rail is no more than five millimeters, transverse to the direction of movement of said mold walls.
9. Inlet as defined in claim 6 or 7, wherein said pouring body exit portion presents an exit edge and said guide rails come no closer than thirty millimeters to said exit edge, in the direction of movement of said mold walls.
10. Inlet as defined in claim 6 or 7, wherein said pouring body exit portion presents an exit edge and said guide rails come no closer than fifty millimeters to said exit edge, in the direction of movement of said mold walls.
11. Inlet as defined in claim 6 and 7, wherein said guide rails are held such that they are movable in said pouring body.
12. Inlet as defined in claim 6 or 7, wherein said guide rails are constructed of the same material as said exit portion of said pouring body.
13. Inlet as defined in claim 1 or 2, wherein said exit portion of said pouring body defines a central bore which constitutes said passage and which widens in the manner of a funnel in the casting direction.
14. Inlet as defined in claim 1 or 2, wherein said pouring body further has a main portion located upstream of said exit portion, with respect to the direction of flow of molten metal in the casting direction, and connected to said exit portion in a manner to allow for thermally induced changes in the dimensions of said exit and main portions.
15. Inlet as defined in claim 1 or 2 further comprising means for introducing an inert gas into each said gap in the region of said exit portion at a pressure which lies slightly below the metallostatic pressure of liquid metal adjacent to said exit portion.
16. Inlet as defined in claim 1 or 2, wherein said pouring body, on its outer side facing said mold walls, defines an annular channel which is connected to a source of inert gas located outside of said mold, and said inlet further comprises means forming a seal between said mold walls and said pouring body at the side of said channel remote from end of said pouring body from which metal exits.
17. Inlet as defined in claim 1 or 2, wherein said body further has a main portion located upstream of said exit portion, with respect to the direction of flow of molten metal in the casting direction, and said exit portion is constructed of a material having a good thermal conductivity which is higher than the thermal conductivity of said main portion.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3029223A DE3029223C2 (en) | 1980-08-01 | 1980-08-01 | Inlet for the molten metal in continuous casting devices |
| DEP3029223.0 | 1980-08-01 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1182617A true CA1182617A (en) | 1985-02-19 |
Family
ID=6108679
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000382933A Expired CA1182617A (en) | 1980-08-01 | 1981-07-31 | Metal inlet in continuous casters having moving mold walls |
Country Status (9)
| Country | Link |
|---|---|
| EP (1) | EP0045365B1 (en) |
| JP (1) | JPS5752549A (en) |
| AT (1) | ATE6215T1 (en) |
| BR (1) | BR8104956A (en) |
| CA (1) | CA1182617A (en) |
| DD (1) | DD201650A5 (en) |
| DE (2) | DE3029223C2 (en) |
| ES (1) | ES503761A0 (en) |
| ZA (1) | ZA815269B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5636681A (en) * | 1994-07-19 | 1997-06-10 | Alcan International Limited | Process and apparatus for casting metal strip |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3325716C2 (en) * | 1983-07-16 | 1985-08-14 | Fried. Krupp Gmbh, 4300 Essen | Casting nozzle mouthpiece for continuous casting molds processing steel melt with mold walls moving in the casting direction |
| DE3345982C2 (en) * | 1983-12-20 | 1985-11-14 | Fried. Krupp Gmbh, 4300 Essen | Inlet for the molten metal in continuous casting devices that have a fixed, refractory casting nozzle and a mold with mold walls that are only moved in the direction of casting |
| DE3401024C2 (en) * | 1984-01-13 | 1986-01-16 | Fried. Krupp Gmbh, 4300 Essen | Casting nozzle consisting of several longitudinal sections for feeding molten metal into a continuous casting mold and method for producing the mouthpiece of such a casting nozzle |
| DE3403152C2 (en) * | 1984-01-31 | 1986-02-20 | Fried. Krupp Gmbh, 4300 Essen | Method for feeding molten steel from an intermediate container into a double-band continuous casting mold and intermediate container for carrying out the method |
| EP0237478B1 (en) * | 1986-03-10 | 1989-05-24 | Larex Ag | Sealing means for a nozzle in the casting space of a continuous casting machine with moving belt |
| AT405254B (en) * | 1996-02-20 | 1999-06-25 | Hulek Anton | TRACKED CHILLER FOR A CONTINUOUS CASTING SYSTEM |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1094517A (en) * | 1953-11-25 | 1955-05-20 | Casting plant for molten metals | |
| US3598173A (en) * | 1968-10-17 | 1971-08-10 | Olin Mathieson | Continuous casting machine having a variable mold length and adapted for casting in a variety of sizes at high speed |
| CH508433A (en) * | 1970-06-24 | 1971-06-15 | Prolizenz Ag C O Schweiz Kredi | Nozzle for feeding the molten metal into the caterpillar mold during strip casting |
| FR2121418A1 (en) * | 1971-01-12 | 1972-08-25 | Technicon Instr | Horizontal continuous casting |
| CH618366A5 (en) * | 1977-05-05 | 1980-07-31 | Prolizenz Ag |
-
1980
- 1980-08-01 DE DE3029223A patent/DE3029223C2/en not_active Expired
-
1981
- 1981-06-12 DE DE8181104544T patent/DE3162265D1/en not_active Expired
- 1981-06-12 AT AT81104544T patent/ATE6215T1/en not_active IP Right Cessation
- 1981-06-12 EP EP81104544A patent/EP0045365B1/en not_active Expired
- 1981-07-08 ES ES503761A patent/ES503761A0/en active Granted
- 1981-07-30 JP JP56118565A patent/JPS5752549A/en active Pending
- 1981-07-30 DD DD81232223A patent/DD201650A5/en unknown
- 1981-07-31 BR BR8104956A patent/BR8104956A/en unknown
- 1981-07-31 CA CA000382933A patent/CA1182617A/en not_active Expired
- 1981-07-31 ZA ZA815269A patent/ZA815269B/en unknown
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5636681A (en) * | 1994-07-19 | 1997-06-10 | Alcan International Limited | Process and apparatus for casting metal strip |
| US5671800A (en) * | 1994-07-19 | 1997-09-30 | Alcan International Ltd. | Injector for casting metal strip |
Also Published As
| Publication number | Publication date |
|---|---|
| ZA815269B (en) | 1982-10-27 |
| JPS5752549A (en) | 1982-03-29 |
| ATE6215T1 (en) | 1984-03-15 |
| ES8205366A1 (en) | 1982-06-01 |
| DE3162265D1 (en) | 1984-03-22 |
| EP0045365B1 (en) | 1984-02-15 |
| DE3029223C2 (en) | 1984-09-27 |
| EP0045365A1 (en) | 1982-02-10 |
| ES503761A0 (en) | 1982-06-01 |
| DD201650A5 (en) | 1983-08-03 |
| DE3029223A1 (en) | 1982-11-04 |
| BR8104956A (en) | 1982-04-20 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |