Metallic material containment systems in metal product casting

Abstract

A containment system (1) for laterally containing a liquid metal material or liquid alloy in an open end of a passage defined between two casting members, the system comprising a pneumatic device (2) terminating in a hollow end element (3) adapted to be positioned near the open end of the passage, the hollow end element (3) defining a chamber (4) therein, the pneumatic device (2) being adapted to supply a compressed gaseous substance into the chamber (4), the hollow end element (3) being provided with at least one blowing surface (6, 7) for blowing the compressed gaseous substance out of the chamber (4) towards a lateral containment zone for the liquid metal.

Description

[Technical field]

[0001] The present invention relates to a system for containing a liquid or semi-liquid metallic material (e.g., aluminum, zinc, magnesium, or any alloy) during a casting operation, preferably of a flat metallic product (e.g., strip), according to a technique commonly known as twin roll casting, or other alternative casting techniques that use two casting members to form a flat metallic product. [Background technology]

[0002] The technique commonly known as twin roll casting is a well-known technique used since the middle of the 20th century to produce solid metal semi-finished products starting from liquid material. This technique is mainly used for the production of flat strips, but it can also be adapted to be used for long products (such as billets or bars) because of the increased productivity of thin formats (typically up to 10 mm in thickness or diameter) and because such shapes can be cast at higher speeds with twin roll casting compared to other casting techniques. Another advantage of twin roll casting is that it allows the thin-walled sizes and small formats of the semi-finished products to be closer to the shape of the final product, thus reducing the forming operations (rolling, drawing) in downstream processes and contributing to obtaining a final product that is cheap and produced in large quantities.

[0003] A variety of materials can be used in twin roll casting, including ferrous and non-ferrous alloys or pure metals.

[0004] In conventional steel casting configurations, twin-roll casting is operated by a two-tiered stand in which cooled horizontal rolls are arranged side-by-side in parallel and with their axes lying on a common horizontal plane, while two cooled horizontal rolls for casting aluminum, magnesium, zinc, and / or their alloys are arranged, for example, one above the other with their axes lying on a common vertical plane or on a common plane inclined to the vertical. The space defined by the casting rolls is fed by an ejector which brings the liquid metal material into contact with the cooled roll to initiate solidification. The ejector, in its operation of feeding and containing the material, is assisted by side barriers or edge dams, which prevent the liquid or semi-liquid material from spreading laterally before it is completely solidified and can be part of the ejector itself or a separate component. Generally, the ejector is fed by a system of channels and furnaces, which differ depending on the material to be cast and its properties. Generally, the liquid material is transported using gravity or pumping means, and the channels need to be made of a material that has both isolating properties to prevent the drop in temperature and undesired local solidification of the material, and suitable mechanical resistance to ensure structural integrity and chemical compatibility with the alloy in the liquid state.

[0005] One of the most significant problems in the casting of metal strip is the lateral spreading of the liquid material caused by the edge machining conditions and solidification parameters.

[0006] Typically, when the casting load is increased, the liquid flow conditions and lower casting speeds promote preferential cooling of the strip edges, resulting in localized lateral spreading of the strip, improving dimensional control and reducing the risk of leakage. However, this can result in localized degradation of the strip quality and the need to trim the side portions of the strip.

[0007] The processing conditions could be modified to obtain more uniform casting conditions even on the flanks, but this would lead to increased lateral leakage of the liquid material, which could then adhere to the casting rolls, damaging the equipment and inducing process stoppages. This could be avoided by improving the lateral containment of the strip before solidification by mechanical barriers, but there are certain limitations from a technical point of view to obtain these results.

[0008] Indeed, the mechanical side containment system or the mechanical edge dam must not be made of a material that may react with the liquid material coming out of the casting device, and if they are made of an isolating material, they cannot contain the material effectively. Moreover, such materials must not be too resistant to the rolls, in order to avoid slippage damage to the rolls due to accidental contact. In general, to meet these requirements, such materials are preferably soft materials, for example oxide refractory materials. Also, when the casting load is reduced, it is necessary to ensure effective side containment at a point close to the exit of the roll bite, but also at a point quite far from the ejector exit, i.e., at the point where the distance between the casting rolls is minimal, which requires the use of very long and very thin edge dams. The above-mentioned materials cannot achieve the required shape of the edge dam or operate in the required shape without incurring yielding of the edge dam itself or damage to the surface of the casting rolls. Instead, constructing the edge dam using alternative materials such as steel or metal carries the risk of damaging the surface of the casting roll due to the adhesive effect of the liquid metal material (e.g., aluminum or its alloys) in addition to rapid wear caused by chemical reactions, corrosion, and / or abrasion phenomena.

[0009] Therefore, it is felt that there is a need to provide a containment system that can overcome the aforementioned drawbacks. Summary of the Invention [Problem to be solved by the invention]

[0010] The object of the present invention is to provide a system for lateral containment of liquid metal material, in particular aluminum, magnesium, zinc or an alloy based on one of these metals, preferably in the casting of flat metal products, which system makes it possible to improve performance both in terms of containing the liquid metal material at any casting load and in terms of extending the lateral containment area, while at the same time avoiding direct contact between the lateral containment devices and the liquid metal material.

[0011] The system of the present invention may be applied to castings carried out according to the technique commonly known as twin roll casting, or according to an alternative casting technique that uses two casting members to define a flat metal product.

[0012] Another object of the present invention is to provide a containment system that is flexible and therefore capable of casting metal products of various widths without the need to change casting components. [Means for solving the problem]

[0013] The present invention relates to a containment system for laterally containing at least partially liquid metallic material in an open end of a passage defined between two cast members, said system comprising a supply device for supplying at least one compressed gaseous substance, the supply device is provided with a hollow end element adapted to be positioned adjacent the open end of the passage; the hollow end element defines at least one chamber therein; the supply device is adapted to supply at least one compressed gaseous substance into the at least one chamber; the hollow end element is provided with at least one blowing surface for blowing the at least one compressed gaseous substance out of the at least one chamber towards a lateral containment zone for the at least partially liquid metallic material, The at least one blowing surface is provided with a plurality of through holes, At least one of such objectives, as well as other objectives which will become apparent in light of this description, is achieved by a system in which two or more non-coplanar outlet surfaces are provided for directing the flow of the at least one gaseous substance in different directions, or a single outlet surface is provided with two or more groups of through holes, each group being oriented in a different direction from the other groups.

[0014] Another aspect of the present invention is a casting machine for casting a metallic material product, comprising: Two cast parts, a first containment system as described above; and Preferably, a second containment system as described above; and Equipped with the two casting members defining a passageway having two open ends for solidifying a liquid metallic material delivered into a space between the casting members to form a product; a first containment system disposed proximate a first open end of the passage; a second containment system disposed proximate a second open end of the passage; Preferably, the two casting members are counter rotating rolls, belts, tracks, or combinations thereof.

[0015] Another aspect of the invention relates to a casting method for casting a metallic material product carried out by the casting machine described above, the method comprising the steps of: providing a liquid metal material into a space between two cast members; solidifying the metallic material to form a product within the passage between the two cast members; Including, A side containment of the liquid metal material is provided at at least one of the two open side ends of the passage by a first containment system; The lateral containment of the liquid metal material is obtained by supplying at least one compressed gaseous substance to at least one chamber of said hollow end element, which blows said at least one compressed gaseous substance out of the at least one chamber towards a lateral containment zone of said liquid metal material by means of at least one blowing surface, Preferably, the casting method relates to a first side containment of the liquid metal material provided at a first open end of the passage by said first containment system and a second side containment of the liquid metal material provided at a second open end of the passage by a second containment system.

[0016] In this description, reference will be made, by way of example, to the twin-roll casting technique, which uses two counter-rotating rolls as the casting members.

[0017] The solution of the present invention is to provide a barrier consisting of a compressed gaseous substance that can confine the edges of a flat metal product (e.g., a strip) during the solidification process by pushing the liquid metal material towards the center of the strip and applying a force to said edges to prevent the molten material from spreading or leaking to the sides.

[0018] The principle of the invention is based on the use of at least one compressed gaseous substance feeder, which may be partially molded to be located very close to the rolls of the caster, either on the side where the material enters the rolls, or on the side where the material leaves the rolls, or even on the side of the rolls themselves. Such a feeder is configured to blow at least one compressed gaseous substance (e.g. air or an inert gas) into the space between the rolls from one side towards the center. This compressed air-like substance has the dual effect of cooling the liquid material at the edges of the strip, accelerating its solidification locally, and of exerting a mechanical containment effect that prevents the liquid material from spreading.

[0019] Such a solution has many advantages.

[0020] First, the mechanical action is performed while avoiding contact between the liquid metal material and other materials, thus avoiding chemical reactions, corrosion or wear.

[0021] More specifically, the inventive solution does not provide direct contact either between the hollow end element and any surface of the casting roll, or between the hollow end element and the liquid metal material.

[0022] In particular, both when the hollow end element is completely outside the casting rolls and when it is at least partially inserted between said casting rolls, for example by means of the wedge shape of the hollow end element, there is always a non-zero distance between the hollow end element and any surface of the casting rolls.

[0023] At least one blowing surface of the hollow end element exerts a lateral containment action on the metal material by only blowing out compressed gaseous matter without providing any contact thereof with the solidifying material to prevent the material from escaping laterally from the roll.

[0024] Another advantage is that the containment can be achieved at any point between the rolls, which in the prior art could not be achieved by a physical barrier due to the limited space. For example, a jet of air or inert gas can be directed at the center of the roll bite, even if the thickness of the casting is very thin. Indeed, in this case, a physical barrier cannot be inserted between the rolls very close to the roll bite, due to the limited clearance imposed by the final thickness of the cast product (e.g. strip).

[0025] Finally, a major advantage of the blowing action is that it allows the gap between the rolls to be sealed without the need for adjustments, even if the roll position is changed. For example, the inventive solution continues to function in the case of software-controlled roll positions and in the case of unexpected changes in load settings due to casting conditions that may dictate occasional roll movements.

[0026] The containment system of the present invention can be adapted to the operating conditions to produce a more concentrated or divergent jet according to its geometry, so as to distribute the containment action by minimizing the consumption of air or inert gas, and the pressure of the injected gas and the mechanical thrust action can be adjusted to compensate for different metallostatic pressures of the molten material.

[0027] The pneumatic system or edge dam solution of the present invention meets the following requirements: To laterally contain metallic materials subjected to high pressures (e.g. liquid metal heads up to 100-120 mm); the length of the relevant side containment areas may vary (e.g. from 45 to 70 mm (setback)); The system is flexible and can cast a variety of strip widths without the need to exchange the casting rolls for other rolls of different lengths; It is also possible to satisfy the following.

[0028] Other features and advantages of the present invention will become more apparent in view of the detailed description of non-limiting exemplary embodiments.

[0029] The dependent claims describe particular embodiments of the invention.

[0030] In describing the invention, reference is made to the accompanying drawings, which are provided as non-limiting examples. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 shows a diagram of a horizontal casting machine equipped with a side containment system according to the present invention. [Diagram 2] 1 shows a perspective view of a system of the present invention. [Diagram 3] 1 shows a cross section of the caster showing the solidification area. [Figure 4] FIG. 3 shows a perspective view of the components of the system of FIG. 2. [Diagram 5] FIG. 2 shows a side view of a first variant of a component inserted between two casting rolls. [Figure 6] 6 shows a cross-sectional view of the components of FIG. 5. [Figure 7] 13 shows a side view of another variation of a component. [Figure 8] 13 shows a side view of another variation of a component. [Figure 9] 13 shows a side view of another variation of a component. [Figure 10] 13 shows a side view of another variation of a component. [Figure 11] 13 shows a side view of another variation of a component. [Figure 12] 13 shows a side view of another variation of a component. [Figure 13] 13 shows a side view of another variation of a component. [Figure 14] 13 shows a side view of another variation of a component. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] In the drawings, identical elements or components are given the same reference numerals.

[0033] The containment system of the present invention may be applied to castings carried out according to the technique commonly known as twin roll casting, or according to alternative casting techniques that use two casting members to define a flat metal product.

[0034] For example, this alternative casting technique: Single roll casting, in which a flat metal product is solidified by contact with a single water-cooled rotating roll, starting from a space bounded by the roll and a nozzle of an ejector (e.g., a tundish), where the two casting members are the single roll and the nozzle; Twin belt or twin track casting (also known as twin block casting), in which the flat metal product solidifies in a passage between two counter-rotating belts or tracks; Roll belt, roll track or combined track belt castings; It can be one of the following:

[0035] In this detailed description, reference will be made, by way of example, to the twin-roll casting technique, which uses two counter-rotating rolls as the casting members.

[0036] 1 shows an example of a horizontal caster with two horizontal casting rolls 20, 21 arranged one above the other, whose axes lie in a common vertical plane, the caster being equipped with a pair of containment systems 1, 1' according to the invention. However, the system of the invention can also be used in casters in which the axes of the two rolls lie in a common plane inclined to the vertical. In particular, vertical casters can be used in which the two casting rolls are arranged parallel side by side and whose axes lie in a common horizontal plane.

[0037] In the version shown in Figures 1-2, a casting machine for casting flat metallic material products (e.g. strip), preferably made of aluminum, zinc, magnesium or alloys thereof, comprises: two counter-rotating superposed casting rolls 20, 21 defining an exit passage for the metal material to be cast having two open ends for solidifying the liquid metal material to form a flat product; a supply means for supplying a liquid metal material into the space between the two casting rolls toward a passageway defined between the two casting rolls; a first containment system 1 disposed near a first open end of the passageway; a second containment system 1' preferably disposed near the second open end of the passage; Equipped with.

[0038] If it is necessary to laterally contain the liquid metal material only at one of the two side ends of the passage, it may be sufficient to use a single containment system.

[0039] Supply means known per se include: a tundish 34 for collecting liquid metal material, e.g. coming from an inlet channel (not shown); a discharge device 35, preferably made of ceramic material, for feeding the liquid metal material coming from the tundish 34 towards the passage bounded by the two casting rolls 20, 21; Equipped with.

[0040] Movement means (not shown) may be provided for moving the first containment system 1 and / or the second containment system 1′ to adjust their distance from each other along a direction parallel to a plane containing the rotation axes of the two casting rolls 20, 21. Such movement means may for example be linear actuators, such as hydraulic, pneumatic, mechanical actuators or combinations thereof.

[0041] This allows metal products (e.g. strip) of various widths to be cast without the need to change the casting rolls. The transition from one size of the produced strip to the other only requires a lateral movement of at least one of the two lateral containment systems 1, 1' relative to the casting rolls 20, 21 along the above-mentioned direction. This also applies in the case of a single containment system.

[0042] Thus, if the casting rolls are of equal (fixed) width, the side containment system can be moved to define different widths of the strip to be cast, eliminating the need to have dedicated roll sets as in the prior art, where the casting rolls must be changed every time a strip of a different width is to be cast, since the containment system cannot be moved laterally.

[0043] The containment systems 1, 1' in Figure 1 are arranged on the side where the metallic material (liquid metal) enters the space between the two casting rolls 20, 21, while Figure 2 shows a single containment system 1, which is arranged on the side where the metallic material (cast product) exits the casting rolls 20, 21. The feed direction of the metallic material is indicated by the arrow F in Figure 2.

[0044] In another variation, one or two containment systems can be provided on both the metal material inlet side and the metal material outlet side.

[0045] In all embodiments of the invention, each lateral containment system 1, 1' of the material to be cast comprises, at the respective open end of the passage defined between the two casting rolls 20, 21, a supply device 2 for supplying at least one compressed gaseous substance, comprising a hollow end element 3 adapted to be positioned near the open end of the passage defined by the casting rolls 20, 21 (Figure 2).

[0046] The hollow end element 3 may have an at least partially wedge shape so that it can be at least partially inserted between two casting rolls at the open end of the passage.

[0047] As an alternative to the wedge shape, the hollow end element 3 may have the shape of a rectangular or pyramidal parallelepiped, or any other shape suitable for positioning a hollow element near a passage defined between two casting rolls, and the hollow end element 3 may be at least partially inserted between the two casting rolls at the open end of the passage.

[0048] In the example of the drawing, the hollow end element 3 is wedge-shaped.

[0049] Preferably, each feeder 2 and therefore each hollow end element 3 is arranged in a laterally outer position (eg completely outer position) with respect to the zone occupied by the discharger 35 .

[0050] As shown in the non-limiting variant of Figure 6, the hollow end element 3 defines at least one chamber 4 (e.g., a single chamber) therein. In other variants, between 2 and 6 chambers can be provided. However, variants in which the number of chambers is greater than 6, or even significantly greater than 6, are not excluded, for example if the chambers correspond to the porosity of the material from which the hollow element 3 is made.

[0051] The supply device 2 is configured to supply at least one compressed gaseous substance, such as air or an inert gas, inside at least one chamber 4 .

[0052] Advantageously, the hollow end element 3 is provided with at least one blowing surface for blowing the compressed gaseous substance from the at least one chamber 4 towards a lateral containment zone of the metallic material being cast between the casting rolls 20, 21.

[0053] As shown in the non-limiting example of FIG. 2, each containment system 1 can be mounted at a first end thereof on a chock 23 of the lower casting roll 21 and includes a support arm 24 that supports a corresponding hollow end element 3 at a second end opposite the first end of the system.

[0054] A moving means 40 can be provided for moving one or both hollow end elements 3 of the containment systems 1, 1' in order to adjust their distance from one another along a direction parallel to a plane containing the rotation axes of the two casting rolls 20, 21.

[0055] For example, one transfer means 40 is provided for each containment system 1, 1'.

[0056] In particular, the movement means 40 are configured to move the support arm 24 of the hollow end element 3 along a direction parallel to a plane containing the axes of rotation of the two casting rolls 20,21.

[0057] Such a moving means 40 can be, for example, a linear actuator, such as a hydraulic, pneumatic or mechanical actuator. Preferably, at least one blowing surface is provided with a plurality of through holes communicating with at least one chamber 4 or is made of a porous matrix material to ensure the emission of a jet of air or inert gas.

[0058] In all embodiments of the invention, the hollow end element 3 comprises a first outer surface 10 adapted to face a lateral containment zone and comprising at least one blowing surface.

[0059] Preferably, the hollow end element 3 also comprises a second outer surface 11 opposite the first surface 10 and preferably provided with at least one inlet hole 5 for at least one compressed gaseous substance; a third outer surface 8 and a fourth outer surface 9 facing each other and connecting the first surface 10 to the second surface 11; Equipped with.

[0060] In one non-limiting example, the hollow end element 3 has at least a partial wedge shape suitable for being inserted between two casting rolls, where the third outer surface 8 and the fourth outer surface 9 define the wedge shape of the hollow end element 3 (FIGS. 7-14).

[0061] The third surface 8 and the fourth surface 9 may be flat or curved, or partly flat and partly curved, and converge towards the central plane Z of the hollow element 3 so as to define a wedge shape.

[0062] In the case of the curved or partially curved surfaces 8 and 9, the radius of curvature is substantially equal to the outer radius of the corresponding casting roll.

[0063] By way of example only, during operation of the containment system of the present invention, the minimum distance between the hollow end element 3 and the casting rolls 20, 21, i.e. the minimum distance between the surfaces 8, 9 and the corresponding casting rolls, is about 0.5-2 mm, e.g. about 1 mm. Preferably, the distance between the hollow end element 3 and the edge of the liquid metal material is about 8-12 mm, e.g. 10 mm.

[0064] In a variant of the hollow end element 3, at least one inlet hole 5 may be provided in a fifth surface 16 (FIG. 4) that is distal to the wedge-shaped tip 25 and connects both the first surface 10 to the second surface 11 and the third surface 8 to the fourth surface 9.

[0065] In the example of Figures 4 and 5, the third surface 8 and the fourth surface 9 defining the wedge shape are curved, but also have respective flat portions 8', 9' proximal to the fifth surface 16. At least one inlet hole for the at least one chamber 4 can also or only be provided in the flat portions 8' and / or 9'. It is also possible that no flat portions 8', 9' are provided, in which case the third surface 8 and the fourth surface 9 are entirely curved and define the wedge shape of the hollow end element 3.

[0066] Preferably, the third surface 8 and the fourth surface 9 are arranged symmetrically with respect to the central plane Z of the hollow element 3 .

[0067] Advantageously, in all embodiments of the invention, the hollow end element 3 can be made in a single piece by means of a 3D printer, preferably from a material chosen from graphite, calcium silicate, copper, bronze.

[0068] Alternatively, the hollow end element 3 can be made from several parts, each made from different materials.

[0069] For example, a part or component with at least one blowing surface, or a plurality of parts or components with respective blowing surfaces, can be made of a porous matrix material (e.g., sintered bronze or ceramic foam) or can be defined by woven metal filaments, or in which the matrix is ​​obtained by additive manufacturing techniques.

[0070] Preferably, but not necessarily, the supply device 2 may be a pneumatic device or any device adapted to compress and supply a gaseous substance.

[0071] In a first embodiment of the hollow end element 3, the first surface 10 is provided with two or more non-coplanar blowing surfaces in order to direct the flow of gaseous material towards the containment zone in different directions. This configuration allows blowing jets of air or inert gas in at least two directions and thus towards at least two different zones of the enclosed space between the two casting rolls, allowing an improved lateral containment of the liquid metal material and / or an increased extension of the containment area.

[0072] For example, the through-holes in each effusion surface are parallel to one another and inclined at a non-zero angle relative to the through-holes in the other effusion surfaces.

[0073] Preferably, inside the hollow end element 3, a number of chambers 4 equal to the number of blowing surfaces can be provided, each chamber providing a respective blowing surface.

[0074] In the variations of this first embodiment shown in Figures 5, 6, 7, 8, 9 and 11, the hollow end element 3 has a wedge shape, but as mentioned above the hollow element can have a shape other than a wedge shape.

[0075] A first variant of the first embodiment shown in FIG. 5 provides two blowing surfaces 6 , 7 on a first surface 10 .

[0076] The blowing surface 6 defines a plane X, and preferably the blowing surface 7 adjacent to the blowing surface 6 defines a plane Y incident to the plane X.

[0077] Blowing surface 6 is distal to tip 25 of hollow end element 3 and blowing surface 7 is proximal to the tip.

[0078] For example, the blowing surface 6 is flat and rectangular, preferably elongated, and the blowing surface 7 is flat and triangular, preferably in the shape of an isosceles triangle, the base of the isosceles triangle preferably being adjacent to one of the two shorter sides of the rectangular shape of the blowing surface 6.

[0079] The central plane Z divides the two blowing surfaces 6, 7 into two equal parts.

[0080] When the containment system is mounted at the open end of the passage defined between the two counter rotating casting rolls 20, 21, the blowing surface 6 is disposed perpendicular to the metal material feed surface and the blowing surface 7 has a first end proximal to both the blowing surface 6 and the side containment zone and a second end distal to both the blowing surface 6 and the side containment zone.

[0081] In other words, as the blowing surface 7 approaches the roll bite, it diverges relative to the center plane of the casting rolls perpendicular to the plane containing both rotation axes of the casting rolls. Thus, taking into account the feed direction of the metal material, the blowing surface 7 diverges relative to the edge of the metal material entering between the casting rolls if the system is located on the side where the material enters between the casting rolls, or converges relative to the edge of the metal material exiting the casting rolls if the system is located on the side where the material exits the rolls. Instead, the blowing surface 6 is substantially parallel to the edge. This configuration allows for a jet of air or inert gas to be blown towards the edge of the material and also towards the innermost zone proximal to the roll bite in the space between the two casting rolls, increasing side containment in zones that are difficult to access with prior art mechanical barriers.

[0082] In the example of FIG. 5, a plurality of through holes 14 are provided in the blowing surface 6, while a plurality of through holes 15 are provided in the blowing surface 7. In the example of FIG.

[0083] Through-holes 14 may be parallel to one another or may be inclined, for example at an acute angle, preferably 5° to 45°, more preferably 10° to 35°, relative to the parallel through-holes 15. Arrows A and B in Figure 6 indicate the direction of the jets issuing from through-holes 14 and 15, respectively.

[0084] As an alternative to through holes, the outlet surfaces 6, 7 can be made of a porous matrix material.

[0085] A second variation of the first embodiment shown in Figure 7 provides a first surface 10 with four non-coplanar outlet surfaces 6, 7, 12 for directing the flow of gaseous material towards the containment zone in different directions.

[0086] In addition to the two blowing surfaces 6, 7 of the first variant, this second variant provides two side blowing surfaces 12 adjacent to the blowing surface 6 and arranged symmetrically with respect to the central plane Z of the hollow end element 3 which divides both blowing surfaces 6 and 7 into two equal parts.

[0087] When the containment system is attached to the open end of the passage defined between the two casting rolls, the two blowing surfaces 12 have respective first ends proximal to the blowing surface 6 but distal from the side containment zone, and respective second ends distal from the blowing surface 6 but proximal to the side containment zone.

[0088] In other words, each blowing surface 12 defines a respective plane incident on and adjacent to the plane X of the blowing surface 6, diverging from the plane X towards the central plane Z so as to be able to blow out additional jets of air or inert gas, and converging, for example from both the upper and lower surfaces in the case of a horizontal casting machine, towards the supply surface of the metal material, in particular towards the edges of the metal material during the casting step, in order to enhance lateral containment of the liquid metal.

[0089] In particular, the side blowing surface 12 and the central blowing surface 6 define a groove in the first surface 10 .

[0090] By way of example only, the blowing surface 12 is flat and rectangular or trapezoidal, preferably in the shape of a right-angled trapezoid, with the greatest base of the right-angled trapezoid preferably adjacent one of the two long sides of the rectangular shape of the blowing surface 6.

[0091] In the example of FIG. 7, blowing surface 6 is provided with a plurality of through holes 14, blowing surface 7 is provided with a plurality of through holes 15, and two blowing surfaces 12 are provided with a plurality of through holes 17.

[0092] The through holes 14 may be parallel to each other and may be inclined, for example, at an acute angle, preferably 5° to 45°, more preferably 10° to 35°, with respect to the parallel through holes 15.

[0093] The through holes 17 may also be parallel to one another or may be inclined with respect to the through holes 14, for example at an acute angle, preferably between 5° and 45°, more preferably between 10° and 35°. However, the axis of the through holes 17 in the blowing surface 12 is inclined with respect to the axis of the through holes 15 in the blowing surface 7.

[0094] As an alternative to through holes, the blowing surfaces 6, 7, 12 can be made of a porous matrix material.

[0095] A third variation of the first embodiment shown in Figure 8 provides a first surface 10 with four non-coplanar outlet surfaces 6, 7, 13 for directing the flow of gaseous material towards the containment zone in different directions.

[0096] In addition to the two blowing surfaces 6, 7 of the first variant, this third variant provides two side blowing surfaces 13 adjacent to the blowing surface 7 and arranged symmetrically with respect to the central plane Z of the hollow end element 3, which divides both the blowing surface 6 and the blowing surface 7 into two equal parts.

[0097] When the containment system is attached to the open end of the passage defined between the two casting rolls, the two blowing surfaces 13 have respective first ends proximal to both the blowing surface 7 and the side containment zone, and respective second ends distal to both the blowing surface 7 and the side containment zone.

[0098] In other words, each outlet surface 13 defines respective planes that are incident on the plane Y of the outlet surface 7 and adjacent thereto, and diverges with respect to the central plane Z such that, starting from the plane Y, one of the two outlet surfaces 13 faces the casting roll 20 and the other faces the casting roll 21, and thus does not face the supply surface of the metallic material. This enables additional jets of air or inert gas to be blown towards the casting roll 20 and the casting roll 21, so that the same casting roll confines air in the space bounded between them, thus determining a zone of increased pressure in front of the edge of the product being cast, and thus further reducing the spread of the liquid metal in the vicinity of the roll bite.

[0099] As a mere example, the outlet surface 13 is flat and rectangular or trapezoidal, preferably with the smallest base of the trapezoid adjacent to one of the two equal sides of the isosceles triangle of the outlet surface 7.

[0100] In the example of FIG. 8, a plurality of through holes 14 are provided in the outlet surface 6, a plurality of through holes 15 are provided in the outlet surface 7, and a plurality of through holes 18 are provided in the two outlet surfaces 13.

[0101] The through holes 14 can be parallel to each other and can be inclined with respect to the through holes 15 that are parallel to each other, for example, at an acute angle, preferably 5° to 45°, more preferably 10° to 35°.

[0102] The through holes 18 can be parallel to each other and can be inclined with respect to the through holes 15, for example, at an acute angle, preferably 5° to 45°, more preferably 10° to 35°.

[0103] Preferably, the axis of the through hole 18 of the outlet surface 13 is inclined with respect to the axis of the through hole 14 of the outlet surface 6.

[0104] Instead of the through holes, it is possible to make the outlet surfaces 6, 7, 13 of a porous matrix material.

[0105] A fourth variation of the first embodiment shown in Figure 9 provides a first surface 10 with six non-coplanar outlet surfaces 6, 7, 12, 13 for directing the flow of gaseous material towards the containment zone in different directions.

[0106] In addition to the two blowing surfaces 6, 7 of the first variant, this fourth variant provides both the two additional blowing surfaces 13 provided in the third variant and the two additional blowing surfaces 12 provided in the second variant.

[0107] A fifth variation of the first embodiment shown in Figure 11 provides a first surface 10 with three non-coplanar outlet surfaces 6', 12' for directing the flow of gaseous material towards the containment zone in different directions.

[0108] The central blowing surface 6 defines a first plane X, and the two lateral blowing surfaces 12' are adjacent to the blowing surface 6 and are arranged symmetrically with respect to a central plane Z of the hollow end element 3 which divides the blowing surface 6 into two equal parts.

[0109] When the containment system is attached to the open end of the passage defined between the two casting rolls, the two blowing surfaces 12' have respective first ends proximal to the blowing surface 6' but distal from the side containment zone, and respective second ends distal from the first blowing surface 6' but proximal to the side containment zone.

[0110] In other words, each blowing surface 12' defines a respective plane incident on and adjacent to the plane X of the blowing surface 6', diverging from the plane X with respect to the central plane Z so as to be able to blow out additional jets of air or inert gas, and converging, for example from both the upper and lower surfaces in the case of a horizontal casting machine, towards the supply surface of the metal material, in particular towards the edges of the metal material during the casting step, in order to enhance lateral containment of the liquid metal.

[0111] In particular, the side blowing surface 12 ′ and the central blowing surface 6 ′ define a groove in the first surface 10 .

[0112] For example, the central blowing surface 6' is flat and has a triangular, preferably isosceles, shape, and the blowing surface 12' is flat and rectangular or trapezoidal in shape with one side adjacent to one of the equal sides of the isosceles triangular shape of the blowing surface 6'.

[0113] In the example of FIG. 11, a plurality of through holes 14' are provided in the blowing surface 6', and a plurality of through holes 17' are provided in the two blowing surfaces 12'.

[0114] The through holes 17' of each side blowing surface 12' may be parallel to each other and may be inclined, for example, at an acute angle, preferably 5° to 45°, more preferably 10° to 35°, relative to the through hole 14'.

[0115] As an alternative to through holes, the outlet surfaces 6', 12' can be made of a porous matrix material.

[0116] In a second embodiment of the hollow end element 3, the first surface 10 is provided with a single blowing surface in which two or more groups of through holes, preferably of various sizes, are provided, each group being oriented in a different direction from the other groups, to direct the flow of gaseous material towards the containment zone in a different direction. This configuration allows blowing a jet of air or inert gas in at least two directions towards the edge of the material and thus towards at least two different zones of the space enclosed between the two casting rolls, improving the lateral containment and enhancing the extension of the containment area.

[0117] For example, the through-holes in each group are parallel to one another and inclined at a non-zero angle relative to the through-holes in the other groups.

[0118] Preferably, one, two or more chambers 4 are provided inside the hollow end element 3 .

[0119] In the variations of this second embodiment shown in Figures 10, 12, 13 and 14, the hollow end element 3 has a wedge shape, but as mentioned above the hollow element can have a shape other than a wedge shape.

[0120] A first variant of the second embodiment, shown in FIG. 10, provides a single blowing surface 6 on the first surface 10, which is preferably made in a recess in the first surface 10.

[0121] The central blowing surface 6 is a flat surface or a curved surface.

[0122] When the containment system is mounted at the open end of the passage defined between the two counter rotating casting rolls, the blowing surface 6 is disposed perpendicular to the metal material feed surface, if the blowing surface 6 is flat.

[0123] Instead, for curved surfaces, as the surface approaches the roll bite, it diverges relative to the center plane of the casting rolls, which is perpendicular to the plane containing both rotational axes of the casting rolls. Thus, considering the feed direction of the metal material, the blowing surface 6 diverges relative to the edge of the metal material entering between the casting rolls if the system is located on the side where the material enters between the casting rolls, or converges relative to the edge of the metal material exiting the casting rolls if the system is located on the side where the material exits the rolls. This configuration allows for a jet of air or inert gas to be blown towards the edge of the material and also towards the innermost zone of the space between the two casting rolls proximal to the roll bite, increasing side containment in zones that are difficult to access with prior art mechanical barriers.

[0124] In the example of FIG. 10, the blowing surface 6 is a triangle whose apex is the apex 25 of the wedge-shaped hollow end element 3 .

[0125] The central plane Z divides the blowing surface 6 into two equal parts.

[0126] In the example of FIG. 10, the blowing surface 6 is provided with a plurality of through holes 14.

[0127] For example, two or more groups of different sized through holes 14 can be provided, with each group of holes having a different orientation or inclination than the other groups to differently direct the flow of gaseous material towards the containment zone, thereby providing differently directed jets of air or inert gas in a manner similar to the jets provided in the various variations of the first embodiment providing two or more blowing surfaces.

[0128] A second variant of the second embodiment shown in FIG. 12 is identical to the variant of FIG. 10, except that it has a blowing surface 6 which has a substantially triangular shape, with a preferably rounded apex conveniently spaced from the point 25 of the wedge-shaped hollow end element 3.

[0129] A third and fourth variant of the second embodiment, shown in figures 13 and 14 respectively, provides a completely flat or curved first surface 10 coinciding with a unique blowing surface.

[0130] Surface 10 is preferably provided with two or more groups of perforations of various sizes, each group oriented in a different direction from the other groups to differently direct the flow of gaseous material towards the containment zone.

[0131] For example, two or more groups of through holes can be provided, with the holes in each group having a different orientation or inclination relative to the other groups, to obtain differently directed jets of air or inert gas in a manner similar to the jets obtained by various variations of the first embodiment providing two or more blowing surfaces.

[0132] In the example of Figure 13, the through-holes are distributed in a different manner over the entire surface 10 but only in the central zone of the surface 10. In particular, the through-holes can be divided into six groups corresponding respectively to the through-holes 14, 15, 17, 18 of the variant of Figure 9 providing six blowing surfaces.

[0133] In the example of FIG. 14, the through holes 14 are distributed in a different manner but substantially over the surface 10 .

[0134] In all the above-shown variants (figures 5 to 14), the through-holes can be arranged in a honeycomb structure on one or more blowing faces, i.e. with the through-holes distributed in offset rows. Preferably, the density of the holes on the surface 10 of the hollow end element 3 is obtained such that the total area of ​​the holes on the surface 10 is 50% to 70% of the area of ​​the surface 10.

[0135] The solidification process of liquid metal material by a casting machine is shown in Fig. 1-3. In this process, a product (e.g., strip or sheet) is directly cast by feeding liquid metal material through a discharge device 35 between two cooled and counter-rotating casting rolls 20, 21. A cross-sectional view of the solidification area is shown in Fig. 3. As soon as the liquid metal material contacts the rolls 20, 21, a solid shell begins to form and increases by moving towards the exit passage 38. The solid shells attached to the upper roll 20 and the lower roll 21 meet at the solidification point 36 just before the exit passage 38 (usually, for a conventional process with a casting speed of about 1.2 m / min and a metal sheet thickness of 5 mm, the total solidification length is about 10-20 mm), from where the metal product is deformed by the casting rolls 20, 21 to obtain the cast product 37.

[0136] The containment system of the present invention in any one of its embodiments can be used to manipulate the liquid metal or alloy, in particular by applying pressure along the sump depth 39 (FIG. 3, corresponding to the actual solidification length) during casting. This pressure, generated exclusively by air or inert gas blown by the feeder 2, controls the position of the side edges of the metallic material in the area between the ejector 35 and the outlet passage 38, where no actual physical containment exists.

[0137] The containment system of the present invention may also be used downstream of the exit passage 38 to contain any liquid metal material still present at the exit from the casting rolls.

Claims

1. A containment system (1) for laterally containing at least partially liquid metallic material in an open end of a passage defined between two cast members, the system comprising: a supply device (2) for supplying at least one compressed gaseous substance, The supply device (2) is provided with a hollow end element (3) adapted to be placed near the open end of the passage, The hollow end element (3) has at least one chamber (4) therein, said supply device (2) being adapted to supply said at least one compressed gaseous substance into said at least one chamber (4); said hollow end element (3) is provided with at least one blowing surface (6, 7) for blowing said at least one compressed gaseous substance out of said at least one chamber (4) towards a lateral containment zone of said at least partially liquid metallic material, The at least one blowing surface (6, 7) is provided with a plurality of through holes (14, 15), two or more non-coplanar outlet surfaces (6, 7; 6', 12') are provided for directing the flow of said at least one compressed gaseous substance in different directions, or A containment system (1) provided with only one outlet surface provided with two or more groups of through holes, each group oriented in a different direction from the other groups.

2. In the case of two or more non-coplanar blowing surfaces (6, 7; 6', 12'), the through holes of each blowing surface are parallel to each other and inclined at a non-zero angle to the through holes of the other blowing surfaces, or 2. The system of claim 1, wherein in the case of only one outlet surface having two or more groups of through holes, the through holes of each group are parallel to each other and inclined at a non-zero angle relative to the through holes of the other groups.

3. 3. The system according to claim 1 or 2, wherein the hollow end element (3) has at least partially a wedge shape suitable to be inserted between the two cast parts.

4. The hollow end element (3) comprises at least one first outer surface (10) adapted to face the lateral containment zone and comprises the at least one blowing surface (6, 7), The hollow end element (3) a second outer surface (11) opposite said first outer surface (10); a third outer surface (8) and a fourth outer surface (9) opposite each other and connecting said first outer surface (10) to said second outer surface (11); The system according to any one of claims 1 to 3, further comprising:

5. The system according to claim 4, wherein the third outer surface (8) and the fourth outer surface (9) define a wedge shape of the hollow end element (3).

6. There is provided a first outlet surface (6) defining a first plane X and a second outlet surface (7) defining a second plane Y incident on said first plane X, The system according to any one of claims 1 to 5, wherein when the system is installed at the open end of the passage, the first blowing surface (6) is arranged perpendicular to the liquid metal supply surface and the second blowing surface (7) has a first end proximal to both the first blowing surface (6) and the side containment zone, and a second end distal to both the first blowing surface (6) and the side containment zone.

7. said hollow end element (3) has a central plane perpendicular to said plane X and is provided with two third blowing surfaces (12), said two third blowing surfaces (12) being adjacent to said first blowing surface (6) and arranged symmetrically with respect to said central plane, 7. The system of claim 6, wherein when the system is attached to the open end of the passage, the third outlet surfaces (12) have respective first ends proximal to the first outlet surface (6) but distal from the side containment zone, and respective second ends distal from the first outlet surface (6) but proximal to the side containment zone.

8. said hollow end element (3) has a central plane perpendicular to said plane X and is provided with two further blowing surfaces (13) adjacent to a second blowing surface (7) and arranged symmetrically with respect to said central plane, 8. A system as claimed in claim 6 or 7, wherein when the system is attached to the open end of the passage, the other blowing surfaces (13) have respective first ends proximal to both the second blowing surface (7) and the side containment zone, and respective second ends distal to both the second blowing surface (7) and the side containment zone.

9. A system according to any one of the preceding claims, wherein the hollow end element (3) is made in one piece.

10. 1. A casting machine for casting a metallic material product, comprising: Two cast members (20, 21); A first containment system (1) according to any one of claims 1 to 9, Equipped with the two casting members (20, 21) define a passageway having two open ends for solidifying the at least partially liquid metallic material delivered into the space between the casting members to form a product; The first containment system (1) is disposed near a first open end of the passageway.

11. 11. A casting machine according to claim 10, wherein the two casting members (20, 21) are two casting rolls arranged one above the other with their axes of rotation lying in a common plane.

12. 12. A caster according to claim 11, wherein the hollow end element (3) of the first containment system (1) has at least partially a wedge shape for being at least partially inserted between the two casting rolls (20, 21).

13. 13. A caster as claimed in claim 12, in which a non-zero distance is provided between the hollow end element (3) and either surface of the casting rolls when the hollow end element is completely outside the casting rolls and when the hollow end element is at least partially inserted between the casting rolls by the wedge shape of the hollow end element.

14. A casting method for casting a metallic material product, which can be carried out by a casting machine according to claim 11 or 12, comprising the steps of: supplying said at least partially liquid metallic material into said space between said two casting members (20, 21); allowing said at least partially liquid metallic material to solidify and form a product in said passage between said two casting members (20, 21); Including, a lateral containment of the at least partially liquid metallic material is provided at at least one of the two open ends of the passage by a first containment system (1); 1. A casting method according to claim 1 , wherein said lateral containment of said at least partially liquid metallic material is obtained by supplying at least one compressed gaseous substance to said at least one chamber (4) of said hollow end element (3), which blows said at least one compressed gaseous substance out of said at least one chamber (4) towards said lateral containment zone of said at least partially liquid metallic material by means of at least one blowing surface (6, 7).

15. 15. The casting method according to claim 14, wherein said at least one blowing surface (6, 7; 6', 12') exerts a lateral containment action on said at least partially liquid metallic material only by blowing said at least one compressed gaseous substance without providing contact between said at least one blowing surface and said at least partially liquid metallic material during solidification.

16. A casting machine as described in claim 10, wherein a second containment system (1') as described in claim 1 is positioned near a second open end of the passage.

17. A casting machine as described in claim 10, wherein the two casting members (20, 21) are counter-rotating rolls, belts, tracks, or combinations thereof.

18. A casting machine as described in claim 11, wherein the at least partially liquid metallic material is aluminum, magnesium, zinc, or an alloy based on one of these metals.

19. The two casting members (20, 21) are two casting rolls arranged one above the other so as to be positioned on a common plane, 17. A casting machine according to claim 16, wherein means (40) for moving the hollow end element (3) of the first containment system (1) and / or the hollow end element (3) of the second containment system (1') are provided for adjusting the distance between them along a direction parallel to a plane containing the axes of rotation of the two casting rolls (20, 21).

20. A casting machine as described in claim 19, wherein the hollow end element (3) of the first containment system (1) and the hollow end element (3) of the second containment system (1') have at least partially a wedge shape for being at least partially inserted between the two casting rolls (20, 21).

21. A casting machine as described in claim 14, wherein a first side containment of the at least partially liquid metal material is provided at a first open end of the passage by the first containment system (1) and a second side containment of the at least partially liquid metal material is provided at a second open end of the passage by the second containment system (1').

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