EP0592360A1 - Machine for vertical continuous casting in a magnetic field - Google Patents

Abstract

In the mould (10), the casting machine has a baffle plate (66) with a lower guide surface (80) for the cooling water (20) sprayed on at high pressure and/or has a supporting plate with an upper guide surface for cooling water (20) flowing out at low pressure. Both guide surfaces consist of an insulating material. The electromagnetic screening (18, 76) is cooled on the inside at least in the active area. The mould housing (32) preferably consists of a perforated sheet (34) bent several times. The active area of the screening is preferably designed as a U- or V-shaped screening sheet with an insert or a coating to attenuate the magnetic effect of the inductor (12) to an increasing extent from the bottom towards the top. The guide surface (80) upon which the water impinges is displaced and/or swung backwards and forwards continuously in a predetermined rhythm. The water curtain (22), which is independent of the electromagnetic screening (18), is thereby moved upwards and downwards on the strand (14) over a height (h). <IMAGE>

Description

The invention relates to a casting machine with at least one precisely and reproducibly oriented, water-cooled mold for the continuous casting of a vertical strand in the magnetic field of a closed, partially shielded inductor, at an acute angle via at least one guide surface to form a water film on the strand directed cooling water channels and a corresponding, lowerable approach floor per mold. The invention further relates to a method for cooling a strand in a casting machine.

In continuous casting processes, also called continuous casting processes, metals are cast in the form of bars or bolts several meters long, which are used as primary material for various subsequent processing steps, such as for pressing, rolling or forging.

The most important link in a continuous casting machine are molds, which determine the cross section of the cast strand in conventional processes. Depending on the number of cast strands, a casting machine is equipped with a corresponding number of lowerable approach floors, which are firmly connected to a casting table.

As the molds slowly fill with the melt, the metal on the start-up floors begins to solidify. These are cooled and lowered at such a speed that the solidus line of the solidifying metal always remains within the mold frame. The strands, the solidification of which is accelerated by water cooling, grow to the same extent as the approach floors are lowered. The casting process is uninterrupted within a predetermined length of a strand.

The most important parameters of continuous casting include a correctly controlled lowering speed and the cooling of the metal in the right place and with the right intensity. These parameters have a strong influence on the surface of the ingot. If the parameters are controlled poorly, segregation, melt leakage through the solidified shell, tearing or lime binding can occur.

Magnetic field casting (EMC), which has only recently reached industrial maturity, is based on the complete elimination of mechanical contact between the mold and the solidifying metal. The liquid metal is kept exactly in the cross-sectional shape of the strand by controllable electromagnetic forces.

With the EMC process, not only can a homogeneous internal structure be achieved, but also a smooth surface of the cast metal, which leads to better physical and chemical properties of the pressed or forged billets and billets. With the EMC process, costly post-treatments such as the removal of the surface skin or the edges are no longer necessary.

The starting phase is very important for magnetic field casting because the solidification front is held in a narrow mold height range of around 10 mm. This is necessary because with an EMC mold, the magnetic forces have to compensate for the metallostatic pressure of the melt above the solidification front. Therefore, complete control of the cooling, especially during the start-up phase, is essential. The lowering speed and the cooling of a certain alloy and ingot dimensioning have to be optimized as a function of time.

• Mit der Verwendung von kohlendioxidhaltigem Kühlwasser kann die Kühlintensität um einen Faktor bis etwa 5 gesenkt werden. Die Verwendung von CO₂-haltigem Kühlwasser bringt jedoch auch Nachteile mit sich. Das Kohlendioxid muss in Druckflaschen abgefüllt, transportiert und gelagert werden. Weiter muss CO₂-haltiges Kühlwasser bis kurz vor dem Austritt unter hohem Druck gehalten werden, was konstruktiv und werkstoffmässig zu einem höheren Aufwand führt.
• Nach einer weiteren Variante wird wenigstens während der Startphase des Giessens pulsierend Kühlwasser aufgespritzt. Dieses Verfahren hat sich beispielsweise beim Giessen der meisten Aluminiumlegierungen bewährt, bei harten Legierungen können jedoch Haarrisse entstehen.

The bar foot curvature and local crack formation can largely can be eliminated if the shock effect and the intensity of the cooling water can be reduced:

• With the use of carbon dioxide-containing cooling water, the cooling intensity can be reduced by a factor of up to about 5. However, the use of CO₂-containing cooling water also has disadvantages. The carbon dioxide has to be filled, transported and stored in pressure bottles. Furthermore, CO₂-containing cooling water must be kept under high pressure until shortly before the outlet, which leads to a higher outlay in terms of design and materials.
• According to a further variant, cooling water is pulsed on at least during the starting phase of the casting. This method has proven itself, for example, when casting most aluminum alloys, but hairline cracks can occur with hard alloys.

• Das aus rostfreiem Stahl, insbesondere INOX, bestehende Material der Abschirmung absorbiert die den Strang formenden elektromagnetischen Kräfte in gleichem Masse zunehmend, wie das Material zunimmt. Dies führt zu einer zusätzlichen Erwärmung.
• Die polierte Aussenfläche einer Abschrägung der Abschirmung wirkt zugleich als Leitfläche für das Kühlwasser, wobei auf der Leitfläche vorerst ein Kühlwasserfilm, dann ein auf den Strang aufspritzender Wasservorhang gebildet wird. Als Nebenwirkung wird die elektromagnetische Abschirmung durch das auftreffende Wasser gekühlt. INOX beispielsweise ist ein ausgesprochen schlechter thermischer Leiter.

The downward wedge-shaped electromagnetic shielding of known molds for EMC casting machines simultaneously fulfills two functions:

• The shielding material made of stainless steel, in particular INOX, increasingly absorbs the electromagnetic forces that form the strand to the same extent as the material increases. This leads to additional warming.
• The polished outer surface of a bevel of the shield also acts as a guide surface for the cooling water, a cooling water film being formed first on the guide surface, then a water curtain spraying onto the strand. As a side effect, the electromagnetic shield is cooled by the water that hits it. INOX, for example, is an extremely poor thermal conductor.

• Auf der polierten Aussenseite der elektromagnetischen Abschirmung, der Leitfläche, lagert sich Kalk ab und führt zu einer ungenügenden Filmbildung durch das Kühlwasser und zu schwachen Kühlung der Abschirmung. Da diese Kühlung hinreichend sein muss, sind aufwendige Unterhaltskosten unumgänglich.
• Die elektromagnetische Abschirmung ist starr an der Kokille befestigt, die Lage der Leitfläche kann also nicht verändert werden.
• Die Bestandteile der Kokille bestehen aus Aluminium, Eisen und Kupfer, was zu Korrosionsproblemen führt.

This results in some problems for known EMC molds:

• Lime deposits on the polished outside of the electromagnetic shield, the guiding surface, and leads to inadequate film formation due to the cooling water and weak cooling of the shield. Since this cooling must be sufficient, expensive maintenance costs are unavoidable.
• The electromagnetic shield is rigidly attached to the mold, so the position of the guide surface cannot be changed.
• The components of the mold consist of aluminum, iron and copper, which leads to corrosion problems.

The inventors have set themselves the task of creating a casting machine of the type mentioned which, thanks to its simpler design and lower losses of electromagnetic energy from the molds, is more economical both in terms of the production costs and in terms of the operating costs. The mold should be flexible in the application of cooling water and should be cooled using a process that can be used more gently than before.

With regard to the casting machine, the object is achieved according to the invention in that the guide surface (s) of the mold for the cooling water consists of an insulating material and the electromagnetic shield is internally cooled, at least in the active area. Special and further developing embodiments of the casting machine are the subject of dependent patent claims.

According to a particularly advantageous embodiment of the invention, the mold housing consists of a multi-edged, Appropriately about 3 mm thick perforated plate, with welded side walls. Compared to the known state of the art, this means a huge advance in economic and technical terms, the expensive metal moldings, which are solid and usually made of aluminum, can be made from a stainless steel sheet metal housing, the same material as the shield be. Because of the large amounts of cooling medium that are passed through, molded parts made of plastic can be inserted into the sheet metal housing, which brings enormous advantages in terms of processing technology and cost. In addition, the corrosion problems mentioned above are completely eliminated.

Further advantages of the bent mold housing are that the loss of electromagnetic energy is less and the largely one-piece embodiment does not cause any sealing problems.

The guide surface for the cooling water of the mold, which consists of an insulating material according to the invention, is preferably the surface of a separately and expediently interchangeable deflection plate. The continuous intensive cooling allows production from plastic, which is also a processing-technically simple and extremely cheap embodiment. The baffle plate is preferably displaceable and / or pivotable. The position of the baffle plate can be adjusted by means known per se. The cooling water hitting in the unchangeable direction can thus be deflected within a certain angular range. In other words, the impact height of the water curtain formed on this guide surface and sprayed onto the strand can be set, for example over a range from 5 to 20 mm with a mold height which cannot be adjusted.

This means compared to the deflection of the cooling water on a guide surface of the magnetic shield, which is rigid is a significant advance. The cooling water curtain can be applied with simple means where it can really have an optimal effect.

The uniform formation of a water film on the guide surface of the baffle can be further improved by the fact that longitudinal grooves are formed. The term longitudinal flow here means the flow direction of the cooling water.

Hard aluminum alloys, for example, are cast at a lower lowering speed, which means that less cooling water is required. In contrast to the impact of a lot of water with a relatively high pressure on the guide surface, where a largely uniform water film is formed, the water hits the guide surface with too little pressure at too low a pressure, the cooling water runs off without film formation and can already on the already sensitive strands do not develop an optimal cooling effect. A support plate can therefore be formed in the mold under the baffle plate or under the emerging cooling water, which is longer compared to the baffle plate, that is, it leads closer to the strand.

The cooling water is sprayed onto the support plate, the guide surface of the deflection plate is little or not wetted at lower pressure. The surface of the support plate made of the same material as the deflection plate and facing the deflection plate is also designed as a guide surface for cooling water. This support plate, which is preferably interchangeable like the baffle plate, is likewise preferably displaceable and / or pivotable, expediently with the same drive elements as the baffle plate. The level of the cooling water curtain hitting the strand can only be varied with a movable support plate.

The support plate can have holes in sensitive metal strands or have slots for draining cooling water. Because the cooling water discharged in this way never hits the hot strand, the cooling effect can be further reduced.

Although the deflection and the support plate are at least partially arranged between the inductor and the electromagnetic shielding, they cannot heat up due to the electromagnetic action, they consist of an insulating material, preferably of plastic, for example polyethylene or polypropylene. In any case, the lime formation is significantly less than on a guide surface of a shield of a previously known type.

In the active area of the inductor, a U-shaped or V-shaped bent plate, through which cooling water flows, that is to say internally cooled, is arranged, which, like the shielding body lying outside the active area of the inductor, preferably consists of stainless steel. The laterally closed shield, which preferably consists of about 1 to 2 mm thick, INOX sheets, only acts as a functional part if an insert or coating made of a material that shields better electromagnetically is arranged. Otherwise the bent stainless steel sheet has a purely protective and supporting function.

Known shields of EMC molds are also solid in the lowest area, as mentioned, they run in a wedge shape. As a result, shielding that increases from bottom to top is achieved with a large amount of material and with external cooling, as is the case with EMC continuous casting.

• Das U- oder V-förmig umzubiegende Blech aus rostfreiem Stahl wird bevorzugt mit Silber oder Kupfer beschichtet und dann mit dieser Schicht nach innen umgebogen. Das Beschichten erfolgt mit üblichen Verfahren, beispielsweise galvanisch, chemischer Abscheidung aus der Gasphase, Aufspritzen, Abscheidung aus einem Plasma.
• Das U- oder V-förmige Blech wird nach dem Umbiegen entsprechend beschichtet.
• Wenigstens eine Folie oder ein Blech aus Silber, Kupfer oder Messing, wird in das U- oder V-förmige Blech eingelegt. Diese Folie oder dieses Blech kann umgebogen, gefaltet oder mehrschichtig ausgebildet sein, wobei eine Abstufung oder eine kontinuierliche Dickenveränderung in der Weise erfolgt, dass die Abschirmung von unten nach oben stufenweise oder kontinuierlich zunimmt.

According to the embodiment of the mold according to the invention, an insert or coating in the U-shaped or V-shaped part of the shield increasingly weakens the electromagnetic action of the inductor in the upward direction. This gradually or continuously increasing electromagnetic Shielding is achieved, for example, by the following measures:

• The U or V-shaped sheet of stainless steel to be bent is preferably coated with silver or copper and then bent inwards with this layer. Coating is carried out using customary methods, for example galvanic, chemical deposition from the gas phase, spraying, deposition from a plasma.
• The U-shaped or V-shaped sheet is coated accordingly after the bending.
• At least one foil or sheet made of silver, copper or brass is placed in the U- or V-shaped sheet. This film or sheet can be bent, folded or multilayered, with a gradation or a continuous change in thickness in such a way that the shield increases step by step or continuously from bottom to top.

By inserting a film or sheet on the one hand or coating on the other hand from one of the metals mentioned, the shielding from the bent steel sheet can be multiplied by a factor of several hundred, depending on the material and thickness.

An insert or coating made of silver is expediently 0.05 to 0.2 mm thick, made of copper 0.2 to 0.4 mm and brass 0.5 to 2 mm, depending on the specific absorbency, the thickness of this layer being continuous or can gradually increase from bottom to top.

With regard to the method for cooling a strand in a casting machine, in which the cooling water is sprayed at an acute angle onto a guide surface, a regular water film is formed and is sprayed onto the strand, the Solution of the task according to the invention characterized in that the water-bearing guide surface is continuously shifted back and forth in a predetermined rhythm and / or pivoted, and thereby the water curtain independent of the electromagnetic shielding is moved up and down the strand over a certain height. Special and further developing embodiments of the method are the subject of dependent patent claims.

With the method according to the invention, the advantages of pulsating water cooling can be exploited and improved in that the relatively hard transition from "cooling" to "non-cooling" occurs continuously in a greatly reduced form. This way, hairline cracks can be avoided even with sensitive alloys, such as hard aluminum alloys.

With respect to the time sequence, the water-bearing guide surface is preferably moved sinusoidally, in particular with a time period of 1 to 3 seconds per half-wave. The water curtain on the strand preferably performs an up and down movement of 5 to 20 mm. In a manner known per se, the movement of the water-bearing guide surface is preferably carried out with a pneumatic, hydraulic or electromagnetic drive, controlled by a microprocessor.

The cooling water is expediently sprayed on with a constant pressure in the range from 0.01 to 0.5 bar, starting with the lowering of the start-up floor, which corresponds to about 0 to 3 minutes after the start of the pouring. Because the start-up phase is particularly critical, the movement of the water-bearing guide surface can be continued for 3 to 7 minutes in practice. Of course, the movement of the guide surface is only stopped if this allows the sensitivity of the alloy.

The strand can be vibrated electromagnetically during cooling, in particular continuously.

• Durch eine vom Magnetfeld nicht erwärmte, wasserbeaufschlagte Leitfläche wird die Abscheidung von Kalk auf der polierten Oberfläche der Abschirmung vermieden und dadurch die Unterhaltskosten entsprechend herabgesetzt.
• Durch eine einstellbare wasserbeaufschlagte Leitfläche kann das Niveau des Kühlwasservorhangs auf den Strang eingestellt werden.
• Wenigstens in der Anfahrphase und/oder bei empfindlichen Legierungen kann der Wasservorhang in einem einstellbaren Rhythmus gehoben und gesenkt werden. Die Pulswasserkühlung wird verfeinert, indem die Schockwirkung der plötzlichen Wasserzugabe eliminiert und dauernd Kühlwasser auf den Strang geführt wird. Dadurch entstehen keine kurzzeitigen Ueberhitzungen.
• Die Zugabe von CO₂, welche beim EMC-Stranggiessen üblich ist, entfällt.
• Durch die Ausbildung eines abgekanteten Kokillengehäuses aus rostfreiem Stahlblech, dem gleichen Material wie die elektromagnetische Abschirmung, entfallen Korrosionsprobleme.

The advantages achieved with the invention can be summarized as follows:

• The deposition of lime on the polished surface of the shield is avoided by a water surface that is not heated by the magnetic field and the maintenance costs are reduced accordingly.
• The level of the cooling water curtain can be adjusted to the strand by means of an adjustable water-bearing guide surface.
• At least in the start-up phase and / or with sensitive alloys, the water curtain can be raised and lowered in an adjustable rhythm. Pulse water cooling is refined by eliminating the shock effect of the sudden addition of water and continuously supplying cooling water to the line. As a result, there are no short-term overheating.
• The addition of CO₂, which is common in continuous EMC casting, is eliminated.
• Corrosion problems are eliminated by forming a bent mold housing made of stainless steel, the same material as the electromagnetic shielding.

The inventive design of the mold housing as a bent sheet, in particular a perforated sheet made of stainless steel, is not inevitably bound to the guiding surface for the cooling water and the internally cooled shield, nor is it bound to that of the active area of the electromagnetic shield in the form of a U or V-shaped sheet of stainless steel with an insert or coating.

- Fig. 1

eine den Stand der Technik darstellende, in eine Giessmaschine eingesetzte EMC-Kokille,

- Fig. 2

eine Teilansicht eines Lochblechs für ein Kokillengehäuse,

- Fig. 3

einen Schnitt durch eine Kokille in Längsrichtung des Stranges,

- Fig. 4

eine Variante von Fig. 3,

- Fig. 5

den aktiven Teil einer elektromagnetischen Abschirmung,

- Fig. 6

einen Teilschnitt durch einen Schenkel einer Fig. 5 entsprechenden elektromagnetischen Abschirmung,

- Fig. 7

ein Einlageblech für eine elektromagnetische Abschirmung, und

- Fig. 8

eine Variante gemäss Fig. 7.

The invention is explained in more detail with reference to exemplary embodiments shown in the drawing, which are also the subject of dependent claims. They show schematically:

- Fig. 1

an EMC mold which represents the prior art and is inserted in a casting machine,

- Fig. 2

a partial view of a perforated plate for a mold housing,

- Fig. 3

a section through a mold in the longitudinal direction of the strand,

- Fig. 4

a variant of Fig. 3,

- Fig. 5

the active part of an electromagnetic shield,

- Fig. 6

5 shows a partial section through one leg of an electromagnetic shield corresponding to FIG. 5,

- Fig. 7

an insert for electromagnetic shielding, and

- Fig. 8

a variant according to FIG. 7.

Fig. 1 shows a known basic principle of a casting machine for vertical magnetic field continuous casting. A casting machine can comprise one or more molds 10.

A closed-circuit inductor 12 for a medium-frequency high-voltage system generates a magnetic field and thereby the force in the strand 14 which prevents the cast metal from touching the mold inner wall 16.

A wedge-shaped electromagnetic shield 18 partially shields the inductor 12 and thereby reduces the magnetic field in the upward direction. Finally, the shield 18 determines the zone in which the cooling water 20 is in shape a cooling water curtain 22 sprayed onto the strand 14.

A start-up floor 24 is mounted on an invisible casting table. The start-up floor 24 forms the foot 26 of the cast strand 14 during the starting phase and supports it during the entire casting phase.

This basic principle of continuous magnetic field casting according to FIG. 1 is improved according to the invention with regard to the guide surface 28 for the cooling water 20, the active region 30 of the electromagnetic shielding 18 and the shaped, solidly constructed mold housing 32, but is otherwise retained essentially unchanged.

FIG. 2 shows an approximately 3 mm thick stainless steel sheet 34 (INOX) for producing a mold housing 32 by folding and welding on side walls. The steel sheet 34 already includes holes 34 with a diameter of about 3 mm, which are later used for the outlet of the cooling water, at regular intervals a of about 10 mm.

The mold 10 of a casting machine shown in FIG. 3 comprises a mold housing 32 which is bent several times and is made of a stainless steel sheet 34. The interior formed is filled with cooling water 20 and provided with a water distributor block 38 made of plastic. An electromagnetic shield 18 made of stainless steel has two inner grooves 42 for inserting the steel plates 34 at the front end of the mold housing 32. The steel plates 34 and the water distributor block 38 made of plastic are penetrated by a bolt 44, on which a screw 46 in the electromagnetic shield 40 attacks and tightens the water distributor block 38 and thus the steel sheet 34.

The water distributor block 38 has a relatively deep groove 50, from which a (Fig. 2) cooling water channels 52 are formed, which open into a hole 36 in the steel sheet 34. The direction of the exiting cooling water 20 is determined by the direction of the cooling water channels 52.

By loosening the screws 46, the electromagnetic shield 18 and, after the bolt 44 has been removed, the water distributor block 38 can also be removed or replaced.

Two screwed-together, molded plastic blocks 58, 60 are connected to the mold housing 22 via a screwed-on clamp 54 and a bevel 56.

A circular, plate-shaped inductor 12, which in the present case consists of copper, is screwed to the plastic block 58 with the interposition of a temperature-resistant insulation layer 62.

In a recess in the plastic block 60, the positioning and movement mechanism of a plastic deflection plate 66 for the cooling water 20 is arranged. An inflatable bellows 68 displaces, depending on the pressure, a sealing washer 70 with a push rod 72 which passes through a corresponding bore in the plastic block 60 and the fold 56. The deflecting plate 66 is articulated on this push rod 72. With a spring 74 also fastened to the push rod 72, the deflection plate 66 is pivoted against the U-shaped shielding plate 76 of the electromagnetic shielding 18. The electromagnetic shielding device 18 is internally cooled with water 78 at least in the area of the U-shaped shielding plate 76 because the cooling water 20 for the strand 14 does not come into external contact with the electromagnetic shielding 18, in particular the shielding plate 76.

Coming out of the cooling water channels 52 at a pressure of, for example, 0.5 bar, the cooling water 20 strikes the guide surface 80 of the baffle plate 66 at an acute angle. flows with the formation of a water film along this guide surface, forms a homogeneous cooling water curtain 22 when detached from the baffle plate, which in turn acts on the strand 14 to be cooled.

3, the baffle 66 is drawn in two extreme positions. The water curtain can appear on the strand 14 in any adjustable position within a height h of 5 to 20 mm, in particular 5 to 10 mm. This means that the mold 10 is very flexible even with rigid electromagnetic shielding. However, the water curtain can also be raised and lowered continuously, for example in the form of a sinusoidal movement.

In the mold 10 according to FIG. 4, instead of the deflection plate 66, a support plate 82, which is likewise pivotably connected to the push rod 72, is arranged. This plastic support plate 82 is used to distribute cooling water 20 flowing out at low pressure, for example less than 0.05 bar. The cooling water does not reach the guide surface 80 of the baffle 66. So that the cooling water 20 flowing off as a film on the guide surface 84 of the support plate 82 reaches the strand 14, the support plate 82 is longer than the deflection plate 66 and extends into the nearer region of the strand 14.

Holes 86 or slots are formed in the support plate 82 so that part of the cooling water can be drained off without reaching the strand 14.

An insert plate 88 made of copper is clamped in the shielding plate 76 and has a high degree of absorption for the magnetic field generated by the inductor 12. In the upper area, two copper sheets are connected to each other by soldering, riveting or gluing, which means that more shielding is provided in this area.

On the water distributor block 38, a flange 90 is fastened with an inlet opening 92 for the cooling water 20, for example with screws. A large chamber 93 and a small chamber for the cooling water 20 which is identical to the groove 50 in the water distributor block 38 are thereby formed. With the flange 90, the cooling water 20 can be introduced into the cooling water channels 52 more smoothly.

FIG. 5 shows a detail with respect to the active zone of the shield 18, which is formed by the shield plate 76 bent in a U-shape and fastened to the shield body. 0.3 mm thick coatings 94 made of copper, which are of different lengths, are applied to the two legs of the shielding plate 76. This creates a graded effective electromagnetic shielding, which - as in conventional embodiments - is stronger at the top than at the bottom.

A variant is shown in Fig. 6. A part 94 of the shielding plate 76 has a coating 94 which becomes thicker from bottom to top and which produces a shielding effect which increases continuously from bottom to top.

In FIG. 7 is an insert plate 88 bent up to the longitudinal center for a U or V-shaped shielding plate 76 (FIGS. 3, 4). The electromagnetic shielding effect is equivalent to FIG. 5.

FIG. 8 shows two bent insert sheets 88 lying one on top of the other, which result in a finer gradation compared to FIG. 7.

Claims (14)

Casting machine with at least one precisely and reproducibly oriented, water-cooled mold (10) for the continuous casting of a vertical strand (14) in the magnetic field of a closed, partially shielded inductor (12), at an acute angle over at least one guide surface (28, 80, 84) ) cooling water channels (52) directed onto the strand (14) and a corresponding, lowerable approach floor (24) per mold (10) to form a water film,
characterized in that
the guide surface (s) (80, 84) of the mold (10) for the cooling water (20) consists of an insulating material, and the electromagnetic shield (18, 76) is internally cooled at least in the active area. Casting machine according to claim 1, characterized in that the mold housing (32) consists of a multiply folded sheet (34), preferably a perforated sheet made of stainless steel, with welded-in side walls. Casting machine according to claim 2, characterized in that the mold housing (32), which is open at the end, is inserted into corresponding inner grooves (42) of the shield (18) and screwed to it, preferably via an inserted, shaped water distributor block (38), preferably made of Plastic existing water distributor block (38), the cooling channels (52) for the cooling water (20) are recessed. Casting machine according to one of claims 1 to 3, characterized in that the guide surface (80) for the cooling water (20) of the mold (10) is the surface of a preferably displaceable and / or pivotable baffle plate (66). Casting machine according to claim 4, characterized in that the exchangeable baffle plate (66) consists of plastic and its guide surface (80) preferably has grooves guiding the cooling water in the direction of the cooling water channels (52). Casting machine according to claim 4 or 5, characterized in that a preferably likewise displaceable and / or pivotable support plate (82) with a corresponding guide surface (84) for cooling water (20) is arranged instead of or below the deflection plate (66). Casting machine according to claim 6, characterized in that the support plate (82) has holes (86) or slots for draining cooling water (20). Casting machine according to one of claims 1 to 7, characterized in that the electromagnetic shield (18) in the active region of the inductor as a U- or V-shaped bent, through which water (78) through which shielding plate (76), preferably made of 1 to 2 mm is made of thick, stainless steel, an insert (88) or coating (94) in the U-shaped or V-shaped part increasingly weakening the magnetic action of the inductor (12) in the upward direction. Casting machine according to claim 8, characterized in that an insert plate (88) which becomes thicker step by step or continuously from bottom to top or a correspondingly thicker from bottom to top Layer (94) is arranged on the shielding plate (76). Casting machine according to claim 8 or 9, characterized in that the insert (88) or coating (94) made of silver, preferably 0.05 to 0.2 mm thick, copper, preferably 0.2 to 0.4 mm thick, or brass , preferably 0.5 - 2 mm thick. A method for cooling a strand (14) in a casting machine according to one of claims 1 to 10, in which the cooling water (20) is sprayed at an acute angle onto a guide surface (80, 84), a regular water film is formed and is applied as a water curtain (22) the strand (14) is sprayed,
characterized in that
the water-loaded guide surface (80, 84) is continuously shifted back and forth in a predetermined rhythm and / or pivoted and thereby the water curtain (22) independent of the electromagnetic shielding (18) on the line (14) over a height (h) up and is moved. A method according to claim 11, characterized in that the water-bearing guide surface (80, 84) is moved sinusoidally, preferably with a time period of 1 to 3 seconds per half-wave and an upward and downward movement of the water curtain (22) on the strand (14) a height (h) of 5 to 20 mm, preferably 5 to 10 mm. Method according to claim 11 or 12, characterized in that the guide surface (80, 84) is preferably moved in a program-controlled manner with a pneumatic, hydraulic or electromagnetic drive. Method according to one of claims 11 to 13, characterized in that the strand (14) is electromagnetically vibrated during the cooling, preferably continuously.

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