MXPA99011731A - Method and device for producing thin slabs - Google Patents

Abstract

La invención se relaciona con un método para producir lingotes angostos asícomo con una instalación de fundición continua para este propósito que comprende una lingotera lateralmente ajustable en la cual penetra una boquilla de inmersión, y en la cual una sección transversal pequeña análogamente abombada delárea central por el lado de la salida de la cuerda se enfrenta por el lado de la alimentación de la colada a una sección transversal abomabada más grande, y pares de rodillos de apoyo y conducción traspuestos a la lingotera que tienen un calibre adaptado a la cuerda abombada que sale. En esto a)la boquilla de inmersión tiene una desembocadura en forma de pala, con un grosor máximo correspondiente a d=0.3 a 0.5 x DE, siendo que DE es la distancia de los lados anchos de la lingotera en elárea de alimentación de la colada, b)las partes de los lados anchos cuando menos en elárea sumergida de la boquilla de inmersión tienen partes centrales que correspondientemente a sus líneas de altura están dispuestas paralelas una a otra, C)las plaCa3 de los lados anchos cuando menos en elárea de ajuste de las placas de 103 lados angostos están configuradas como superficies laterales planas d)las superficies laterales planas están dispuestas de manera que se estrechan cónicamente en dirección de los lados angostos, e)la placa central de superficie plana estáunida con las superficies laterales de superficies planas mediante partes de transición, f)las partes de transición se extienden en la dirección de la transportación de la cuerda estrechAndO3e a manera de cuña, y la punta de la cuña termina a la distancia a medida a partir del canto superior de la lingotera, en que a=0. 5 a 0. 8 x L, con L=longitud de la lingotera, y g)los rodillos de apoyo y conducción tienen un contorno que corresponde a la placa central de superficie plana y a las placas laterales de superficies planas, de los lados anchos de la lingotera en elárea de la desembocadura de la lingotera. (Figura 1)

Description

METHOD AND DEVICE FOR MANUFACTURING ANGOSTOS ANGLES Description of the invention The invention relates to a method for producing narrow ingots with a pre-established bulging of their wide sides, in a continuous casting in which an immersion nozzle penetrates into an ingot mold followed by a conduction of the laundry rope, and a corresponding device to carry out the method. DE 41 31 829 C2 discloses a liquid-cooled, adjustable-width plate mold for the continuous casting of steel strings in the form of narrow ingots, in particular for a thickness of less than 100 mm of ingots, in which the shape of the plates of the wide sides at the end of the exit of the chord of the ingot mold corresponds to the string format to be produced, being that the plates of the wide sides are configured as a flat surface in the area of adjustment of the plates of the narrow sides. In this document an indication can not be found in the sense that the format of the string to be produced must also have a bulge after having left the ingot mold. DE 36 27 991 discloses a device for the continuous casting of flat ingots, in particular a steel ingot with a thickness of less than 80 mm in which a smaller cross-section similarly domed from the central area on the side of the exit of the chute from the ingot mold faces a larger convex cross-section of the supply side of the laundry, and at least one roller of at least one pair of rollers of the support and driving elements arranged subsequently the ingot mold has a caliber adapted to the domed rope that comes out. The shape of the ingot mold known through this document, as well as the shape of the supporting and driving elements arranged next to the ingot mold are designed so that in the area of the edges the ingot mold has a form adapted to the format of the rope, that is to say that already in the ingot mold there are areas of parallel side walls that continue in the support rollers and conduction of the driving frame of the rope.From DE 44 03 0 45 a continuous casting installation is known for drive ingots whose wide-sided plates have a concave design and the concavity is constant from the upper edge of the ingot mold to the outlet of the ingot mold and also to the last roller of the rope conduction In this the concave shape is conveniently developed from the beginning of one of the plates of the narrow side to the beginning of the other plate of the opposite narrow side. Wide-width casing known from this document relates to a relatively complicated shape in which the curvature of the roll and the actual wear substantially influence. In the central area of the width of the ingot mold, and consequently in the area of the funnel, the shell of the rope is disadvantageously subjected to a constant deformation by bending until the exit of the funnel area by virtue of the extraction movement. With respect to the deformation of the thickness of the rope with liquid crater directly below the ingot mold, in the cited documents the staggering of the thickness reduction steps with respect to the width profile of the rope can not be defined unequivocally. The invention pursues the goal of creating with a simple construction means a continuous casting with an ingot mold and rope driving rollers that reduce the load on the laundry rope, and minimize the risk of longitudinal cracks, as well as breaks. The invention achieves this goal by the distinguishing features of claim 1 of the method and claim 4 of the device. The subordinate claims show advantageous refinements of the invention. According to the invention, the wide sides of the ingot mold are largely composed of parts of flat surface, and the conductor rolls of the rope have an outline that is substantially composed of straight lines. Already from the entrance of the ingot mold a flat surface is provided in the central area which is conserved in the direction of the conveyance of the rope and which is completely adopted by the central parts of the driving rollers after the mouth of the ingot mold. On both sides of this flat central part flat surfaces are also provided in the direction towards the narrow sides. Both the shape as well as the inclination of these flat surfaces are conserved exactly from the entrance of the ingot mold to the end of the driving frame of the rope. Transition parts are provided between the flat central surface of the ingot mold and the flat side surfaces disposed on both sides. The extension of these transition parts ends inside the ingot mold, so that the lower area corresponds to the format of the string. In addition, this form allows a simple introduction and exit of the cold rope when pouring the casting from the continuous casting. In an advantageous design, the central part of the laundry feed area is designed with a flat surface. The flat central parts of both broad sides of the ingot taper conically in the direction of the conveyance of the rope until, when forming in the ingot mold what is known as "crown", they are conducted parallel to the mouth of the ingot mold. In another advantageous design, the central parts in the feeding area are conducted flat and parallel, and outside the submerged area of the immersion nozzle in the direction of the transport of the rope are joined with the central part that presents a "crown" in the area of the mouth of the ingot mold by a joining part. For this, the central parts have a shape whose lines of height are parallel to each other and whose longitudinal extension in the direction of the transport of the rope is configured in the form of S. The mouth of this form of S is tangentially transformed in each case on the adjacent surfaces. The ingot produced in an ingot mold according to the invention has wide sides which are constituted by flat surfaces, the lateral surfaces having a conical configuration and the central surface having a high configuration in comparison with the area of the edges. By means of this form of ingot, it is possible to center the ingot better, even more so at the currently common bullion extraction speeds. This avoids an uncontrolled movement of the rope in the ingot mold and a jiggling, which is known as snaking, in the driving frame of the rope. The external shape of the shell of the ingot rope produced in this way remains constant at least until the peak of the crater. The only modification of the ingot takes place in the direction of the thickness, where only the narrow sides are deformed. The area of central width of the ingot mold, specifically the area configured as a tundish, remains unchanged from its flat shape until complete solidification and guarantees the most advantageous lubrication conditions in the ingot mold. By means of the shape of the mold according to the invention, the casting powder moistens the surface of the rope in a predeterminable quantity with certainty in the area of greatest sensitivity to the longitudinal fissuring. In other words, the shell of the rope, thanks to its flat shape, is not subjected to a bending tension, which creates favorable conditions for cracks close to the surface, in this central area of width of the ingot mold. A special influence is exerted on the solidification conditions of the rope hull in the area of the transition parts and of the connection part by means of an independent refrigerant pipe. The driving frame of the rope that follows has support and driving rollers that guarantee a safe transport of the ingot that still has a crater. In accordance with the invention, various roller shapes are proposed, specifically complete rolls or also divided rolls. In the case of the divided rolls, simple cylindrical rollers are also used which adapt to one another, in accordance with the design of the central and lateral surfaces of the shape of the ingot pre-established by the ingot mold. It is also proposed to divide the rollers in the ratio of 2/3 to 1/3, and to carry out this division alternately. In this the roller 2/3 has a contour corresponding to the association of the central part with the lateral part, depending on the width of the ingot can be used complete rollers that have as outline the negative shape of the bottom of the ingot mold , in particular in the case of smaller dimensions. An example of the invention is shown in the annexed example. They show: figure 1 casting mold in rope with constant central part, figure 2 casting mold in rope with constant side parts, figure 3 cutting through the continuous casting plant, figure 4 seen in plan on the installation of continuous cast iron, figure 5 cut through the driving frame of the rope. Figures 1 and 2 show in perspective an ingot mold with subsequent driving frame of the rope. In this the ingot has wide sides 21 between which narrow sides 22 are enclosed. The wide sides have a central surface 23 whose surface is of flat design, and extends from the entrance to the mouth of the ingot mold. In the region of introduction of the laundry counted up to a length a from the entrance of the ingot mold, the central parts are arranged parallel to each other in relation to their height line and are tapered in conical total in the direction of transportation of the rope. In this area the central portions 23 are connected with the lateral parts 24 and 25 through transition parts 26 and 27. The transition parts 26 and 27 are wedge-shaped, the tip 28 of the wedge still inside the ingot mold being spaced apart by the distance a with respect to the entrance of the ingot mold. On the narrow sides 22, adjustment elements 31 are provided by which the narrow sides 22 enclosed between the wide sides 21 can be moved to modify the shape of the ingot. Rolls are provided under the ingot mold 41 support and driving. In the present example, divided rolls 43-45 having a cylindrical shape are shown. In FIG. 1, the width of the central part 23 is designated b. In the present figure the width b is kept constant starting from the area of introduction of the laundry into the mold to the mouth of the ingot mold. In the insertion area of the ingot mold, the side plates have a width f, which widens to the width g following the wedge-shaped transition part 26 or 27, and from there it remains constant up to the mouth of the ingot mold. In FIG. 2, the central plate has a width c in the casting introduction area following the wedge-shaped transition portions 26, 27 in the direction of the casting of the cord up to the length a of the ingot mold, it widens to the width b and remains constant from there to the mouth of the ingot mold. In the case of this design, the width f of the side plates 24 and 25 remains constant throughout the entire length L of the ingot mold. An immersion nozzle 11 comprising a tubular part 12 and a rectangular part 14 penetrates into the ingot mold. Its mouth 13 penetrates to below the SP level (striped line) of the casting. Figure 3 shows a section aa through the wide sides 21 of the ingot mold. In the left part of the figure, the central plate 23 with a flat surface is represented, which, at distance a, becomes a straight area driven parallel to the opposite central plate. In the right part of the figure, a first segment of the central plate 23 is guided in a superficially planar shape and parallel to the central axis 1. To this parallel part is attached with tangential transition a joining part 29 that in section has a contour in the form of s and in turn is transformed into the parallel part of the central plate 23 in the direction of the mouth. In the entrance area, the shovel-shaped part 14 of the immersion nozzle 11 penetrates into the ingot mold up to below the level Sp of the casting. Support and driving rollers 41 are shown below the ingot mold. The striped line represents the separation distance Ds of the side plates 24 and 25 and consequently also the narrow side of the ingot. Figure 4 shows a plan view on a wide side of the ingot mold together with the nozzle 11 of immersion with its tubular part 12 and its rectangular part 14 as well as the mouth 13 penetrating to below the SP level of the casting. In the right part of the figure, the side plate 24 having a constant width g is shown. In the left part of the figure, the side plate 25 is shown which, in the entrance area of the ingot mold, has a width f and which, conically following the conical transition part, has a width g from the tip 28 of the wedge. The central plate 23 has a constant width b with a view to the left side of the figure.

Looking to the right side the central plate 23 has a width c that becomes wider according to the conical transition part 26 and that from the point 28 of the wedge has a constant width b. Various rollers 43, 44 are shown below the ingot mold. Immediately after the ingot mold, a total of three rollers 43, 44 are shown in the present figure, which in each case have a cylindrical shape and are inclined towards each other correspondingly to the inclination of the mold. the sides and the central surface of the ingot to be produced. The rollers shown in position 3 and 4 of the frame consist of a roller 46 of 2/3 and a roller 44 cylindrical. The roller 46 has a cylindrical segment and a conical part adapted to the inclination of the lateral surfaces. In positions 5 and 6, rollers whose full contour corresponds to that of the ingot produced in the ingot mold placed in the central area as well as in the lateral areas are represented. Figure 5 shows a cut through the driving frame and the ingot which in this area still has a crater. In the upper part of the figure the situation is shown with the pairs of rollers that face in the central area 43 and in the areas 44, 45 lateral. These rollers support the wide sides 51 of the shell box which is composed of the wide sides 51 and the narrow sides 52. In this case the casing of the shell surrounds the laundry S which in this area forms the crater inside the ingot. In the lower area the situation is represented with a complete roller 42 having a cylindrical central part and lateral areas that enlarge conically. In addition, a roller 46 of 2/3 is shown which supports most of the wide side 51 of the ingot and which is followed in the right part of the figure by a cylindrical roller 44 which supports the area of the narrow sides. The present sketch clearly shows the ingot that has a "crown", which through the roller shapes proposed here can be accurately driven through the rope driving frame.

List of reference symbols Feeding 11 Immersion nozzle 12 Tubular part 13 Shovel-shaped opening 14 Rectangular part Installing the ingot mold 21 Wide sides of the ingot mold 22 Narrow sides of the ingot mold 23 Center surface 24 First side surface 25 Second side surface 26 First transition part 27 Second transverse part 28 Wedge tip 29 Joint part Adjustment device 31 Adjustment element Driving device 41 Support and driving rollers 42 Domed roller 43 Center split roller 44 Roller divided side 45 Roller divided 2nd side 46 Roller 2/3 47 Bearing Ds Distance narrow sides DE Larger distance wide sides d Immersion nozzle thickness S Casting S Casting level B Rope casings L Ingot length a Distance from the entrance to the ingot mold b Width constant central part c Width of the central part feeding area of the co side f Width of the laundry feed area side part g Constant width side part 1 Center axis

Claims (1)

1. CLAIMS Method for producing narrow ingots with pre-established bulging of their wide sides in a continuous casting in which the immersion nozzle penetrates into an ingot mold composed of wide sides and narrow sides followed by a rope conduction through which it drives the ingot that still has a rope shell that surrounds a liquid crater, characterized by the following stages: a) The wide sides of the casting shell are shaped as flat surfaces in the area of an immersion nozzle configured in the form of a shovel, in this they are parallel with respect to their height lines, and b) as flat surfaces in the submerged area of the immersion nozzle and tapering conically towards the narrow sides. c) In the direction of the cord casting, the central parts of the broad sides of the ingot formed as flat surfaces that lie within the submerged area are conically narrowed to a longitudinal extent of 40 to 60% of the ingot mold. lateral edges adapt with the ends of the flat parts of the wide side of the ingot tapering narrowly towards the narrow sides, and d) the wedge-shaped joining parts join with the central parts of flat surface of the wide sides of the ingot with the respective parts of the flat surface edge of the wide sides of the ingot lying outside the submerged area of the immersion nozzle. e) Then the bulge formed by in each case three flat surface parts of the wide sides of the strand cast remains constant in its form up to the peak of the ingot crater, both in the area of the mouth and after leaving the ingot mold Method according to claim 1, characterized in that the narrow sides of the ingot are deformed exclusively for the reduction of the thickness of the ingot in the area of the driving frame. Method according to claim 1, characterized in that the wedge-shaped transitions between the central part of the ingot of flat shape that is in the submerged area of the immersion nozzle and the wide-side parts of the ingot that taper conically the narrow sides are given a shape which in the longitudinal extensions of the central parts of the ingot enclose an angle < 5 ° and reproduce a bulged surface that with a central inversion point is joined by its edges tangentially to the two adjacent surfaces. Continuous casting facility for producing narrow ingots comprising a laterally adjustable ingot mold in which an immersion nozzle penetrates, and in which a small cross-section similarly domed from the central area on the side of the exit of the cord is faced on the side from feeding the laundry to a larger, domed cross section, and pairs of support and driving rollers transposed to the ingot mold having a gauge adapted to the bulging rope that exits, in order to carry out the method according to claim 1 , characterized a) because the immersion nozzle has a shovel-shaped opening, with a corresponding maximum thickness ad = 0.3 to 0.5 X DE, where DE is the distance of the wide sides of the mold in the feed area of the laundry, b) because the wide-side parts at least in the submerged area of the immersion nozzle have central parts correspondingly their height lines are parallel to each other, c) because the plates of the wide sides at least in the adjustment areas of the plates of the narrow sides are configured as flat side surfaces, d) because the flat side surfaces are arranged so that they taper in the direction of the narrow sides, e) because the central flat surface plate is joined to the lateral surfaces of flat surfaces by transition parts, f) because the transition parts extend in the direction of the conveyance of the rope tapering like a wedge, and the tip of the wedge ends at the distance measured from the upper edge of the ingot mold, in which a = 0.5 to 0.8 x L, with L = length of the ingot mold, and g) because the support and conduction rollers have a contour corresponding to the central plate of flat surface and to the lateral plates of flat surfaces of the wide sides of the ingot mold in the area of the mouth of the ingot mold. Continuous casting installation according to claim 4, characterized in that the central plates are configured as flat surfaces which in the direction of conveyance of the cord taper conically at an angle a = 5 to 10 ° with a = 0.5 to 0.8 x L. Continuous casting installation according to claim 4, characterized in that the central plates are configured with flat surfaces and conducted parallel to each other in the submerged area of the immersion nozzle up to a = 0.5 to 0.8 x L, and because they provide connecting parts that, with respect to their height lines, are parallel and in the transport direction of the rope have an s-shaped contour, their ends being tangentially transformed in the front and back of the plate tangentially central and whose transition parts in its longitudinal extension to the tip of the wedge are adapted to the joint part. Continuous casting installation according to claim 4, characterized in that the transition parts are configured as a bulged surface, the bulged surface abutting tangentially at one end with the side plate of the respective ingot and at the other end with the central plate of the barrel. ingot and has a central inversion point. Continuous casting installation according to claim 4, characterized in that the support and guide rollers are configured as divided rollers, the respective bearings being provided in the area of the central flat surface plate. Continuous casting installation according to claim 4, characterized in that rollers are provided in the driving frame corresponding to the shape of the ingot, which in the central area are configured in a cylindrical shape and in the lateral areas conically with a diameter that increases outward. Continuous casting installation according to claim 4 or 7, characterized in that the transition parts are connected to an independent cooling device. SUMMARY The invention relates to a method for producing narrow ingots as well as to a continuous casting facility for this purpose comprising a laterally adjustable ingot mold into which an immersion nozzle penetrates, and in which a small, slightly bulging cross section of the The central area on the side of the exit of the rope faces on the side of the feed of the laundry to a larger abo abogada cross section, and pairs of support and driving rollers transposed to the ingot mold having a caliber adapted to the bulging rope that comes out. In this a) the immersion nozzle has a shovel-shaped opening, with a corresponding maximum thickness ad = 0.3 to 0.5 x DE, where DE is the distance of the wide sides of the ingot mold in the supply area of the laundry , b) the wide-sided parts at least in the submerged area of the immersion nozzle have central parts corresponding to their height lines are dipustas parallel to each other, c) the wide-sided plates at least in the ares of adjustment of the plates of the narrow sides are configured as flat side surfaces, d) the flat side surfaces are arranged so that they narrow conically in the direction of the narrow sides, e) the central plate of flat surface is joined with the surfaces laterals of flat surfaces by means of transition parts, f) the transition parts extend in the direction of the transportation of the cord by narrowing a of wedge, and the tip of the wedge ends at the distance as measured from the upper edge of the ingot mold, where a = 0.5 to 0.8 L, with L = length of the ingot mold, and g) the support and conduction rollers they have a contour corresponding to the central plate of flat surface and to the side plates of flat surfaces of the wide sides of the ingot mold in the area of the mouth of the ingot mold. (Figure 1)