EP0391824A1 - Method and device for casting thin metallic products with thickness reduction under the casting mould - Google Patents

Method and device for casting thin metallic products with thickness reduction under the casting mould Download PDF

Info

Publication number
EP0391824A1
EP0391824A1 EP90470009A EP90470009A EP0391824A1 EP 0391824 A1 EP0391824 A1 EP 0391824A1 EP 90470009 A EP90470009 A EP 90470009A EP 90470009 A EP90470009 A EP 90470009A EP 0391824 A1 EP0391824 A1 EP 0391824A1
Authority
EP
European Patent Office
Prior art keywords
product
thickness
mold
thickness reduction
cylinders
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
EP90470009A
Other languages
German (de)
French (fr)
Inventor
Jean-Marc Jolivet
Bernard Robert
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Techmetal Promotion SA
Original Assignee
Techmetal Promotion SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Techmetal Promotion SA filed Critical Techmetal Promotion SA
Publication of EP0391824A1 publication Critical patent/EP0391824A1/en
Ceased legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/12—Accessories for subsequent treating or working cast stock in situ
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
    • B21B1/46—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling metal immediately subsequent to continuous casting
    • B21B1/463—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling metal immediately subsequent to continuous casting in a continuous process, i.e. the cast not being cut before rolling
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/12—Accessories for subsequent treating or working cast stock in situ
    • B22D11/1206—Accessories for subsequent treating or working cast stock in situ for plastic shaping of strands

Definitions

  • the present invention relates to a process for casting thin metallic products, in particular steel, such as thin slabs according to which the molten metal is poured into an ingot mold of elongated section and the thickness of the product coming from the ingot mold is reduced directly to the output thereof while the core of said product is not yet solidified
  • It also relates to a casting installation, allowing the implementation of this process, comprising a mold with cooled fixed walls and a device located directly downstream of the mold, intended to reduce the thickness of the cast product to bring it to the 'final thickness desired for the thin product, this device comprising two clamping members, to bring together and unify the solidified walls of the product from the ingot mold, generally constituted by cylinders acting on said product in the manner of rolling cylinders.
  • the mold has, at least in its upper part, a central flare, the large faces then having for example a section in the form of a "gendarme hat".
  • the cast product passes immediately downstream of the mold between two cylinders which bring the large faces of the product together to bring them parallel to each other.
  • the thickness of the product from the ingot mold is reduced immediately downstream of it, while the core is not yet solidified, to bring the cast product to the desired thickness.
  • the thin slabs obtained by these methods can have defects of the "long edge" type well known to laminators, and, on the other hand, the elongation of the edges can induce large faces in the solidified skins. tensile stresses such as breakthroughs can occur by rupture of these skins.
  • the rolling of the edges requires a force for tightening the thickness reduction cylinders, much greater than the force necessary to bring the solidified skins closer to the central parts of the large faces, which leads to oversizing the device ensuring the "rolling" .
  • the purpose of the present invention is to solve the problems set out above, and to allow obtaining thin products, such as thin slabs, of good quality, while limiting the dimensions and therefore the size of the installation. Manufacturing.
  • the subject of the present invention is a process for casting thin metallic products, in particular thin slabs, of the type according to which liquid metal is poured into a continuous casting mold of elongated section from which the metal partially solidified is continuously extracted and the thickness of the product from the ingot mold is reduced, by a thickness reduction device located directly downstream thereof, while the core of said product is not yet solidified.
  • this process is characterized in that the thickness is reduced only to a central zone of the product from the ingot mold, that is to say to the exclusion of the solidified edges of said product, to a value less than half the thickness of said edges, and, after said reduction in thickness, the edges of the product which have not been subjected to it are dropped.
  • the thickness reduction is carried out so as to obtain, immediately downstream of the thickness reduction device, a completely solidified product.
  • the "long edge" defects mentioned above are eliminated or at least considerably reduced.
  • there is no rolling of the solidified areas of the product Only a central zone of the product, the width of which corresponds to the width of the liquid or pasty well, is subjected to the reduction in thickness.
  • the solidified skins of the large faces of the product are in fact brought closer to one another without their elongation, the metal of the non-solidified core being somehow pushed back towards the ingot mold.
  • the solidified skins of the small faces of the product are not laminated and therefore do not undergo elongation either.
  • all the zones of the product of which the metal has solidified in an ingot mold retain their length, which avoids the appearance of differential stresses in the final product, and its deformation.
  • the invention also relates to an installation for casting thin metallic products comprising an ingot mold for continuous casting of elongated section, and a device for reducing the thickness of the product coming from the ingot mold, placed directly downstream of the latter.
  • the installation is characterized in that the thickness reduction device comprises thickness reduction means having an active width less than the width of the large faces of the mold at its lower end, and in what it includes cutting means for falling the edges of the product, located downstream of the thickness reduction means.
  • these thickness reduction means comprise at least one pair of cylinders whose active length is less than the width of the large faces of the mold at its lower end.
  • the installation according to the invention makes it possible to obtain a product practically free from skin constraints.
  • the thickness reduction cylinders, their supports and their drive means possible may be reduced in size, since the forces to which they are subjected during rolling on a liquid core are much lower than those which would be necessary to actually laminate the solidified edges of the product.
  • FIGS. 1 and 2 The installation shown in FIGS. 1 and 2 comprises a continuous casting mold 1 of elongated rectangular horizontal section, and a thickness reduction device 20 comprising a pair of cylinders 22 driven in rotation by drive means 21 and placed just below the mold, the axes of the cylinders being parallel to the large walls 11 of the mold.
  • the large walls 11 and the small walls 12 of the mold as well as the cylinders 22 are cooled in a conventional manner, for example by internal circulation of a cooling fluid.
  • the active length of the cylinders 22, that is to say the length of their generatrix, is less than the width of the large walls of the mold.
  • the liquid metal 3 is poured into the mold, where it begins to solidify on contact with the cooled walls, forming solid skins 4,4 ′.
  • the section of product 1, shown in FIG. 3 a comprises a solidified peripheral zone formed by the skins 4, 4 ′, and a non-solidified core 5.
  • the skins 4, solidified in contact with the large walls 11 of the mold are brought together one from the other, in the central zone 6 of the product from the ingot mold, by the rolling effect of the cylinders. Against by the edges 7 of the product do not pass into the grip of the cylinders and therefore retain their thickness.
  • the skins 4 ′ solidified in contact with the small walls 12 of the mold are not laminated and therefore do not undergo elongation. Similarly, the width of the product is not appreciably increased.
  • the section of the product is as shown in FIG. 3 b , having an elongated "dog bone" shape.
  • the thickness of the non-solidified core 5 is progressively reduced as the product advances, due to the approximation of the skins 4.
  • the skins 4 are joined together and form the core 6 ′ of the product, the section of which shown in FIG. 3 c , has the shape of an "I", the wings of which 7 ′, have kept a width substantially equal to that of the small faces of the mold, while the thickness of the central part of the product is substantially equal to half of this width, that is to say the thickness of the edges of the product from the mold.
  • the reduction in thickness of the central part can be considerably greater, for example this thickness can be reduced to only one fifth of the thickness of the edges.
  • the bottom of the solidification well is maintained at the level of the plane of the axes of the cylinders 22, which ensures good connection of the two skins 4, this being done in the pasty zone from the bottom of the well.
  • it must be ensured that the thickness of the solidified skins below the level of the axes of the cylinders is sufficient to prevent them from deforming and swelling of the product. Additional cooling can in particular be provided for this purpose to accelerate the solidification of the product.
  • the installation also comprises means 8 for falling the wings 7 ′ of the solidified product obtained after passage between the cylinders 22, such as a shear or any suitable cutting means.
  • the thin slab 9 obtained has a rectangular section (FIG. 3d), the thick of which seur is equal to the spacing of the cylinders, and the width determined by the wing drop operation.
  • the cylinders are driven in rotation by drive means 21. It is then these cylinders which constitute the means for extracting the product from the ingot mold.
  • the extraction can also be carried out by specific extraction means, such as extractor rollers, of the types commonly used in continuous casting, placed downstream of the thickness reduction device.
  • the extraction speed is then determined by the extraction means, and the speed of the thickness reduction cylinders is controlled by that of the extraction means.
  • the extraction means can also be independent of the thickness reduction device.
  • the rolling rolls can be free to rotate, the extraction being carried out only by specific extraction means.
  • the edges of the cylinders 22 will be shaped so as not to create significant stresses in the skin of the product at the connection 13 between the central zone 6, and the edges 7.
  • the edge of the cylinders may for example be shaped as a rounded 16 connecting the cylindrical surface 14 with the side faces 15 of the cylinders. The radius of curvature of this rounding will be adapted according to the desired thickness reduction and the nature of the metal being cast.
  • the invention is not limited to the use of a mold of constant rectangular section. This may for example have large concave walls, the product which results therefrom then having a thickness in its middle greater than that of the edges.
  • It may also have a rectangular section only at the outlet of the mold, at its lower end.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)

Abstract

Selon l'invention on coule le métal liquide 3 dans une lingotière de coulée continue 10 et on réduit l'épaisseur du produit 1 issu de la lingotière par un dispositif de réduction d'épaisseur 20, alors que le coeur 5 dudit produit n'est pas encore solidifié.L'épaisseur du produit 1 n'est réduite que dans une zone centrale, à l'exclusion des bords solidifiés du produit, par des moyens de réduction d'épaisseur tels que des cylindres 22 dont la longueur active est inférieure à la largeur des grandes faces 11 de la lingotière.Pour la fabrication de brames minces 9 des moyens 8 sont prévus en aval des cylindres 22 pour chuter les bords 7′ du produit.According to the invention, the liquid metal 3 is poured into a continuous casting mold 10 and the thickness of the product 1 coming from the mold is reduced by a thickness reduction device 20, while the core 5 of said product is not The thickness of the product 1 is reduced only in a central zone, excluding the solidified edges of the product, by thickness reduction means such as cylinders 22, the active length of which is less than the width of the large faces 11 of the ingot mold. For the manufacture of thin slabs 9, means 8 are provided downstream of the cylinders 22 for dropping the edges 7 'of the product.

Description

La présente invention concerne un procédé de coulée de produits métalliques minces, notamment en acier, tels que des brames minces selon lequel on coule le métal en fusion dans une lingotière de section allongée et on réduit l'épaisseur du produit issu de la lingotière directement à la sortie de celle-ci alors que le coeur dudit produit n'est pas encore solidifiéThe present invention relates to a process for casting thin metallic products, in particular steel, such as thin slabs according to which the molten metal is poured into an ingot mold of elongated section and the thickness of the product coming from the ingot mold is reduced directly to the output thereof while the core of said product is not yet solidified

Elle concerne également une installation de coulée, permettant la mise en oeuvre de ce procédé, comportant une lingotière à parois fixes refroidies et un dispositif situé directement en aval de la lingotière, destiné à réduire l'épaisseur du produit coulé pour l'amener à l'épaisseur finale souhaitée pour le produit mince, ce dispositif comportant deux organes de pincement, pour rapprocher et unir les parois solidifiées du produit issu de la lingotière, généralement constitués par des cylindres agissant sur ledit produit à la manière de cylindres de laminage.It also relates to a casting installation, allowing the implementation of this process, comprising a mold with cooled fixed walls and a device located directly downstream of the mold, intended to reduce the thickness of the cast product to bring it to the 'final thickness desired for the thin product, this device comprising two clamping members, to bring together and unify the solidified walls of the product from the ingot mold, generally constituted by cylinders acting on said product in the manner of rolling cylinders.

De tels procédés et installations sont déjà connus, visant à produire des brames minces, c'est-à-dire dont la largeur est généralement supérieure à trois fois l'épaisseur, celle-ci étant inférieure à environ 120 mm.Such methods and installations are already known, aiming to produce thin slabs, that is to say whose width is generally greater than three times the thickness, the latter being less than about 120 mm.

Il a par exemple été déjà proposé de couler le métal liquide dans une lingotière dont les petites faces ont une largeur faible par rapport à la largeur des grandes faces. Notamment afin de pouvoir faire pénétrer la busette de coulée entre les grandes faces, la lingotière présente, au moins dans sa partie supérieure, un évasement central, les grandes faces ayant alors par exemple une section en forme de "chapeau de gendarme". Pour ramener le produit coulé à une section rectangulaire, soit l'élargissement se réduit progressivement du haut vers le bas de la lingotière, où celle-ci retrouve une section rectangulaire, soit le produit coulé passe immédiatement en aval de la lingotière entre deux cylindres qui rapprochent les grandes faces du produit pour les ramener parallèles l'une à l'autre.For example, it has already been proposed to pour the liquid metal into an ingot mold, the small faces of which have a small width compared to the width of the large faces. In particular in order to be able to penetrate the pouring nozzle between the large faces, the mold has, at least in its upper part, a central flare, the large faces then having for example a section in the form of a "gendarme hat". To reduce the cast product to a rectangular section, either the enlargement is gradually reduced from the top to the bottom of the mold, where it finds a rectangular section, or the cast product passes immediately downstream of the mold between two cylinders which bring the large faces of the product together to bring them parallel to each other.

Il a également été proposé de couler dans une lingotière de section rectangulaire allongée sensiblement constante, la busette ayant alors une section fortement aplatie pour pouvoir s'insérer entre les parois de la lingotière.It has also been proposed to flow into a mold of substantially constant elongated rectangular section, the nozzle then having a strongly flattened section so as to be able to be inserted between the walls of the mold.

Dans tous les cas, l'épaisseur du produit issu de la lingotière est réduite immédiatement en aval de celle-ci, alors que le coeur n'est pas encore solidifié, pour amener le produit coulé à l'épaisseur désirée.In all cases, the thickness of the product from the ingot mold is reduced immediately downstream of it, while the core is not yet solidified, to bring the cast product to the desired thickness.

Toutefois ces procédés présentent un inconvénient majeur résultant du laminage des bords du produit issu de la lingotière. En effet, comme cela a été indiqué ci-dessus, le laminage est réalisé alors que le coeur du produit est encore liquide. En fait il ne s'agit pas réellement d'un laminage, mais plutôt d'un écrasement du produit issu de la lingotière pour rapprocher jusqu'au contact les peaux solidifiées des grandes faces de celui-ci. La partie centrale des grandes faces ne subit donc pas d'allongement sensible lors de cet écrasement. Par contre, du fait de la solidification des bords du produit dans la lingotière, ceux-ci sont réellement laminés ce qui conduit à une déformation et un allongement des bords. Il s'ensuit que d'une part les brames minces obtenues par ces procédés peuvent présenter des défauts du type "bords longs" bien connus des lamineurs, et d'autre part l'allongement des bords peut induire dans les peaux solidifiées des grandes faces des contraintes de traction telles que des percées peuvent subvenir par rupture de ces peaux.However, these methods have a major drawback resulting from the rolling of the edges of the product from the mold. In fact, as indicated above, the rolling is carried out while the core of the product is still liquid. In fact it is not really a rolling, but rather a crushing of the product from the mold to bring closer until contact the solidified skins of the large faces thereof. The central part of the large faces therefore does not undergo significant elongation during this crushing. By cons, due to the solidification of the edges of the product in the mold, these are actually laminated which leads to deformation and elongation of the edges. It follows that, on the one hand, the thin slabs obtained by these methods can have defects of the "long edge" type well known to laminators, and, on the other hand, the elongation of the edges can induce large faces in the solidified skins. tensile stresses such as breakthroughs can occur by rupture of these skins.

De plus le laminage des bords nécessite un effort de serrage des cylindres de réduction d'épaisseur, bien supérieur à l'effort nécessaire pour rapprocher les peaux solidifiées des parties centrales des grandes faces, ce qui conduit à surdimensionner le dispositif assurant le "laminage".In addition, the rolling of the edges requires a force for tightening the thickness reduction cylinders, much greater than the force necessary to bring the solidified skins closer to the central parts of the large faces, which leads to oversizing the device ensuring the "rolling" .

Le but de la présente invention est de résoudre les problèmes exposés ci-dessus, et de permettre l'obtention de produits minces, tels que des brames minces, de bonne qualité, tout en limitant les dimensions et donc l'encombrement de l'installation de fabrication.The purpose of the present invention is to solve the problems set out above, and to allow obtaining thin products, such as thin slabs, of good quality, while limiting the dimensions and therefore the size of the installation. Manufacturing.

Avec ces objectifs en vue, la présente invention a pour objet un procédé de coulée de produits métalliques minces, notamment de brames minces, du type selon lequel on coule le métal liquide dans une lingotière de coulée continue de section allongée d'où le métal partiellement solidifié est extrait en continu et on réduit l'épaisseur du produit issu de la lingotière, par un dispositif de réduction d'épaisseur situé directement en aval de celle-ci, alors que le coeur dudit produit n'est pas encore solidifié.With these objectives in view, the subject of the present invention is a process for casting thin metallic products, in particular thin slabs, of the type according to which liquid metal is poured into a continuous casting mold of elongated section from which the metal partially solidified is continuously extracted and the thickness of the product from the ingot mold is reduced, by a thickness reduction device located directly downstream thereof, while the core of said product is not yet solidified.

Selon l'invention ce procédé est caractérisé en ce que on réduit l'épaisseur uniquement d'une zone centrale du produit issu de la lingotière, c'est-à-dire à l'exclusion des bords solidifiés dudit produit, jusqu'à une valeur inférieure à la moitié de l'épaisseur desdits bords, et, après ladite réduction d'épaisseur, on chute les bords du produit qui n'y ont pas été soumis.According to the invention, this process is characterized in that the thickness is reduced only to a central zone of the product from the ingot mold, that is to say to the exclusion of the solidified edges of said product, to a value less than half the thickness of said edges, and, after said reduction in thickness, the edges of the product which have not been subjected to it are dropped.

Préférentiellement la reduction d'épaisseur est menée de manière à obtenir, immédiatement en aval du dispositif de réduction d'épaisseur, un produit totalement solidifié.Preferably, the thickness reduction is carried out so as to obtain, immediately downstream of the thickness reduction device, a completely solidified product.

Grâce à la présente invention, les défauts de "bords longs" évoqués précédemment sont supprimés ou tout au moins considérablement réduits. En effet, dans le procédé selon l'invention, il n'y a pas de laminage des zones solidifiées du produit. Seule une zone centrale du produit, dont la largeur correspond à la largeur du puits liquide ou pâteux, est soumise à la réduction d'épaisseur. Les peaux solidifiées des grandes faces du produit sont en fait rapprochées l'une de l'autre sans qu'il y ait allongement de celles-ci, le métal du coeur non solidifié étant en quelque sorte repoussé vers la lingotière. Les peaux solidifiées des petites faces du produit ne sont pas laminées et ne subissent donc pas non plus d'allongement. Il en résulte que toutes les zones du produit dont le métal s'est solidifié en lingotière conservent leur longueur, ce qui évite l'apparition de contraintes différentielles dans le produit final, et sa déformation.Thanks to the present invention, the "long edge" defects mentioned above are eliminated or at least considerably reduced. In fact, in the process according to the invention, there is no rolling of the solidified areas of the product. Only a central zone of the product, the width of which corresponds to the width of the liquid or pasty well, is subjected to the reduction in thickness. The solidified skins of the large faces of the product are in fact brought closer to one another without their elongation, the metal of the non-solidified core being somehow pushed back towards the ingot mold. The solidified skins of the small faces of the product are not laminated and therefore do not undergo elongation either. As a result, all the zones of the product of which the metal has solidified in an ingot mold retain their length, which avoids the appearance of differential stresses in the final product, and its deformation.

L'invention a aussi pour objet une installation de coulée de produits métalliques minces comportant une lingotière de coulée continue de section allongée, et un dispositif de réduction d'épaisseur du produit issu de la lingotière, disposé directement en aval de celle-ci.The invention also relates to an installation for casting thin metallic products comprising an ingot mold for continuous casting of elongated section, and a device for reducing the thickness of the product coming from the ingot mold, placed directly downstream of the latter.

Selon l'invention, l'installation est caractérisée en ce que le dispositif de réduction d'épaisseur, comporte des moyens de réduction d'épaisseur ayant une largeur active inférieure à la largeur des grandes faces de la lingotière à son extrémité inférieure, et en ce qu'elle comporte des moyens de découpe pour chuter les bords du produit, situés en aval des moyens de réduction d'épaisseur.According to the invention, the installation is characterized in that the thickness reduction device comprises thickness reduction means having an active width less than the width of the large faces of the mold at its lower end, and in what it includes cutting means for falling the edges of the product, located downstream of the thickness reduction means.

Préférentiellement, ces moyens de réduction d'épaisseur comprennent au moins une paire de cylindres dont la longueur active est inférieure à la largeur des grandes faces de la lingotière à son extrémité inférieure.Preferably, these thickness reduction means comprise at least one pair of cylinders whose active length is less than the width of the large faces of the mold at its lower end.

L'installation selon l'invention permet d'obtenir un produit pratiquement exempt de contraintes de peau. De plus les cylindres de réduction d'épaisseur, leurs supports et leurs moyens d'entraînement éventuels peuvent être réduits en dimension, puisque les efforts auxquels ils sont soumis lors du laminage sur coeur liquide sont bien inférieurs à ceux qui seraient nécessaires pour laminer réellement les bords solidifiés du produit.The installation according to the invention makes it possible to obtain a product practically free from skin constraints. In addition the thickness reduction cylinders, their supports and their drive means possible may be reduced in size, since the forces to which they are subjected during rolling on a liquid core are much lower than those which would be necessary to actually laminate the solidified edges of the product.

D'autres caractéristiques et avantages apparaîtront dans la description qui va être faite à titre d'exemple d'un procédé et d'une installation conforme à l'invention, appliqués à la coulée de brames minces.Other characteristics and advantages will appear in the description which will be given by way of example of a method and of an installation in accordance with the invention, applied to the casting of thin slabs.

On se reportera aux dessins annexés dans lesquels :

  • - la figure 1 est une représentation schématique en coupe d'une installation de coulée continue de brames minces conforme à l'invention ;
  • - la figure 2 est une vue partielle de l'installation selon la flèche F de la figure 1 ;
  • - la figure 3 est une représentaion de l'évolution de la section du produit au cours de la fabrication.
Reference is made to the appended drawings in which:
  • - Figure 1 is a schematic sectional view of a continuous casting installation of thin slabs according to the invention;
  • - Figure 2 is a partial view of the installation according to arrow F in Figure 1;
  • - Figure 3 is a representation of the evolution of the section of the product during manufacture.

L'installation représentée aux figures 1 et 2 comporte une lingotière de coulée continue 1 de section horizontale rectangulaire allongée, et un dispositif de réduction d'épaisseur 20 comprenant une paire de cylindres 22 entraînés en rotation par des moyens d'entraînement 21 et placés juste en-dessous de la lingotière, les axes des cylindres étant parallèles aux grandes parois 11 de la lingotière.The installation shown in FIGS. 1 and 2 comprises a continuous casting mold 1 of elongated rectangular horizontal section, and a thickness reduction device 20 comprising a pair of cylinders 22 driven in rotation by drive means 21 and placed just below the mold, the axes of the cylinders being parallel to the large walls 11 of the mold.

Les grandes parois 11 et les petites parois 12 de la lingotière ainsi que les cylindres 22 sont refroidis de manière classique, par exemple par circulation interne d'un fluide de refroidissement.The large walls 11 and the small walls 12 of the mold as well as the cylinders 22 are cooled in a conventional manner, for example by internal circulation of a cooling fluid.

Ainsi que l'on peut le voir sur la figure 2, la longueur active des cylindres 22 c'est-à-dire la longueur de leur génératrice, est inférieure à la largeur des grandes parois de la lingotière.As can be seen in FIG. 2, the active length of the cylinders 22, that is to say the length of their generatrix, is less than the width of the large walls of the mold.

Le métal liquide 3 est coulé dans la lingotière, où il commence à se solidifier au contact des parois refroidies en formant des peaux solidifiées 4,4′. A la sortie de la lingotière (niveau a), la section du produit 1, représentée à la figure 3a, comporte une zone périphérique solidifiée formée par les peaux 4, 4′, et un coeur non solidifié 5.The liquid metal 3 is poured into the mold, where it begins to solidify on contact with the cooled walls, forming solid skins 4,4 ′. At the outlet of the ingot mold (level a ), the section of product 1, shown in FIG. 3 a , comprises a solidified peripheral zone formed by the skins 4, 4 ′, and a non-solidified core 5.

Au niveau b situé au dessus du plan des axes des cylindres 22 et en dessous de leurs génératrices supérieures, les peaux 4, solidifiées au contact des grandes parois 11 de la lingotière, sont rapprochées l'une de l'autre, dans la zone centrale 6 du produit issu de la lingotière, par l'effet de laminage des cylindres. Par contre les bords 7 du produit ne passent pas dans l'emprise des cylindres et conservent de ce fait leur epaisseur. Les peaux 4′ solidifiées au contact des petites parois 12 de la lingotière ne sont pas laminées et ne subissent donc pas d'allongement. De même la largeur du produit n'est pas sensiblement accrue. Au niveau b, la section du produit est telle que représentée à la figure 3b, présentant une forme en "os de chien" allongée. L'épaisseur du coeur 5 non solidifié se réduit progressivement au fur et à mesure de l'avance du produit, du fait du rapprochement des peaux 4.At level b located above the plane of the axes of the cylinders 22 and below their upper generatrices, the skins 4, solidified in contact with the large walls 11 of the mold, are brought together one from the other, in the central zone 6 of the product from the ingot mold, by the rolling effect of the cylinders. Against by the edges 7 of the product do not pass into the grip of the cylinders and therefore retain their thickness. The skins 4 ′ solidified in contact with the small walls 12 of the mold are not laminated and therefore do not undergo elongation. Similarly, the width of the product is not appreciably increased. At level b , the section of the product is as shown in FIG. 3 b , having an elongated "dog bone" shape. The thickness of the non-solidified core 5 is progressively reduced as the product advances, due to the approximation of the skins 4.

Au niveau c, correspondant au plan des axes des cylindres, les peaux 4 sont réunies et forment l'âme 6′ du produit dont la section représentée à la figure 3c, a une forme de "I", dont les ailes 7′, ont conservé une largeur sensiblement égale à celles des petites faces de la lingotière, alors que l'épaisseur de la partie centrale du produit est sensiblement égale à la moitié de cette largeur, c'est-à-dire de l'épaisseur des bords du produit issu de la lingotière. Bien entendu, la réduction d'épaisseur de la partie centrale peut être considérablement plus forte, par exemple cette épaisseur peut être ramenée à seulement un cinquième de l'épaisseur des bords.At level c , corresponding to the plane of the axes of the cylinders, the skins 4 are joined together and form the core 6 ′ of the product, the section of which shown in FIG. 3 c , has the shape of an "I", the wings of which 7 ′, have kept a width substantially equal to that of the small faces of the mold, while the thickness of the central part of the product is substantially equal to half of this width, that is to say the thickness of the edges of the product from the mold. Of course, the reduction in thickness of the central part can be considerably greater, for example this thickness can be reduced to only one fifth of the thickness of the edges.

De préférence, comme cela a été décrit ci-dessus, le fond du puits de solidification est maintenu au niveau du plan des axes des cylindres 22, ce qui assure une bonne liaison des deux peaux 4, celle-ci se faisant dans la zone pâteuse du fond de puits. Il est cependant possible de procéder de manière que la fin de solidification se produise en aval des cylindres, notamment dans le cas où l'épaisseur finale désirée de la brame est suffisante. Il faut cependant dans ce cas veiller à ce que l'épaisseur des peaux solidifiées en dessous du niveau des axes des cylindres soit suffisante pour éviter la déformation de celles-ci et un gonflement du produit. Un refroidissement complémentaire peut notamment être prévu à cet effet pour accélérer la solidification du produit.Preferably, as has been described above, the bottom of the solidification well is maintained at the level of the plane of the axes of the cylinders 22, which ensures good connection of the two skins 4, this being done in the pasty zone from the bottom of the well. However, it is possible to proceed so that the end of solidification occurs downstream of the cylinders, in particular in the case where the desired final thickness of the slab is sufficient. In this case, however, it must be ensured that the thickness of the solidified skins below the level of the axes of the cylinders is sufficient to prevent them from deforming and swelling of the product. Additional cooling can in particular be provided for this purpose to accelerate the solidification of the product.

Dans le cas exemplifié de la fabrication de brames minces, l'installation comporte aussi des moyens 8 pour chuter les ailes 7′ du produit solidifié obtenu après passage entre les cylindres 22, tels qu'une cisaille ou tous moyens de découpe appropriés. La brame mince 9 obtenue présente une section rectangulaire (figure 3d), dont l'épais­ seur est égale à l'écartement des cylindres, et la largeur déterminée par l'opération de chutage des ailes.In the exemplified case of the manufacture of thin slabs, the installation also comprises means 8 for falling the wings 7 ′ of the solidified product obtained after passage between the cylinders 22, such as a shear or any suitable cutting means. The thin slab 9 obtained has a rectangular section (FIG. 3d), the thick of which seur is equal to the spacing of the cylinders, and the width determined by the wing drop operation.

Conformément à la disposition préférentielle du procédé et de l'installation prises en exemple, les cylindres sont entraînés en rotation par des moyens d'entraînement 21. Ce sont alors ces cylindres qui constituent les moyens d'extraction du produit issu de la lingotière.In accordance with the preferred arrangement of the method and of the installation taken as an example, the cylinders are driven in rotation by drive means 21. It is then these cylinders which constitute the means for extracting the product from the ingot mold.

L'extraction peut aussi être réalisée par des moyens d'extraction spécifiques, tels que des rouleaux extracteurs, de types couramment utilisés en coulée continue, placés en aval du dispositif de réduction d'épaisseur.The extraction can also be carried out by specific extraction means, such as extractor rollers, of the types commonly used in continuous casting, placed downstream of the thickness reduction device.

La vitesse d'extraction est alors déterminée par les moyens d'extraction, et on asservit la vitesse des cylindres de réduction d'épaisseur à celle des moyens d'extraction.The extraction speed is then determined by the extraction means, and the speed of the thickness reduction cylinders is controlled by that of the extraction means.

Les moyens d'extraction peuvent aussi être indépendants du dispositif de réduction d'épaisseur. Par exemple, les cylindres de laminage peuvent être libres en rotation, l'extraction étant réalisée uniquement par les moyens d'extraction spécifiques.The extraction means can also be independent of the thickness reduction device. For example, the rolling rolls can be free to rotate, the extraction being carried out only by specific extraction means.

Ces dernières dispositions présentent notamment l'avantage d'assurer un défilement régulier du produit, et d'éviter le patinage éventuel des cylindres de laminage sur le produit, patinage qui risquerait de se produire surtout dans le cas où le fond du puits de solidification se situerait en dessous du niveau des axes des cylindres.These latter arrangements have in particular the advantage of ensuring regular movement of the product, and of avoiding possible slippage of the rolling rolls on the product, slippage which would risk occurring especially in the case where the bottom of the solidification well is would be located below the level of the axes of the cylinders.

Avantageusement, les bords des cylindres 22 seront conformés de manière à ne pas créer de contraintes importantes dans la peau du produit au niveau du raccordement 13 entre la zone centrale 6, et les bords 7. A cet effet, le bord des cylindres pourra par exemple être conformé en un arrondi 16 de raccordement de la surface cylindrique 14 avec les faces latérales 15 des cylindres. Le rayon de courbure de cet arrondi sera adapté en fonction de la réduction d'épaisseur voulue et de la nature du métal coulé.Advantageously, the edges of the cylinders 22 will be shaped so as not to create significant stresses in the skin of the product at the connection 13 between the central zone 6, and the edges 7. For this purpose, the edge of the cylinders may for example be shaped as a rounded 16 connecting the cylindrical surface 14 with the side faces 15 of the cylinders. The radius of curvature of this rounding will be adapted according to the desired thickness reduction and the nature of the metal being cast.

L'invention n'est pas limitée à l'utilisation d'une lingotière de section rectangulaire constante. Celle-ci pourrra par exemple avoir des grandes parois concaves, le produit qui en est issu présentant alors une épaisseur en son milieu supérieure à celle des bords.The invention is not limited to the use of a mold of constant rectangular section. This may for example have large concave walls, the product which results therefrom then having a thickness in its middle greater than that of the edges.

Elle pourra aussi n'avoir une section rectangulaire que en sortie de lingotière, à son extrémité inférieure.It may also have a rectangular section only at the outlet of the mold, at its lower end.

Claims (10)

1) Procédé de coulée continue de produits métalliques minces notamment de brames minces, du type selon lequel on coule le métal liquide dans une lingotière de coulée continue de section allongée dont on extrait en continu le métal partiellement solidifié, et on réduit l'épaisseur du produit issu de la lingotière, par un dispositif de réduction d'épaisseur situé directement en aval de celle-ci, alors que le coeur dudit produit n'est pas encore solidifié, caractérisé en ce qu'on réduit l'épaisseur uniquement d'une zone centrale du produit issu de la lingotière, à l'exclusion des bords solidifiés dudit produit, jusqu'à une valeur inférieure à la moitié de l'épaisseur desdits bords, et après ladite réduction d'épaisseur, on chute les bords du produit qui n'y ont pas été soumis.1) Process for the continuous casting of thin metallic products, in particular thin slabs, of the type according to which liquid metal is poured into a continuous casting mold of elongated section from which the partially solidified metal is continuously extracted, and the thickness of the product from the mold, by a thickness reduction device located directly downstream thereof, while the core of said product is not yet solidified, characterized in that the thickness is reduced only by central zone of the product from the ingot mold, excluding the solidified edges of said product, up to a value less than half the thickness of said edges, and after said reduction in thickness, the edges of the product are dropped which have not been submitted to it. 2) Procédé selon la revendication 1, caractérisé en ce que la section en sortie de la lingotière est sensiblement rectangulaire.2) Method according to claim 1, characterized in that the section at the outlet of the mold is substantially rectangular. 3) Procédé selon la revendication 1 caractérisé en ce que ladite réduction d'épaisseur est menée de manière à obtenir immédiatement en aval du dispositif de réduction d'épaisseur un produit totalement solidifié.3) Method according to claim 1 characterized in that said thickness reduction is carried out so as to immediately obtain downstream of the thickness reduction device a fully solidified product. 4) Procédé selon la revendication 1, caractérisé en ce que le dispositif de réduction d'épaisseur comporte des cylindres et on entraîne ces cylindres en rotation.4) Method according to claim 1, characterized in that the thickness reduction device comprises cylinders and these cylinders are driven in rotation. 5) Procédé selon la revendication 1, caractérisé en ce qu'on extrait le produit par des moyens d'extraction indépendants du dispositif de réduction d'épaisseur..5) Method according to claim 1, characterized in that the product is extracted by means of extraction independent of the thickness reduction device. 6) Procédé selon la revendication 4 caractérisé en ce qu'on extrait le produit par des moyens d'extraction et on asservit la vitesse des cylindres de réduction d'épaisseur à celle desdits moyens d'extraction.6) Method according to claim 4 characterized in that the product is extracted by extraction means and the speed of the thickness reduction cylinders is controlled to that of said extraction means. 7) Installation de coulée de produits métalliques minces, comportant une lingotière (1) de coulée continue de section allongée, et un dispositif de réduction d'épaisseur du produit issu de la lingotière, disposé directement en aval de celle-ci, caractérisée en ce que le dispositif de réduction d'épaisseur comporte des moyens de réduction d'épaisseur ayant une largeur active inférieure à la largeur des grandes faces de la lingotière à son extrémité inférieure, et en ce qu'elle comporte des moyens de découpe (8) pour chuter les bords du produit, situés en aval des moyens de réduction d'épaisseur.7) Installation for casting thin metal products, comprising an ingot mold (1) for continuous casting of elongated section, and a device for reducing the thickness of the product coming from the ingot mold, disposed directly downstream of the latter, characterized in that that the thickness reduction device comprises thickness reduction means having an active width less than the width of the large faces of the mold at its lower end, and in that it comprises cutting means (8) for drop the edges of the product, located downstream of the thickness reduction means. 8) Installation selon la revendication 7, caractérisée en ce que les moyens de réduction d'épaisseur comprennent au moins une paire de cylindres (22) dont la longueur active est inférieure à la largeur des grandes faces de la lingotière à son extrémité inférieure.8) Installation according to claim 7, characterized in that the thickness reduction means comprise at least one pair of cylinders (22) whose active length is less than the width of the large faces of the mold at its lower end. 9) Installation selon la revendication 7, caractérisée en ce que la section de sortie de la lingotière est sensiblement rectangulaire.9) Installation according to claim 7, characterized in that the outlet section of the mold is substantially rectangular. 10) Installation selon la revendication 8, caractérisée en ce que les bords de la surface cylindrique (14) des cylindres (22) se raccordent aux faces latérales (15) de ceux-ci selon un arrondi.10) Installation according to claim 8, characterized in that the edges of the cylindrical surface (14) of the cylinders (22) are connected to the lateral faces (15) thereof in a rounded.
EP90470009A 1989-04-06 1990-03-16 Method and device for casting thin metallic products with thickness reduction under the casting mould Ceased EP0391824A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8904857 1989-04-06
FR8904857A FR2647377B1 (en) 1989-04-06 1989-04-06 PROCESS AND INSTALLATION FOR CASTING THIN METAL PRODUCTS WITH REDUCTION OF THICKNESS UNDER THE LINGOTIERE

Publications (1)

Publication Number Publication Date
EP0391824A1 true EP0391824A1 (en) 1990-10-10

Family

ID=9380657

Family Applications (1)

Application Number Title Priority Date Filing Date
EP90470009A Ceased EP0391824A1 (en) 1989-04-06 1990-03-16 Method and device for casting thin metallic products with thickness reduction under the casting mould

Country Status (11)

Country Link
US (1) US5042563A (en)
EP (1) EP0391824A1 (en)
JP (1) JPH02295658A (en)
KR (1) KR900015839A (en)
CA (1) CA2013855A1 (en)
CS (1) CS163990A2 (en)
DD (1) DD293283A5 (en)
FR (1) FR2647377B1 (en)
HU (1) HUT57105A (en)
PL (1) PL284679A1 (en)
RU (1) RU1833244C (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1993004802A1 (en) * 1991-09-12 1993-03-18 Giovanni Arvedi A process and apparatus for the manufacture of billets and blooms from a continuously last steel showing high or excellent quality
EP0545510A1 (en) * 1991-11-26 1993-06-09 MANNESMANN Aktiengesellschaft Process for manufacture of steel long products
AU658451B2 (en) * 1991-09-12 1995-04-13 Giovanni Arvedi A process and an apparatus for the manufacture of billets and blooms from a continuously cast steel showing high or excellent quality

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL9100911A (en) * 1991-03-22 1992-10-16 Hoogovens Groep Bv Mfg. hot-rolled steel strip with single pass - for the sole reduction means through two-high roll stand
DE4123956C2 (en) * 1991-07-19 1994-07-21 Thyssen Stahl Ag Process and plant for producing a metal strand by casting
ES2089317T3 (en) * 1991-09-19 1996-10-01 Schloemann Siemag Ag PROCEDURE AND INSTALLATION FOR THE MANUFACTURE OF STEEL BELT.
DE4438118C2 (en) * 1994-10-26 2003-02-13 Siemens Ag Two-roll casting machine
US6496120B1 (en) * 1998-11-05 2002-12-17 Steel Authority Of India Limited System for on line continuous skidding detection in rolling mills
DE10112716A1 (en) * 2001-03-16 2002-09-19 Sms Demag Ag Production of a metallic hot rolled strip from a cast thin strip comprises edging the hot rolled strip before it enters roll stands
DE10119550A1 (en) * 2001-04-21 2002-10-24 Sms Demag Ag Production of continuously cast pre-material comprises casting strands in a continuous casting device, deforming below the mold and/or within or outside the strand guide using roller pairs to form pre-profiles, and rolling into profiles
JP5262845B2 (en) * 2009-03-04 2013-08-14 富士通株式会社 How to remove electronic parts
JP7127484B2 (en) * 2018-10-30 2022-08-30 日本製鉄株式会社 Metal plate manufacturing method and metal plate manufacturing equipment

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1102392A (en) * 1953-07-04 1955-10-19 Mannesmann Ag Process for extrusion casting of beads without shrinkage, of shapeable metals, in particular of steel or other hot-workable iron alloys
FR1470209A (en) * 1966-02-28 1967-02-17 Mannesmann Ag Transport rollers for continuous casting installations
CH490912A (en) * 1967-08-12 1970-05-31 Olsson Ag Erik Method for closing cavities in cast semi-finished products
DE2733276A1 (en) * 1976-07-30 1978-02-02 Jernkontoret Fa PROCESS IN CONTINUOUS CASTING OF STEEL AND METAL ALLOYS WITH A SLAGGING SENSITIVITY AND DEVICE FOR CARRYING OUT THE PROCESS

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5568102A (en) * 1978-11-14 1980-05-22 Nippon Kokan Kk <Nkk> Widening method for breadth of cast billet in continuous casting work
JPS60184455A (en) * 1984-03-01 1985-09-19 Nippon Steel Corp Production of continuous casting billet with application of rolling down
JPS61132247A (en) * 1984-11-30 1986-06-19 Kawasaki Steel Corp Continuous casting method

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1102392A (en) * 1953-07-04 1955-10-19 Mannesmann Ag Process for extrusion casting of beads without shrinkage, of shapeable metals, in particular of steel or other hot-workable iron alloys
FR1470209A (en) * 1966-02-28 1967-02-17 Mannesmann Ag Transport rollers for continuous casting installations
CH490912A (en) * 1967-08-12 1970-05-31 Olsson Ag Erik Method for closing cavities in cast semi-finished products
DE2733276A1 (en) * 1976-07-30 1978-02-02 Jernkontoret Fa PROCESS IN CONTINUOUS CASTING OF STEEL AND METAL ALLOYS WITH A SLAGGING SENSITIVITY AND DEVICE FOR CARRYING OUT THE PROCESS

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN, vol. 10, no. 25 (M-450)[2082], 31 janvier 1986, page 149 M 450; & JP-A-60 184 455 (SHIN NIPPON SEITETSU K.K.) 19-09-1985 *
PATENT ABSTRACTS OF JAPAN, vol. 10, no. 326 (M-532)[2382], 6 novembre 1986, page 57 M 532; & JP-A-61 132 247 (KAWASAKI STEEL CORP.) 19-06-1986 *
PATENT ABSTRACTS OF JAPAN, vol. 4, no. 108 (M-24)[590], 5 août 1980, page 143 M 24; JP-A-55 068 102 (NIPPON KOKAN K.K.) 22-05-1980 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1993004802A1 (en) * 1991-09-12 1993-03-18 Giovanni Arvedi A process and apparatus for the manufacture of billets and blooms from a continuously last steel showing high or excellent quality
AU658451B2 (en) * 1991-09-12 1995-04-13 Giovanni Arvedi A process and an apparatus for the manufacture of billets and blooms from a continuously cast steel showing high or excellent quality
US5497821A (en) * 1991-09-12 1996-03-12 Giovanni Arvedi Manufacture of billets and blooms from a continuously cast steel
EP0545510A1 (en) * 1991-11-26 1993-06-09 MANNESMANN Aktiengesellschaft Process for manufacture of steel long products

Also Published As

Publication number Publication date
CS163990A2 (en) 1991-11-12
FR2647377B1 (en) 1993-04-30
DD293283A5 (en) 1991-08-29
CA2013855A1 (en) 1990-10-06
RU1833244C (en) 1993-08-07
FR2647377A1 (en) 1990-11-30
JPH02295658A (en) 1990-12-06
KR900015839A (en) 1990-11-10
PL284679A1 (en) 1991-08-26
HUT57105A (en) 1991-11-28
US5042563A (en) 1991-08-27
HU902044D0 (en) 1990-08-28

Similar Documents

Publication Publication Date Title
EP0391824A1 (en) Method and device for casting thin metallic products with thickness reduction under the casting mould
EP0230433B1 (en) Method and machine for continuous casting of a thin metal product
FR2554029A1 (en) PROCESS FOR THE PREPARATION OF A FIBER REINFORCED COMPOSITE MATERIAL
FR2491374A1 (en) METHOD FOR MECHANICALLY REMOVING MATERIAL FROM SURFACES OF CONTINUOUS CASTING OF STEEL AND GRINDING APPARATUS
EP0407323B1 (en) Method and apparatus for twin roll continuous casting of thin metallic products suitable for cold rolling
FR2487233A1 (en) METHOD FOR MANUFACTURING CARTRIDGE SLEEVES AND CARTRIDGE SLEEVES OBTAINED THEREBY
CH502855A (en) Deep roller profiling of cylindrical metal blanks with- - out internal cracking
EP0392952A1 (en) Method of and installation for casting thin metallic products
FR2627405A1 (en) PROCESS FOR WIREDING METAL, ESPECIALLY ALUMINUM, AND WELDING PRESS FOR IMPLEMENTING THE METHOD
EP0350345B1 (en) Method of and installation for continuous casting thin metallic products
EP0066524B1 (en) Process and apparatus for continuous casting with a grooved casting wheel
FR2522547A1 (en) METHOD AND DEVICE FOR CONTROLLING THE WIDTH AND THICKNESS OF A STRIP
FR2818268A1 (en) Device for the production of glass drops involves using a membrane body incorporating channels for the introduction of a levitating gas under pressure
CH363316A (en) Process for manufacturing a tubular body and tubular body obtained by this process
FR2522287A1 (en) PROCESS FOR THE MANUFACTURE OF STEEL SHEETS OR PLATES
FR2474908A1 (en) CLOSED CHAMBER EXTRUSION METHOD AND DEVICE FOR CONFIGURING A METAL ROD IN A TULIP-SHAPED WORKPIECE
EP0290423B1 (en) Device for continuously manufacturing a thin metal strip
CA2251007C (en) Facility and method for the continuous casting of metals and its installation
CA2023504A1 (en) Direct continuous casting device and method for thin metallic products
CA2247538A1 (en) Lateral face for blocking the casting space in a facility for continuous casting metal strips between cylinders, and casting facility so equipped
FR2796810A1 (en) Manufacture of pre-filled bread rolls by enclosing a filling in bread dough before cooking in a high speed process
FR2550479A1 (en) Horizontal continuous casting method for metals in the form of round semi-finished products and device for carrying it out
CH338299A (en) Method and apparatus for the continuous manufacture of a tubular part
FR2684576A1 (en) DEVICE FOR CONTINUOUSLY CASTING A THIN METAL STRIP BETWEEN CYLINDERS.
BE545005A (en)

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES GB GR IT LI LU NL SE

17P Request for examination filed

Effective date: 19910311

17Q First examination report despatched

Effective date: 19920327

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN REFUSED

18R Application refused

Effective date: 19930617