EP1194255B1 - Treatment for improving the castability of aluminium killed continuously cast steel - Google Patents

Treatment for improving the castability of aluminium killed continuously cast steel Download PDF

Info

Publication number
EP1194255B1
EP1194255B1 EP00915236A EP00915236A EP1194255B1 EP 1194255 B1 EP1194255 B1 EP 1194255B1 EP 00915236 A EP00915236 A EP 00915236A EP 00915236 A EP00915236 A EP 00915236A EP 1194255 B1 EP1194255 B1 EP 1194255B1
Authority
EP
European Patent Office
Prior art keywords
ppm
steel
casting
magnesium
bath
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP00915236A
Other languages
German (de)
French (fr)
Other versions
EP1194255A1 (en
Inventor
Florence Bertrand
Jean Lehmann
Laurent Sosin
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.)
USINOR SA
Original Assignee
USINOR 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 USINOR SA filed Critical USINOR SA
Publication of EP1194255A1 publication Critical patent/EP1194255A1/en
Application granted granted Critical
Publication of EP1194255B1 publication Critical patent/EP1194255B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/10—Supplying or treating molten metal
    • 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
    • B22D11/10—Supplying or treating molten metal
    • B22D11/11—Treating the molten metal
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/0056—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 using cored wires
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/04—Removing impurities by adding a treating agent
    • C21C7/06—Deoxidising, e.g. killing

Definitions

  • the present invention relates to the continuous casting of steel. It relates more particularly to the prevention of blockages in the pouring nozzle during the casting of slabs, or strips, of calmed steel, in particular low or ultra low carbon steel (so-called UBC or IFS steels).
  • fattening is a phenomenon of progressive narrowing, from the periphery towards the center, of the conduit which the nozzle offers to the liquid metal for its passage in the mold.
  • the origin of this phenomenon is the deposition on the inner wall of the nozzle of solid particles, which are the non-metallic inclusions of deoxidation of the liquid metal.
  • These inclusions are already present in the metal bath following the metallurgical treatments previously undergone by it, or are formed during the very passage of the nozzle, if the latter is not sufficiently tight with respect to the oxygen from the surrounding atmosphere.
  • these non-metallic inclusions are more or less numerous, more or less bulky, more or less solidified at the temperature of the molten metal.
  • Calming of this type of steel is conventionally carried out in a refining ladle by adding aluminum, a deoxidizer commonly used in the steel industry.
  • the deoxidation reaction produces aluminates which decant mainly on the surface of the metal bath, first in a pocket, then in the distributor.
  • some of these non-metallic inclusions inevitably remain in suspension within the liquid metallic mass at the time of casting. It is in particular these particles which, during their transit in the nozzle, cling to the wall of the tube and, by phenomenon of accretion over time, end up blocking the passage.
  • preventive measures it is also known to fight against blockages of the nozzle by means of preventive measures, the primary interest of which is to be able to do without "bubbling argon".
  • One of them consists in adding to the metal bath before casting, therefore in the distributor, or preferably already in a refining ladle, a flux, such as Ca (for example in the form of Si-Ca or Ca -Fe) which will complex with the deoxidizing aluminates to form more fusible inclusions, which will therefore in principle remain in the liquid state at the casting temperature.
  • a preventive treatment of this type by adding calcium is described, for example, in document EP-A-0 512 118, the general teaching of which will be considered as incorporated into the present document by reference.
  • the object of the invention is precisely to achieve a better fluidity of the deoxidation inclusions that have been formed by calcium treatment of the metal bath before casting.
  • the subject of the invention is a metallurgical treatment in a ladle of steel to be continuously cast, according to which, in a bath of ultra low or low carbon molten steel, calmed with aluminum (or during calming) to reach a given oxygen content, calcium is added in order to form deoxidation inclusions with a melting point lower than the casting temperature of the steel in the mold, characterized in that, in the processing chain which goes from the ladle to the casting mold, the metal bath is maintained at a dissolved magnesium content close to at least 2 ppm, without exceeding the content, depending on that of oxygen in the bath, beyond which solid spinels based on magnesium may form.
  • the basis of the invention is the discovery of the beneficial action of magnesium in small quantities on the maintenance in liquid phase of the deoxidation inclusions present after calming or formed during casting in the presence of calcium . It has been observed in fact that the presence of magnesium in small quantities within a metallic bath treated with calcium (namely of the order of 2 ppm of Mg at least, and being able to go up to 8-10 ppm for the oxygen contents which one usually meets in low or very low carbon steels calmed aluminum) influenced the physical nature of the inclusionary population of cast steel: the element magnesium significantly expands the range of existence of liquid lime aluminates at the temperature of casting steel (approximately 1520-1570 ° C).
  • the UBC steel considered here has the following weight composition, given in thousandths of%, except for nitrogen (N) which is given in ppm: VS mn P S al Yes Ti Cr Or NOT ⁇ 5 90-140 5-15 3-10 35-50 10-35 65-75 15-30 20 25-45 ppm
  • This steel bath from an oxygen converter for example, first undergoes a decarburization treatment "under vacuum” in a refining station (pocket-shading furnace equipped with an installation under vacuum, or in an RH unit). Then, the metal bath is calmed by adding aluminum.
  • This element is provided in sufficient quantity to reach the desired residual contents of total oxygen in the bath, namely, taking into account the time necessary for the settling of the inclusions of aluminas, of the order of 20 to 30 ppm of total oxygen ( dissolved and bound) at the distributor, so just before pouring.
  • magnesium it can be introduced at any time after deoxidation by aluminum, either separately or simultaneously with calcium if the latter is provided after deoxidation.
  • magnesium in small quantities in accordance with the invention can be carried out in a ladle, or possibly in the distributor, using a fused metallic wire, for example made of a Ni-Mg alloy, which melts in the bath of molten steel as it is introduced into it.
  • the minimum targeted content of 2 ppm of dissolved Mg can also be reached by metal-slag balance using a slag of suitable composition which is to be formed on the metal bath in a ladle.
  • a slag of suitable composition which is to be formed on the metal bath in a ladle.
  • a basic slag containing up to 10% MgO by weight may be suitable, and an example of constitution of which is given below (the values are percentages by weight): Al 2 O 3 : 56% - MgO: 3 % - CaO: 41%.
  • the level of dissolved calcium beyond which liquid oxides are formed corresponds well to the level of dissolved calcium beyond which the flowability of the steel is improved.
  • FIG. 3 shows precisely, in the form of a graph, the upper limit value of the Mg content as a function of that of total oxygen in the bath from which these undesirable spinels will form within the bath of molten steel at the casting temperature.
  • the Ca content considered corresponds to the minimum value for having oxides in the liquid state without the addition of Mg.
  • the curve representative of this upper limit value is regularly increasing with the rising oxygen contents. Thanks to the characteristics of its low origin, it can be seen that a content of about 2 ppm of Mg makes it possible to always be below the limit threshold for the formation of spinels whatever the level of oxygenation of the metal bath.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Treatment Of Steel In Its Molten State (AREA)
  • Continuous Casting (AREA)
  • Analysing Materials By The Use Of Radiation (AREA)
  • Coating With Molten Metal (AREA)

Abstract

According to this treatment, calcium is added to ultra low molten steel or low carbon which is aluminum killed (or in the course of being killed) in order to form non-metallic deoxidation inclusions that have a melting point which is below the casting temperature; the molten metal is maintained in the chain of treatment ranging from the ladle refining installation to the copper mold with a low minimum low magnesium content of approximately 2 ppm. The inventive method increases the scope of fusibility of the inclusionary population of steels, thereby improving the castability of high aluminum-killed ultra low carbon grades without the need for argon bubbling.

Description

La présente invention a trait à la coulée continue de l'acier. Elle concerne plus particulièrement la prévention des bouchages de la busette de coulée lors de la coulée de brames, ou de bandes, d'acier calmé, notamment d'acier à bas ou ultra bas carbone (aciers dits UBC ou IFS).The present invention relates to the continuous casting of steel. It relates more particularly to the prevention of blockages in the pouring nozzle during the casting of slabs, or strips, of calmed steel, in particular low or ultra low carbon steel (so-called UBC or IFS steels).

On sait que la coulée continue de demi-produits à large section droite (brames, brames minces, bandes...) impose classiquement l'usage d'une busette immergée pour l'alimentation en métal en fusion de la lingotière de coulée depuis le répartiteur placé au-dessus.It is known that the continuous casting of semi-finished products with a wide cross section (slabs, thin slabs, strips, etc.) conventionally requires the use of an immersed nozzle for supplying molten metal to the casting mold from the distributor located above.

On sait aussi que ces busettes sont sujettes à engraissement conduisant, à plus ou moins long terme, à leur bouchage total et, par conséquent, à l'arrêt immédiat de la coulée en cours.We also know that these nozzles are subject to fattening leading, in the more or less long term, to their total blockage and, consequently, to the immediate stop of the casting in progress.

On rappelle que l'engraissement est un phénomène de rétrécissement progressif, depuis la périphérie vers le centre, du conduit qu'offre la busette au métal liquide pour son passage en lingotière. L'origine de ce phénomène est le dépôt sur la paroi intérieure de la busette de particules solides, que sont les inclusions non métalliques de désoxydation du métal liquide. Ces inclusions sont déjà présentes au sein du bain métallique suite aux traitements métallurgiques subits précédemment par celui-ci, ou se forment lors de la traversée même de la busette, si celle-ci n'est pas suffisamment étanche à l'égard de l'oxygène de l'atmosphère ambiante. Selon les nuances d'acier coulées, ces inclusions non métalliques sont plus ou moins nombreuses, plus ou moins volumineuses, plus ou moins solidifiées à la température du métal en fusion.It is recalled that fattening is a phenomenon of progressive narrowing, from the periphery towards the center, of the conduit which the nozzle offers to the liquid metal for its passage in the mold. The origin of this phenomenon is the deposition on the inner wall of the nozzle of solid particles, which are the non-metallic inclusions of deoxidation of the liquid metal. These inclusions are already present in the metal bath following the metallurgical treatments previously undergone by it, or are formed during the very passage of the nozzle, if the latter is not sufficiently tight with respect to the oxygen from the surrounding atmosphere. Depending on the grades of cast steel, these non-metallic inclusions are more or less numerous, more or less bulky, more or less solidified at the temperature of the molten metal.

Il est connu que des difficultés sérieuses de coulabilité à cet égard peuvent se rencontrer particulièrement dans le cas de la coulée d'aciers bas ou ultra bas carbone (du type IFS par exemple), donc sur des aciers fortement calmés.It is known that serious flowability difficulties in this regard can be encountered particularly in the case of the casting of low or ultra low carbon steels (of the IFS type for example), therefore on steels which are strongly quenched.

Le calmage de ce type d'aciers s'opère classiquement en poche d'affinage par ajout d'aluminium, désoxydant couramment utilisé en sidérurgie. La réaction de désoxydation produit des aluminates qui décantent majoritairement à la surface du bain métallique, en poche d'abord, dans le répartiteur ensuite. Néanmoins, une partie de ces inclusions non métalliques restent inévitablement en suspension au sein de la masse métallique liquide au moment de la coulée. Ce sont en particulier ces particules qui, lors de leur transit dans la busette, s'accrochent à la paroi du tube et, par phénomène d'accrétion au cours du temps, finissent par obturer le passage.Calming of this type of steel is conventionally carried out in a refining ladle by adding aluminum, a deoxidizer commonly used in the steel industry. The deoxidation reaction produces aluminates which decant mainly on the surface of the metal bath, first in a pocket, then in the distributor. However, some of these non-metallic inclusions inevitably remain in suspension within the liquid metallic mass at the time of casting. It is in particular these particles which, during their transit in the nozzle, cling to the wall of the tube and, by phenomenon of accretion over time, end up blocking the passage.

Il est connu de lutter contre ces bouchages en faisant passer un courant de gaz inerte de balayage (de l'argon notamment) dans la busette. Le, ou plus vraisemblablement, les mécanismes par lesquels un tel balayage gazeux lutte contre l'engraissement ne sont pas encore parfaitement élucidés, mais le résultat est généralement plutôt satisfaisant si le bullage est mis en place dès le début de la séquence de coulée. Sinon des amas inclusionnaires peuvent se détacher et venir dramatiquement polluer le métal, faisant de cette pratique un remède alors pire que le mal.It is known to combat these blockages by passing a stream of inert sweeping gas (notably argon) through the nozzle. The, or more likely, the mechanisms by which such a gas sweep fight fattening are not yet fully understood, but the result is generally rather satisfactory if the bubbling is set up at the start of the casting sequence. Otherwise inclusive clusters can detach and dramatically pollute the metal, making this practice a cure worse than the disease.

Toutefois, la méthode, même correctement menée, n'est pas sans effets secondaires indésirables. Des défauts de type "boursouflures" sur bandes au cours de laminage ultérieur peuvent apparaître, dont on sait qu'ils résultent d'un phénomène d'emprisonnement de bulles de gaz dans le métal solidifié en lingotière.However, the method, even if properly carried out, is not without unwanted side effects. Defects of the "blistering" type on strips during subsequent rolling may appear, which are known to result from a phenomenon of trapping of gas bubbles in the metal solidified in the mold.

Il est également connu de lutter contre les bouchages de la busette au moyen de mesures préventives, dont l'intérêt premier est de pouvoir se passer du "bullage argon". L'une d'entre elles consiste à ajouter au bain métallique avant coulée, donc dans le répartiteur, ou de préférence déjà en poche d'affinage, un fondant, tel que du Ca (par exemple sous forme de Si-Ca ou de Ca-Fe) qui va complexer avec les aluminates de désoxydation pour former des inclusions plus fusibles, qui resteront donc en principe à l'état liquide à la température de coulée. Un traitement préventif de ce type par ajout de calcium est décrit par exemple dans le document EP-A-0 512 118, dont on considérera l'enseignement général comme incorporé au présent mémoire par référence.It is also known to fight against blockages of the nozzle by means of preventive measures, the primary interest of which is to be able to do without "bubbling argon". One of them consists in adding to the metal bath before casting, therefore in the distributor, or preferably already in a refining ladle, a flux, such as Ca (for example in the form of Si-Ca or Ca -Fe) which will complex with the deoxidizing aluminates to form more fusible inclusions, which will therefore in principle remain in the liquid state at the casting temperature. A preventive treatment of this type by adding calcium is described, for example, in document EP-A-0 512 118, the general teaching of which will be considered as incorporated into the present document by reference.

Cependant, ce type de traitement chimique du bouchage ne donne pas toujours les résultats escomptés. Il se trouve parfois, en effet, que les inclusions formées même en présence de calcium sont à l'état solide déjà dans le répartiteur, et ce même en cas de coulée avec surchauffe importante du métal.However, this type of chemical capping treatment does not always give the expected results. It sometimes happens, in fact, that the inclusions formed even in the presence of calcium are in the solid state already in the distributor, and this even in the case of casting with significant overheating of the metal.

Le but de l'invention est précisément d'aboutir à une meilleure fluidité des inclusions de désoxydation que l'on a formées par traitement au calcium du bain métallique avant coulée.The object of the invention is precisely to achieve a better fluidity of the deoxidation inclusions that have been formed by calcium treatment of the metal bath before casting.

A cet effet, l'invention a pour objet un traitement métallurgique en poche d'un acier devant être coulé en continu, selon lequel, à un bain d'acier en fusion ultra bas ou bas carbone, calmé à l'aluminium (ou en cours de calmage) pour atteindre une teneur donnée en oxygène, on ajoute du calcium afin de former des inclusions de désoxydation à point de fusion inférieur à la température de coulée de l'acier en lingotière, caractérisé en ce que, dans la chaîne de traitement qui va de la poche à la lingotière de coulée, on maintient le bain métallique à une teneur en magnésium dissous voisine de 2 ppm au moins, sans excéder la teneur, dépendant de celle en oxygène du bain, au-delà de laquelle des spinelles solides à base de magnésium peuvent se former.To this end, the subject of the invention is a metallurgical treatment in a ladle of steel to be continuously cast, according to which, in a bath of ultra low or low carbon molten steel, calmed with aluminum (or during calming) to reach a given oxygen content, calcium is added in order to form deoxidation inclusions with a melting point lower than the casting temperature of the steel in the mold, characterized in that, in the processing chain which goes from the ladle to the casting mold, the metal bath is maintained at a dissolved magnesium content close to at least 2 ppm, without exceeding the content, depending on that of oxygen in the bath, beyond which solid spinels based on magnesium may form.

Comme on l'aura compris, à la base de l'invention se trouve la découverte de l'action bénéfique du magnésium en faible quantité sur le maintien en phase liquide des inclusions de désoxydation présentes après calmage ou formées pendant la coulée en présence de calcium. On a pu observer en effet que la présence de magnésium en faible quantité au sein d'un bain métallique traité au calcium (à savoir de l'ordre de 2 ppm de Mg au moins,et pouvant aller jusqu'à 8-10 ppm pour les teneurs d'oxygène que l'on rencontre habituellement dans les aciers bas ou très bas carbone calmés aluminium) influait sur la nature physique de la population inclusionnaire de l'acier coulé: l'élément magnésium élargit notablement le domaine d'existence des aluminates de chaux liquides à la température de coulée de l'acier (1520-1570°C environ). Il doit être souligné également la grande sensibilité d'un tel élargissement à la présence du magnésium même en très faibles quantités, une faible variation d'une très basse teneur en Mg (variation de moins de 1 ppm) pouvant entraîner comme on le verra un élargissement conséquent de la plage de fusibilité.As will be understood, the basis of the invention is the discovery of the beneficial action of magnesium in small quantities on the maintenance in liquid phase of the deoxidation inclusions present after calming or formed during casting in the presence of calcium . It has been observed in fact that the presence of magnesium in small quantities within a metallic bath treated with calcium (namely of the order of 2 ppm of Mg at least, and being able to go up to 8-10 ppm for the oxygen contents which one usually meets in low or very low carbon steels calmed aluminum) influenced the physical nature of the inclusionary population of cast steel: the element magnesium significantly expands the range of existence of liquid lime aluminates at the temperature of casting steel (approximately 1520-1570 ° C). It should also be emphasized the great sensitivity of such an enlargement to the presence of magnesium even in very small quantities, a small variation of a very low Mg content (variation of less than 1 ppm) which can lead, as will be seen, to a Substantial widening of the fuse range.

L'invention sera bien comprise et d'autres aspects apparaîtront au vu de la description qui suit, donnée à titre d'exemple en référence à la planche de dessins unique annexée sur laquelle:

  • la figure 1 est un diagramme de phases montrant les domaines de précipitation inclusionnaire à 1 560°C (température de coulée) dans une nuance d'acier Ultra Bas Carbone en fonction de la teneur en calcium, mise en ordonnées, et en oxygène total (dissous et lié) mise en abscisses, et ce en l'absence de magnésium, autrement qu'à l'état de traces (inférieur à 0.1 ppm).
  • la figure 2 est un diagramme analogue à celui de la figure 1 montrant la même situation, mais en présence d'une teneur en magnésium du bain métallique à hauteur de 2 ppm.
    (Ces deux diagrammes sont enrichis de symboles représentatifs de séquences de coulée pour lesquelles des bouchages ont eu lieu (symboles pleins) ou n'ont pas eu lieu (symboles vides));
  • la figure 3 est un graphique montrant l'évolution de la teneur maximale permise en magnésium dissous dans le bain d'acier en fusion en fonction de la teneur de ce dernier en oxygène total (dissous et lié), sachant que la teneur en calcium considérée correspond à la valeur minimale requise pour avoir des oxydes liquides sans addition de magnésium.
The invention will be well understood and other aspects will appear on reading the following description, given by way of example with reference to the attached single sheet of drawings in which:
  • FIG. 1 is a phase diagram showing the areas of inclusive precipitation at 1,560 ° C. (pouring temperature) in a grade of Ultra Low Carbon steel as a function of the calcium content, on the ordinate, and in total oxygen ( dissolved and bound) on the abscissa, in the absence of magnesium, other than in trace amounts (less than 0.1 ppm).
  • Figure 2 is a diagram similar to that of Figure 1 showing the same situation, but in the presence of a magnesium content of the metal bath up to 2 ppm.
    (These two diagrams are enriched with symbols representative of pouring sequences for which blockages have taken place (solid symbols) or have not taken place (empty symbols));
  • FIG. 3 is a graph showing the evolution of the maximum permitted content of dissolved magnesium in the molten steel bath as a function of the total oxygen content of the latter (dissolved and bound), knowing that the calcium content considered corresponds to the minimum value required to have liquid oxides without the addition of magnesium.

L'acier UBC considéré ici a la composition pondérale suivante, donnée en millièmes de %, sauf pour l'Azote (N) qui est donnée en ppm: C Mn P S Al Si Ti Cr Ni N <5 90-140 5-15 3-10 35-50 10-35 65-75 15-30 20 25-45 ppm The UBC steel considered here has the following weight composition, given in thousandths of%, except for nitrogen (N) which is given in ppm: VS mn P S al Yes Ti Cr Or NOT <5 90-140 5-15 3-10 35-50 10-35 65-75 15-30 20 25-45 ppm

Ce bain d'acier, issu d'un convertisseur à l'oxygène par exemple, subit d'abord un traitement de décarburation "sous vide" dans une station d'affinage (four-poche de mise à la nuance équipé d'une installation de mise sous dépression, ou dans une unité RH). Puis, le bain métallique est calmé par addition d'aluminium. Cet élément est apporté en quantité suffisante pour atteindre les teneurs résiduelles voulues en oxygène total du bain, à savoir, compte tenu du temps nécessaire à la décantation des inclusions d'alumines, de l'ordre de 20 à 30 ppm d'oxygène total (dissous et lié) au niveau du répartiteur, donc juste avant la coulée.This steel bath, from an oxygen converter for example, first undergoes a decarburization treatment "under vacuum" in a refining station (pocket-shading furnace equipped with an installation under vacuum, or in an RH unit). Then, the metal bath is calmed by adding aluminum. This element is provided in sufficient quantity to reach the desired residual contents of total oxygen in the bath, namely, taking into account the time necessary for the settling of the inclusions of aluminas, of the order of 20 to 30 ppm of total oxygen ( dissolved and bound) at the distributor, so just before pouring.

Dans le même temps, ou juste après l'apport d'aluminium, un ajout de calcium est effectué au moyen de l'introduction dans le bain de métal en fusion d'un fil fusible fourré au Si-Ca. Selon les besoins, et compte tenu du faible rendement de dissolution dans le bain d'un élément à forte tension de vapeur de ce type (rendement de l'ordre de 10-15% si l'on opère avec soins), l'apport de Ca est réglé de manière à obtenir une teneur de l'ordre de 25 ppm en Ca total (dissous et lié sous forme d'aluminates et de sulfures).At the same time, or just after the addition of aluminum, calcium is added by means of the introduction into the bath of molten metal of a fusible wire filled with Si-Ca. According to the needs, and taking into account the low efficiency of dissolution in the bath of an element with high vapor pressure of this type (efficiency of the order of 10-15% if one operates with care), the contribution of Ca is adjusted so as to obtain a content of the order of 25 ppm of total Ca (dissolved and bound in the form of aluminates and sulphides).

Quant au magnésium, il peut être introduit à tout moment après désoxydation par l'aluminium, soit séparément, soit simultanément au calcium si celui-ci est apporté après désoxydation.As for magnesium, it can be introduced at any time after deoxidation by aluminum, either separately or simultaneously with calcium if the latter is provided after deoxidation.

L'ajout de magnésium en faible quantité conformément à l'invention peut s'opérer en poche, ou éventuellement au répartiteur, à l'aide d'un fil métallique fusible fourré, en un alliage de Ni-Mg par exemple, et qui fond dans le bain d'acier en fusion à mesure qu'on l'y introduit.The addition of magnesium in small quantities in accordance with the invention can be carried out in a ladle, or possibly in the distributor, using a fused metallic wire, for example made of a Ni-Mg alloy, which melts in the bath of molten steel as it is introduced into it.

La teneur minimale visée de 2 ppm en Mg dissous peut également être atteinte par équilibre métal-laitier à l'aide d'un laitier de composition appropriée qui est à former sur le bain métallique en poche. Par exepmple, pourra convenir un laitier basique contenant jusqu'à 10% de MgO en poids, et dont un exemple de constitution est donné ci-après (les valeurs sont des pourcentages pondéraux): Al2O3: 56 % - MgO: 3 % - CaO: 41 %.The minimum targeted content of 2 ppm of dissolved Mg can also be reached by metal-slag balance using a slag of suitable composition which is to be formed on the metal bath in a ladle. For example, a basic slag containing up to 10% MgO by weight may be suitable, and an example of constitution of which is given below (the values are percentages by weight): Al 2 O 3 : 56% - MgO: 3 % - CaO: 41%.

Les résultats obtenus, à la température de coulée de 1560 °C, sur l'élargissement de la plage des inclusions fusibles grâce au traitement au magnésium présent avec sa teneur minimale de 2 ppm sont visibles sur la figure 2 par rapprochement avec la figure 1 qui, elle, consigne, toute chose égale par ailleurs, la situation sans traitement au magnésium.The results obtained, at the casting temperature of 1560 ° C., on the widening of the range of fusible inclusions thanks to the magnesium treatment present with its minimum content of 2 ppm are visible in FIG. 2 by comparison with FIG. 1 which , it notes, all other things being equal, the situation without magnesium treatment.

La comparaison, simplement visuelle, entre les figures 1 et 2 révèle immédiatement l'influence bénéfique de la présence de magnésium à faible teneur sur l'élargissement du domaine de fusibilité I des inclusions de désoxydation (aluminates de chaux) au sein d'un bain en fusion d'acier UBC. L'élargissement s'opère en fait par le bas, c'est-à-dire vers les teneurs en calcium de traitement les plus faibles, ou, exprimé autrement, pour une teneur donnée en calcium, vers les teneurs les plus élevées en oxygène. On observe d'ailleurs, en même temps qu'un déplacement global vers le bas, un élargissement corrélatif du domaine voisin inférieur II (% Ca faible) dans lequel les oxydes sont partiellement liquides, alors que le domaine voisin supérieur IV (% Ca élevé) demeure celui des oxydes liquides, mais conjointement avec un précipité de sulfure de calcium. On notera que la limite haute de la plage de fusibilité (passage de la zone I à la zone IV) dépend, non pas de la teneur en Mg, mais de celle en soufre, toutes choses égales par ailleurs bien entendu.The comparison, simply visual, between FIGS. 1 and 2 immediately reveals the beneficial influence of the presence of low-grade magnesium on the widening of the fusibility range I of deoxidation inclusions (lime aluminates) within a bath. in UBC steel fusion. Enlargement is actually done from the bottom, i.e. towards the lowest treatment calcium contents, or, expressed otherwise, for a given calcium content, towards the highest oxygen contents . We observe, moreover, at the same time as a global downward displacement, a correlative enlargement of the lower neighboring domain II (% Ca low) in which the oxides are partially liquid, while the upper neighboring domain IV (% Ca high ) remains that of liquid oxides, but together with a precipitate of calcium sulfide. It will be noted that the upper limit of the fusibility range (passage from zone I to zone IV) depends, not on the Mg content, but on that of sulfur, all other things being equal of course.

En revanche, toute la zone III des diagrammes située en dessous du domaine de transition II, à savoir celle où les inclusions de désoxydation sont en phase solide, est largement amputée par un effet d'élargissements conjugués du domaine liquide I et du domaine voisin inférieur de transition II.On the other hand, the entire zone III of the diagrams situated below the transition domain II, namely that where the deoxidation inclusions are in solid phase, is largely amputated by an effect of conjugate enlargements of the liquid domain I and the lower neighboring domain of transition II.

En portant son attention à présent sur les petits symboles circulaires placés sur chacune de ces deux figures, on pourra se rendre compte de la bonne corrélation qui existe entre l'élargissement du domaine de fusibilité I grâce au magnésium en faible quantité, conformément à l'invention, et le phénomène de bouchage de la busette de coulée. Les petits symboles géométriques vides consignent les coulées réussies, donc sans bouchage, alors que les symboles pleins noirs pointent les coulées ayant subi des bouchages importants. Il est précisé que ces symboles traduisent des analyses en calcium et oxygène total d'échantillons d'analyse prélevés à mi-coulée au sein du répartiteur .By paying attention now to the small circular symbols placed on each of these two figures, one will be able to realize the good correlation which exists between the enlargement of the fusibility range I thanks to the magnesium in small quantity, in accordance with the invention, and the plugging phenomenon of the pouring nozzle. The small empty geometric symbols record successful flows, therefore without blockage, while the solid black symbols point to flows that have been subjected to significant blockages. It should be noted that these symbols represent analyzes of calcium and total oxygen of analysis samples taken mid-casting within the distributor.

Comme on le voit, le niveau de calcium dissous au delà duquel on forme des oxydes liquides correspond bien au niveau de calcium dissous au delà duquel on améliore la coulabilité de l'acier.As can be seen, the level of dissolved calcium beyond which liquid oxides are formed corresponds well to the level of dissolved calcium beyond which the flowability of the steel is improved.

Conformément à l'invention, l'obtention d'une faible valeur de la teneur en magnésium, et son maintien à ce niveau depuis la poche de coulée (lieu où se fait la métallurgie secondaire d'ajustement à la nuance finale et le calmage) jusqu'à la lingotière de coulée, confèrent dès lors :

  • une souplesse accrue au traitement par le calcium en poche, puisque la plage en teneurs admissibles est plus grande en présence de magnésium, notamment vers les bas calcium comme on l'a vu;
  • ainsi qu'une meilleure reproductibilité des résultats: l'effet du magnésium même en très faible quantité, étant très sensible sur le domaine de précipitation inclusionnaire, on peut aisément passer à côté du domaine des oxydes en phase liquide, si on ne le contrôle pas.
According to the invention, obtaining a low value of the magnesium content, and maintaining it at this level from the ladle (place where the secondary metallurgy of adjustment to the final shade and the calming is done) up to the casting mold, therefore confer:
  • increased flexibility in the pocket calcium treatment, since the range of admissible contents is greater in the presence of magnesium, in particular towards the lower calcium levels, as we have seen;
  • as well as a better reproducibility of the results: the effect of magnesium even in very small quantity, being very sensitive on the domain of inclusion precipitation, one can easily miss the domain of the oxides in liquid phase, if one does not control it .

Il va de soi que l'invention ne saurait se limiter à l'exemple décrit, mais s'étend à de multiples variantes ou équivalents dans la mesure où est respectée sa définition donnée par les revendications jointes.It goes without saying that the invention cannot be limited to the example described, but extends to multiple variants or equivalents insofar as its definition given by the appended claims is respected.

En particulier, on aura compris que si les résultats visés par l'invention peuvent être obtenus déjà à partir d'une mise en oeuvre de celle-ci avec une teneur minimale du bain métallique de 2 ppm en magnésium environ, cette valeur n'est qu'une limite inférieure qui, compte tenu des teneurs habituelles en oxygène du bain final, garantit à coup sûr une amélioration de la coulabilité. Autrement dit, l'invention pourra produire des résultats encore meilleurs sur l'élargissement de la plage de fusibilité I des inclusions si l'on prend soin d'ajuster la teneur en Mg en fonction de la teneur réelle en oxygène du bain métallique de manière à s'approcher, mais en prenant garde de ne pas l'atteindre, la valeur à laquelle le Mg commence à former des spinelles solides de MgO, dont la présence alors au sein du métal à couler annihilerait alors les bienfaits de l'invention sur la prévention des bouchages de busette.In particular, it will be understood that if the results targeted by the invention can already be obtained from an implementation thereof with a minimum content of the metal bath of approximately 2 ppm of magnesium, this value is not that a lower limit which, taking into account the usual oxygen contents of the final bath, certainly guarantees an improvement in flowability. In other words, the invention will be able to produce even better results on the widening of the fusibility range I of the inclusions if care is taken to adjust the Mg content as a function of the actual oxygen content of the metal bath so to approach, but taking care not to reach it, the value at which the Mg begins to form solid spinels of MgO, whose presence then within the metal to be poured would then annihilate the benefits of the invention on prevention of nozzle clogging.

La figure 3 montre précisément, sous forme d'un graphique, la valeur limite supérieure de la teneur en Mg en fonction de celle en oxygène total du bain à partir de laquelle ces spinelles indésirables vont se former au sein du bain d'acier en fusion à la température de coulée. On rappelle que la teneur en Ca considérée correspond à la valeur minimale pour avoir des oxydes à l'état liquide sans addition de Mg. Comme on le voit, la courbe représentative de cette valeur limite supérieure est régulièrement croissante avec les teneurs montantes en oxygène. Grâce aux caractéristiques de son origine basse, on voit bien qu'une teneur de 2 ppm environ en Mg permet d'être toujours en deca du seuil limite de formation de spinelles quelle que soit le niveau d'oxygénation du bain métallique. On voit également, en portant son attention à la mi-courbe, qu'à des teneurs en oxygène total de 20 à 30 ppm, qui sont des valeurs ordinairement atteintes de nos jours pour des aciers Ultra Bas Carbone, la valeur limite à ne pas dépasser se situe autour de 6 ppm, à plus ou moins 2 ppm si l'on se trouve proche des 30 ppm d'oxygène, ou proche des 20 ppm.FIG. 3 shows precisely, in the form of a graph, the upper limit value of the Mg content as a function of that of total oxygen in the bath from which these undesirable spinels will form within the bath of molten steel at the casting temperature. It will be recalled that the Ca content considered corresponds to the minimum value for having oxides in the liquid state without the addition of Mg. As can be seen, the curve representative of this upper limit value is regularly increasing with the rising oxygen contents. Thanks to the characteristics of its low origin, it can be seen that a content of about 2 ppm of Mg makes it possible to always be below the limit threshold for the formation of spinels whatever the level of oxygenation of the metal bath. We also see, paying attention to the mid-curve, that at total oxygen contents of 20 to 30 ppm, which are values usually reached today for Ultra Low Carbon steels, the limit value not exceeding is around 6 ppm, more or less 2 ppm if we are close to 30 ppm of oxygen, or close to 20 ppm.

Claims (3)

  1. Method for metallurgical ladle treatment of a steel for continuous casting, according to which, in a bath of cast, ultra-low or low-carbon steel, killed (or in course of killing) with aluminium to attain a certain oxygen content, calcium is added to form desoxydation inclusions with a melting point below the casting temperature of the steel in the mold, characterised in that in the processing chain, reaching from the ladle to the casting mold, the content of soluble magnesium in the steel bath is kept between a minimum value of about 2 ppm and a maximum value of 10 ppm.
  2. Method according to claim 1, characterised in that magnesium is introduced in the casting ladle and that its content in the metallic bath is maintained by metal-slag exchange, with the help of a basic slag that can titrate up to 10% of MgO by weight.
  3. Method according to claim 1, characterised in that magnesium in the form of fusable cored wire is introduced.
EP00915236A 1999-04-15 2000-03-29 Treatment for improving the castability of aluminium killed continuously cast steel Expired - Lifetime EP1194255B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR9904703A FR2792234B1 (en) 1999-04-15 1999-04-15 TREATMENT TO IMPROVE THE CASABILITY OF CALM STEEL WITH CONTINUOUS CAST ALUMINUM
FR9904703 1999-04-15
PCT/FR2000/000779 WO2000062957A1 (en) 1999-04-15 2000-03-29 Treatment for improving the castability of aluminium killed continuously cast steel

Publications (2)

Publication Number Publication Date
EP1194255A1 EP1194255A1 (en) 2002-04-10
EP1194255B1 true EP1194255B1 (en) 2003-01-29

Family

ID=9544416

Family Applications (1)

Application Number Title Priority Date Filing Date
EP00915236A Expired - Lifetime EP1194255B1 (en) 1999-04-15 2000-03-29 Treatment for improving the castability of aluminium killed continuously cast steel

Country Status (12)

Country Link
US (1) US6685763B1 (en)
EP (1) EP1194255B1 (en)
JP (1) JP2002542034A (en)
KR (1) KR100676656B1 (en)
AT (1) ATE231758T1 (en)
AU (1) AU3661700A (en)
BR (1) BR0009724A (en)
CA (1) CA2370437C (en)
DE (1) DE60001320T2 (en)
ES (1) ES2191615T3 (en)
FR (1) FR2792234B1 (en)
WO (1) WO2000062957A1 (en)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003042419A1 (en) * 2001-11-13 2003-05-22 Fundacion Inasmet Method of producing products made from carbide-reinforced, structural metal materials
EP1715065A3 (en) * 2005-04-20 2007-08-15 Corus Staal BV A cored-wire for injecting into a steel melt and process of treating a steel melt using said wire
US9254256B2 (en) * 2005-11-09 2016-02-09 The Invention Science Fund I, Llc Remote controlled in vivo reaction method
FR2928153B1 (en) * 2008-03-03 2011-10-07 Affival NEW ADDITIVE FOR THE TREATMENT OF RESULTS STEELS
CN102211155B (en) * 2011-06-01 2012-10-10 武汉钢铁(集团)公司 Calcium treatment method of low-carbon low silicon aluminium killed steels under CSP (Cast Steel Plate) condition
CN103305659B (en) * 2012-03-08 2016-03-30 宝山钢铁股份有限公司 The non-oriented electromagnetic steel sheet of excellent magnetic and calcium treating method thereof
CN102653810A (en) * 2012-05-07 2012-09-05 本钢板材股份有限公司 Ferro-silico-manganese alloy for smelting low-silicon low-carbon steel
CN116673453A (en) * 2023-08-03 2023-09-01 东北大学 Method for controlling nonmetallic inclusion liquid separation in continuous casting process

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5214511A (en) * 1975-07-25 1977-02-03 Hitachi Cable Ltd Process for producing a linear additive
DE2948636A1 (en) * 1979-12-04 1981-06-11 Metallgesellschaft Ag, 6000 Frankfurt WIRE-SHAPED AGENT FOR TREATING METAL MELT
JPS58100952A (en) * 1981-12-10 1983-06-15 Daido Steel Co Ltd Continuous casting method
JPS611457A (en) * 1984-06-12 1986-01-07 Kawasaki Steel Corp Continuous casting method of titaniferous aluminum killed steel
JP2559692B2 (en) * 1985-05-31 1996-12-04 川崎製鉄株式会社 Anti-blurring defect prevention method for ultra low carbon cold rolled steel sheet
JPH0199761A (en) * 1987-10-13 1989-04-18 Kawasaki Steel Corp Method for continuously casting aluminum killed steel
JPH0699737B2 (en) * 1989-02-01 1994-12-07 株式会社メタル・リサーチ・コーポレーション Method for producing clean steel
US5297614A (en) * 1990-11-28 1994-03-29 Kawasaki Steel Corporation Process for continuous casting of ultra low carbon aluminum killed steel
JP2887535B2 (en) * 1991-05-02 1999-04-26 新日本製鐵株式会社 Detoxification of inclusions in steel
JP3230070B2 (en) * 1993-08-04 2001-11-19 新日本製鐵株式会社 How to add Mg to molten steel
JPH08225822A (en) * 1995-02-17 1996-09-03 Nippon Steel Corp Reformation of aluminum inclusion in molten steel
JPH091303A (en) * 1995-06-20 1997-01-07 Nippon Steel Corp Manufacture of low temperature use steel excellent in ctod property of heat affected zone
JPH09217109A (en) * 1996-02-13 1997-08-19 Nisshin Steel Co Ltd Simultaneous deoxidizing and desulfurizing agent for molten steel and simultaneously deoxidizing and desulfurizing method
JPH09225601A (en) * 1996-02-27 1997-09-02 Nippon Steel Corp Quality control method for continuously cast seam piece
JP3626278B2 (en) * 1996-03-25 2005-03-02 Ｊｆｅスチール株式会社 Method for producing Al-killed steel without clusters
JP3647969B2 (en) * 1996-04-22 2005-05-18 新日本製鐵株式会社 Method for refinement of harmful inclusions in steel
JPH1034300A (en) * 1996-07-22 1998-02-10 Nippon Steel Corp Treatment of ca into molten steel

Also Published As

Publication number Publication date
JP2002542034A (en) 2002-12-10
CA2370437A1 (en) 2000-10-26
ATE231758T1 (en) 2003-02-15
US6685763B1 (en) 2004-02-03
ES2191615T3 (en) 2003-09-16
FR2792234A1 (en) 2000-10-20
WO2000062957A1 (en) 2000-10-26
AU3661700A (en) 2000-11-02
FR2792234B1 (en) 2001-06-01
DE60001320D1 (en) 2003-03-06
CA2370437C (en) 2008-10-14
DE60001320T2 (en) 2004-01-22
KR20010113797A (en) 2001-12-28
KR100676656B1 (en) 2007-01-31
EP1194255A1 (en) 2002-04-10
BR0009724A (en) 2002-01-02

Similar Documents

Publication Publication Date Title
EP1194255B1 (en) Treatment for improving the castability of aluminium killed continuously cast steel
EP0123632B1 (en) Process for the production of steels with high machinability
EP1323837B1 (en) Process for manufacturing steel product made from carbon steel particularly suitable for galvanisation.
EP2252712B1 (en) Novel additive for treating resulphurized steel
EP0342082B1 (en) Method for cooling a metallic continuous casting product
EP0190089B1 (en) Process for treating liquid metals by a calcium-containing cored wire
CA2243048C (en) Carbon steel or low alloy cast steel, with improved machinability, and the steel-making process involved
EP2197608B1 (en) Method of manufacturing stainless steels comprising fine carbonitrides, and product obtained from this method
FR2493201A1 (en) METHOD FOR CASTING A METAL, IN PARTICULAR FOR PRODUCING INGOTS
EP2918688B1 (en) Method of desulphurisation of liquid cast iron, and flux-cored wire for implementing same
RU2183680C1 (en) Steel production method
FR2654961A1 (en) MAGNESIUM PROCESSING METHOD AND DEVICE FOR IMPLEMENTING SAID METHOD.
RU2312903C2 (en) Pseudo-rimming steel production method
RU2151199C1 (en) Method of treating steel outside furnace
FR2917096A1 (en) NEW ADDITIVE CONTAINING LEAD AND / OR A LEAD ALLOY INTENDED TO TREAT LIQUID STEEL BATHS.
Chattopadhyay et al. Thermodynamic Evaluation of Inclusion Formation and Nozzle Clogging During Slab Casting [C]
JP3474451B2 (en) Manufacturing method of continuous cast billet of mild steel
FR2576320A1 (en) Process for the treatment of liquid ferrous metals using a cored wire containing calcium
RU2440423C1 (en) Out-of-furnace steel treatment method
Watanabe et al. Improvement in the production of high grade wire rods and bars by using a billet caster
JPH0645816B2 (en) Calcium treatment method for molten steel
Zhordaniya et al. Refining of liquid steel during injection processing of the metal in the ladle through the casting device with the sliding gate valve
FR2551372A1 (en) Methods for adding reactive metals to continuously cast steels
FR2475434A1 (en) Cooling continuous casting having high degree of axial symmetry - by more intense cooling of separate axially symmetric surface regions
EP2714943A1 (en) Process for producing clean steels and clean steel produced thereby

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

17P Request for examination filed

Effective date: 20011115

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20030129

Ref country code: IE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20030129

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20030129

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: FRENCH

REF Corresponds to:

Ref document number: 60001320

Country of ref document: DE

Date of ref document: 20030306

Kind code of ref document: P

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20030329

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030329

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030331

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20030429

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20030429

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20030429

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
LTIE Lt: invalidation of european patent or patent extension

Effective date: 20030129

REG Reference to a national code

Ref country code: IE

Ref legal event code: FD4D

Ref document number: 1194255E

Country of ref document: IE

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2191615

Country of ref document: ES

Kind code of ref document: T3

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

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

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20031030

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040331

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040331

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20100323

Year of fee payment: 11

Ref country code: FR

Payment date: 20100324

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 20100312

Year of fee payment: 11

Ref country code: GB

Payment date: 20100322

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: ES

Payment date: 20100408

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20100429

Year of fee payment: 11

Ref country code: BE

Payment date: 20100322

Year of fee payment: 11

Ref country code: NL

Payment date: 20100304

Year of fee payment: 11

BERE Be: lapsed

Owner name: *USINOR

Effective date: 20110331

REG Reference to a national code

Ref country code: NL

Ref legal event code: V1

Effective date: 20111001

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20110329

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20110329

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20111130

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20110331

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20110331

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20111001

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20111001

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 60001320

Country of ref document: DE

Effective date: 20111001

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20110329

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20110329

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20120423

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20110330