EP0471608B1 - Method of and installation for producing nonoxidizable half ferritic steel strips from liquid metal - Google Patents

Method of and installation for producing nonoxidizable half ferritic steel strips from liquid metal Download PDF

Info

Publication number
EP0471608B1
EP0471608B1 EP91402200A EP91402200A EP0471608B1 EP 0471608 B1 EP0471608 B1 EP 0471608B1 EP 91402200 A EP91402200 A EP 91402200A EP 91402200 A EP91402200 A EP 91402200A EP 0471608 B1 EP0471608 B1 EP 0471608B1
Authority
EP
European Patent Office
Prior art keywords
strip
ingot mould
cylinders
solidified
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
EP91402200A
Other languages
German (de)
French (fr)
Other versions
EP0471608A1 (en
Inventor
Philippe Demarez
Jean-Michel Hauser
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.)
Thyssen Stahl AG
USINOR SA
Original Assignee
Thyssen Stahl AG
USINOR Sacilor 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 Thyssen Stahl AG, USINOR Sacilor SA filed Critical Thyssen Stahl AG
Publication of EP0471608A1 publication Critical patent/EP0471608A1/en
Application granted granted Critical
Publication of EP0471608B1 publication Critical patent/EP0471608B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime 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
    • B22D11/124—Accessories for subsequent treating or working cast stock in situ for cooling
    • B22D11/1241—Accessories for subsequent treating or working cast stock in situ for cooling by transporting the cast stock through a liquid medium bath or a fluidized bed
    • 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
    • B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
    • B22D11/0622—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars formed by two casting wheels
    • 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
    • B22D11/124—Accessories for subsequent treating or working cast stock in situ for cooling
    • B22D11/1245—Accessories for subsequent treating or working cast stock in situ for cooling using specific cooling agents
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/56—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering characterised by the quenching agents
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/56—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering characterised by the quenching agents
    • C21D1/607—Molten salts
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys

Definitions

  • the subject of the present invention is a method and a device for manufacturing a strip of semi-ferritic stainless steel, from a bath of molten metal.
  • the invention relates to a continuous casting device, on two cylinders, of semi-ferritic stainless steel in thin strip.
  • ferri-ferritic means that the ferritic structure, whose crystallographic arrangement is cubic centered, is capable of transforming, at high temperature (900 - 1100 ° C), partially into an austenitic structure, whose crystallographic arrangement is cubic with centered faces.
  • the metal is solidified in a continuous casting mold made up of two cooled cylinders, rotating in opposite directions and arranged one opposite the other, with their parallel axes and at a determined spacing, defining between them a casting space. closed at opposite ends of the cylinders by closing plates.
  • the installation described in document EP-181,090 comprises a device for cooling a strip, of Fe-Si alloy for example, cast between two cylinders, installed just before a device for rolling and winding said strip.
  • this cooling device is installed very downstream of the mold, and on the other hand, it uses cooling medium code a gas or a mist, imposing only a relatively moderate cooling rate on the strip.
  • Document EP-A 0 378 705 describes a process for manufacturing a strip of austenitic stainless steel with fine grains.
  • the metal is solidified in a continuous casting mold with two cooled cylinders turning in opposite directions and arranged one opposite the other.
  • Cooling consists in imposing on the strip at the outlet of the cylinders (while it is at a temperature of about 1300 ° C.) first a first rapid forced cooling, or at a speed of the order (see example 1 p . 15-16) from 220 to 400 ° C / sec, but only for a very short time (about 1 sec), so as to bring the strip to a temperature of about 1200 ° C.
  • a first rapid forced cooling or at a speed of the order (see example 1 p . 15-16) from 220 to 400 ° C / sec, but only for a very short time (about 1 sec), so as to bring the strip to a temperature of about 1200 ° C.
  • the strip cools naturally at a low speed and undergoes hot rolling, then it finally undergoes a second forced cooling at a more moderate speed (50 ° C / sec is sufficient) which brings it in 3.5 - 4 sec from a temperature of 900-1000 ° C to a temperature of around 550
  • the invention therefore aims to provide a method and a device for eliminating these shortcomings.
  • the method includes the features mentioned in claim 1.
  • a bath of molten alloy based on lead, tin and zinc or two of these metals or a bath of only one of them is used as quenching medium.
  • ci, or a molten salt in which the lower part of the cylinders and the top of the strip are immersed, and said quenching means are prevented from being entrained by the running of the strip, for example by blowing jets of fluid on the strip at the outlet of the quench bath or using electromagnetic fields.
  • This mixture melts around 140 ° C and can be used between 160 and 500 ° C.
  • an inert gas refrigerated in the liquid state is used as the quenching means, which is projected onto the top of the strip on its opposite faces and under the cylinders.
  • the device intended for the implementation of this process comprises a continuous casting mold formed by two cooled cylinders, rotating in opposite directions and arranged one opposite the other so as to define a casting space between them, and quenching means to subject the solidified steel strip, under the mold, to cooling sufficiently rapid to prevent the formation of austenite.
  • quenching means to subject the solidified steel strip, under the mold, to cooling sufficiently rapid to prevent the formation of austenite.
  • these means make it possible to ensure a cooling rate of 300 ° C / s at least up to a temperature of the cast strip of around 500 ° C at least.
  • Figure 1 is a schematic end elevational view of a continuous casting device of a metal strip between two cylinders, equipped with a container placed under the cylinders and containing a liquid bath for quenching the strips extracted from the device.
  • Figure 2 is a schematic end elevational view, similar to Fig.1, of a second embodiment of the device according to the invention.
  • This device forms a mold for continuous casting, the cylinders 2 being cooled and driven in rotation in opposite directions to each other according to the arrows shown in Fig.1, by means known in themselves and not shown.
  • the device is completed by a container 4 placed under the cylinders 2, the bottom of which is pierced in its central zone with an opening 5 for passage of the strip. 3, and which contains a liquid bath 6 for quenching the strip 3.
  • the dimensions of the container 4 and the level of the bath 6 therein are such that the lower part of the cylinders 2 and the upper part of the strip 3 are scrolled are immersed in the bath 6.
  • the liquid bath 6 must be at a temperature which does not exceed 300 to 350 ° C. approximately, into which the strip 3 is therefore suddenly plunged at approximately 1300 ° C.
  • the bath 6 must be chosen from a non-polluting material which is prohibitive for the strip 3.
  • a quenching bath consisting by a molten alloy of lead, zinc and tin, or two of these metals, or a bath of only one of these metals. It is also possible to use a molten salt such as the above-mentioned mixture of sodium and potassium salts.
  • the casting device also comprises means for retaining the quenching liquid entrained by the movement of the strip 3.
  • these means consist of two rows of nozzles 7, placed under the bottom of the container 4 on each side of the strip 3, and oriented towards the intersection of the latter and the opening 5, so as to be able to project a fluid onto the surface of the strip 3 as it leaves the container 4.
  • the fluid may be water at room temperature (20 ° C for example) or a water-air atomized mixture at a sufficient flow rate to retain inside the container 4 the liquid of the bath 6.
  • this flow rate can be 50 m 3 / h for a linear speed of travel of the strip 3 of the order of 1 m / s, corresponding to cylinders 2 with a diameter of 1.50 m rotating at less than a quarter turn / second.
  • the latter In order to avoid the formation of austenite in the strip 3 during its cooling, the latter must be cooled from approximately 1300 ° C. to 500 ° C. at a speed of 300 ° C./s.
  • the abovementioned baths allow a cooling rate of approximately 2700 ° C./s.
  • the appropriate height of the bath 6 crossed by the strip 3 can be about 40cm, so that the strip 3 comes out of the bath at about 500 ° vs.
  • the strip can be deflected, for example by rollers, so as to leave the bath by crossing its surface.
  • Such an arrangement has the effect, at equal bath depth, of increasing the residence time of the strip in the bath compared to the configuration described above.
  • the second embodiment of the device (Fig. 2) targeted by the invention comprises, in addition to the cylinders 2, quenching means consisting in nozzles 8 for spraying a liquefied inert gas onto the solidified strip 3 immediately after it leaves the casting space.
  • quenching means consisting in nozzles 8 for spraying a liquefied inert gas onto the solidified strip 3 immediately after it leaves the casting space.
  • These nozzles 8 are arranged in two rows placed under the cylinders 2 on either side of the strip, in an arrangement similar to that of the nozzles 7 (Fig.1).
  • the blowing openings of the nozzles 8 are directed on the opposite faces of the upper part of the strip 3, immediately after its detachment from the surface of the cylinders 2.
  • the inert gas may for example be argon or nitrogen, used in the liquid state to benefit from its vaporization on contact with the solidified metal. This gas can be blown at a flow rate of 100,000 Nm 3 / h for example, for a running speed of
  • the device is advantageously completed by a cover 9 schematically represented, arranged under the mold formed by the cylinders 2, dimensioned so as to envelop both the rows of nozzles 8 and the strip 3 while being closed at its ends by means not shown. .
  • the cover 9 has at its lower end an opening 10 allowing the strip 3 to be extracted continuously, to an installation not shown. It makes it possible to confine the gas projected onto the strip 3, over a line length sufficient to ensure protection of said strip against surface oxidation by the surrounding air, adding to the quenching obtained by the projection of the inert gas by nozzles 8.
  • the metal obtained by the process and the device according to the invention is easier to shear and to wind at the outlet of the casting line, thanks to the almost total removal of martensite in the ferritic matrix.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)
  • Coating With Molten Metal (AREA)
  • Treatment Of Steel In Its Molten State (AREA)
  • Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
  • Heat Treatment Of Strip Materials And Filament Materials (AREA)
  • Heat Treatment Of Sheet Steel (AREA)
  • Catalysts (AREA)
  • Artificial Fish Reefs (AREA)
  • Hydroponics (AREA)

Abstract

According to this method, the metal is solidified in a continuous-casting ingot mould consisting of two cooled rolls (2) rotating in opposite directions and arranged opposite each other so as to define a casting space between them, a solidified steel strip (3) is extracted continuously from the ingot mould, and, under the ingot mould, the said strip is subjected to a quenching medium (6) in order to cool it sufficiently rapidly in order to prevent the formation of austenite. This medium may consist of a quenching bath, placed in a container (4) arranged under the rolls (2), and whose bottom is pierced with an opening (5) for the passage of the solidified strip (3). It may also consist of an inert gas in the liquid state sprayed onto the product by nozzles. The steel strips obtained are easier to trim and to coil on exit from the casting line, by virtue of the absence of martensite in the ferritic matrix. <IMAGE>

Description

La présente invention a pour objet un procédé et un dispositif de fabrication d'une bande en acier inoxydable semi-ferritique, à partir d'un bain de métal en fusion.The subject of the present invention is a method and a device for manufacturing a strip of semi-ferritic stainless steel, from a bath of molten metal.

Plus particulièrement l'invention concerne un dispositif de coulée continue, sur deux cylindres, d'acier inoxydable semi-ferritique en bande mince.More particularly the invention relates to a continuous casting device, on two cylinders, of semi-ferritic stainless steel in thin strip.

On rappelle que le terme "semi-ferritique" signifie que la structure ferritique, dont l'arrangement cristallographique est cubique centré, est susceptible de se transformer, à température élevée (900 - 1100°C), partiellement en structure austénitique, dont l'arrangement cristallographique est cubique à faces centrées.Recall that the term "semi-ferritic" means that the ferritic structure, whose crystallographic arrangement is cubic centered, is capable of transforming, at high temperature (900 - 1100 ° C), partially into an austenitic structure, whose crystallographic arrangement is cubic with centered faces.

Comme on le sait, les procédés et dispositifs de coulée continue de bandes d'acier en épaisseur mince sont encore actuellement expérimentaux. Le métal est solidifié dans une lingotière de coulée continue constituée de deux cylindres refroidis, tournant dans des sens opposés et disposés l'un en regard de l'autre, avec leurs axes parallèles et à un écartement déterminé, définissant entre eux un espace de coulée obturé aux extrémités opposées des cylindres par des plaques de fermeture.As is known, the methods and devices for continuous casting of thin steel strips are still currently being tested. The metal is solidified in a continuous casting mold made up of two cooled cylinders, rotating in opposite directions and arranged one opposite the other, with their parallel axes and at a determined spacing, defining between them a casting space. closed at opposite ends of the cylinders by closing plates.

Compte tenu de la vitesse de refroidissement à l'air des bandes d'acier solidifiées extraites en continue de l'espace de coulée, on constate que si l'on veut couler des bandes d'acier inoxydable semi-ferritique, il se forme au cours du refroidissement de l'austénite. Cette dernière, absente initialement de la structure monophasée ferritique, se transforme en fin de refroidissement en martensite dure. Plus précisément, et par exemple pour des nuances semi-ferritiques contenant 17% Cr et environ 0,050%C, alors que pendant et juste après la solidification, la structure de l'acier est monophasée ferritique, l'austénite apparaît au cours du refroidissement, en proportion maximale de 40 à 50%. La martensite résultant ensuite de la transformation de l'austénite est une phase très dure par rapport à la ferrite environnante.Given the speed of air cooling of the solidified steel strips continuously extracted from the casting space, it can be seen that if one wishes to cast semi-ferritic stainless steel strips, it forms at during the cooling of austenite. The latter, initially absent from the single-phase ferritic structure, transforms at the end of cooling into hard martensite. More precisely, and for example for semi-ferritic grades containing 17% Cr and around 0.050% C, then that during and just after solidification, the steel structure is single-phase ferritic, austenite appears during cooling, in a maximum proportion of 40 to 50%. The martensite then resulting from the transformation of the austenite is a very hard phase compared to the surrounding ferrite.

Cette structure hétérogène entraîne des difficultés de manipulation et de déformation du métal au cours de l'enroulage et du déroulage de la bande, et du laminage à froid direct de la structure brute de coulée, en particulier des difficultés pour cisailler et bobiner les bandes en sortie de ligne de coulée. Un autre inconvénient résultant de ce procédé de coulée réside dans le fait que la bande sortant de la lingotière subit une oxydation superficielle au contact de l'air environnant.This heterogeneous structure causes difficulties in handling and deformation of the metal during the winding and unwinding of the strip, and in direct cold rolling of the raw casting structure, in particular difficulties in shearing and winding the strips in pouring line outlet. Another drawback resulting from this casting process lies in the fact that the strip leaving the ingot mold undergoes surface oxidation on contact with the surrounding air.

L'installation décrite dans le document EP-181 090 comporte un dispositif de refroidissement d'une bande, d'alliage Fe-Si par exemple, coulée entre deux cylindres, implanté juste avant un dispositif de laminage et de bobinage de ladite bande. Toutefois, elle n'est aucunement adaptée à la coulée d'acier inox semi-ferritique, car, d'une part, ce dispositif de refroidissement est implanté très en aval de la lingotière, et d'autre part, il utilise code milieu refroidissant un gaz ou un brouillard, n'imposant qu'une vitesse de refroidissement relativement modérée à la bande.The installation described in document EP-181,090 comprises a device for cooling a strip, of Fe-Si alloy for example, cast between two cylinders, installed just before a device for rolling and winding said strip. However, it is in no way suitable for the casting of semi-ferritic stainless steel, because, on the one hand, this cooling device is installed very downstream of the mold, and on the other hand, it uses cooling medium code a gas or a mist, imposing only a relatively moderate cooling rate on the strip.

Le document EP-A 0 378 705 décrit un procédé de fabrication d'une bande en acier inoxydable austénitique à grains fins. Le métal est solidifié dans une lingotière de coulée continue à deux cylindres refroidis tournant en sens opposés et disposés l'un en regard de l'autre.Document EP-A 0 378 705 describes a process for manufacturing a strip of austenitic stainless steel with fine grains. The metal is solidified in a continuous casting mold with two cooled cylinders turning in opposite directions and arranged one opposite the other.

Le refroidissement consiste a imposer à la bande en sortie des cylindres (alors qu'elle se trouve à une température de 1300°C environ) d'abord un premier refroidissement forcé rapide, soit a une vitesse de l'ordre (voir exemple 1 p. 15-16) de 220 à 400°C/sec, mais seulement pendant un laps de temps très bref (de 1 sec environ), de manière à amener la bande à une température de 1200°C environ. Dans les 2-3 sec suivantes, la bande se refroidit naturellement à une vitesse faible et subit un laminage a chaud, puis elle subit enfin un deuxième refroidissement forcé à une vitesse plus modérée (50°C/sec sont suffisants) qui l'amène en 3,5 - 4 sec d'une température de 900-1000°C a une température de 550°C environ.Cooling consists in imposing on the strip at the outlet of the cylinders (while it is at a temperature of about 1300 ° C.) first a first rapid forced cooling, or at a speed of the order (see example 1 p . 15-16) from 220 to 400 ° C / sec, but only for a very short time (about 1 sec), so as to bring the strip to a temperature of about 1200 ° C. In the following 2-3 sec, the strip cools naturally at a low speed and undergoes hot rolling, then it finally undergoes a second forced cooling at a more moderate speed (50 ° C / sec is sufficient) which brings it in 3.5 - 4 sec from a temperature of 900-1000 ° C to a temperature of around 550 ° C.

L'invention a donc pour but de réaliser un procédé et un dispositif permettant d'éliminer ces insuffisances.The invention therefore aims to provide a method and a device for eliminating these shortcomings.

Conformément à l'invention, le procédé comporte les caractéristiques mentionnées a la revendication 1.According to the invention, the method includes the features mentioned in claim 1.

En refroidissant très rapidement à partir d'une température supérieure à la température limite d'existence de l'austénite (température qui est généralement de l'ordre de 1200° à 1250°C pour les nuances considérées), et inférieure à la température de fin de solidification, on constate en effet qu'il est possible de figer la structure ferritique, et d'empécher la formation d'austénite.By cooling very quickly from a temperature higher than the limit temperature of existence of austenite (temperature which is generally of the order of 1200 ° to 1250 ° C for the nuances considered), and lower than the temperature of end of solidification, it is indeed found that it is possible to freeze the ferritic structure, and to prevent the formation of austenite.

En refroidissant de plus la bande juste en dessous des cylindres de coulée, on profite de l'effet de trempe de la peau du métal par le matériau conducteur des cylindres de coulée, la bande étant refroidie à partir d'une température supérieure à la température d'apparition de l'austénite dans la matrice ferritique.By further cooling the strip just below the casting rolls, one takes advantage of the quenching effect of the metal skin by the conductive material of the casting rolls, the strip being cooled from a temperature higher than the temperature appearance of austenite in the ferritic matrix.

Suivant un premier mode de réalisation de l'invention, on utilise comme milieu de trempe un bain d'alliage fondu à base de plomb, d'étain et de zinc ou de deux de ces métaux ou un bain d'un seul de ceux-ci, ou un sel fondu, dans lequel sont immergés la partie inférieure des cylindres et le haut de la bande, et on empêche ledit moyen de trempe d'être entraîné par le défilement de la bande, par exemple par soufflage de jets de fluide sur la bande à la sortie du bain de trempe ou à l'aide de champs électromagnétiques.According to a first embodiment of the invention, a bath of molten alloy based on lead, tin and zinc or two of these metals or a bath of only one of them is used as quenching medium. ci, or a molten salt, in which the lower part of the cylinders and the top of the strip are immersed, and said quenching means are prevented from being entrained by the running of the strip, for example by blowing jets of fluid on the strip at the outlet of the quench bath or using electromagnetic fields.

Le sel fondu peut être avantageusement le mélange suivant (% en masse) :

  • 50 à 60% KNO3
  • 40 à 50% NaNO2
  • 0 à 10% NaNO3
The molten salt can advantageously be the following mixture (% by mass):
  • 50 to 60% KNO3
  • 40 to 50% NaNO2
  • 0 to 10% NaNO3

Ce mélange fond vers 140°C et est utilisable entre 160 et 500°C.This mixture melts around 140 ° C and can be used between 160 and 500 ° C.

Suivant un second mode de réalisation du procédé visé par l'invention, on utilise comme moyen de trempe un gaz inerte réfrigéré à l'état liquide, qu'on projette sur le haut de la bande sur ses faces opposées et sous les cylindres.According to a second embodiment of the process targeted by the invention, an inert gas refrigerated in the liquid state is used as the quenching means, which is projected onto the top of the strip on its opposite faces and under the cylinders.

Le dispositif destiné à la mise en oeuvre de ce procédé comprend une lingotière de coulée continue formée de deux cylindres refroidis, tournant dans des sens opposés et disposés l'un en regard de l'autre de manière à définir entre eux un espace de coulée, et des moyens de trempe pour faire subir à la bande d'acier solidifiée, sous la lingotière, un refroidissement suffisamment rapide pour empêcher la formation d'austénite. Préférentiellement ces moyens permettent d'assurer une vitesse de refroidissement de 300°C/s au moins jusqu'à une température de la bande coulée d'environ 500°C au moins.The device intended for the implementation of this process comprises a continuous casting mold formed by two cooled cylinders, rotating in opposite directions and arranged one opposite the other so as to define a casting space between them, and quenching means to subject the solidified steel strip, under the mold, to cooling sufficiently rapid to prevent the formation of austenite. Preferably, these means make it possible to ensure a cooling rate of 300 ° C / s at least up to a temperature of the cast strip of around 500 ° C at least.

D'autres particularités et avantages de l'invention apparaîtront au cours de la description qui va suivre, faite en référence aux dessins annexés qui en illustrent deux modes de réalisation à titre d'exemples non limitatifs.Other features and advantages of the invention will become apparent during the description which follows, given with reference to the appended drawings which illustrate two embodiments thereof by way of nonlimiting examples.

La figure 1 est une vue en élévation en bout schématique d'un dispositif de coulée continue d'une bande de métal entre deux cylindres, équipé d'un récipient placé sous les cylindres et contenant un bain liquide de trempe des bandes extraites du dispositif.Figure 1 is a schematic end elevational view of a continuous casting device of a metal strip between two cylinders, equipped with a container placed under the cylinders and containing a liquid bath for quenching the strips extracted from the device.

La figure 2 est une vue en élévation en bout schématique, analogue à la Fig.1, d'une seconde forme de réalisation du dispositif selon l'invention.Figure 2 is a schematic end elevational view, similar to Fig.1, of a second embodiment of the device according to the invention.

En se reportant à la Fig.1, on voit un dispositif de coulée continue d'un bain de métal liquide 1 entre deux cylindres 2 disposés horizontalement et parallèlement l'un à l'autre, de manière à délimiter entre eux un espace de coulée d'une bande mince solidifiée 3. Ce dispositif forme une lingotière de coulée continue, les cylindres 2 étant refroidis et entraînés en rotation dans des sens opposés l'un à l'autre suivant les flèches portées sur la Fig.1, par des moyens connus en eux-mêmes et non représentés.Referring to Fig.1, we see a device for continuously casting a liquid metal bath 1 between two cylinders 2 arranged horizontally and parallel to each other, so as to delimit between them a casting space of a solidified thin strip 3. This device forms a mold for continuous casting, the cylinders 2 being cooled and driven in rotation in opposite directions to each other according to the arrows shown in Fig.1, by means known in themselves and not shown.

Afin de permettre plus particulièrement la fabrication de bandes 3 en acier inoxydable semi-ferritique, le dispositif est complété par un récipient 4 placé sous les cylindres 2, dont le fond est percé dans sa zone centrale d'une ouverture 5 de passage de la bande 3, et qui contient un bain liquide 6 de trempe de la bande 3. Les dimensions du récipient 4 et le niveau du bain 6 dans celui-ci sont tels que la partie inférieure des cylindres 2 et la partie supérieure de la bande 3 en défilement continu sont immergées dans le bain 6.In order to allow more particularly the manufacture of strips 3 of semi-ferritic stainless steel, the device is completed by a container 4 placed under the cylinders 2, the bottom of which is pierced in its central zone with an opening 5 for passage of the strip. 3, and which contains a liquid bath 6 for quenching the strip 3. The dimensions of the container 4 and the level of the bath 6 therein are such that the lower part of the cylinders 2 and the upper part of the strip 3 are scrolled are immersed in the bath 6.

Le bain liquide 6 doit être à une température qui n'excède pas 300 à 350°C environ, dans lequel est donc brutalement plongée la bande 3 à environ 1300°C. De plus, le bain 6 doit être choisi en un matériau non polluant de manière rédhibitoire pour la bande 3.The liquid bath 6 must be at a temperature which does not exceed 300 to 350 ° C. approximately, into which the strip 3 is therefore suddenly plunged at approximately 1300 ° C. In addition, the bath 6 must be chosen from a non-polluting material which is prohibitive for the strip 3.

A titre d'exemples non limitatifs, il est ainsi possible d'utiliser un bain de trempe constitué par un alliage fondu de plomb, de zinc et d'étain, ou de deux de ces métaux, ou un bain d'un seul de ces métaux. On peut également utiliser un sel fondu tel que le mélange précité de sels de sodium et de potassium.By way of nonlimiting examples, it is thus possible to use a quenching bath consisting by a molten alloy of lead, zinc and tin, or two of these metals, or a bath of only one of these metals. It is also possible to use a molten salt such as the above-mentioned mixture of sodium and potassium salts.

Le dispositif de coulée comprend également des moyens pour retenir le liquide de trempe entraîné par le défilement de la bande 3. Dans l'exemple représenté, ces moyens consistent en deux rangées de buses 7, placées sous le fond du récipient 4 de chaque côté de la bande 3, et orientées vers l'intersection de cette dernière et de l'ouverture 5, de manière à pouvoir projeter un fluide sur la surface de la bande 3 à sa sortie du récipient 4. Le fluide peut être de l'eau à température ambiante (20°C par exemple) ou un mélange atomisé eau-air à un débit suffisant pour retenir à l'intérieur du récipient 4 le liquide du bain 6.The casting device also comprises means for retaining the quenching liquid entrained by the movement of the strip 3. In the example shown, these means consist of two rows of nozzles 7, placed under the bottom of the container 4 on each side of the strip 3, and oriented towards the intersection of the latter and the opening 5, so as to be able to project a fluid onto the surface of the strip 3 as it leaves the container 4. The fluid may be water at room temperature (20 ° C for example) or a water-air atomized mixture at a sufficient flow rate to retain inside the container 4 the liquid of the bath 6.

A titre d'exemple numérique indicatif, ce débit peut être de 50 m3/h pour une vitesse linéaire de défilement de la bande 3 de l'ordre de 1m/s, correspondant à des cylindres 2 d'un diamètre de 1,50m tournant à moins d'un quart de tour/seconde. Afin d'éviter la formation d'austénite dans la bande 3 au cours de son refroidissement, celle-ci doit être refroidie de 1300°C à 500°C environ à une vitesse de 300°C/s. Or, les bains précités permettent une vitesse de refroidissement de 2700°C/s environ.As an indicative numerical example, this flow rate can be 50 m 3 / h for a linear speed of travel of the strip 3 of the order of 1 m / s, corresponding to cylinders 2 with a diameter of 1.50 m rotating at less than a quarter turn / second. In order to avoid the formation of austenite in the strip 3 during its cooling, the latter must be cooled from approximately 1300 ° C. to 500 ° C. at a speed of 300 ° C./s. However, the abovementioned baths allow a cooling rate of approximately 2700 ° C./s.

De ce fait, pour une bande de 3,5mm d'épaisseur défilant à 1m/s, la hauteur appropriée du bain 6 traversée par la bande 3, peut être de 40cm environ, pour que la bande 3 sorte du bain à environ 500°C.Therefore, for a strip of 3.5mm thickness traveling at 1m / s, the appropriate height of the bath 6 crossed by the strip 3, can be about 40cm, so that the strip 3 comes out of the bath at about 500 ° vs.

Bien entendu, il n'est pas nécessaire que la bande sorte du bain de trempe par le fond du récipient. A l'intérieur du bain, la bande peut être déviée, par exemple par des rouleaux, de manière à sortir du bain en traversant sa surface. Une telle disposition a pour effet, à profondeur de bain égale, d'augmenter le temps de séjour de la bande dans le bain par rapport à la configuration précédemment décrite.Of course, it is not necessary for the strip to come out of the quench bath through the bottom of the container. Inside the bath, the strip can be deflected, for example by rollers, so as to leave the bath by crossing its surface. Such an arrangement has the effect, at equal bath depth, of increasing the residence time of the strip in the bath compared to the configuration described above.

Des essais de laboratoire ont été réalisés pour les nuances d'acier inoxydable suivantes : AISI 430 (norme ASTM A176) pour l'étude de la précipitation éventuelle d'austénite et de sa transformation en martensite; AISI 304 (norme ASTM A167) pour l'évaluation des vitesses de refroidissement : la finesse de la structure dendritique de solidification d'un acier austénitique est prévisible par attaque métallographique, et peut être reliée aux conditions de refroidissement. Les résultats d'essais effectués avec des échantillons de ces nuances d'acier, à une température de trempe de 1500°C dans un bain 6 d'étain liquide à 300°C, refroidi en 0,45 seconde environ, à une température de 500°C, sont les suivants :

  • la nuance AISI 430 présente une structure ferritique contenant très peu de phase martensitique (moins de 1%),
  • la vitesse de refroidissement estimée à partir de la taille de structure de la nuance austénitique AISI 304, est comprise entre 5000°C/s et 15000°C/s.
Laboratory tests have been carried out for the following stainless steel grades: AISI 430 (ASTM A176 standard) to study the possible precipitation of austenite and its transformation into martensite; AISI 304 (ASTM A167 standard) for the evaluation of cooling rates: the fineness of the dendritic solidification structure of an austenitic steel is predictable by metallographic attack, and can be related to the cooling conditions. The results of tests carried out with samples of these grades of steel, at a quenching temperature of 1500 ° C. in a bath 6 of liquid tin at 300 ° C., cooled in approximately 0.45 seconds, at a temperature of 500 ° C, are as follows:
  • grade AISI 430 has a ferritic structure containing very little martensitic phase (less than 1%),
  • the cooling rate estimated from the structure size of the AISI 304 austenitic grade is between 5000 ° C / s and 15000 ° C / s.

Ces essais ont donc confirmé la validité du procédé selon l'invention pour atteindre le but recherché.These tests therefore confirmed the validity of the method according to the invention to achieve the desired goal.

La seconde forme de réalisation du dispositif (Fig.2) visée par l'invention comprend, outre les cylindres 2, des moyens de trempe consistant dans des buses 8 de projection d'un gaz inerte liquéfié sur la bande solidifiée 3 immédiatement à sa sortie de l'espace de coulée. Ces buses 8 sont disposées en deux rangées placées sous les cylindres 2 de part et d'autre de la bande, en une disposition similaire à celle des buses 7 (Fig.1). En effet les ouvertures de soufflage des buses 8 sont dirigées sur les faces opposées de la partie supérieure de la bande 3, immédiatement après son décollement de la surface des cylindres 2. Le gaz inerte peut être par exemple de l'argon ou de l'azote, utilisé à l'état liquide pour bénéficier de sa vaporisation au contact du métal solidifié. Ce gaz peut être soufflé à un débit de 100 000 Nm3/h par exemple, pour une vitesse de défilement de la bande 3 d'environ 1m/s.The second embodiment of the device (Fig. 2) targeted by the invention comprises, in addition to the cylinders 2, quenching means consisting in nozzles 8 for spraying a liquefied inert gas onto the solidified strip 3 immediately after it leaves the casting space. These nozzles 8 are arranged in two rows placed under the cylinders 2 on either side of the strip, in an arrangement similar to that of the nozzles 7 (Fig.1). In fact, the blowing openings of the nozzles 8 are directed on the opposite faces of the upper part of the strip 3, immediately after its detachment from the surface of the cylinders 2. The inert gas may for example be argon or nitrogen, used in the liquid state to benefit from its vaporization on contact with the solidified metal. This gas can be blown at a flow rate of 100,000 Nm 3 / h for example, for a running speed of the strip 3 of approximately 1 m / s.

Le dispositif est avantageusement complété par un capot 9 schématiquement représenté, disposé sous la lingotière formée par les cylindres 2, dimensionné de manière à envelopper à la fois les rangées de buses 8 et la bande 3 en étant fermé à ses extrémités par des moyens non représentés. Le capot 9 présente à son extrémité inférieure une ouverture 10 permettant l'extraction de la bande 3, en continu, vers une installation non représentée. Il permet de confiner le gaz projeté sur la bande 3, sur une longueur de ligne suffisante pour assurer une protection de ladite bande contre l'oxydation superficielle par l'air environnant, s'ajoutant à la trempe obtenue par la projection du gaz inerte par les buses 8.The device is advantageously completed by a cover 9 schematically represented, arranged under the mold formed by the cylinders 2, dimensioned so as to envelop both the rows of nozzles 8 and the strip 3 while being closed at its ends by means not shown. . The cover 9 has at its lower end an opening 10 allowing the strip 3 to be extracted continuously, to an installation not shown. It makes it possible to confine the gas projected onto the strip 3, over a line length sufficient to ensure protection of said strip against surface oxidation by the surrounding air, adding to the quenching obtained by the projection of the inert gas by nozzles 8.

Des essais de laboratoire ont été réalisés pour la nuance d'acier inoxydable AISI 430 (norme ASTM A176) à l'aide d'un dilatomère absolu. Un échantillon de métal a été refroidi en 2,5s, à partir de 1250°C jusqu'à une température de 500°C, par projection d'hélium à l'état gazeux dans le four. La structure de l'échantillon est ferritique et contient moins de 1% de martensite.Laboratory tests have been carried out for the grade of AISI 430 stainless steel (ASTM A176 standard) using an absolute dilatomer. A metal sample was cooled in 2.5 s, from 1250 ° C to a temperature of 500 ° C, by spraying helium in the gaseous state in the furnace. The structure of the sample is ferritic and contains less than 1% martensite.

Ces essais ont également confirmé la validité du procédé selon l'invention pour atteindre le but recherché.These tests also confirmed the validity of the method according to the invention to achieve the desired goal.

Le métal obtenu par le procédé et le dispositif selon l'invention est plus aisé à cisailler et à bobiner en sortie de ligne de coulée, grâce à la suppression quasi-totale de martensite dans la matrice ferritique.The metal obtained by the process and the device according to the invention is easier to shear and to wind at the outlet of the casting line, thanks to the almost total removal of martensite in the ferritic matrix.

Claims (7)

  1. Process for manufacturing a strip (3) of semiferritic stainless steel from a bath (1) of molten metal comprising: C < = 0.12 %; Mn ≦ 1.00 %; Si ≦ 1.00 %; Cr = 16-18 %; P ≦ 0.04 %, S ≦ 0.030 %, the remainder consisting of iron and residual impurities,
    characterised in that the metal is solidified in a continuous casting ingot mould consisting of two cooled cylinders (2) rotating in opposite directions and arranged facing one another so as to define a casting space between them, in that a solidified steel strip (3) is continuously removed from the ingot mould, and in that, under the ingot mould, the strip is subjected to a tempering medium so as to cool said strip (3) under the ingot mould at a minimum speed of 300°C/s, at least to a temperature of about 500°C, in order to cool it rapidly enough and for long enough to prevent the formation of austenite.
  2. Process according to claim 1, characterised in that the strip (3) is cooled below the ingot mould just after it has left the cooled cylinders (2).
  3. Process according to claim 1, characterised in that a bath of molten alloy (6) based on lead, tin and zinc or two of these molten metals, or only one of them, or a molten salt such as a mixture of KNO3, NaNO2 and NaNO3 is used as she tempering medium, in which the lower part of the cylinders (2) and the top of the strip (3) are immersed.
  4. Process according to claim 1, characterised in that an inert gas, cooled to the liquid state, is used as the tempering medium, which is sprayed over the top of the strip (3) over its opposing surfaces and under the cylinders (2) just after the strip has detached itself from these cylinders.
  5. Apparatus for carrying out the process according to claim 1, of the type comprising a continuous casting ingot mould formed by two cooled cylinders (2) rotating in opposite directions and arranged opposite one another so as to define a casting space between them, and means for tempering the solidified steel strip (3) arranged below the ingot mould, characterised in that said tempering means comprise a liquid bath (6) arranged below the ingot mould (2), through which the solidified steel strip (3) can be removed, this bath being contained in a container (4) the base of which is provided with an opening (5) for the solidified strip to pass through.
  6. Apparatus according to claim 5, characterized in that means are provided for holding the liquid carried along with the strip (3), such as nozzles (7) placed below the container (4) on each side of the strip, which are capable of spraying a fluid such as water or an atomised mixture of water and air over the strip as it leaves the container.
  7. Apparatus for carrying out the process according to claim 1, of the type comprising a continuous casting ingot mould formed by two cooled cylinders (2) rotating in opposite directions and arranged opposite one another so as to define a casting space between them, and means for tempering the solidified steel strip (3) which are arranged below the ingot mould, characterised in that the tempering means comprise nozzles (8) for spraying a liquefied inert gas over the solidified strip (3) as it leaves the casting space, which are located below the cylinders (2) on each side of the strip.
EP91402200A 1990-08-13 1991-08-06 Method of and installation for producing nonoxidizable half ferritic steel strips from liquid metal Expired - Lifetime EP0471608B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9010304 1990-08-13
FR9010304A FR2665652A1 (en) 1990-08-13 1990-08-13 METHOD AND DEVICE FOR MANUFACTURING A SEMI-FERRITIC STAINLESS STEEL STRIP FROM MOLTEN METAL.

Publications (2)

Publication Number Publication Date
EP0471608A1 EP0471608A1 (en) 1992-02-19
EP0471608B1 true EP0471608B1 (en) 1996-08-07

Family

ID=9399643

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91402200A Expired - Lifetime EP0471608B1 (en) 1990-08-13 1991-08-06 Method of and installation for producing nonoxidizable half ferritic steel strips from liquid metal

Country Status (17)

Country Link
US (1) US5201363A (en)
EP (1) EP0471608B1 (en)
JP (1) JP2919125B2 (en)
AT (1) ATE141066T1 (en)
AU (1) AU644672B2 (en)
CA (1) CA2048769A1 (en)
DE (1) DE69121222T2 (en)
DK (1) DK0471608T3 (en)
ES (1) ES2090274T3 (en)
FI (1) FI95360C (en)
FR (1) FR2665652A1 (en)
GR (1) GR3020882T3 (en)
IE (1) IE912856A1 (en)
NO (1) NO179780C (en)
PT (1) PT98623A (en)
TW (1) TW198735B (en)
ZA (1) ZA916292B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1029617B2 (en) † 1999-02-05 2017-01-04 Castrip, LLC Continuous casting steel strip method

Families Citing this family (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU676101B2 (en) * 1993-11-18 1997-02-27 Bluescope Steel Limited Casting stainless steel strip on surface with specified roughness
US6264767B1 (en) 1995-06-07 2001-07-24 Ipsco Enterprises Inc. Method of producing martensite-or bainite-rich steel using steckel mill and controlled cooling
FR2763960B1 (en) * 1997-05-29 1999-07-16 Usinor PROCESS FOR PRODUCING FERRITIC STAINLESS STEEL THIN STRIPS AND THIN STRIPS THUS OBTAINED
AU4596899A (en) 1998-07-10 2000-02-01 Ipsco Inc. Method and apparatus for producing martensite- or bainite-rich steel using steckel mill and controlled cooling
US7073565B2 (en) 1999-02-05 2006-07-11 Castrip, Llc Casting steel strip
AT411025B (en) * 2002-02-27 2003-09-25 Voest Alpine Ind Anlagen DEVICE FOR CONTINUOUSLY POOLING METAL MELT
EP1452252A1 (en) * 2003-02-28 2004-09-01 Hubert Dipl.-Ing. Sommerhofer Continuous casting method
JP4580280B2 (en) * 2005-05-31 2010-11-10 三菱日立製鉄機械株式会社 Twin roll type continuous casting machine and twin roll type continuous casting method
CN101265516B (en) * 2008-04-23 2010-06-02 浙江佰耐钢带有限公司 Steel band quenching technique and cooling medium used for the same
KR101203694B1 (en) 2010-06-30 2012-11-21 주식회사 에스티 Method and apparatus for manufacturing quenching ribbon for electric contact material
DE102013224851A1 (en) * 2013-12-04 2015-06-11 Schaeffler Technologies AG & Co. KG chain element
JP6474965B2 (en) * 2014-04-10 2019-02-27 権田金属工業株式会社 Twin roll casting method
CN112355259B (en) * 2020-11-09 2022-04-19 中铝材料应用研究院有限公司 Preparation device and preparation method for liquid continuous solidification forming of aluminum alloy sheet
CN113751680B (en) * 2021-09-09 2022-05-06 中南大学 Method for manufacturing ultra-fine grain maraging steel thin strip

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3658117A (en) * 1970-05-07 1972-04-25 Fromson H A Continuous metal casting method and apparatus
JPS61293638A (en) * 1985-06-20 1986-12-24 Mitsubishi Heavy Ind Ltd Device for preventing bulging
JPS62112751A (en) * 1985-11-09 1987-05-23 Nippon Steel Corp Manufacturer of ferrous shape memory alloy sheet metal or wire
ATE39333T1 (en) * 1986-02-13 1989-01-15 Larex Ag ROLL CASTING PROCESS AND ROLL CASTING PLANT FOR CARRYING OUT THE SAME.
JPS62197247A (en) * 1986-02-21 1987-08-31 Nippon Yakin Kogyo Co Ltd Production of thin autstenitic stainless steel strip
US4723997A (en) * 1987-04-20 1988-02-09 L'air Liquide Method and apparatus for shielding a stream of liquid metal
JPH01299745A (en) * 1988-05-25 1989-12-04 Ishikawajima Harima Heavy Ind Co Ltd Method for casting austenitic stainless steel by twin roll type continuous casting machine
WO1990000454A1 (en) * 1988-07-08 1990-01-25 Nippon Steel Corporation PROCESS FOR PRODUCING THIN Cr-Ni STAINLESS STEEL SHEET EXCELLENT IN BOTH SURFACE QUALITY AND QUALITY OF MATERIAL

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
* EP-A-0352716 *EP-A-0378705 *Stahlschlüssel Wegst, (1983), p. 344; *
454)(2773), 23 octobre 1987; & JP - A - 62112751 (NIPPON STEEL) 23.05.1987 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1029617B2 (en) † 1999-02-05 2017-01-04 Castrip, LLC Continuous casting steel strip method

Also Published As

Publication number Publication date
ZA916292B (en) 1993-03-31
NO179780C (en) 1996-12-18
AU644672B2 (en) 1993-12-16
FI95360B (en) 1995-10-13
US5201363A (en) 1993-04-13
GR3020882T3 (en) 1996-11-30
FI913822A0 (en) 1991-08-12
FI913822A (en) 1992-02-14
NO179780B (en) 1996-09-09
NO913077L (en) 1992-02-14
JP2919125B2 (en) 1999-07-12
PT98623A (en) 1993-08-31
EP0471608A1 (en) 1992-02-19
NO913077D0 (en) 1991-08-08
IE912856A1 (en) 1992-02-26
TW198735B (en) 1993-01-21
FI95360C (en) 1996-01-25
CA2048769A1 (en) 1992-02-14
ES2090274T3 (en) 1996-10-16
AU8242991A (en) 1992-02-20
ATE141066T1 (en) 1996-08-15
FR2665652A1 (en) 1992-02-14
DE69121222D1 (en) 1996-09-12
FR2665652B1 (en) 1994-12-30
DE69121222T2 (en) 1997-03-20
JPH0623491A (en) 1994-02-01
DK0471608T3 (en) 1996-12-23

Similar Documents

Publication Publication Date Title
EP0471608B1 (en) Method of and installation for producing nonoxidizable half ferritic steel strips from liquid metal
EP1072689B1 (en) Process of manufacturing thin &#34;TRIP&#34; type steel strips and strips obtained thereby
CA2299674C (en) Procedure for the fabrication of carbon steel bands by continuous casting between two cylinders
FR2659087A1 (en) PROCESS FOR MANUFACTURING A SOLIDIFIED MATERIAL IN AN AMORPHOUS ALLOY.
EP1466024B1 (en) Method for the production of a siderurgical product made of carbon steel with a high copper content, and siderurgical product obtained according to said method
CA1268044A (en) Manufacture of calmed steel with low nitrogen content
EP0092477B1 (en) Process and apparatus for casting hollow steel ingots
EP0342082B1 (en) Method for cooling a metallic continuous casting product
FR2610551A1 (en) PROCESS FOR PRODUCING PHOSPHORUS BRONZE THIN STRIPS
JPH0615413A (en) Method and device for direct casting of continuous metal strip
EP0709151B1 (en) Casting surface for a continuous metal casting mould with movable walls
KR100225685B1 (en) Method and device for manufacturing a semi-ferritic stainless steel strip
EP0425402B1 (en) Process and apparatus for continuous twin-roll casting of thin metallic products
RU2025198C1 (en) Method and device for manufacturing strip from semiferritic stainless steel
FR2783443A1 (en) PROCESS FOR THE MANUFACTURE OF A STAINLESS STEEL THIN STRIP
WO1998012007A1 (en) Plant and method for making amorphous metal tape or fibre by overhardening
FR2480155A1 (en) Casting pipe on base of tundish in continuous casting plant - has two tangential outlet holes through which molten metal flows into rotating mould, esp. to cast round steel bars
CZ366791A3 (en) process and apparatus for producing semi-ferritic strip of stainless steel from a molten metal
FR2543031A2 (en) Method and device for manufacturing a hollow steel ingot
BE428474A (en)
PL169531B1 (en) Method of making semi-ferritic stainless steel strip and apparatus therefor
HU215987B (en) Method and apparatus for continuous producing half-ferrited stainless strip steel carrying out from metal melt
BE712693A (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: 19920613

17Q First examination report despatched

Effective date: 19940714

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

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: THYSSEN STAHL AKTIENGESELLSCHAFT

Owner name: USINOR SACILOR

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

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

REF Corresponds to:

Ref document number: 141066

Country of ref document: AT

Date of ref document: 19960815

Kind code of ref document: T

REF Corresponds to:

Ref document number: 69121222

Country of ref document: DE

Date of ref document: 19960912

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2090274

Country of ref document: ES

Kind code of ref document: T3

ITF It: translation for a ep patent filed

Owner name: INVENTION S.N.C.

REG Reference to a national code

Ref country code: GR

Ref legal event code: FG4A

Free format text: 3020882

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2090274

Country of ref document: ES

Kind code of ref document: T3

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 19961112

REG Reference to a national code

Ref country code: DK

Ref legal event code: 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
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20000713

Year of fee payment: 10

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

Ref country code: DK

Payment date: 20000714

Year of fee payment: 10

Ref country code: AT

Payment date: 20000714

Year of fee payment: 10

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

Ref country code: CH

Payment date: 20000717

Year of fee payment: 10

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

Ref country code: SE

Payment date: 20000719

Year of fee payment: 10

Ref country code: GR

Payment date: 20000719

Year of fee payment: 10

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

Ref country code: DE

Payment date: 20000720

Year of fee payment: 10

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

Ref country code: ES

Payment date: 20000726

Year of fee payment: 10

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

Ref country code: GB

Payment date: 20000801

Year of fee payment: 10

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

Ref country code: LU

Payment date: 20000821

Year of fee payment: 10

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

Ref country code: BE

Payment date: 20000822

Year of fee payment: 10

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

Ref country code: LU

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

Effective date: 20010806

Ref country code: GB

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

Effective date: 20010806

Ref country code: DK

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

Effective date: 20010806

Ref country code: AT

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

Effective date: 20010806

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 NON-PAYMENT OF DUE FEES

Effective date: 20010807

Ref country code: ES

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

Effective date: 20010807

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

Ref country code: LI

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

Effective date: 20010831

Ref country code: CH

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

Effective date: 20010831

Ref country code: BE

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

Effective date: 20010831

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

Ref country code: GR

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

Effective date: 20020209

BERE Be: lapsed

Owner name: THYSSEN STAHL A.G.

Effective date: 20010831

Owner name: USINOR SACILOR

Effective date: 20010831

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

Ref country code: NL

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

Effective date: 20020301

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

Effective date: 20010806

EUG Se: european patent has lapsed

Ref document number: 91402200.9

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

REG Reference to a national code

Ref country code: DK

Ref legal event code: EBP

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 20020301

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

Ref country code: DE

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

Effective date: 20020501

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20020911

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

Ref country code: IT

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

Effective date: 20050806