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EP1285972A1 - Process for hot-dip galvanising of high-strength steel strips - Google Patents

Process for hot-dip galvanising of high-strength steel strips Download PDF

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Publication number
EP1285972A1
EP1285972A1 EP02292018A EP02292018A EP1285972A1 EP 1285972 A1 EP1285972 A1 EP 1285972A1 EP 02292018 A EP02292018 A EP 02292018A EP 02292018 A EP02292018 A EP 02292018A EP 1285972 A1 EP1285972 A1 EP 1285972A1
Authority
EP
European Patent Office
Prior art keywords
strip
atmosphere
steel
dew point
oven
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.)
Withdrawn
Application number
EP02292018A
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German (de)
French (fr)
Inventor
Didier Delaunay
Francois Mignard
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.)
Fives Stein SA
Original Assignee
Stein Heurtey 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 Stein Heurtey SA filed Critical Stein Heurtey SA
Publication of EP1285972A1 publication Critical patent/EP1285972A1/en
Withdrawn legal-status Critical Current

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Classifications

    • 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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
    • 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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
    • C21D9/54—Furnaces for treating strips or wire
    • C21D9/56—Continuous furnaces for strip or wire
    • C21D9/561—Continuous furnaces for strip or wire with a controlled atmosphere or vacuum
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/02—Pretreatment of the material to be coated, e.g. for coating on selected surface areas
    • C23C2/022—Pretreatment of the material to be coated, e.g. for coating on selected surface areas by heating
    • C23C2/0222—Pretreatment of the material to be coated, e.g. for coating on selected surface areas by heating in a reactive atmosphere, e.g. oxidising or reducing atmosphere
    • 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
    • C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
    • C21D1/76—Adjusting the composition of the atmosphere

Definitions

  • the present invention relates to dip galvanizing steel strips with improved mechanical properties in vertical ovens. It more specifically targets a process for performing chemical treatments of the strip, simultaneously or not with the heat treatment of the annealing, such as oxidation-reduction, etc., in atmospheres different from those of the usual sections from the oven.
  • the tape circulates in an atmosphere reducing from the inlet to the outlet of the oven or, if there is an open preheating zone, from the outlet of it at the outlet of the oven.
  • the reducing atmosphere is therefore kept in the oven at the latest from the exit from preheating is traditionally at a strip temperature from 650 to 700 ° C.
  • the purpose of this process is purpose of limiting the formation of oxides, mainly of iron, to the surface of the strip and to reduce them if any exists or if it has formed in the preheater in order to allow good attachment of zinc to the surface of the strip to obtain a good quality galvanized product.
  • the stay of the strip under this reducing atmosphere must be done in sufficient conditions (temperature, residence time, dew point of the furnace atmosphere) to allow cleaning of the tape compatible with good quality of subsequent coating, in particular zinc adhesion.
  • the invention proposes to solve the technical problem exposed above by providing a process which makes it possible to hot-dip galvanizing of very different grades of steel loaded with hardening elements in furnaces traditional construction.
  • this invention relates to a method of continuous metal strip thermochemical treatment, of the oxidation-reduction type according to which the strip moves at the through an oven, in a protective atmosphere, characterized in that the strip passes through at least a partial or total isolation device, positioned at within at least one section of the oven, or between two sections, the strip being heated in this device isolation, in dew point atmospheres suitable for each strip, depending on the specific composition of steel and applied thermal cycle.
  • the process which is the subject of the invention mainly consists of allowing the strip to be heated in different dew point atmospheres depending on temperature ranges different from those known in the state of the art, and in particular at points of dew above the usual values, thanks to isolation devices.
  • Oxygen goes then oxidize the atoms of Si, ... inside the metal. he then there will no longer be enough Si, ... available to migrate towards the surface and feed the surface oxidation, especially since the kinetics of oxygen diffusion through the joints is faster than the diffusion of atoms oxidizable in metal. Furthermore, this oxidation internal will block the diffusion of these atoms towards the surface, which further limits the amount of these oxides trained.
  • the implementation of the method according to the invention consists in allow to precisely control the dew point of this atmosphere in the heating chamber so that this atmosphere is oxidizing for the targeted elements but remains reductive for iron, which should not be oxidize.
  • the downstream section of the oven - the end of maintenance and the cooling - will remain reducing, to reduce iron oxides which may have been possibly formed in the high dew point section, which will not reverse the internal oxidation process of metallic additives steel, because the oxides formed from these additives are more stable than iron oxides.
  • the dew point of the atmosphere can be modified according to the thermal cycle, i.e. the oven section temperature and the stay of the band in the latter, to integrate the variations in strip thickness.
  • the process which is the subject of the invention therefore proposes to be able to confine a controlled atmosphere whose dew point is higher than that used in ovens according to the state art in order to be less reductive, this in a section of the high temperature oven of a line of conventional galvanization.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Coating With Molten Metal (AREA)
  • Heat Treatment Of Strip Materials And Filament Materials (AREA)
  • Furnace Details (AREA)

Abstract

Procédé de traitement thermochimique en continu de bandes métalliques, notamment d'acier, du type oxydo-réduction, selon lequel la bande se déplace au travers d'un four dans une atmosphère protectrice, caractérisé en ce que ladite bande passe au travers d'au moins un dispositif d'isolement partiel ou total, positionné au sein d'au moins une section du four, ou entre deux sections, la bande étant chauffée, dans ce dispositif d'isolement, dans des atmosphères à point de rosée adapté à chaque bande en fonction de la composition spécifique de l'acier, de manière que l'atmosphère soit oxydante pour certains éléments d'addition, mais demeure réductrice pour le fer.Method of continuous thermochemical treatment of metal strips, in particular of steel, of the oxidation-reduction type, according to which the strip moves through an oven in a protective atmosphere, characterized in that said strip passes through at least at least one partial or total isolation device, positioned within at least one section of the furnace, or between two sections, the strip being heated, in this isolation device, in dew point atmospheres adapted to each strip depending on the specific composition of the steel, so that the atmosphere is oxidizing for certain elements of addition, but remains reducing for iron.

Description

La présente invention concerne la galvanisation au trempé de bandes d'aciers à propriétés mécaniques améliorées dans des fours verticaux. Elle vise plus particulièrement un procédé permettant de réaliser des traitements chimiques de la bande, simultanément ou non au traitement thermique du recuit, tels que oxydo-réduction, etc..., dans des atmosphères différentes de celles des sections habituelles du four.The present invention relates to dip galvanizing steel strips with improved mechanical properties in vertical ovens. It more specifically targets a process for performing chemical treatments of the strip, simultaneously or not with the heat treatment of the annealing, such as oxidation-reduction, etc., in atmospheres different from those of the usual sections from the oven.

Les fours de galvanisation en continu selon l'état actuel de la technique sont traditionnellement composés de plusieurs zones que la bande traverse successivement :

  • dans certains cas, une zone de préchauffage à feu nu, c'est-à-dire munie de brûleurs qui développent leur flamme directement dans l'enceinte. Cette zone permet traditionnellement de porter la bande de la température ambiante à une température d'environ 650 à 700°C.
  • une zone de chauffage par tubes radiants dans laquelle la température de la bande est portée à environ 700 à 900°C. Cette zone de chauffage est placée sous atmosphère réductrice afin de permettre la réduction des oxydes formés à la surface de la bande, en particulier les oxydes de fer, et dans tous les cas de ne pas créer d'oxyde s'il n'y en avait pas auparavant ;
  • une zone de maintien où la bande reste à une température de palier et durant un temps défini par le type de cycle thermique à réaliser ;
  • une ou plusieurs zones de refroidissement suivant des pentes contrôlées selon le type de cycle thermique à réaliser. Ce refroidissement est effectué jusqu'à une température proche de celle du bain de zinc, typiquement 460°C.
The continuous galvanizing ovens according to the current state of the art are traditionally composed of several zones which the strip passes successively:
  • in certain cases, a zone of preheating on naked fire, that is to say provided with burners which develop their flame directly in the enclosure. This zone traditionally makes it possible to bring the strip from room temperature to a temperature of around 650 to 700 ° C.
  • a zone of heating by radiant tubes in which the temperature of the strip is brought to approximately 700 to 900 ° C. This heating zone is placed under a reducing atmosphere in order to allow the reduction of the oxides formed on the surface of the strip, in particular the iron oxides, and in all cases not to create oxide if there is none. hadn't before;
  • a holding zone where the strip remains at a plateau temperature and for a time defined by the type of thermal cycle to be carried out;
  • one or more cooling zones following controlled slopes according to the type of thermal cycle to be carried out. This cooling is carried out to a temperature close to that of the zinc bath, typically 460 ° C.

On constate que dans les fours de galvanisation suivant l'état de l'art, la bande circule dans une atmosphère réductrice depuis l'entrée jusqu'à la sortie du four ou, s'il existe une zone de préchauffage à feu nu, de la sortie de celle-ci à la sortie du four. L'atmosphère réductrice est donc maintenue dans le four au plus tard à partir de la sortie de la préchauffe soit traditionnellement à une température de bande de 650 à 700°C. Ce procédé a pour objet de limiter la formation d'oxydes, principalement de fer, à la surface de la bande et à les réduire s'il en existe ou s'il s'en est formé dans la préchauffe afin de permettre un bon accrochage du zinc à la surface de la bande pour obtenir un produit galvanisé de bonne qualité.It can be seen that in the following galvanizing ovens state of the art, the tape circulates in an atmosphere reducing from the inlet to the outlet of the oven or, if there is an open preheating zone, from the outlet of it at the outlet of the oven. The reducing atmosphere is therefore kept in the oven at the latest from the exit from preheating is traditionally at a strip temperature from 650 to 700 ° C. The purpose of this process is purpose of limiting the formation of oxides, mainly of iron, to the surface of the strip and to reduce them if any exists or if it has formed in the preheater in order to allow good attachment of zinc to the surface of the strip to obtain a good quality galvanized product.

Le séjour de la bande sous cette atmosphère réductrice doit se faire dans des conditions suffisantes (température, temps de séjour, point de rosée de l'atmosphère du four) pour y permettre un nettoyage de la bande compatible avec une bonne qualité de revêtement ultérieur, en particulier d'adhérence du zinc.The stay of the strip under this reducing atmosphere must be done in sufficient conditions (temperature, residence time, dew point of the furnace atmosphere) to allow cleaning of the tape compatible with good quality of subsequent coating, in particular zinc adhesion.

Les développements actuels des aciers s'orientant vers l'augmentation de leur résistance mécanique conduisent à l'augmentation de la teneur en éléments d'alliage tels que : Si, Cr, Mn ....Current steel developments moving towards the increase in their mechanical strength lead to increasing the content of alloying elements such as that: Si, Cr, Mn ....

On remarque que ces nouveaux éléments d'additions forment des oxydes plus stables que ceux du fer composant la structure de la bande. Ces éléments sont donc avides d'oxygène, ce qui va provoquer leur oxydation dans un premier temps à la surface de la bande où l'oxygène est présent, même en faible concentration. La formation de ces oxydes ayant consommé les atomes de Si, Cr,... disponibles en surface, ces éléments s'y retrouvent en plus faible concentration. Pour compenser cette baisse de concentration, les atomes de Si, Cr,... voisins vont donc migrer par diffusion de l'intérieur vers la surface, ce qui va alimenter la réaction d'oxydation. Cette migration est thermiquement activée, c'est-à-dire accélérée par le temps et surtout par la température. En conséquence, elle ne se fait pas dans la section de préchauffe à feu nu, car bien que l'atmosphère soit riche en oxygène, la bande y reste trop peu de temps à haute température en raison de la grande vitesse de chauffage. En revanche, la diffusion des atomes oxydables sera importante dans les sections de chauffage et de maintien car la bande y est plus chaude, atteignant sa température maximale avec des temps de séjour plus importants.We notice that these new additions form oxides more stable than those of the iron making up the band structure. These elements are therefore greedy of oxygen, which will cause them to oxidize in a first time at the surface of the strip where oxygen is present, even in low concentrations. The formation of these oxides having consumed the atoms of Si, Cr, ... available in surface, these elements are found there in weaker concentration. To compensate for this drop in concentration, the neighboring Si, Cr, ... atoms therefore go migrate by diffusion from the inside to the surface, which will feed the oxidation reaction. This migration is thermally activated, i.e. time accelerated and especially by the temperature. Consequently, it does not not in the preheat section over open heat, because the atmosphere is rich in oxygen, the band stays there too little time at high temperature due to the high heating speed. On the other hand, the dissemination of oxidizable atoms will be important in the sections of heating and holding because the strip is warmer there, reaching its maximum temperature with residence times more important.

Dans la section de réduction du four, les oxydes de fer, qui sont plus facilement réductibles, seront éliminés. Les oxydes de Si, etc... plus stables, seront plus difficilement réduits et vont subsister, formant un film continu ou discontinu qui fait obstacle à la bonne adhérence du revêtement de zinc.In the reduction section of the oven, iron oxides, which are more easily reducible, will be eliminated. The more stable Si oxides, etc. will be more difficult reduced and will remain, forming a continuous film or discontinuous which obstructs the good adhesion of the zinc coating.

Les fours existants ne sont donc pas adaptés à la galvanisation des aciers nouveaux à haute résistance mécanique, de par leur richesse en éléments oxydables tels que Si, Cr..... Ils doivent être galvanisés :

  • soit à froid, c'est-à-dire par voie électrolytique. Cette solution permet d'utiliser la nuance souhaitée, mais elle est beaucoup plus coûteuse à mettre en oeuvre.
  • soit à chaud, mais dans ce cas, il faut ou refroidir rapidement l'acier (trempe) ou affiner sa nuance :
    Tremper l'acier permet d'en limiter la concentration en éléments d'addition, mais nécessite de réaliser après recuit un refroidissement rapide. Ce refroidissement permet la formation de structures multiphasées qui fournissent les propriétés durcissantes souhaitées. Cependant, cette technique est encore peu utilisée.
Existing ovens are therefore not suitable for galvanizing new steels with high mechanical resistance, due to their richness in oxidizable elements such as Si, Cr ..... They must be galvanized:
  • either cold, that is to say electrolytically. This solution makes it possible to use the desired shade, but it is much more expensive to implement.
  • either hot, but in this case, it is necessary either to cool the steel quickly (hardening) or to refine its nuance:
    Dipping the steel limits its concentration in addition elements, but requires rapid cooling after annealing. This cooling allows the formation of multiphase structures which provide the desired hardening properties. However, this technique is still little used.

L'invention se propose de résoudre le problème technique exposé ci-dessus en apportant un procédé qui permet de réaliser une galvanisation à chaud d'aciers de nuances très chargées en éléments durcisseurs dans des fours de construction traditionnelle.The invention proposes to solve the technical problem exposed above by providing a process which makes it possible to hot-dip galvanizing of very different grades of steel loaded with hardening elements in furnaces traditional construction.

Le procédé objet de cette invention permet de limiter, voire d'éviter, la formation de dépôts oxydés des éléments d'additions métalliques durcissantes tels que par exemple Si, Cr... à la surface de la bande, dépôts qui forment un film continu ou discontinu s'opposant à l'adhérence du revêtement de zinc à la surface de la tôle.The process which is the subject of this invention makes it possible to limit, or even to avoid, the formation of oxidized deposits of the elements hardening metallic additions such as for example If, Cr ... on the surface of the strip, deposits which form a continuous or discontinuous film opposing the adhesion of the zinc coating on the surface of the sheet.

En conséquence, cette invention concerne un procédé de traitement thermochimique de bande métallique en continu, de type oxydo-réduction selon lequel la bande se déplace au travers d'un four, dans une atmosphère protectrice, caractérisé en ce que la bande passe au travers d'au moins un dispositif d'isolement partiel ou total, positionné au sein d'au moins une section du four, ou entre deux sections, la bande étant chauffée dans ce dispositif d'isolement, dans des atmosphères à point de rosée adapté à chaque bande, en fonction de la composition spécifique de l'acier et du cycle thermique appliqué.Accordingly, this invention relates to a method of continuous metal strip thermochemical treatment, of the oxidation-reduction type according to which the strip moves at the through an oven, in a protective atmosphere, characterized in that the strip passes through at least a partial or total isolation device, positioned at within at least one section of the oven, or between two sections, the strip being heated in this device isolation, in dew point atmospheres suitable for each strip, depending on the specific composition of steel and applied thermal cycle.

Ainsi qu'on le comprend, le procédé objet de l'invention consiste principalement à permettre de chauffer la bande dans des atmosphères à point de rosée différents suivant des plages de températures différentes de celles connues dans l'état de l'art, et en particulier à des points de rosée supérieurs aux valeurs habituelles, grâce à des dispositifs d'isolement.As will be understood, the process which is the subject of the invention mainly consists of allowing the strip to be heated in different dew point atmospheres depending on temperature ranges different from those known in the state of the art, and in particular at points of dew above the usual values, thanks to isolation devices.

En effet, lorsque l'on augmente le point de rosée, c'est-à-dire la concentration en oxygène, on va favoriser la diffusion de l'oxygène vers l'intérieur du métal par les défauts et surtout par les joints de grains. L'oxygène va alors oxyder les atomes de Si,... à l'intérieur du métal. Il n'y aura alors plus assez de Si,... disponible pour migrer vers la surface et alimenter l'oxydation superficielle, d'autant plus que la cinétique de diffusion de l'oxygène par les joints est plus rapide que la diffusion des atomes oxydables dans le métal. Par ailleurs, cette oxydation interne va bloquer la diffusion de ces atomes vers la surface, ce qui limite encore la quantité de ces oxydes formés.Indeed, when we increase the dew point, that is to say the oxygen concentration, we will favor the diffusion of oxygen towards the interior of the metal by the defects and especially by the grain boundaries. Oxygen goes then oxidize the atoms of Si, ... inside the metal. he then there will no longer be enough Si, ... available to migrate towards the surface and feed the surface oxidation, especially since the kinetics of oxygen diffusion through the joints is faster than the diffusion of atoms oxidizable in metal. Furthermore, this oxidation internal will block the diffusion of these atoms towards the surface, which further limits the amount of these oxides trained.

La mise en oeuvre du procédé selon l'invention consiste à permettre de maitriser avec précision le point de rosée de cette atmosphère dans la chambre de chauffage afin que cette atmosphère soit oxydante pour les éléments ciblés mais reste réductrice pour le fer, qu'il ne faut pas oxyder. La section aval du four - la fin du maintien et le refroidissement - restera réductrice, pour réduire les oxydes de fer qui auront pu être éventuellement formés dans la section à point de rosée élevé, ce qui n'inversera pas le processus d'oxydation interne des additifs métalliques de l'acier, car les oxydes formés à partir de ces additifs sont plus stables que les oxydes de fer.The implementation of the method according to the invention consists in allow to precisely control the dew point of this atmosphere in the heating chamber so that this atmosphere is oxidizing for the targeted elements but remains reductive for iron, which should not be oxidize. The downstream section of the oven - the end of maintenance and the cooling - will remain reducing, to reduce iron oxides which may have been possibly formed in the high dew point section, which will not reverse the internal oxidation process of metallic additives steel, because the oxides formed from these additives are more stable than iron oxides.

Selon l'invention, le point de rosée de l'atmosphère peut être modifié en fonction du cycle thermique, c'est-à-dire de la température de la section du four et du temps de séjour de la bande dans cette dernière, pour intégrer les variations d'épaisseur de la bande.According to the invention, the dew point of the atmosphere can be modified according to the thermal cycle, i.e. the oven section temperature and the stay of the band in the latter, to integrate the variations in strip thickness.

Le procédé objet de l'invention se propose donc de pouvoir confiner une atmosphère contrôlée dont le point de rosée est supérieur à celui utilisé dans les fours suivant l'état de l'art de façon à être moins réductrice, ceci dans une section du four à haute température d'une ligne de galvanisation conventionnelle.The process which is the subject of the invention therefore proposes to be able to confine a controlled atmosphere whose dew point is higher than that used in ovens according to the state art in order to be less reductive, this in a section of the high temperature oven of a line of conventional galvanization.

La mise en oeuvre du procédé est réalisée par l'implantation de dispositifs de séparation d'atmosphère entre les différentes sections du four, implantation permettant :

  • d'éviter l'oxydation du fer et donc de garantir l'adhérence ;
  • d'adapter la composition chimique de l'atmosphère recherchée ;
  • de développer l'oxydation interne des éléments d'addition avant qu'ils ne puissent diffuser en surface et y être oxydés.
The implementation of the process is carried out by the installation of devices for separating the atmosphere between the different sections of the furnace, installation allowing:
  • avoid the oxidation of iron and therefore guarantee adhesion;
  • adapt the chemical composition of the desired atmosphere;
  • to develop the internal oxidation of the addition elements before they can diffuse on the surface and be oxidized there.

Claims (2)

Procédé de traitement thermochimique en continu de bandes métalliques, notamment d'acier, du type oxydo-réduction, selon lequel la bande se déplace au travers d'un four dans une atmosphère protectrice, caractérisé en ce que ladite bande passe au travers d'au moins un dispositif d'isolement partiel ou total, positionné au sein d'au moins une section du four, ou entre deux sections, la bande étant chauffée, dans ce dispositif d'isolement, dans des atmosphères à point de rosée adapté à chaque bande en fonction de la composition spécifique de l'acier, de manière que l'atmosphère soit oxydante pour certains éléments d'addition, mais demeure réductrice pour le fer.Method of continuous thermochemical treatment of metal strips, in particular of steel, of the oxidation-reduction type, according to which the strip moves through an oven in a protective atmosphere, characterized in that said strip passes through at least at least one partial or total isolation device, positioned within at least one section of the furnace, or between two sections, the strip being heated, in this isolation device, in dew point atmospheres adapted to each strip depending on the specific composition of the steel, so that the atmosphere is oxidizing for certain elements of addition, but remains reducing for iron. Procédé selon la revendication 1, caractérisé en ce que le point de rosée de ladite atmosphère peut être modifiée en fonction du cycle thermique, c'est-à-dire de la température de la section du four et du temps de séjour de la bande dans cette dernière, pour intégrer les variations d'épaisseur de la bande.Process according to claim 1, characterized in that the dew point of said atmosphere can be modified as a function of the thermal cycle, that is to say the temperature of the section of the furnace and the residence time of the strip in the latter, to integrate the variations in thickness of the strip.
EP02292018A 2001-08-21 2002-08-09 Process for hot-dip galvanising of high-strength steel strips Withdrawn EP1285972A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR0110957 2001-08-21
FR0110957A FR2828888B1 (en) 2001-08-21 2001-08-21 METHOD FOR HOT GALVANIZATION OF HIGH STRENGTH STEEL METAL STRIPS

Publications (1)

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EP1285972A1 true EP1285972A1 (en) 2003-02-26

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EP02292018A Withdrawn EP1285972A1 (en) 2001-08-21 2002-08-09 Process for hot-dip galvanising of high-strength steel strips

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US (1) US6913658B2 (en)
EP (1) EP1285972A1 (en)
JP (1) JP2003183799A (en)
BR (1) BR0203383A (en)
DE (1) DE1285972T1 (en)
ES (1) ES2188434T1 (en)
FR (1) FR2828888B1 (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1457580A1 (en) * 2003-03-12 2004-09-15 STEIN HEURTEY, Société Anonyme: Method for the control of oxidation of sheets before hot dip galvanizing and galvanizing line
WO2006061151A1 (en) * 2004-12-09 2006-06-15 Thyssenkrupp Steel Ag Method for hot dip coating a strip of heavy-duty steel
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ES2425916T5 (en) * 2010-11-30 2024-08-09 Tata Steel Uk Ltd Procedure for galvanizing a steel strip in a continuous tempering hot-dip galvanizing line
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3925579A (en) * 1974-05-24 1975-12-09 Armco Steel Corp Method of coating low alloy steels
US4183983A (en) * 1978-08-17 1980-01-15 Selas Corporation Of America Method for reducing metal oxide formation on a continuous metal sheet in the hot dip coating thereof
JPH02285057A (en) * 1989-04-27 1990-11-22 Sumitomo Metal Ind Ltd Method for continuously annealing steel sheet to be galvanized
BE1011131A6 (en) * 1997-04-28 1999-05-04 Centre Rech Metallurgique Method of coating a steel strip by hot-dip galvanising
EP1076105A1 (en) * 1999-02-25 2001-02-14 Kawasaki Steel Corporation Steel plate, hot-dip steel plate and alloyed hot-dip steel plate and production methods therefor

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6635313B2 (en) * 2001-11-15 2003-10-21 Isg Technologies, Inc. Method for coating a steel alloy

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3925579A (en) * 1974-05-24 1975-12-09 Armco Steel Corp Method of coating low alloy steels
US4183983A (en) * 1978-08-17 1980-01-15 Selas Corporation Of America Method for reducing metal oxide formation on a continuous metal sheet in the hot dip coating thereof
JPH02285057A (en) * 1989-04-27 1990-11-22 Sumitomo Metal Ind Ltd Method for continuously annealing steel sheet to be galvanized
BE1011131A6 (en) * 1997-04-28 1999-05-04 Centre Rech Metallurgique Method of coating a steel strip by hot-dip galvanising
EP1076105A1 (en) * 1999-02-25 2001-02-14 Kawasaki Steel Corporation Steel plate, hot-dip steel plate and alloyed hot-dip steel plate and production methods therefor

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 015, no. 056 (C - 0804) 8 February 1991 (1991-02-08) *

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FR2852330A1 (en) * 2003-03-12 2004-09-17 Stein Heurtey METHOD OF CONTROLLED OXIDATION OF STRIPS BEFORE CONTINUOUS GALVANIZATION AND GALVANIZATION LINE
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US8609192B2 (en) 2007-09-03 2013-12-17 Siemens Vai Metals Technologies Sas Method and device for controlling oxidizing-reducing of the surface of a steel strip running continuously through a radiant tubes furnace for its galvanizing
CN101796203B (en) * 2007-09-03 2011-12-14 西门子Vai金属科技有限公司 Controlled method and device for oxidation/reduction of the surface of a steel strip running continuously through a radiant tube oven for galvanisation thereof
WO2009030823A1 (en) * 2007-09-03 2009-03-12 Siemens Vai Metals Technologies Sas Controlled method and device for oxidation/reduction of the surface of a steel strip running continuously through a radiant tube oven for galvanisation thereof
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US9090951B2 (en) 2007-12-20 2015-07-28 Voestalpine Stahl Gmbh Method for producing coated and hardened components of steel and coated and hardened steel strip therefor

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