EP0792949A1 - Process for pickling a steel workpiece, in particular stainless steel sheet strip - Google Patents

Process for pickling a steel workpiece, in particular stainless steel sheet strip Download PDF

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Publication number
EP0792949A1
EP0792949A1 EP97400433A EP97400433A EP0792949A1 EP 0792949 A1 EP0792949 A1 EP 0792949A1 EP 97400433 A EP97400433 A EP 97400433A EP 97400433 A EP97400433 A EP 97400433A EP 0792949 A1 EP0792949 A1 EP 0792949A1
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EP
European Patent Office
Prior art keywords
pickling
solution
strip
liter
ions
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Granted
Application number
EP97400433A
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German (de)
French (fr)
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EP0792949B1 (en
Inventor
Henri Giraud
Bernard Vialatte
Martine Lauvergne
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Ugine SA
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USINOR SA
USINOR Sacilor SA
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Classifications

    • 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
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
    • C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
    • C23G1/08—Iron or steel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B45/00—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
    • B21B45/04—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills for de-scaling, e.g. by brushing
    • B21B45/06—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills for de-scaling, e.g. by brushing of strip material
    • 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
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
    • C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
    • C23G1/08—Iron or steel
    • C23G1/086—Iron or steel solutions containing HF
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
    • B21B1/22—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length
    • B21B1/30—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a non-continuous process
    • B21B1/32—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a non-continuous process in reversing single stand mills, e.g. with intermediate storage reels for accumulating work
    • B21B1/36—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a non-continuous process in reversing single stand mills, e.g. with intermediate storage reels for accumulating work by cold-rolling
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
    • B21B1/22—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length
    • B21B2001/228—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length skin pass rolling or temper rolling
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B15/00—Arrangements for performing additional metal-working operations specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
    • B21B2015/0071—Levelling the rolled product
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B3/00—Rolling materials of special alloys so far as the composition of the alloy requires or permits special rolling methods or sequences ; Rolling of aluminium, copper, zinc or other non-ferrous metals
    • B21B3/02—Rolling special iron alloys, e.g. stainless steel

Definitions

  • the invention relates to a process for pickling a steel part and in particular a strip of stainless steel sheet.
  • air blowing has the sole function of stirring the solution because it is well known that in a sulfuric medium the oxidation potential of iron is such that a simple stirring in air does can oxidize iron Fe 2+ to Fe 3+ .
  • the object of the invention is to propose a pickling process which ensures, in a very short time, the pickling of a steel part and in particular of a stainless steel strip, the pickling time being compatible with the durations imposed on a production line for the sheet metal part or strip.
  • the subject of the invention is a process for pickling a piece of steel and in particular a strip of stainless steel sheet, consisting in applying an aqueous pickling solution consisting of hydrochloric acid and ferric and ferrous pickling ions. in solution, and, in order to maintain a constant pickling power of the aqueous hydrochloric acid solution having a pH of less than 1, to maintain the concentration of Fe 3+ ions at a value of between 1 g / liter and 300 g / liter, by reoxidation by means of oxygenation of the Fe 2+ ions generated during pickling, the REDOX potential being maintained at a value between 0 and 800 mV, potential measured between a platinum electrode and a Ag / AgCl reference electrode placed in the solution.
  • the invention also relates to the use of the pickling method according to the invention in the field of accelerated pickling of a steel part and in particular of a stainless steel strip on an on-line production installation, continuously of the strip. in steel.
  • pickling baths based on hydrochloric acid are considered to generate corrosion of the surface of the pickled parts, this corrosion being of the pitting type.
  • the non-polluting pickling processes preferably use solutions comprising, alone or in combination, in different concentrations, sulfuric and hydrofluoric acids.
  • the pickling tests were carried out with a single acid so as to avoid the formation of insoluble complex compounds, the solution being intended to be recycled, that is to say reused in pickling.
  • pickling solutions have been tested for pickling efficiency, taking into account their maximum efficiency by adjusting the REDOX potential corresponding to the different acid concentrations used.
  • the residence time is adapted to the composition of the steel and to the type of oxide to be etched.
  • the REDOX potential is fixed at 460 mV relative to an Ag / AgCl reference electrode, the potential being kept constant by injection of air and additional supply of peroxide. hydrogen.
  • Table 1 below presents the different pickling speeds measured in loss of material in grams per square meter and per second for different grades of steel: Steel Solution A Solution B Solution C The invention AISI 304 0.41; 0.37 0.42; 0.37 0.59 0.28; 0.27 0.31; 0.27 0.63-0.56 AISI 316L 0.31 0.40 0.53 AISI 430 0.46 - 0.46 0.92; 0.90 1.6 - 1.1 AISI 430 Ti 0.65 - 0.67 1.01; 0.99 1.5 - 1.8 AISI 409 0.55 - 0.58 0.93; 0.96 1.3 - 1.6
  • the surface of the strip stripped with a hydrochloric solution has a white appearance, without pitting, while the surface of the strip stripped with an aqueous sulfuric acid solution has a blackish appearance.

Abstract

In a steel pickling process, especially for stainless steel strip, employing an aqueous hydrochloric acid pickling solution, the Fe(III) ion concentration is maintained at 1-300 g/l, for constant pickling capacity of the solution of pH less than 1, by oxygenation (preferably aeration) to effect re-oxidation of the Fe(II) ions generated during pickling, the redox potential being maintained at a value of 0-800 (preferably 400-600) mV as measured between a Pt electrode and an Ag/AgCl reference electrode in the solution. Also claimed is a continuous rolled steel (especially stainless steel) strip production line employing the above process, in which the strip is subjected to mechanical treatment (e.g. stretch-levelling and/or peening), primary pickling, working (e.g. rolling), annealing, final pickling and finishing (e.g. skin pass rolling), at least one of the pickling operations being carried out by the above process.

Description

L'invention concerne un procédé de décapage d'une pièce en acier et notamment d'une bande de tôle en acier inoxydable.The invention relates to a process for pickling a steel part and in particular a strip of stainless steel sheet.

Il est connu du brevet japonais N° JP S 56-171638 un procédé de décalaminage de fil d'acier dans lequel le fil est décapé dans un bain d'acide chlorhydrique pendant un intervalle de temps compris entre 20 et 40 minutes, le bain ayant une concentration en acide chlorhydrique compris entre 10 et 20% en poids. Pour accélérer le décapage, on modifie la concentration en acide du bain. Cependant, il est enseigné qu'une solution trop concentrée occasionne des dégagements de fumées et oblige à sur-dimensionner la taille des installations au détriment du coût. Selon la technique proposée dans ce document, on ajoute une quantité de FeCl2 à une concentration pouvant aller jusqu'à la saturation ainsi qu'une quantité de FeCl3 de manière que les potentiels d'oxydo-réduction de Fe3+/ Fe2+ soit mesurés au cours du décalaminage. Le potentiel est ajusté par addition de FeCl3 via une busette d'injection. Le processus de décapage consiste en la dissolution par HCl du substrat ferreux ce qui engendre un dégagement d'hydrogène.It is known from Japanese Patent No. JP S 56-171638 a process for descaling steel wire in which the wire is pickled in a hydrochloric acid bath for a time interval between 20 and 40 minutes, the bath having a hydrochloric acid concentration of between 10 and 20% by weight. To accelerate the pickling, the acid concentration of the bath is modified. However, it is taught that an excessively concentrated solution gives off smoke and obliges to oversize the size of the installations at the expense of cost. According to the technique proposed in this document, an amount of FeCl 2 is added at a concentration which can go up to saturation as well as an amount of FeCl 3 so that the redox potentials of Fe 3+ / Fe 2 + be measured during descaling. The potential is adjusted by adding FeCl 3 via an injection nozzle. The pickling process consists of the HCl dissolution of the ferrous substrate, which gives off hydrogen.

Il est également précisé dans ce document que, de manière générale, les bains de décapage à base d'acide chlorhydrique génèrent une corrosion de l'acier du type par piqûre.It is also specified in this document that, generally, pickling baths based on hydrochloric acid generate corrosion of steel of the pitting type.

Il est également connu, par exemple du brevet JP H2-205692, un bain de décapage des aciers inoxydables dans lequel des produits laminés à chaud ou soumis à un recuit sont décapés dans une solution d'acide sulfurique contenant des ions Fe3+ et Fe2+, ladite solution contenant au moins 10 g/litre de fer, le décapage étant effectué en aérant la solution par de l'air insufflé à un débit d'au moins 100 ml/mn et par litre de solution.It is also known, for example from patent JP H2-205692, a pickling bath for stainless steels in which hot rolled or annealed products are pickled in a sulfuric acid solution containing Fe 3+ and Fe ions 2+ , said solution containing at least 10 g / liter of iron, pickling being carried out by aerating the solution with blown air at a flow rate of at least 100 ml / min and per liter of solution.

Dans ce type de bain, l'insufflation d'air a pour unique fonction le brassage de la solution car il est bien connu qu'en milieu sulfurique le potentiel d'oxydation du fer est tel qu'un simple brassage à l'air ne peut oxyder le fer Fe2+ en Fe3+.In this type of bath, air blowing has the sole function of stirring the solution because it is well known that in a sulfuric medium the oxidation potential of iron is such that a simple stirring in air does can oxidize iron Fe 2+ to Fe 3+ .

Il est également connu du certificat d'utilité N° FR 2551465, associé au brevet EP N° 0236 354, un procédé de décapage en continu d'une bande d'acier inoxydable dans lequel on utilise un bain de décapage composé principalement d'acide fluorhydrique contenant des ions ferriques, le décapage de la bande d'acier étant réalisé en maintenant la teneur en fer ferrique à au moins 15 g/l par l'oxydation du bain au moyen d'une injection d'air ou de l'introduction complémentaire d'un autre oxydant tout en maintenant le potentiel REDOX dudit bain dans un intervalle de valeurs compris entre 0 et 800 mV.It is also known from utility certificate No. FR 2551465, associated with patent EP No. 0236 354, a continuous pickling process for a strip of stainless steel in which a pickling bath composed mainly of acid is used. hydrofluoric containing ferric ions, the pickling of the steel strip being carried out by maintaining the ferric iron content at least 15 g / l by the oxidation of the bath by means of an air injection or the introduction complementary to another oxidant while maintaining the REDOX potential of said bath in a range of values between 0 and 800 mV.

Il est enseigné dans ces documents le rôle oxydant de l'air qui oxyde les ions Fe2+ en ions Fe3+, la réaction de décapage s'effectuant sans dégagement d'hydrogène.It is taught in these documents the oxidizing role of air which oxidizes Fe 2+ ions to Fe 3+ ions, the pickling reaction being carried out without release of hydrogen.

Nous retrouvons également dans le domaine du décapage des aciers inoxydables un nombre conséquent de documents qui décrivent des procédés de décapage dont les bains sont constitués d'un mélange de deux ou trois des acides cités précédemment dans le but d'éviter l'utilisation classique de l'acide nitrique qui a l'inconvénient de générer des dérivés polluants de cet acide du type NOx.We also find in the field of pickling of stainless steels a considerable number of documents which describe pickling processes in which the baths consist of a mixture of two or three of the acids mentioned above in order to avoid the conventional use of nitric acid which has the drawback of generating polluting derivatives of this NOx type acid.

Dans le cadre de la production d'une bande de tôle laminée d'acier et notamment d'acier inoxydable, sur une ligne, en continu, la tôle est soumise successivement à:

  • un traitement mécanique, par exemple de planage sous traction et/ou grenaillage,
  • un décapage primaire,
  • une opération de transformation comme par exemple de laminage,
  • des opérations de recuit,
  • un décapage final,
  • une opération de finition comme par exemple un laminage à froid de type " skin pass".
In the context of the production of a strip of steel and especially stainless steel rolled sheet, on a continuous line, the sheet is successively subjected to:
  • mechanical treatment, for example leveling under tension and / or shot blasting,
  • a primary pickling,
  • a transformation operation such as for example rolling,
  • annealing operations,
  • a final stripping,
  • a finishing operation such as for example cold rolling of the "skin pass" type.

Une réduction très importante de la durée du traitement de décapage de l'acier est imposée pour éviter une accumulation de la bande entre les différents dispositifs de la ligne. Une telle ligne d'élaboration a l'avantage de réduire la manutention intermédiaire et le stock.A very significant reduction in the duration of the pickling treatment of the steel is imposed to avoid an accumulation of the strip between the various devices of the line. Such a production line has the advantage of reducing intermediate handling and stock.

Se pose, sur cette ligne, le problème du décapage et en particulier d'un décapage en un temps imposé court, pour éviter, de manière impérative, une accumulation de la bande traitée entre les différents dispositifs en enchaînement sur la ligne de production de la bande.On this line, there is the problem of pickling and in particular of pickling in a short imposed time, to avoid, imperatively, an accumulation of the treated strip between the various devices in sequence on the production line of the bandaged.

Un nombre important d'options, dans les procédés de décapage a été envisagé en tenant compte du critère le plus important du décapage qui devient la vitesse de décapage ou encore la durée minimale pendant laquelle la bande doit être en contact avec la solution de décapage.A large number of options in the pickling processes have been considered, taking into account the most important criterion of pickling which becomes the pickling speed or the minimum duration during which the strip must be in contact with the pickling solution.

L'invention a pour but de proposer un procédé de décapage qui assure, en un temps très court, le décapage d'une pièce en acier et notamment d'une bande en acier inoxydable, le temps de décapage étant compatible avec les durées imposées sur une ligne de production de la pièce ou bande de tôle.The object of the invention is to propose a pickling process which ensures, in a very short time, the pickling of a steel part and in particular of a stainless steel strip, the pickling time being compatible with the durations imposed on a production line for the sheet metal part or strip.

L'invention a pour objet un procédé de décapage d'une pièce en acier et notamment d'une bande de tôle en acier inoxydable, consistant à appliquer une solution aqueuse de décapage constituée d'acide chlorhydrique et d'ions ferriques et ferreux de décapage en solution, et, en vue de conserver un pouvoir décapant constant de la solution aqueuse d'acide chlorhydrique ayant un pH inférieur à 1, à maintenir la concentration en ions Fe3+ à une valeur comprise entre 1 g/litre et 300 g/litre, par réoxydation au moyen d'un oxygénation des ions Fe2+ générés lors du décapage, le potentiel REDOX étant maintenu à une valeur comprise entre 0 et 800 mV, potentiel mesuré entre une électrode de platine et une électrode de référence Ag/AgCl placées dans la solution.The subject of the invention is a process for pickling a piece of steel and in particular a strip of stainless steel sheet, consisting in applying an aqueous pickling solution consisting of hydrochloric acid and ferric and ferrous pickling ions. in solution, and, in order to maintain a constant pickling power of the aqueous hydrochloric acid solution having a pH of less than 1, to maintain the concentration of Fe 3+ ions at a value of between 1 g / liter and 300 g / liter, by reoxidation by means of oxygenation of the Fe 2+ ions generated during pickling, the REDOX potential being maintained at a value between 0 and 800 mV, potential measured between a platinum electrode and a Ag / AgCl reference electrode placed in the solution.

Les autres caractéristiques de l'invention sont :

  • la réoxydation des ions Fe2+ par oxygénation est réalisée par aération de la solution décapante,
  • l'aération de la solution décapante est réalisée par des moyens choisis parmi : pompage et refoulement de la solution à l'air libre, bullage, brassage, injection d'un gaz contenant l'élément oxygène, aspersion de la solution décapante dans une enceinte contenant de l'air,
  • la réoxydation est complétée par addition de composés choisis parmi : les peroxydes et/ou les persels et de préférence le peroxyde d'hydrogène (H2O2) et/ou le permanganate de potassium (KMnO4),
  • la solution traitante présente, de préférence, une concentration en acide chlorhydrique comprise entre 35 g/litre et 250 g/litre,
  • la solution traitante est appliquée à une température comprise entre 10°C et 95°C et de préférence entre 65°C et 85°C.
  • on chauffe la pièce à traiter préalablement à l'application de la solution,
  • le temps d'application de la solution sur la bande est inférieur à 2 mn.
  • on ajuste le potentiel REDOX entre 0 mV et 800 mV et de préférence entre 400 mV et 600 mV, par apport d'un composé et/ou d'un gaz oxydant.
The other characteristics of the invention are:
  • the reoxidation of the Fe 2+ ions by oxygenation is carried out by aeration of the pickling solution,
  • the stripping solution is aerated by means chosen from: pumping and delivery of the solution in the open air, bubbling, stirring, injection of a gas containing the oxygen element, spraying of the stripping solution into an enclosure containing air,
  • reoxidation is completed by addition of compounds chosen from: peroxides and / or persalts and preferably hydrogen peroxide (H 2 O 2 ) and / or potassium permanganate (KMnO 4 ),
  • the treating solution preferably has a hydrochloric acid concentration of between 35 g / liter and 250 g / liter,
  • the treating solution is applied at a temperature between 10 ° C and 95 ° C and preferably between 65 ° C and 85 ° C.
  • the part to be treated is heated prior to the application of the solution,
  • the application time of the solution on the strip is less than 2 min.
  • the REDOX potential is adjusted between 0 mV and 800 mV and preferably between 400 mV and 600 mV, by adding a compound and / or an oxidizing gas.

L'invention concerne également l'utilisation du procédé de décapage selon l'invention dans le domaine du décapage accéléré d'une pièce en acier et notamment d'une bande en acier inoxydable sur une installation de production en ligne, en continu de la bande en acier.The invention also relates to the use of the pickling method according to the invention in the field of accelerated pickling of a steel part and in particular of a stainless steel strip on an on-line production installation, continuously of the strip. in steel.

L'invention concerne également une ligne de production, en continu, d'une bande de tôle laminée en acier et notamment en acier inoxydable dans laquelle la bande est soumise successivement à :

  • un traitement mécanique, par exemple de planage sous traction et/ou grenaillage,
  • un décapage primaire,
  • une opération de transformation comme par exemple de laminage,
  • des opérations de recuit,
  • un décapage final,
  • une opération de finition comme par exemple un laminage à froid de type "skin pass", l'un au moins des décapages consistant à appliquer une solution aqueuse de décapage constituée d'acide chlorhydrique et d'ions ferriques et ferreux de décapage en solution, et, en vue de conserver un pouvoir décapant constant de la solution aqueuse d'acide chlorhydrique ayant un pH inférieur à 1, à maintenir la concentration en ions Fe3+, à une valeur comprise entre 1 g/litre et 300 g/litre, par réoxydation au moyen d'une oxygénation des ions Fe2+ générés lors du décapage, le potentiel REDOX étant maintenu à une valeur comprise entre 0 et 800 mV, potentiel mesuré entre une électrode de platine et une électrode de référence Ag/AgCl placées dans la solution.
The invention also relates to a production line, continuously, of a strip of sheet steel laminated in steel and in particular stainless steel in which the strip is successively subjected to:
  • mechanical treatment, for example leveling under tension and / or shot blasting,
  • a primary pickling,
  • a transformation operation such as for example rolling,
  • annealing operations,
  • a final stripping,
  • a finishing operation such as for example cold rolling of the "skin pass" type, at least one of the pickling operations consisting in applying an aqueous pickling solution consisting of hydrochloric acid and of ferric and ferrous pickling ions in solution, and, in order to maintain a constant pickling power of the aqueous hydrochloric acid solution having a pH of less than 1, to maintain the concentration of Fe 3+ ions, at a value of between 1 g / liter and 300 g / liter, by reoxidation by means of oxygenation of the Fe 2+ ions generated during pickling, the REDOX potential being maintained at a value between 0 and 800 mV, potential measured between a platinum electrode and an Ag / AgCl reference electrode placed in the solution.

La description qui suit fera bien comprendre l'invention.The following description will make the invention clear.

Parmi les différents procédés de décapage connus les bains de décapage à base d'acide chlorhydrique sont considérés comme générant une corrosion de la surface des pièces décapées, cette corrosion étant du type par piqûre.Among the various known pickling processes, pickling baths based on hydrochloric acid are considered to generate corrosion of the surface of the pickled parts, this corrosion being of the pitting type.

Les procédés de décapage non polluants utilisent, de préférence, des solutions comprenant seuls ou en combinaison, en différentes concentrations, les acides sulfurique et fluorhydrique.The non-polluting pickling processes preferably use solutions comprising, alone or in combination, in different concentrations, sulfuric and hydrofluoric acids.

Différentes solutions décapantes ont été testées dans le but d'obtenir un décapage rapide notamment sur une bande d'acier inoxydable, afin que celle-ci puisse être utilisable, en continu, après décapage, dans une installation en ligne de production d'une bande de tôle, l'installation de décapage étant insérée, dans la ligne, entre des dispositifs de transformation de l'acier comme par exemple une planeuse sous traction et un laminoir.Various pickling solutions have been tested with the aim of obtaining rapid pickling, in particular on a strip of stainless steel, so that it can be used, continuously, after pickling, in an installation for the production of a strip. of sheet metal, the pickling installation being inserted, in the line, between steel processing devices such as for example a planer under tension and a rolling mill.

De préférence, les tests de décapage ont été réalisés avec un seul acide de manière à éviter la formation de composés complexes insolubles, la solution étant destinée à être recyclée, c'est-à-dire réutilisée en décapage.Preferably, the pickling tests were carried out with a single acid so as to avoid the formation of insoluble complex compounds, the solution being intended to be recycled, that is to say reused in pickling.

Dans un test comparatif de solutions décapantes contenant un acide sulfurique, fluorhydrique ou chlorhydrique, il a été constaté que l'acide chlorhydrique en solution concentrée présentait une efficacité surprenante dans le domaine de la vitesse de décapage.In a comparative test of pickling solutions containing sulfuric, hydrofluoric or hydrochloric acid, it was found that hydrochloric acid in concentrated solution showed surprising efficiency in the field of pickling speed.

Il a été comparé :

  • une solution décapante A aqueuse d'acide sulfurique de normalité 4 N, correspondant à une concentration de 196 g/litre d'acide et contenant 60 g/litre de fer total.
  • une solution décapante B aqueuse d'acide fluorhydrique de normalité 4N, correspondant à une concentration de 80 g/litre d'acide et contenant 60 g/litre de fer total.
  • une solution décapante C aqueuse d'acide chlorhydrique de normalité 4N correspondant à une concentration de 146 g/litre d'acide et contenant 60 g/litre de fer total.
It was compared:
  • an aqueous stripping solution A of sulfuric acid of normality 4 N, corresponding to a concentration of 196 g / liter of acid and containing 60 g / liter of total iron.
  • an aqueous pickling solution B of hydrofluoric acid of normality 4N, corresponding to a concentration of 80 g / liter of acid and containing 60 g / liter of total iron.
  • an aqueous pickling solution C of hydrochloric acid of normality 4N corresponding to a concentration of 146 g / liter of acid and containing 60 g / liter of total iron.

Ces solutions décapantes ont été testées en efficacité de décapage, en tenant compte de leur efficacité maximale par le réglage du potentiel REDOX correspondant à différentes concentrations d'acide utilisées. Le temps de séjour est adapté à la composition de l'acier et au type d'oxyde à décaper.These pickling solutions have been tested for pickling efficiency, taking into account their maximum efficiency by adjusting the REDOX potential corresponding to the different acid concentrations used. The residence time is adapted to the composition of the steel and to the type of oxide to be etched.

Dans le test de décapage avec la solution aqueuse d'acide chlorhydrique, le potentiel REDOX est fixé à 460 mV par rapport à une électrode de référence Ag/AgCl, le potentiel étant maintenu constant par injection d'air et apport complémentaire de peroxyde d'hydrogène.In the pickling test with the aqueous hydrochloric acid solution, the REDOX potential is fixed at 460 mV relative to an Ag / AgCl reference electrode, the potential being kept constant by injection of air and additional supply of peroxide. hydrogen.

Le tableau 1 ci-dessous présente les différentes vitesses de décapage mesurées en perte de matière en grammes par mètre carré et par seconde pour différentes nuances d'acier : Acier Solution A Solution B Solution C L'invention AISI 304 0,41; 0,37 0,42; 0,37 0,59 0,28; 0,27 0,31; 0,27 0,63-0,56 AISI 316L 0,31 0,40 0,53 AISI 430 0,46 - 0,46 0,92; 0,90 1,6 - 1,1 AISI 430 Ti 0,65 - 0,67 1,01; 0,99 1,5 - 1,8 AISI 409 0,55 - 0,58 0,93; 0,96 1,3 - 1,6 Table 1 below presents the different pickling speeds measured in loss of material in grams per square meter and per second for different grades of steel: Steel Solution A Solution B Solution C The invention AISI 304 0.41; 0.37 0.42; 0.37 0.59 0.28; 0.27 0.31; 0.27 0.63-0.56 AISI 316L 0.31 0.40 0.53 AISI 430 0.46 - 0.46 0.92; 0.90 1.6 - 1.1 AISI 430 Ti 0.65 - 0.67 1.01; 0.99 1.5 - 1.8 AISI 409 0.55 - 0.58 0.93; 0.96 1.3 - 1.6

Il en résulte que le décapage en solution chlorhydrique est d'une efficacité remarquable dans le domaine de la vitesse de décapage. De plus, il est constaté que pour une même durée de décapage les restes d'oxydes sont nettement moindres après décapage en solution chlorhydrique.As a result, pickling in hydrochloric solution is remarkably effective in the area of pickling speed. In addition, it is found that for the same pickling time the oxide residues are significantly less after pickling in hydrochloric solution.

Par ailleurs, la surface de la bande décapée avec une solution chlorhydrique présente un aspect blanc, sans piqûre, alors que la surface de la bande décapée avec une solution aqueuse d'acide sulfurique présente un aspect noirâtre.Furthermore, the surface of the strip stripped with a hydrochloric solution has a white appearance, without pitting, while the surface of the strip stripped with an aqueous sulfuric acid solution has a blackish appearance.

Après cette comparaison remarquable, différents essais ont été effectués pour délimiter les différents paramètres d'optimisation de la solution décapante :

  • Variation de la concentration en acide chlorhydrique:
    Des essais de décapage ont été effectués avec des solutions décapantes C aqueuses d'acide chlorhydrique de normalité comprise entre 3N et 5N correspondant à une concentration comprise entre 108 g/litre et 180 g/litre d'acide et contenant 60 g/litre de fer total.
    Dans ces essais de décapage, le potentiel REDOX est fixé à 460 mV par rapport à une électrode de référence Ag/AgCl, le potentiel étant maintenu constant par injection d'air et apport complémentaire de peroxyde d'hydrogène, la température de la solution étant maintenue à 80°C.
    Dans ces conditions, la vitesse de décapage augmente avec la concentration en acide et peut atteindre des valeurs jusqu'à deux à trois fois supérieures à ce qu'elles sont avec les bains de référence A ou B.
    Pour parvenir à une telle efficacité de décapage, on contrôle le potentiel d'oxydo réduction du bain selon l'invention, contrôle effectué par addition notamment de peroxyde d'hydrogène en complément d'injection d'air, ce qui permet de garder un haut niveau d'agressivité et de traiter en continu, notamment sur une ligne de laminage, les bandes de tôle sur lesquelles est appliquée la solution.
  • Variation de la concentration en fer total :
    Des essais de décapage ont été effectués avec des solutions décapantes C aqueuses d'acide chlorhydrique de normalité 4N correspondant à une concentration de 146 g/litre d'acide et contenant de 30 g/litre à 250 g/litre de fer total.
    Avec une concentration en fer d'environ 250 g/litre, le fer est en limite de solubilité dans la solution d'acide.
    Dans ces essais de décapage avec la solution chlorhydrique, le potentiel REDOX est fixé à 460 mV par rapport à une électrode de référence Ag/AgCl, le potentiel étant maintenu constant par injection d'air et apport complémentaire de peroxyde d'hydrogène, la température de la solution étant maintenue à 80°C.
    Dans ces conditions, la vitesse de décapage augmente avec la concentration en fer et atteint des valeurs jusqu'à trois fois supérieures à ce qu'elles sont avec les bains classiques A ou B.
  • Variation de la température:
    Les températures de la solution de décapage peuvent varier de 10°C à 95°C et varient de préférence entre 65 °C et 85 °C. La vitesse de décapage croit avec la température. Au-dessous de 70°C, la vitesse de décapage croit modérément avec la température, lorsque la température atteint de 70°C à 85°C, la vitesse de décapage augmente de près de 20%. Bien qu'au-dessus d'une certaine température, il peut se produire une évaporation non négligeable, on peut envisager dans une installation, une enceinte fermée, qui permet l'utilisation de la solution à une température supérieure à 85°C, associée à un dispositif de condensation de la solution pour un retour en utilisation.
    Pour mettre à profit l'effet de la température, il est possible de chauffer la pièce ou la bande de tôle pour compenser les effets d'inertie thermique.
  • Variation du potentiel REDOX:
    La mesure du potentiel REDOX est un moyen de contrôle de la qualité de décapage de la solution dans une installation industrielle, pour une optimisation de la vitesse du décapage et le maintien de la qualité constante à efficacité constante du décapage.
    La vitesse de décapage peut augmenter de 30% à 50% lorsqu'on porte le potentiel REDOX de 400 mV à 600 mV.
    La vitesse de décapage peut être modulée en ajoutant dans le bain d'acide chlohydrique selon l'invention une quantité d'un autre acide comme par exemple de l'acide fluorhydrique dans une proportion inférieure à 40 g/litre.
After this remarkable comparison, various tests were carried out to delimit the different parameters for optimizing the pickling solution:
  • Variation in hydrochloric acid concentration:
    Pickling tests were carried out with aqueous pickling solutions C of hydrochloric acid of normality between 3N and 5N corresponding to a concentration between 108 g / liter and 180 g / liter of acid and containing 60 g / liter of iron total.
    In these pickling tests, the REDOX potential is fixed at 460 mV with respect to an Ag / AgCl reference electrode, the potential being kept constant by injection of air and additional supply of hydrogen peroxide, the temperature of the solution being maintained at 80 ° C.
    Under these conditions, the pickling speed increases with the acid concentration and can reach values up to two to three times higher than they are with the reference baths A or B.
    To achieve such pickling efficiency, the oxidation reduction potential of the bath according to the invention is controlled, control carried out by addition, in particular, of hydrogen peroxide in addition to air injection, which makes it possible to keep a high level of aggressiveness and continuous treatment, especially on a rolling line, of the sheet metal strips to which the solution is applied.
  • Variation in total iron concentration:
    Pickling tests were carried out with aqueous pickling solutions C of 4N norm hydrochloric acid corresponding to a concentration of 146 g / liter of acid and containing from 30 g / liter to 250 g / liter of total iron.
    With an iron concentration of around 250 g / liter, the iron is at the limit of solubility in the acid solution.
    In these pickling tests with hydrochloric solution, the REDOX potential is fixed at 460 mV relative to an Ag / AgCl reference electrode, the potential being kept constant by injection of air and additional supply of hydrogen peroxide, the temperature of the solution being maintained at 80 ° C.
    Under these conditions, the pickling speed increases with the iron concentration and reaches values up to three times higher than they are with conventional baths A or B.
  • Temperature variation:
    The temperatures of the pickling solution can vary from 10 ° C to 95 ° C and preferably vary between 65 ° C and 85 ° C. The pickling speed increases with temperature. Below 70 ° C, the pickling speed increases moderately with temperature, when the temperature reaches from 70 ° C to 85 ° C, the pickling speed increases by almost 20%. Although above a certain temperature, significant evaporation may occur, we can consider in an installation, a closed enclosure, which allows the use of the solution at a temperature above 85 ° C, associated to a device for condensing the solution for return to use.
    To take advantage of the effect of temperature, it is possible to heat the part or the strip of sheet metal to compensate for the effects of thermal inertia.
  • Variation of REDOX potential:
    Measuring the REDOX potential is a means of controlling the quality of pickling of the solution in an industrial installation, for optimizing the pickling speed and maintaining constant quality at constant pickling efficiency.
    The pickling speed can increase from 30% to 50% when the REDOX potential is increased from 400 mV to 600 mV.
    The pickling speed can be adjusted by adding to the hydrochloric acid bath according to the invention an amount of another acid such as, for example, hydrofluoric acid in a proportion of less than 40 g / liter.

Claims (11)

Procédé de décapage d'une pièce en acier et notamment une bande en acier inoxydable, consistant à appliquer une solution aqueuse de décapage constituée d'acide chlorhydrique et d'ions ferriques et ferreux de décapage en solution, et en vue de conserver un pouvoir décapant constant dans la solution aqueuse d'acide chlorhydrique ayant un pH inférieur à 1, à maintenir la concentration en ions Fe3+, à une valeur comprise entre 1 g/litre et 300 g/litre, par réoxydation au moyen d'une oxygénation des ions Fe2+ générés lors du décapage, le potentiel REDOX étant maintenu à une valeur comprise entre 0 et 800 mV potentiel mesuré entre une électrode de platine et une électrode de référence Ag/AgCl placées dans la solution.Process for pickling a steel part and in particular a stainless steel strip, consisting in applying an aqueous pickling solution consisting of hydrochloric acid and ferric and ferrous pickling ions in solution, and with a view to retaining pickling power constant in the aqueous hydrochloric acid solution having a pH below 1, to maintain the concentration of Fe 3+ ions, at a value between 1 g / liter and 300 g / liter, by reoxidation by means of oxygenation of the Fe 2+ ions generated during pickling, the REDOX potential being maintained at a value between 0 and 800 mV potential measured between a platinum electrode and an Ag / AgCl reference electrode placed in the solution. Procédé selon la revendication 1, caractérisé en ce que la réoxidation des ions Fe2+ par oxygénation est réalisée par aération de la solution décapante.Process according to Claim 1, characterized in that the reoxidation of the Fe 2+ ions by oxygenation is carried out by aeration of the pickling solution. Procédé selon l'une quelconque des revendications 1 et 2, caractérisé en ce que l'aération de la solution décapante est réalisée par des moyens choisis parmi : pompage et refoulement de la solution à l'air libre, bullage, brassage, injection d'un gaz contenant l'élément oxygène, aspersion de la solution décapante dans une enceinte contenant de l'air.Process according to either of Claims 1 and 2, characterized in that the aeration of the pickling solution is carried out by means chosen from: pumping and delivery of the solution in the open air, bubbling, stirring, injection of a gas containing the oxygen element, spraying the pickling solution into an enclosure containing air. Procédé selon l'une quelconque des revendications 1 à 3, caractérisé en ce que la réoxydation est complétée par addition de composés choisis parmi : les peroxydes, les persels, et de préférence le peroxyde d'hydrogène H2O2, le permanganate de potassium KMnO4.Process according to any one of Claims 1 to 3, characterized in that the reoxidation is completed by the addition of compounds chosen from: peroxides, persalts, and preferably hydrogen peroxide H 2 O 2 , potassium permanganate KMnO 4 . Procédé selon l'une quelconque des revendications 1 à 4, caractérisé en ce que la solution présente, de préférence, une concentration en acide chlorhydrique comprise entre 35 g/litre et 250 g/litre.Process according to any one of Claims 1 to 4, characterized in that the solution has, from preferably, a hydrochloric acid concentration of between 35 g / liter and 250 g / liter. Procédé selon l'une quelconque des revendications 1 à 5, caractérisé en ce que la solution traitante est appliquée dans un intervalle de température compris entre 10°C et 95°C et de préférence entre 65°C et 85°C.Process according to any one of Claims 1 to 5, characterized in that the treating solution is applied in a temperature range between 10 ° C and 95 ° C and preferably between 65 ° C and 85 ° C. Procédé selon l'une quelconque des revendications 1 à 6, caractérisé en ce qu'on chauffe la pièce à traiter préalablement à l'application de la solution.Process according to any one of Claims 1 to 6, characterized in that the part to be treated is heated before the application of the solution. Procédé selon l'une quelconque des revendications 1 à 7, caractérisé en ce que le temps d'application de la solution sur la bande est inférieur à 2 mn.Method according to any one of Claims 1 to 7, characterized in that the time for applying the solution to the strip is less than 2 min. Procédé selon l'une quelconque des revendications 1 à 8, caractérisé en ce qu'on ajuste le potentiel REDOX entre 400 mV et 600 mV.Method according to any one of Claims 1 to 8, characterized in that the REDOX potential is adjusted between 400 mV and 600 mV. Utilisation du procédé de décapage selon l'une quelconque des revendications 1 à 9 dans le domaine du décapage accéléré d'une pièce en acier et notamment d'une bande en acier inoxydable, sur une installation de production, en ligne en continu de la bande.Use of the pickling method according to any one of claims 1 to 9 in the field of accelerated pickling of a steel part and in particular of a stainless steel strip, on a production installation, in continuous line of the strip . Ligne de production, en continu, d'une bande de tôle laminée en acier et notamment en acier inoxydable utilisant le procédé de décapage selon l'une quelconque des revendications 1 à 10, caractérisée en ce que la bande est soumise successivement à : - un traitement mécanique, par exemple de planage sous traction et/ou de grenaillage, - un décapage primaire, - une opération de transformation comme par exemple de laminage, - des opérations de recuit, - un décapage final, - une opération de finition comme par exemple un laminage à froid de type " skin pass", l'un au moins des décapages consistant à appliquer une solution aqueuse de décapage constituée d'acide chlorhydrique et d'ions ferriques et ferreux de décapage en solution, et, en vue de conserver un pouvoir décapant constant de la solution aqueuse d'acide chlorhydrique ayant un pH inférieur à 1, à maintenir la concentration en ions Fe3+, à une valeur comprise entre 1 g/litre et 300 g/litre, par réoxydation au moyen d'une oxygénation des ions Fe2+ générés lors du décapage, le potentiel REDOX étant maintenu à une valeur comprise entre 0 et 800 mV, potentiel mesuré entre une électrode de platine et une électrode de référence Ag/AgCl placées dans la solution.Continuous production line for a strip of sheet steel rolled in steel and in particular stainless steel using the pickling process according to any one of Claims 1 to 10, characterized in that the strip is successively subjected to: - mechanical treatment, for example leveling under tension and / or shot blasting, - a primary pickling, - a transformation operation such as for example rolling, - annealing operations, - a final pickling, - a finishing operation such as a cold rolling of the "skin pass" type, at least one of the pickling operations consisting in applying an aqueous pickling solution consisting of hydrochloric acid and of ferric and ferrous pickling ions in solution, and, in order to maintain a constant pickling power of the aqueous hydrochloric acid solution having a pH of less than 1, to maintain the concentration of Fe 3+ ions, at a value between 1 g / liter and 300 g / liter, by reoxidation by means of oxygenation of the Fe 2+ ions generated during pickling, the REDOX potential being maintained at a value between 0 and 800 mV, potential measured between a platinum electrode and an Ag / AgCl reference electrode placed in the solution.
EP97400433A 1996-02-27 1997-02-26 Process for pickling a steel workpiece, in particular stainless steel sheet strip Expired - Lifetime EP0792949B1 (en)

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999027162A1 (en) * 1997-11-24 1999-06-03 Acciai Speciali Terni S.P.A. Method for pickling steel products
WO1999031296A1 (en) * 1997-12-12 1999-06-24 Henkel Kommanditgesellschaft Auf Aktien Method for pickling and passivating special steel
EP0949354A1 (en) * 1998-04-06 1999-10-13 SOLVAY (Société Anonyme) Pickling process
EP0972854A2 (en) * 1998-07-15 2000-01-19 Andritz-Patentverwaltungs-Gesellschaft m.b.H. Process for pickling stainless steel
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Families Citing this family (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT406486B (en) * 1998-12-22 2000-05-25 Andritz Patentverwaltung METHOD FOR STAINLESSING STAINLESS STEEL
FR2807957B1 (en) * 2000-04-21 2002-08-02 Vai Clecim METHOD AND INSTALLATION FOR COLD ROLLING
MXPA03009217A (en) * 2001-04-09 2005-03-07 Ak Properties Inc Apparatus and method for removing hydrogen peroxide from spent pickle liquor.
CA2443695C (en) 2001-04-09 2009-02-24 Vijay N. Madi Hydrogen peroxide pickling scheme for stainless steel grades
WO2002081776A1 (en) 2001-04-09 2002-10-17 Ak Properties, Inc. Hydrogen peroxide pickling of silicon-containing electrical steel grades
DE10160318A1 (en) * 2001-12-07 2003-06-18 Henkel Kgaa Process for pickling martensitic or ferritic stainless steel
KR100777171B1 (en) * 2002-10-15 2007-11-16 헨켈 코만디트게젤샤프트 아우프 악티엔 Pickling or brightening/passivating solution and process for steel and stainless steel
US7306354B2 (en) * 2003-11-28 2007-12-11 Ed Haas Light housing and system for providing a glittering light effect
FR2867991B1 (en) * 2004-03-25 2007-05-04 Ugine Et Alz France Sa AUSTENITIC STAINLESS STEEL STRIP BANDS MATT SURFACE
EP1980650A1 (en) * 2007-04-05 2008-10-15 Kerma S.A. Pickling composition free from nitrates and peroxides, and method using such a composition
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US8859479B2 (en) * 2011-08-26 2014-10-14 United Technologies Corporation Chemical stripping composition and method
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Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5047826A (en) * 1973-08-31 1975-04-28
GB2000196A (en) * 1977-06-24 1979-01-04 Tokai Electro Chemical Co Controlling stainless steel pickling solution by hydrogen peroxide and sulphuric acid addition
FR2399488A1 (en) * 1977-08-01 1979-03-02 Beugin Sa Expl Procedes Pickling bath for steels - contg. acid and ferric chloride
JPS55138081A (en) * 1979-04-11 1980-10-28 Shinko Kosen Kogyo Kk Descaling method for steel or stainless steel
JPS5873778A (en) * 1981-10-26 1983-05-04 Sumitomo Metal Ind Ltd Descaling method for steel wire rod by pickling
FR2551465A3 (en) * 1983-09-02 1985-03-08 Gueugnon Sa Forges Process for acidic pickling of stainless steels and acidic solution for its use
EP0188975A1 (en) * 1985-01-22 1986-07-30 S.A. Ugine Process for the acid pickling of steels, in particular stainless steels
FR2587369A1 (en) * 1985-09-19 1987-03-20 Ugine Gueugnon Sa ACID PICKLING PROCESS OF STAINLESS STEEL PRODUCTS
JPS63216986A (en) * 1987-03-03 1988-09-09 Sumitomo Metal Ind Ltd High-speed pickling method for low cr steel
DE3719604A1 (en) * 1987-06-12 1988-12-22 Markus Maria Dipl In Bringmann Pickling of semifinished articles
JPH02205692A (en) * 1989-02-04 1990-08-15 Nippon Steel Corp Method and equipment for pickling stainless steel
EP0501867A1 (en) * 1991-02-25 1992-09-02 Ugine S.A. Method for etching steel materials such as stainless steels and alloyed steels
EP0505606A1 (en) * 1991-03-29 1992-09-30 Itb S.R.L. Process for pickling and passivating stainless steel without using nitric acid
EP0769574A1 (en) * 1995-10-18 1997-04-23 NOVAMAX ITB s.r.l. Process for stainless steel pickling and passivation without using nitric acid

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR501867A (en) * 1919-07-16 1920-04-28 Jacques Gustave Schulz Motor vehicles with independent motor mechanism
US3445284A (en) * 1963-11-18 1969-05-20 Dravo Corp Process for pickling of steel strip and regeneration of the contact acid
US3310435A (en) * 1963-11-18 1967-03-21 Dravo Corp Process for continuous pickling of steel strip and regeneration of the contact acid
US3385734A (en) * 1964-12-02 1968-05-28 Pennsylvania Ind Chemical Corp Process and composition for pickling steel
US3423240A (en) * 1965-08-19 1969-01-21 Ford Motor Co Pickling process
US4323240A (en) * 1980-08-20 1982-04-06 Stewart Charles G Bowling game
JPS5871336A (en) * 1981-10-21 1983-04-28 Nisshin Steel Co Ltd Production of high-strength austenitic stainless steel plate having excellent fatigue characteristic
FR2657888B1 (en) * 1990-02-08 1994-04-15 Ugine Aciers STRIPPING METHODS FOR STAINLESS STEEL MATERIALS.
FR2683551B1 (en) * 1991-11-07 1994-09-16 Ugine Sa PROCESS FOR STRIPPING STEEL MATERIALS ON A PROCESSING LINE.
DE4423664A1 (en) * 1994-07-07 1996-05-15 Bwg Bergwerk Walzwerk Process for producing cold-rolled steel strips from stainless steel and metal strips, in particular from titanium alloys

Patent Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5047826A (en) * 1973-08-31 1975-04-28
GB2000196A (en) * 1977-06-24 1979-01-04 Tokai Electro Chemical Co Controlling stainless steel pickling solution by hydrogen peroxide and sulphuric acid addition
FR2399488A1 (en) * 1977-08-01 1979-03-02 Beugin Sa Expl Procedes Pickling bath for steels - contg. acid and ferric chloride
JPS55138081A (en) * 1979-04-11 1980-10-28 Shinko Kosen Kogyo Kk Descaling method for steel or stainless steel
JPS5873778A (en) * 1981-10-26 1983-05-04 Sumitomo Metal Ind Ltd Descaling method for steel wire rod by pickling
FR2551465A3 (en) * 1983-09-02 1985-03-08 Gueugnon Sa Forges Process for acidic pickling of stainless steels and acidic solution for its use
EP0188975A1 (en) * 1985-01-22 1986-07-30 S.A. Ugine Process for the acid pickling of steels, in particular stainless steels
FR2587369A1 (en) * 1985-09-19 1987-03-20 Ugine Gueugnon Sa ACID PICKLING PROCESS OF STAINLESS STEEL PRODUCTS
EP0236354A1 (en) * 1985-09-19 1987-09-16 Ugine Gueugnon Sa Method for the acid etching of stainless steel products.
JPS63216986A (en) * 1987-03-03 1988-09-09 Sumitomo Metal Ind Ltd High-speed pickling method for low cr steel
DE3719604A1 (en) * 1987-06-12 1988-12-22 Markus Maria Dipl In Bringmann Pickling of semifinished articles
JPH02205692A (en) * 1989-02-04 1990-08-15 Nippon Steel Corp Method and equipment for pickling stainless steel
EP0501867A1 (en) * 1991-02-25 1992-09-02 Ugine S.A. Method for etching steel materials such as stainless steels and alloyed steels
EP0505606A1 (en) * 1991-03-29 1992-09-30 Itb S.R.L. Process for pickling and passivating stainless steel without using nitric acid
EP0769574A1 (en) * 1995-10-18 1997-04-23 NOVAMAX ITB s.r.l. Process for stainless steel pickling and passivation without using nitric acid

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
CHEMICAL ABSTRACTS, vol. 84, no. 24, 14 June 1976, Columbus, Ohio, US; abstract no. 168136g, MIZUNUMA: "Descaling of stainless steel" XP002016316 *
PATENT ABSTRACTS OF JAPAN vol. 005, no. 012 (C - 040) 24 January 1981 (1981-01-24) *
PATENT ABSTRACTS OF JAPAN vol. 007, no. 167 (C - 177) 22 July 1958 (1958-07-22) *
PATENT ABSTRACTS OF JAPAN vol. 013, no. 011 (C - 558) 11 January 1989 (1989-01-11) *
PATENT ABSTRACTS OF JAPAN vol. 014, no. 497 (C - 0774) 15 August 1990 (1990-08-15) *

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999027162A1 (en) * 1997-11-24 1999-06-03 Acciai Speciali Terni S.P.A. Method for pickling steel products
US6500328B1 (en) 1997-11-24 2002-12-31 Acciai Speciali Terni S.P.A. Method for pickling steel products
WO1999031296A1 (en) * 1997-12-12 1999-06-24 Henkel Kommanditgesellschaft Auf Aktien Method for pickling and passivating special steel
EP0949354A1 (en) * 1998-04-06 1999-10-13 SOLVAY (Société Anonyme) Pickling process
US6210491B1 (en) 1998-04-06 2001-04-03 Solvay Pickling process
US6428625B1 (en) 1998-04-06 2002-08-06 Solvay (Societe Anonyme) Process for pickling a metal using hydrogen peroxide
EP0972854A2 (en) * 1998-07-15 2000-01-19 Andritz-Patentverwaltungs-Gesellschaft m.b.H. Process for pickling stainless steel
EP0972854A3 (en) * 1998-07-15 2000-07-19 Andritz-Patentverwaltungs-Gesellschaft m.b.H. Process for pickling stainless steel
IT202000005848A1 (en) 2020-03-19 2021-09-19 Tenova Spa Process for pickling and / or passivating a stainless steel.

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AU1488497A (en) 1997-09-11
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CN1168823A (en) 1997-12-31
FR2745301A1 (en) 1997-08-29
TW517099B (en) 2003-01-11
CA2198631C (en) 2004-08-31
US5992196A (en) 1999-11-30
DE69704732T2 (en) 2001-09-13
BR9701076A (en) 1998-09-01
JPH101791A (en) 1998-01-06
KR970062075A (en) 1997-09-12
ATE201057T1 (en) 2001-05-15
MX9701425A (en) 1998-03-31
AU711782B2 (en) 1999-10-21
FR2745301B1 (en) 1998-04-03
DE69704732D1 (en) 2001-06-13
ZA971647B (en) 1998-08-26
US5851304A (en) 1998-12-22
CA2198631A1 (en) 1997-08-27
CN1084801C (en) 2002-05-15
EP0792949B1 (en) 2001-05-09
JP4186131B2 (en) 2008-11-26

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