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EP1980650A1 - Pickling composition free from nitrates and peroxides, and method using such a composition - Google Patents

Pickling composition free from nitrates and peroxides, and method using such a composition Download PDF

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Publication number
EP1980650A1
EP1980650A1 EP07105700A EP07105700A EP1980650A1 EP 1980650 A1 EP1980650 A1 EP 1980650A1 EP 07105700 A EP07105700 A EP 07105700A EP 07105700 A EP07105700 A EP 07105700A EP 1980650 A1 EP1980650 A1 EP 1980650A1
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EP
European Patent Office
Prior art keywords
ions
solution
concentration
pickling
steels
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.)
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Application number
EP07105700A
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German (de)
French (fr)
Inventor
Jean-Michel Vincent
Frédéric Groulard
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KERMA SA
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KERMA SA
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Priority to EP07105700A priority Critical patent/EP1980650A1/en
Publication of EP1980650A1 publication Critical patent/EP1980650A1/en
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    • CCHEMISTRY; METALLURGY
    • C23COATING 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
    • C23GCLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G1/00Cleaning or pickling metallic material with solutions or molten salts
    • C23G1/02Cleaning or pickling metallic material with solutions or molten salts with acid solutions
    • C23G1/08Iron or steel
    • C23G1/086Iron or steel solutions containing HF

Definitions

  • the invention relates to the etching or descaling of stainless steels and other special steels such as austenic stainless steel, duplex steels, super-aluene steels, (super) alloys of Ni and Ni / Cr, etc.
  • the specialized literature describes numerous pickling processes for steels of this type.
  • the pickling baths consist of a mixture of two or three acids.
  • the publication EP 1 050 605 describes a method for pickling stainless steel using sulfuric acid (H 2 SO 4 ), hydrofluoric acid (HF), ferric ions (Fe 3+ ), chloride ions (Cl - ), and oxidant capable of oxidizing the ferrous ions produced into ferric ions.
  • the advantage of this method lies in the fact that the oxidant (H 2 O 2 for example) intervenes only for the conversion Fe 2+ to Fe 3+ and there is therefore no problem of stability of the peroxide hydrogen because it is used immediately for conversion.
  • the object of the invention is to provide a method for pickling and / or descaling stainless steels and other special steels (such as austenitic stainless steel, duplex steels, super-aleatic steels, (super) alloys). Ni and Ni / Cr, etc.) more adapted to the rates practiced in such workshops.
  • the first object of the invention is therefore an oxidizing acid solution for pickling stainless steels, duplex steels, super-alumina steels and alloys of Ni and Ni / Cr, essentially free of nitrates and peroxides, comprising Fe 3+ ions in combination with F - ions and Cl - ions, in which the content of Cl - ions is greater than 5g / l.
  • the solution more specifically contains hydrofluoric acid in a concentration of between 1 and 7% by weight, and ferric ions in a concentration of between 3 and 100 g / l (more particularly between 5 and 100 g). / l) and chloride ions in a concentration of between 5 and 70 g / l, and more particularly between 10 and 70 g / l.
  • the Fe 3+ ion content becomes too low (when it drops to about 3 to 5 g / l)
  • the Fe 2+ ferrous ions from the pickling process will be oxidized. of steel, by oxygenation of the treating solution or by addition of an oxidant, such as hydrogen peroxide H 2 O 2 for example.
  • the solution more specifically contains chloride ions in a concentration of between 5 and 35 g / l.
  • a second object of the invention is a pickling process of stainless steels, duplex steels, super-aluene steels and alloys of Ni and Ni / Cr, by means of an oxidizing acid pickling solution, essentially free. of nitrates and peroxides, comprising Fe 3+ ions in combination with F - ions and Cl - ions, in which process the Cl - content of the pickling solution is greater than 5g / l.
  • the pickling operation is carried out at a temperature of between and 50 ° C, preferably at a temperature between 10 and 30 ° C or at a temperature of 5 to 20 ° C ("ambient" temperature).
  • the solution contains hydrofluoric acid in a concentration of between 1 and 7% by weight, ferric ions in a concentration of between 3 and 100 g / l (more particularly between 5 and 100 g / l) and chloride ions in a concentration of between 5 and 70 g / l, and more particularly between 10 and 70 g / l.
  • the solution contains chloride ions in a concentration of between 5 and 35 g / l.
  • the Fe 3+ ion content is specifically less than 15 g / l.
  • the Fe 3+ ions can, however, be introduced in sulphate form, although the chloride form is the preferred form; the Fe 3+ ions can also result from the oxidation of Fe 2+ (dissolved in the form of a ferrous salt) to Fe 3+ , by the addition of an oxidant such as H 2 O 2 or by bubbling of air the F-ions result from the introduction in the form of hydrofluoric acid (HF) or, optionally, the introduction of ammonium bifluoride (in which case all the acidity comes from HCl); the Cl - ions are introduced in HCl and / or ferric chloride form; the acidity is given essentially by HF and HCl (the total acidity is preferably between 2 and 5 g.equivalent / I), but the solution may contain other acids (such as sulfuric acid (H 2 SO 4 ), phosphoric acid (H 3 PO 4 ), etc.); the pH
  • An interesting feature of the invention lies in the fact that the application times of the solution / process according to the invention can spread over a relatively wide range, ranging from a few seconds to a few hours. Preferred ranges of use are between 1 ⁇ 2 to 5 minutes and 1 to 2 hours.
  • the method according to the invention also has the advantage that the monitoring / verification of the bath condition (and its "regeneration") are particularly easy, and can be done at relatively spaced intervals (up to several weeks, depending on use), or even sending control samples to a user service laboratory.
  • etching solution and the etching process according to the invention can be carried out according to various methods, such as in particular in the form of a pickling bath ("static" use), by a circulation or sprinkling / trickle technique, even by spraying techniques in the form of relatively viscous liquid (“dynamic” uses); these various techniques are well known per se in the field of surface cleaning.
  • This pickling solution was used at a temperature of 15 ° C for the etching of 12000 m 2 of 304L stainless steels over a period of 5 weeks.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)

Abstract

Oxidizing acid solution for stripping stainless steel, duplex steel, super- austenitic steel and nickel and nickel/chromium alloys, free of nitrates and peroxides, comprises ferric ions in combination with fluoride ion and chloride ion, where the content of the chloride ion is greater than 5 g/l. An independent claim is included for a process for stripping of stainless steel, duplex steel, super- austenitic steels and nickel and nickel/chromium alloys, comprising using the oxidizing acid solution.

Description

L'invention concerne le décapage ou décalaminage d'aciers inoxydables et autres aciers spéciaux tels que l'acier inoxydable austénique, les aciers duplex, les aciers superausténiques, les (super-) alliages de Ni et Ni/Cr, etc.The invention relates to the etching or descaling of stainless steels and other special steels such as austenic stainless steel, duplex steels, super-aluene steels, (super) alloys of Ni and Ni / Cr, etc.

La littérature spécialisée décrit de nombreux procédés de décapage pour les aciers de ce type. Généralement les bains de décapage sont constitués d'un mélange de deux ou trois acides.The specialized literature describes numerous pickling processes for steels of this type. Generally the pickling baths consist of a mixture of two or three acids.

L'un des plus connus est le mélange d'acide fluorhydrique (caractère acide) et d'acide nitrique (caractère acide et oxydant), qui a cependant l'inconvénient de générer des dérivés polluants du type NOx de l'acide nitrique.
Le décapage des aciers inoxydables, notamment de type austénique, a été amélioré avec le développement de bains dont le composant oxydant est le peroxyde d'hydrogène. L'utilisation de peroxyde d'hydrogène, en particulier avec l'acide fluorhydrique et l'acide sulfurique, a permis d'éliminer l'acide nitrique nocif pour l'environnement.
Ces progrès n'ont toutefois pas permis d'obtenir des résultats entièrement satisfaisants de par la décomposition du peroxyde d'hydrogène dans les milieux fortement acides et en présence de métaux en solution.
Certaines techniques préconisent des méthodes de stabilisation du peroxyde d'hydrogène mais les performances des bains de décapage restent limitées, bien en deçà des performances des bains à base d'acide fluorhydrique et d'acide nitrique.
One of the best known is the mixture of hydrofluoric acid (acidic character) and nitric acid (acidic and oxidizing character), which however has the disadvantage of generating polluting derivatives of the NOx type of nitric acid.
The pickling of stainless steels, in particular of austenic type, has been improved with the development of baths whose oxidizing component is hydrogen peroxide. The use of hydrogen peroxide, in particular with hydrofluoric acid and sulfuric acid, has eliminated nitric acid which is harmful to the environment.
These advances, however, have not made it possible to obtain entirely satisfactory results from the decomposition of hydrogen peroxide in strongly acidic media and in the presence of metals in solution.
Some techniques recommend methods of stabilizing hydrogen peroxide, but the performance of pickling baths is limited, well below the performance of baths based on hydrofluoric acid and nitric acid.

La publication EP 1 050 605 décrit une méthode de décapage de l'acier inoxydable faisant intervenir l'acide sulfurique (H2SO4), l'acide fluorhydrique (HF), des ions ferriques (Fe3+), des ions chlorures (Cl-), et un oxydant capable d'oxyder les ions ferreux produits en ions ferriques. L'avantage de cette méthode réside dans le fait que l'oxydant (H2O2 par exemple) n'intervient que pour la conversion Fe2+ en Fe3+ et il n'y a donc pas de problème de stabilité du peroxyde d'hydrogène car il sert immédiatement à la conversion.
Cette méthode présente cependant l'inconvénient qu'elle est spécifiquement destinée aux installations de production d'acier inoxydable dont la contrainte principale est le décapage en un temps très court (de l'ordre de quelques minutes) et qu'elle n'est de ce fait pas du tout adaptée aux besoins des ateliers de transformation souhaitant pratiquer un traitement de surface d'aciers inoxydables.
The publication EP 1 050 605 describes a method for pickling stainless steel using sulfuric acid (H 2 SO 4 ), hydrofluoric acid (HF), ferric ions (Fe 3+ ), chloride ions (Cl - ), and oxidant capable of oxidizing the ferrous ions produced into ferric ions. The advantage of this method lies in the fact that the oxidant (H 2 O 2 for example) intervenes only for the conversion Fe 2+ to Fe 3+ and there is therefore no problem of stability of the peroxide hydrogen because it is used immediately for conversion.
However, this method has the disadvantage that it is specifically intended for stainless steel production facilities whose main constraint is stripping in a very short time (of the order of a few minutes) and that it is not this is not at all suited to the needs of processing plants wishing to practice a surface treatment of stainless steels.

L'objectif de l'invention est de procurer un procédé de décapage et/ou de décalaminage d'aciers inoxydables et autres aciers spéciaux (tels que l'acier inoxydable austénique, les aciers duplex, les aciers superausténiques, les (super-) alliages de Ni et Ni/Cr, etc.) plus adaptée aux cadences pratiquées dans de tels ateliers.The object of the invention is to provide a method for pickling and / or descaling stainless steels and other special steels (such as austenitic stainless steel, duplex steels, super-aleatic steels, (super) alloys). Ni and Ni / Cr, etc.) more adapted to the rates practiced in such workshops.

Le premier objet de l'invention est donc une solution acide oxydante destinée au décapage d'aciers inoxydables, d'aciers duplex, d'aciers superausténiques et d'alliages de Ni et Ni/Cr, essentiellement exempte de nitrates et de peroxydes, comprenant des ions Fe3+ en association avec des ions F- et des ions Cl-, dans laquelle la teneur en ions Cl- est supérieure à 5g/l.The first object of the invention is therefore an oxidizing acid solution for pickling stainless steels, duplex steels, super-alumina steels and alloys of Ni and Ni / Cr, essentially free of nitrates and peroxides, comprising Fe 3+ ions in combination with F - ions and Cl - ions, in which the content of Cl - ions is greater than 5g / l.

C'est cette dernière caractéristique qui différentie les solutions selon l'invention des solutions connues destinées au décapage industriel dans le contexte d'installations de production d'acier inoxydable, comprenant également des ions Fe3+ (à une teneur d'au moins 15 g/l) en association avec des ions F- (à une teneur en HF entre 0 et 60 g/l) et des ions Cl- , mais dans lesquelles la teneur en ions Cl- est comprise entre 0,1 à 5g/l.It is this last characteristic which differentiates the solutions according to the invention of the known solutions intended for the industrial stripping in the context of stainless steel production facilities, also including Fe 3+ ions (at a level of at least 15 g / l) in combination with F - ions (at a HF content between 0 and 60 g / l) and Cl - ions, but in which the content of Cl - ions is between 0.1 to 5g / l.

Selon une particularité préférée de l'invention, la solution contient plus spécifiquement de l'acide fluorhydrique en concentration entre 1 et 7% en poids, des ions ferriques en concentration comprise entre 3 et 100 g/l (plus particulièrement entre 5 et 100 g/l) et des ions chlorures en concentration comprise entre 5 et 70 g/l, et plus particulièrement entre 10 et 70 g/l.
Lorsqu'en cours d'utilisation de la solution, la teneur en ions Fe3+ devient trop faible (lorsqu'elle descend à environ 3 à 5 g/l) on procédera à l'oxydation des ions ferreux Fe2+ provenant du décapage de l'acier, par oxygénation de la solution traitante ou par ajout d'un oxydant, comme le peroxyde d'hydrogène H2O2 par exemple.
According to a preferred feature of the invention, the solution more specifically contains hydrofluoric acid in a concentration of between 1 and 7% by weight, and ferric ions in a concentration of between 3 and 100 g / l (more particularly between 5 and 100 g). / l) and chloride ions in a concentration of between 5 and 70 g / l, and more particularly between 10 and 70 g / l.
When, during the use of the solution, the Fe 3+ ion content becomes too low (when it drops to about 3 to 5 g / l), the Fe 2+ ferrous ions from the pickling process will be oxidized. of steel, by oxygenation of the treating solution or by addition of an oxidant, such as hydrogen peroxide H 2 O 2 for example.

Selon une autre particularité préférée de l'invention, la solution contient plus spécifiquement des ions chlorures en concentration comprise entre 5 et 35 g/l.According to another preferred feature of the invention, the solution more specifically contains chloride ions in a concentration of between 5 and 35 g / l.

Un second objet de l'invention est un procédé de décapage d'aciers inoxydables, d'aciers duplex, d'aciers superausténiques et d'alliages de Ni et Ni/Cr, au moyen d'une solution acide oxydante de décapage, essentiellement exempte de nitrates et de peroxydes, comprenant des ions Fe3+ en association avec des ions F- et des ions Cl-, dans lequel procédé la teneur en ions Cl- de la solution de décapage est supérieure à 5g/l.A second object of the invention is a pickling process of stainless steels, duplex steels, super-aluene steels and alloys of Ni and Ni / Cr, by means of an oxidizing acid pickling solution, essentially free. of nitrates and peroxides, comprising Fe 3+ ions in combination with F - ions and Cl - ions, in which process the Cl - content of the pickling solution is greater than 5g / l.

Selon une particularité préférée du procédé de décapage selon l'invention, l'opération de décapage est effectuée à une température comprise entre 5 et 50° C, de préférence à une température comprise entre 10 et 30° C ou à une température de 5 à 20 °C (température "ambiante").According to a preferred feature of the pickling process according to the invention, the pickling operation is carried out at a temperature of between and 50 ° C, preferably at a temperature between 10 and 30 ° C or at a temperature of 5 to 20 ° C ("ambient" temperature).

Selon une autre particularité préférée du procédé, selon l'invention, la solution contient de l'acide fluorhydrique en concentration entre 1 et 7% en poids, des ions ferriques en concentration comprise entre 3 et 100 g/l (plus particulièrement entre 5 et 100 g/l) et des ions chlorures en concentration comprise entre 5 et 70 g/l, et plus particulièrement entre 10 et 70 g/l.According to another preferred feature of the process, according to the invention, the solution contains hydrofluoric acid in a concentration of between 1 and 7% by weight, ferric ions in a concentration of between 3 and 100 g / l (more particularly between 5 and 100 g / l) and chloride ions in a concentration of between 5 and 70 g / l, and more particularly between 10 and 70 g / l.

Selon encore une autre particularité préférée du procédé selon l'invention, la solution contient des ions chlorures en concentration comprise entre 5 et 35 g/l.According to yet another preferred feature of the process according to the invention, the solution contains chloride ions in a concentration of between 5 and 35 g / l.

Dans un mode de réalisation particulièrement fonctionnel de l'invention, la teneur en ions Fe3+ est spécifiquement inférieure à 15 g/l.In a particularly functional embodiment of the invention, the Fe 3+ ion content is specifically less than 15 g / l.

Dans la solution et le procédé selon l'invention il n'est donc pas nécessaire d'utiliser de l'acide sulfurique (H2SO4);
les ions Fe3+ peuvent cependant être introduits sous forme de sulfate, bien que la forme chlorure soit la forme préférée; les ions Fe3+ peuvent également résulter de l'oxydation de Fe2+ (mis en solution sous la forme d'un sel ferreux) en Fe3+, par ajout d'un oxydant comme H2O2 ou par barbotage d'air
les ions F résultent de l'introduction sous forme d'acide fluorhydrique (HF) ou, de manière optionnelle, de l'introduction de bifluorure d'ammonium (auquel cas toute l'acidité provient de HCl);
les ions Cl- sont introduits sous forme HCl et/ou chlorure ferrique;
l'acidité est donnée essentiellement par HF et HCl (l'acidité totale est de préférence entre 2 et 5 g.equivalent /I), mais la solution peut contenir d'autres acides (comme l'acide sulfurique (H2SO4), l'acide phosphorique (H3PO4), etc.); le pH est en général de l'ordre de 1
le potentiel rédox de la solution est de préférence situé entre 200 et 600 mV et le ratio Fe2+ : Fe3+ de préférence inférieur à 1.
la solution selon l'invention comprend de préférence des agents mouillants etc., connus en soi.
In the solution and the process according to the invention it is therefore not necessary to use sulfuric acid (H 2 SO 4 );
the Fe 3+ ions can, however, be introduced in sulphate form, although the chloride form is the preferred form; the Fe 3+ ions can also result from the oxidation of Fe 2+ (dissolved in the form of a ferrous salt) to Fe 3+ , by the addition of an oxidant such as H 2 O 2 or by bubbling of air
the F-ions result from the introduction in the form of hydrofluoric acid (HF) or, optionally, the introduction of ammonium bifluoride (in which case all the acidity comes from HCl);
the Cl - ions are introduced in HCl and / or ferric chloride form;
the acidity is given essentially by HF and HCl (the total acidity is preferably between 2 and 5 g.equivalent / I), but the solution may contain other acids (such as sulfuric acid (H 2 SO 4 ), phosphoric acid (H 3 PO 4 ), etc.); the pH is generally of the order of 1
the redox potential of the solution is preferably between 200 and 600 mV and the Fe 2+ : Fe 3+ ratio is preferably less than 1.
the solution according to the invention preferably comprises wetting agents, etc., known per se.

Une particularité intéressante de l'invention réside dans le fait que les temps d'applications de la solution / du procédé selon l'invention peuvent s'étaler sur une plage relativement large, allant de quelques secondes à quelques heures. Les plages d'utilisation préférées se situent entre ½ à 5 minutes et 1 à 2 heures.An interesting feature of the invention lies in the fact that the application times of the solution / process according to the invention can spread over a relatively wide range, ranging from a few seconds to a few hours. Preferred ranges of use are between ½ to 5 minutes and 1 to 2 hours.

La méthode selon l'invention présente par ailleurs l'intérêt que la surveillance / vérification de l'état du bain (et sa "régénération") sont particulièrement aisées, et peuvent être fait à des intervalles relativement espacés (jusqu'à plusieurs semaines, en fonction de l'utilisation), voire par l'envoi d'échantillons de contrôle à un laboratoire de service aux utilisateurs.The method according to the invention also has the advantage that the monitoring / verification of the bath condition (and its "regeneration") are particularly easy, and can be done at relatively spaced intervals (up to several weeks, depending on use), or even sending control samples to a user service laboratory.

La solution de décapage et le procédé de décapage selon l'invention peuvent être mis en oeuvre selon diverses méthodes, comme en particulier sous forme de bain de décapage (utilisation "statique"), par une technique de circulation ou d'aspersion / ruissellement, voire par des techniques de pulvérisation sous forme de liquide relativement visqueux (utilisations "dynamiques"); ces diverses techniques sont bien connues en soi dans le domaine du nettoyage de surfaces.The etching solution and the etching process according to the invention can be carried out according to various methods, such as in particular in the form of a pickling bath ("static" use), by a circulation or sprinkling / trickle technique, even by spraying techniques in the form of relatively viscous liquid ("dynamic" uses); these various techniques are well known per se in the field of surface cleaning.

EXEMPLEEXAMPLE

Une solution de décapage selon l'invention a été préparée en introduisant, dans l'ordre, les ingrédients suivants dans une cuve de 7500 litres :

  • 7200 I d'eau
  • 270 kg d'acide fluorhydrique
  • 150 kg de chlorure ferrique
  • 100 kg de sulfate ferrique
A pickling solution according to the invention was prepared by introducing, in order, the following ingredients into a tank of 7500 liters:
  • 7200 I of water
  • 270 kg hydrofluoric acid
  • 150 kg of ferric chloride
  • 100 kg of ferric sulphate

Les propriétés physico-chimiques de la solution fraichement préparée étaient les suivantes :

  • acidité libre : 1,7 g.équivalent/l
  • acidité totale : 2,1 g.équivalent/l
  • Fe3+ : 10 g/l
  • Cl- : 13,5 g/l
  • SO4 -- : 9,5 g/l
  • F- : 34 g/l
  • pH : 1,3
  • potentiel rédox : 460 mV
The physico-chemical properties of the freshly prepared solution were as follows:
  • free acidity: 1.7 g.equivalent / l
  • total acidity: 2.1 g.equivalent / l
  • Fe 3+ : 10 g / l
  • Cl - : 13.5 g / l
  • SO 4 - : 9.5 g / l
  • F - : 34 g / l
  • pH: 1.3
  • redox potential: 460 mV

Cette solution de décapage, a été utilisée à une température de 15°C pour le décapage de 12000 m2 d'aciers de type inox 304L, sur une période de 5 semaines.This pickling solution was used at a temperature of 15 ° C for the etching of 12000 m 2 of 304L stainless steels over a period of 5 weeks.

Après cette utilisation les propriétés physico-chiques de la solution de décapage étaient les suivantes :

  • acidité libre : 0,9 g.équivalent/l
  • acidité totale : 1,7 g.équivalent/l
  • Fe3+ : 15 g/l
  • Fe2+ : 1 g/l
  • Cl- : 12 g/l
  • potentiel rédox : 350 mV
After this use, the physicochemical properties of the pickling solution were as follows:
  • free acidity: 0.9 g.equivalent / l
  • total acidity: 1.7 g.equivalent / l
  • Fe 3+ : 15 g / l
  • Fe 2+ : 1 g / l
  • Cl - : 12 g / l
  • redox potential: 350 mV

La solution a ensuite été régénérée en y incorporant :

  • 100 I d'acide sulfurique à 96%
  • 150 kg d'acide fluorhydrique à 50%
The solution was then regenerated by incorporating:
  • 100 I of 96% sulfuric acid
  • 150 kg of hydrofluoric acid at 50%

Claims (10)

Solution acide oxydante destinée au décapage d'aciers inoxydables, d'aciers duplex, d'aciers superausténiques et d'alliages de Ni et Ni/Cr, essentiellement exempte de nitrates et de peroxydes, comprenant des ions Fe3+ en association avec des ions F- et des ions Cl- , caractérisée en ce que la teneur en ions Cl- est supérieure à 5g/l.Oxidative acid solution for etching stainless steels, duplex steels, super-aluene steels and alloys of Ni and Ni / Cr, essentially free of nitrates and peroxides, including Fe 3+ ions in combination with ions F - and Cl - ions, characterized in that the content of Cl - ions is greater than 5g / l. Solution, selon la revendication 1, caractérisée en ce que la solution contient de l'acide fluorhydrique en concentration entre 1 et 7% en poids, des ions ferriques en concentration comprise entre 3 et 100 g/l et des ions chlorures en concentration comprise entre 5 et 70 g/l, de préférence entre 10 et 70 g/lSolution according to Claim 1, characterized in that the solution contains hydrofluoric acid in a concentration of between 1 and 7% by weight, ferric ions in a concentration of between 3 and 100 g / l, and chloride ions in a concentration of between 5 and 70 g / l, preferably between 10 and 70 g / l Solution selon l'une ou l'autre des revendications précédentes, caractérisée en ce que la solution contient des ions ferriques en concentration comprise entre 5 et 100 g/l.Solution according to either of the preceding claims, characterized in that the solution contains ferric ions in a concentration of between 5 and 100 g / l. Solution selon l'une ou l'autre des revendications précédentes, caractérisé(e) en ce que la solution contient des ions chlorures en concentration comprise entre 5 et 35 g/l, de préférence entre 10 et 35g/l.Solution according to one or other of the preceding claims, characterized in that the solution contains chloride ions in a concentration of between 5 and 35 g / l, preferably between 10 and 35 g / l. Procédé de décapage d'aciers inoxydables, d'aciers duplex, d'aciers superausténiques et d'alliages de Ni et Ni/Cr, au moyen d'une solution acide oxydante de décapage, essentiellement exempte de nitrates et de peroxydes, comprenant des ions Fe3+ en association avec des ions F- et des ions Cl-, caractérisé en ce que la teneur en ions Cl- de la solution de décapage est supérieure à 5g/l.Process for etching stainless steels, duplex steels, super-aluminum steels and alloys of Ni and Ni / Cr by means of an oxidizing etching solution, essentially free from nitrates and peroxides, comprising ions Fe 3+ in combination with F - ions and Cl - ions, characterized in that the Cl - ion content of the pickling solution is greater than 5g / l. Procédé de décapage selon la revendication 5, caractérisé en ce que l'opération de décapage est effectuée à une température comprise entre 5 et 50° CPickling process according to claim 5, characterized in that the pickling operation is carried out at a temperature of between 5 and 50 ° C Procédé, selon l'une ou l'autre des revendications 5-6, caractérisé en ce que la solution contient de l'acide fluorhydrique en concentration entre 1 et 7% en poids, des ions ferriques en concentration comprise entre 3 et 100 g/l et des ions chlorures en concentration comprise entre 5 et 70 g/l, de préférence entre 10 et 70 g/l.Process according to either of Claims 5-6, characterized in that the solution contains hydrofluoric acid in a concentration of between 1 and 7% by weight and ferric ions in a concentration of between 3 and 100 g / and chloride ions in a concentration of between 5 and 70 g / l, preferably between 10 and 70 g / l. Procédé selon l'une ou l'autre des 5-7, caractérisé en ce que la solution contient des ions ferriques en concentration comprise entre 5 et 100 g/l.Process according to any one of the 5-7, characterized in that the solution contains ferric ions in a concentration of between 5 and 100 g / l. Procédé selon l'une ou l'autre des revendications 5-8, caractérisé en ce que la solution contient des ions chlorures en concentration comprise entre 5 et 35 g/l, de préférence entre 10 et 35g/l.Process according to either of Claims 5-8, characterized in that the solution contains chloride ions in a concentration of between 5 and 35 g / l, preferably between 10 and 35 g / l. Procédé selon l'une ou l'autre des revendications 5-9, caractérisé en ce que l'opération de décapage est effectuée à une température comprise entre 10 et 30° C.Method according to either of claims 5-9, characterized in that the pickling operation is carried out at a temperature between 10 and 30 ° C.
EP07105700A 2007-04-05 2007-04-05 Pickling composition free from nitrates and peroxides, and method using such a composition Withdrawn EP1980650A1 (en)

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EP07105700A EP1980650A1 (en) 2007-04-05 2007-04-05 Pickling composition free from nitrates and peroxides, and method using such a composition

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105256323A (en) * 2015-11-04 2016-01-20 攀钢集团攀枝花钢铁研究院有限公司 Continuous acid pickling method for hot-rolled dual-phase steel

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR88099E (en) * 1964-06-09 1966-12-02 Ver Kunstmestf Mekog Albatros Process for cleaning equipment
EP0769574A1 (en) * 1995-10-18 1997-04-23 NOVAMAX ITB s.r.l. Process for stainless steel pickling and passivation without using nitric acid
US5690748A (en) * 1991-02-25 1997-11-25 Ugine Aciers De Chatillon Et Gueugnon Process for the acid pickling of stainless steel products
WO1998026111A1 (en) * 1996-12-09 1998-06-18 Centro Sviluppo Materiali S.P.A. Method for pickling products in a metal alloy containing iron and in titanium and alloys thereof
JPH11264087A (en) * 1998-03-16 1999-09-28 Parker Corp Treating liquid for descaling stainless steel and its usage
US5992196A (en) * 1996-02-27 1999-11-30 Usinor Process for pickling a piece of steel and in particular a sheet strip of stainless steel
EP1050605A2 (en) * 1999-05-03 2000-11-08 Henkel Kommanditgesellschaft auf Aktien Process for pickling stainless steel in the absence of nitric acid and in the presence of chloride ions
US20060076247A1 (en) * 2002-10-15 2006-04-13 Paolo Giordani Pickling or brightening/passivating solution and process for steel and stainless steel

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR88099E (en) * 1964-06-09 1966-12-02 Ver Kunstmestf Mekog Albatros Process for cleaning equipment
US5690748A (en) * 1991-02-25 1997-11-25 Ugine Aciers De Chatillon Et Gueugnon Process for the acid pickling of stainless steel products
EP0769574A1 (en) * 1995-10-18 1997-04-23 NOVAMAX ITB s.r.l. Process for stainless steel pickling and passivation without using nitric acid
US5992196A (en) * 1996-02-27 1999-11-30 Usinor Process for pickling a piece of steel and in particular a sheet strip of stainless steel
WO1998026111A1 (en) * 1996-12-09 1998-06-18 Centro Sviluppo Materiali S.P.A. Method for pickling products in a metal alloy containing iron and in titanium and alloys thereof
JPH11264087A (en) * 1998-03-16 1999-09-28 Parker Corp Treating liquid for descaling stainless steel and its usage
EP1050605A2 (en) * 1999-05-03 2000-11-08 Henkel Kommanditgesellschaft auf Aktien Process for pickling stainless steel in the absence of nitric acid and in the presence of chloride ions
US20060076247A1 (en) * 2002-10-15 2006-04-13 Paolo Giordani Pickling or brightening/passivating solution and process for steel and stainless steel

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105256323A (en) * 2015-11-04 2016-01-20 攀钢集团攀枝花钢铁研究院有限公司 Continuous acid pickling method for hot-rolled dual-phase steel
CN105256323B (en) * 2015-11-04 2018-01-26 攀钢集团攀枝花钢铁研究院有限公司 Continuous pickling method for hot-rolled dual-phase steel

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