EP0501867B1 - Method for etching steel materials such as stainless steels and alloyed steels - Google Patents
Method for etching steel materials such as stainless steels and alloyed steels Download PDFInfo
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- EP0501867B1 EP0501867B1 EP92400471A EP92400471A EP0501867B1 EP 0501867 B1 EP0501867 B1 EP 0501867B1 EP 92400471 A EP92400471 A EP 92400471A EP 92400471 A EP92400471 A EP 92400471A EP 0501867 B1 EP0501867 B1 EP 0501867B1
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- 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
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- 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
Definitions
- the present invention relates to a method of pickling and descaling of stainless steel materials and / or alloy steel, and in particular over-stripping allowing elimination of an internal oxidation layer located on the surface of the materials, under the scale.
- the oxidation layer internal is formed when the solubility of oxygen is very low, about 100 ppm, at particularly low partial pressure below the scale, on the surface of the metals or metal alloys.
- the internal oxidation results in the formation of oxides of the residual or addition elements, more oxidizable than iron such as aluminum and / or silicon, these elements entering into the formation. of compounds such as iron aluminate (FeAl 2 O 4 ), the formation of these compounds being detrimental to the good performance of the materials in service.
- iron aluminate FeAl 2 O 4
- the oxidation of the material before pickling as a result of more or less weathering significant of the underlying metal or metal alloy generates surface dechromination thereafter a modification, in composition, of the healthy metal.
- the products are immersed in over-pickling baths composed of nitric acid and hydrofluoric acid in a proportion of 60 to 160 g / l of HNO 3 and 10 to 50 g / l of HF, the overblasting bath being used at a temperature above 40 ° C.
- Such a method allows, in use at a temperature above 60 ° C, the pickling of the layer affected by internal oxidation.
- This process has the drawback, on the one hand, of lead to intense release of oxide vapor or particularly toxic nitrogen dioxide and, on the other hand, to generate releases of compounds nitrates, some of which are particularly toxic.
- FR-A-2 587 369 also describes a pickling process for stainless steel products in which a compound pickling bath is used essentially a hydrofluoric acid bath and of water, in a concentration of less than 50 g / l in which dissolves iron into ferric iron and iron ferrous and the ferric iron content is maintained at at least 15 g / l by oxidation of the bath.
- the active pickling agent is the ferric ion Fe 3+ , the acid solution containing H + ions being essentially a vector allowing maintenance in proportion of the ions Fe 2+ and Fe 3+ in the form of complexes, by controlling the redox potential of said pickling bath.
- This process has the disadvantage, when the product surface is sensitive to the formation of a internal oxidation layer, for example during a long-term annealing, not to eliminate this layer.
- GB-A-2 000 196 describes a pickling process at 50 ° C with a solution containing 5% hydrofluoric acid, 50 g / l ferric sulfate and 30 g / l ferrous sulfate and maintaining the potential oxidation-reduction of the bath to a value of +300 mV per addition of hydrogen peroxide and acid to the bath sulfuric.
- the subject of the invention is a method of pickling of metallic materials such as steels stainless and alloy steels allowing in addition to pickling of calamines, a controlled over-stripping of a internal oxidation layer.
- Maintaining the desired value of the redox potential can be obtained by introduction or in situ training in the bath an oxidizing gas chosen from air, ozone, oxygen or by adding compounds to the bath chosen from hydrogen peroxide, persalts, mineral and organic peracids, or any other oxygen source.
- an oxidizing gas chosen from air, ozone, oxygen or by adding compounds to the bath chosen from hydrogen peroxide, persalts, mineral and organic peracids, or any other oxygen source.
- the concentration of ferric iron (which found in complexed state) is usually 20 to 100 g / l.
- the bath temperature is from 40 to 80 ° C.
- FIG. unique represents the sectional image of an oxide layer on which the different compounds of constitution.
- Fig. single is shown in section an oxide layer.
- the various constituent compounds which are present there demonstrate the influence of oxygen and its partial pressure on the chemical form of said compounds.
- a layer 2 of Fe 2 O 3 of a layer 3 of Fe 3 O 4 , of a layer 4 of FeO.
- this set forming the oxide layer also called calamine, there sometimes appears a so-called internal oxidation layer which has a composition close to that of healthy metal, but which is enriched with inclusive oxidized compounds.
- elements of this internal oxidation layer releases elements of constitution such as silicon and aluminum, very sensitive to oxygen, which forms compounds, such as, for example, iron silicates and aluminates, ( SiO 2 , 2FeO); (Al 2 O 3 , 3FeO).
- control of these parameters is ensured in particular, on the one hand, by measuring a potential REDOX and, on the other hand, by the release of hydrogen.
- the Fe +++ / Fe ++ ratio is maintained at a value between 1 and 10 and preferably at a value of 4 by measuring the REDOX potential maintained at 200 mV / Ag / AgCl.
- the amount of hydrogen resulting from reaction (b) is 2 ml / cm 2 .
- Hydrofluoric acid is introduced into the bath to maintain a concentration of 80 g / l.
- the acid concentration is a determining factor in the over-stripping reaction, because it generates H + ions, complexing Fe +++ and Cr +++ ions, protruding and dissolving agent of the silicates present in the layer of internal oxidation.
- the mixed complexes formed between Fe ++ and Fe +++ are of the Fe 2 F 5 nH 2 O type, n being between 2 and 10.
Abstract
Description
La présente invention concerne un procédé de décapage-décalaminage de matériaux en acier inoxydable et/ou en acier allié, et notamment de surdécapage permettant l'élimination d'une couche d'oxydation interne située en surface des matériaux, sous la calamine.The present invention relates to a method of pickling and descaling of stainless steel materials and / or alloy steel, and in particular over-stripping allowing elimination of an internal oxidation layer located on the surface of the materials, under the scale.
Il est connu, dans le domaine de la métallurgie, qu'au cours de l'élaboration et de la transformation des métaux et alliages métalliques, ceux-ci se recouvrent d'une couche de calamine. La formation des calamines est principalement liée à l'existence de l'oxygène sous l'atmosphère naturelle ambiante.It is known, in the field of metallurgy, that during the development and transformation metals and metal alloys, these are covered with a layer of carbon. Training calamines is mainly linked to the existence of oxygen under the surrounding natural atmosphere.
Sous les calamines, il se forme parfois une couche dite "d'oxydation interne". La couche d'oxydation interne est formée lorsque la solubilité de l'oxygène est très faible, c'est-à-dire environ 100 ppm, sous une pression partielle faible particulièrement en dessous de la calamine, à la surface des métaux ou alliages métalliques.Under the calamines, it sometimes forms a so-called "internal oxidation" layer. The oxidation layer internal is formed when the solubility of oxygen is very low, about 100 ppm, at particularly low partial pressure below the scale, on the surface of the metals or metal alloys.
Dans la pratique, l'oxydation interne par exemple des aciers se traduit par la formation d'oxydes des éléments résiduels ou d'addition, plus oxydables que le fer tels que l'aluminium et/ou le silicium, ces éléments entrant dans la formation de composés tel que l'aluminate de fer, (FeAl2O4), la formation de ces composés étant nuisible à la bonne tenue en service des matériaux.In practice, the internal oxidation, for example of steels, results in the formation of oxides of the residual or addition elements, more oxidizable than iron such as aluminum and / or silicon, these elements entering into the formation. of compounds such as iron aluminate (FeAl 2 O 4 ), the formation of these compounds being detrimental to the good performance of the materials in service.
Par ailleurs, l'oxydation du matériau avant décapage, par suite de l'altération plus ou moins importante du métal ou de l'alliage métallique sous-jacent génère une déchromisation en surface entraínant par la suite une modification, en composition, du métal sain.Furthermore, the oxidation of the material before pickling, as a result of more or less weathering significant of the underlying metal or metal alloy generates surface dechromination thereafter a modification, in composition, of the healthy metal.
Les procédés de décapage et/ou de décalaminage permettent d'éliminer les couches de calamines mais n'ont pas toujours les propriétés spécifiques pour éliminer les couches affectées par une oxydation interne.Pickling and / or descaling processes eliminate layers of calamines but do not always have specific properties to remove layers affected by oxidation internal.
Dans un procédé bien connu, de décapage des aciers inoxydables, on plonge les produits, préalablement décapés, dans des bains de surdécapage composés d'acide nitrique et d'acide fluorhydrique dans une proportion de 60 à 160 g/l de HNO3 et de 10 à 50 g/l de HF, le bain de surdécapage étant utilisé à une température supérieure à 40° C.In a well-known process for pickling stainless steels, the products, previously pickled, are immersed in over-pickling baths composed of nitric acid and hydrofluoric acid in a proportion of 60 to 160 g / l of HNO 3 and 10 to 50 g / l of HF, the overblasting bath being used at a temperature above 40 ° C.
Un tel procédé permet, dans une utilisation à une température supérieure à 60° C, le décapage de la couche affectée par l'oxydation interne.Such a method allows, in use at a temperature above 60 ° C, the pickling of the layer affected by internal oxidation.
Ce procédé a l'inconvénient, d'une part, de conduire à un dégagement intense de vapeur d'oxyde ou de dioxyde d'azote particulièrement toxiques et, d'autre part, de générer des rejets de composés nitrés, dont certains sont particulièrement toxiques.This process has the drawback, on the one hand, of lead to intense release of oxide vapor or particularly toxic nitrogen dioxide and, on the other hand, to generate releases of compounds nitrates, some of which are particularly toxic.
FR-A-2 587 369 décrit par ailleurs un procédé de décapage de produits en acier inoxydable dans lequel on utilise un bain de décapage composé essentiellement d'un bain d'acide fluorhydrique et d'eau, en une concentration inférieure à 50 g/l dans lequel on dissout du fer en fer ferrique et fer ferreux et l'on maintient la teneur en fer ferrique à au moins 15 g/l par oxydation du bain.FR-A-2 587 369 also describes a pickling process for stainless steel products in which a compound pickling bath is used essentially a hydrofluoric acid bath and of water, in a concentration of less than 50 g / l in which dissolves iron into ferric iron and iron ferrous and the ferric iron content is maintained at at least 15 g / l by oxidation of the bath.
Dans ce procédé, l'agent actif de décapage est l'ion ferrique Fe3+, la solution acide contenant des ions H+ étant essentiellement un vecteur permettant un maintien en proportion des ions Fe2+ et Fe3+ sous forme de complexes, par un contrôle du potentiel d'oxydoréduction dudit bain de décapage.In this process, the active pickling agent is the ferric ion Fe 3+ , the acid solution containing H + ions being essentially a vector allowing maintenance in proportion of the ions Fe 2+ and Fe 3+ in the form of complexes, by controlling the redox potential of said pickling bath.
Ce procédé a l'inconvénient, lorsque la surface du produit est sensible à la formation d'une couche d'oxydation interne, par exemple lors d'un recuit de longue durée, de ne pas éliminer cette couche.This process has the disadvantage, when the product surface is sensitive to the formation of a internal oxidation layer, for example during a long-term annealing, not to eliminate this layer.
On connaít aussi de EP-A-0 188 975 un procédé de décapage de pièces en acier inoxydable, au moyen d'une solution d'acide fluorhydrique comprenant entre 5 et 50 g/l de HF, ayant un pH compris entre 0 et 3 et contenant des ions ferriques.We also know from EP-A-0 188 975 a process pickling of stainless steel parts, using a hydrofluoric acid solution comprising between 5 and 50 g / l of HF, having a pH between 0 and 3 and containing ferric ions.
GB-A-2 000 196 décrit un procédé de décapage à 50 °C avec une solution contenant 5% d'acide fluorhydrique, 50 g/l sulfate ferrique et 30 g/l sulfate ferreux et en maintenant le potentiel d'oxydoréduction du bain à une valeur de +300 mV par addition dans le bain de peroxyde d'hydrogène et acide sulfurique.GB-A-2 000 196 describes a pickling process at 50 ° C with a solution containing 5% hydrofluoric acid, 50 g / l ferric sulfate and 30 g / l ferrous sulfate and maintaining the potential oxidation-reduction of the bath to a value of +300 mV per addition of hydrogen peroxide and acid to the bath sulfuric.
L'invention a pour objet un procédé de décapage de matériaux métalliqus tels que les aciers inoxydables et aciers alliés permettant outre un décapage des calamines, un surdécapage contrôlé d'une couche d'oxydation interne.The subject of the invention is a method of pickling of metallic materials such as steels stainless and alloy steels allowing in addition to pickling of calamines, a controlled over-stripping of a internal oxidation layer.
Le procédé selon l'invention se caractérise en ce que l'on traite le matériau par un bain contenant :
- de l'acide fluorhydrique (d = 1,25) à une concentration de 80 à 150 g/l,
- des ions ferriques en une concentration d'au moins 20 g/l,
- hydrofluoric acid (d = 1.25) at a concentration of 80 to 150 g / l,
- ferric ions in a concentration of at least 20 g / l,
Ainsi, dans le procédé selon l'invention, on contrôle pendant l'opération de décapage-décalaminage deux réactions chimiques concomitantes pour le surdécapage de la matrice du produit constituant la couche d'oxydation interne, ces deux réactions étant :
- une réaction de réduction du fer ferrique
en fer ferreux :
- une réaction de dissolution des éléments
métalliques M de la matrice du matériau :
- a reaction for reducing ferric iron to ferrous iron:
- a reaction for dissolving the metallic elements M of the matrix of the material:
Le maintien de la valeur désirée du potentiel d'oxydoréduction peut être obtenu par l'introduction ou la formation in situ dans le bain d'un gaz oxydant choisi parmi l'air, l'ozone, l'oxygène ou par l'addition dans le bain de composés choisis parmi le peroxyde d'hydrogène, les persels, les peracides minéraux et organiques, ou toute autre source d'oxygène.Maintaining the desired value of the redox potential can be obtained by introduction or in situ training in the bath an oxidizing gas chosen from air, ozone, oxygen or by adding compounds to the bath chosen from hydrogen peroxide, persalts, mineral and organic peracids, or any other oxygen source.
Dans le cas de l'utilisation d'un gaz oxydant, son volume est généralement compris entre 1 et 10 l/m2 de matériau.In the case of the use of an oxidizing gas, its volume is generally between 1 and 10 l / m 2 of material.
Dans le cas de l'utilisation de peroxyde d'hydrogène à 200 volumes, son volume est généralement compris entre 10 et 100 g/m2 de surface de matériau.In the case of the use of hydrogen peroxide at 200 volumes, its volume is generally between 10 and 100 g / m 2 of material surface.
La concentration en acide fluorhydrique (d = 1,25 à 70 %) du bain est de 80 à 150 g/l.The hydrofluoric acid concentration (d = 1.25 to 70%) of the bath is from 80 to 150 g / l.
La concentration du fer ferrique (qui se trouve à l'état complexé) est généralement de 20 à 100 g/l.The concentration of ferric iron (which found in complexed state) is usually 20 to 100 g / l.
Les quantités d'hydrogène dégagée sont exprimées dans les conditions normales, P : 105 Pa, T = 20° C.The quantities of hydrogen released are expressed under normal conditions, P: 10 5 Pa, T = 20 ° C.
La température du bain est de 40 à 80° C.The bath temperature is from 40 to 80 ° C.
La description détaillée qui suit fera mieux comprendre la présente invention. On se référera au dessin annexé dans lequel la Fig. unique représente l'image en coupe d'une couche d'oxyde sur laquelle sont matérialisés les différents composés de constitution. The following detailed description will do better understand the present invention. We will refer to attached drawing in which FIG. unique represents the sectional image of an oxide layer on which the different compounds of constitution.
A la suite d'études portant sur le décapage de produits métalliques, il a été mis en évidence, d'une part, l'existence, en surface de certains aciers, d'une couche d'oxydation interne affectant dans le temps la qualité en surface de l'acier décapé et, d'autre part, le fait que cette couche d'oxydation interne avait un comportement propre vis-à-vis des bains de décapage-décalaminage.Following studies on stripping of metal products, it was highlighted, on the one hand, the existence, on the surface of certain steels, an internal oxidation layer affecting over time the surface quality of the pickled steel and, on the other hand, the fact that this layer of oxidation internal had its own behavior towards pickling and descaling baths.
Sur la Fig. unique est représentée en coupe une couche d'oxyde. Les différents composés de constitution qui y sont présents mettent en évidence l'influence de l'oxygène et de sa pression partielle sur la forme chimique desdits composés. En analysant les différentes couches sur le métal sain 1, on distingue depuis la surface la présence d'une couche 2 de Fe2O3, d'une couche 3 de Fe3O4, d'une couche 4 de FeO. Sous cet ensemble formant la couche d'oxyde, appelée aussi calamine, il apparaít parfois une couche dite d'oxydation interne qui a une composition proche de celle du métal sain, mais qui s'enrichit en composés oxydés inclusionnaires.In Fig. single is shown in section an oxide layer. The various constituent compounds which are present there demonstrate the influence of oxygen and its partial pressure on the chemical form of said compounds. By analyzing the different layers on the healthy metal 1, one distinguishes from the surface the presence of a layer 2 of Fe 2 O 3 , of a layer 3 of Fe 3 O 4 , of a layer 4 of FeO. Under this set forming the oxide layer, also called calamine, there sometimes appears a so-called internal oxidation layer which has a composition close to that of healthy metal, but which is enriched with inclusive oxidized compounds.
Du fait qu'il y a substitution chrome-fer, il se forme plus précisément en surface, dans la calamine, des oxydes du type (Fe, Cr)2O3; (Fe, Cr)3O4; (Fe, Cr)O. La diffusion du chrome créée en surface et au contact de la couche 6 d'oxydation interne une couche 5 dite "déchromée".Due to the substitution of chromium-iron, it forms more precisely on the surface, in the calamine, oxides of the type (Fe, Cr) 2 O 3 ; (Fe, Cr) 3 O 4 ; (Fe, Cr) O. The diffusion of chromium created on the surface and in contact with layer 6 of internal oxidation a layer 5 called "dechromed".
L'appauvrissement en éléments de cette couche d'oxydation interne libère des éléments de constitution tel que le silicium et l'aluminium, très sensible à l'oxygène, qui forme des composés, comme par exemple, des silicates et aluminates de fer, (SiO2, 2FeO); (Al2O3, 3FeO).The depletion in elements of this internal oxidation layer releases elements of constitution such as silicon and aluminum, very sensitive to oxygen, which forms compounds, such as, for example, iron silicates and aluminates, ( SiO 2 , 2FeO); (Al 2 O 3 , 3FeO).
Plusieurs paramètres doivent être contrôlés pour permettre l'élimination de cette couche d'oxydtion tion interne tels que :
- la concentration en acide fluorhydrique
- la température des bains de décapage
- la teneur en ions Fe++, Fe+++, H+
- la durée d'immersion du matériau dans le bain,
- le brassage de la solution de décapage.
- hydrofluoric acid concentration
- the temperature of the pickling baths
- the content of ions Fe ++ , Fe +++ , H +
- the duration of immersion of the material in the bath,
- stirring of the pickling solution.
Le contrôle desdits paramètres est assuré notamment, d'une part, par la mesure d'un potentiel REDOX et, d'autre part, par le dégagement de l'hydrogène.The control of these parameters is ensured in particular, on the one hand, by measuring a potential REDOX and, on the other hand, by the release of hydrogen.
Dans un exemple d'application selon l'invention, pour le décapage d'un acier de type 304 :
- on utilise une solution composée d'eau et d'acide fluorhydrique d = 1,25 (70 %) à une concentration de 80 g/l.
- On dissout du fer dans une proportion de 60 g/l qui forme des ions ferreux et ferriques.
- using a solution composed of water and hydrofluoric acid d = 1.25 (70%) at a concentration of 80 g / l.
- Iron is dissolved in a proportion of 60 g / l which forms ferrous and ferric ions.
La température du bain est amenée à 60±5° C.
- On contrôle pendant l'opération de décapage-décalaminage,
deux réactions concomitantes de
dissolution de la matrice du matériau pour accélérer
la cinétique de décapage, les deux réactions étant :
- on maintient une teneur de fer total de 60 g/l.
- During the pickling-descaling operation, two concomitant reactions of dissolution of the matrix of the material are controlled to accelerate the pickling kinetics, the two reactions being:
- a total iron content of 60 g / l is maintained.
Il est introduit dans le bain de décapage de l'air comprimé à la température de 80° C à un débit de 1 à 10 l/m2, ainsi que du péroxyde d'hydrogène.It is introduced into the pickling bath of compressed air at a temperature of 80 ° C at a flow rate of 1 to 10 l / m 2 , as well as hydrogen peroxide.
Le rapport Fe+++/Fe++ est maintenu à une valeur comprise entre 1 et 10 et de préférence à une valeur de 4 par mesure du potentiel REDOX maintenu à 200 mV/Ag/AgCl. The Fe +++ / Fe ++ ratio is maintained at a value between 1 and 10 and preferably at a value of 4 by measuring the REDOX potential maintained at 200 mV / Ag / AgCl.
La quantité d'hydrogène résultant de la réaction (b) est de 2 ml/cm2.The amount of hydrogen resulting from reaction (b) is 2 ml / cm 2 .
L'acide fluorhydrique est introduit dans le bain pour maintenir une concentration de 80 g/l.Hydrofluoric acid is introduced into the bath to maintain a concentration of 80 g / l.
La concentration en acide est un facteur déterminant dans la réaction de surdécapage, car il est générateur d'ion H+, complexant des ions Fe+++ et Cr+++, dépassivant et agent de dissolution des silicates présents dans la couche d'oxydation interne. Les complexes mixtes formés entre Fe++ et Fe+++ sont du type Fe2F5 nH2O, n étant compris entre 2 et 10.The acid concentration is a determining factor in the over-stripping reaction, because it generates H + ions, complexing Fe +++ and Cr +++ ions, protruding and dissolving agent of the silicates present in the layer of internal oxidation. The mixed complexes formed between Fe ++ and Fe +++ are of the Fe 2 F 5 nH 2 O type, n being between 2 and 10.
Claims (6)
- Method of etching and decarbonising a material made from steel, chosen particularly from among stainless steels and alloy steels, which enables the elimination of an internal oxidation layer, characterised in that the material is treated in a bath containing:and the reaction conditions are regulated in such a way as be accompanied by a reduction of the ferric iron to ferrous iron and a reaction of dissolution of the metal elements of the matrix of the material, whilst keeping the bath agitated at a temperature of 40 to 80 °C and keeping the oxidoreduction potential of the bath at a value of 100 to 350 mV with respecthydrofluoric acid (d = 1.25) at a concentration of 80 to 150 g/l,ferric ions in a concentration of at least 20 g/l,
to Ag/AgCl, and the concentration of acid such that the quantity of hydrogen evolved is 0.1 to 5 ml/cm2 of material (measured in normal conditions). - Method as claimed in Claim 1, characterised in that iron is dissolved in the bath in a proportion within a range from 20 to 100 g/l.
- Method as claimed in any one of Claims 1 to 2, characterised in that the desired value of the oxidoreduction potential is controlled by the introduction or the formation in situ in the bath of an oxidising gas chosen from amongst air, ozone, oxygen.
- Method as claimed in any one of Claims 1 to 2, characterised in that the desired value of the oxidoreduction potential is controlled by addition into the bath of compounds chosen from amongst H2O2, persalts, mineral and organic per-acids.
- Method as claimed in Claim 3, characterised in that the volume of oxidising gas is between 1 and 10 l/m2 of material surface.
- Method as claimed in Claim 1, characterised in that hydrogen peroxide at 200 volumes is used at a rate of 10 to 100 g/m2 of material surface.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR9102222 | 1991-02-25 | ||
| FR9102222A FR2673200A1 (en) | 1991-02-25 | 1991-02-25 | METHOD FOR OVERDRAWING STEEL MATERIALS SUCH AS STAINLESS STEELS AND ALLIED STEELS. |
| US08/150,254 US5690748A (en) | 1991-02-25 | 1993-11-10 | Process for the acid pickling of stainless steel products |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0501867A1 EP0501867A1 (en) | 1992-09-02 |
| EP0501867B1 true EP0501867B1 (en) | 1999-01-07 |
Family
ID=26228531
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP92400471A Expired - Lifetime EP0501867B1 (en) | 1991-02-25 | 1992-02-24 | Method for etching steel materials such as stainless steels and alloyed steels |
Country Status (9)
| Country | Link |
|---|---|
| US (1) | US5690748A (en) |
| EP (1) | EP0501867B1 (en) |
| AT (1) | ATE175452T1 (en) |
| DE (1) | DE69228080T2 (en) |
| DK (1) | DK0501867T3 (en) |
| ES (1) | ES2127208T3 (en) |
| FI (1) | FI99031C (en) |
| FR (1) | FR2673200A1 (en) |
| GR (1) | GR3029688T3 (en) |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1255655B (en) * | 1992-08-06 | 1995-11-09 | STAINLESS STEEL PICKLING AND PASSIVATION PROCESS WITHOUT THE USE OF NITRIC ACID | |
| DE4237021C1 (en) * | 1992-11-02 | 1994-02-10 | Poligrat Gmbh | Means for pickling the surface of chromium-nickel steels and chrome steels and use of the agent |
| IT1276955B1 (en) | 1995-10-18 | 1997-11-03 | Novamax Itb S R L | PICKLING AND PASSIVATION PROCESS OF STAINLESS STEEL WITHOUT THE USE OF NITRIC ACID |
| US5724668A (en) * | 1995-11-07 | 1998-03-03 | Electronic Power Research Institute | Method for decontamination of nuclear plant components |
| FR2745301B1 (en) * | 1996-02-27 | 1998-04-03 | Usinor Sacilor | PROCESS FOR STRIPPING A STEEL PART AND PARTICULARLY A STAINLESS STEEL SHEET STRIP |
| US20040140288A1 (en) * | 1996-07-25 | 2004-07-22 | Bakul Patel | Wet etch of titanium-tungsten film |
| IT1297076B1 (en) * | 1997-11-24 | 1999-08-03 | Acciai Speciali Terni Spa | METHOD FOR PICKLING OF STEEL PRODUCTS |
| DE19755350A1 (en) * | 1997-12-12 | 1999-06-17 | Henkel Kgaa | Process for pickling and passivating stainless steel |
| GB9807286D0 (en) * | 1998-04-06 | 1998-06-03 | Solvay Interox Ltd | Pickling process |
| USH2087H1 (en) * | 1998-05-19 | 2003-11-04 | H. C. Starck, Inc. | Pickling of refractory metals |
| DE19833990A1 (en) * | 1998-07-29 | 2000-02-10 | Metallgesellschaft Ag | Mordant for stainless steels |
| EP1980650A1 (en) * | 2007-04-05 | 2008-10-15 | Kerma S.A. | Pickling composition free from nitrates and peroxides, and method using such a composition |
| CN109234746A (en) * | 2018-11-12 | 2019-01-18 | 江阴祥瑞不锈钢精线有限公司 | A kind of acid cleaning process method of stainless steel wire |
| JP7176137B2 (en) * | 2020-01-09 | 2022-11-21 | Ｐｒｉｍｅｔａｌｓ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｊａｐａｎ株式会社 | Pickling method and pickling apparatus for steel plate |
| IT202000005848A1 (en) | 2020-03-19 | 2021-09-19 | Tenova Spa | Process for pickling and / or passivating a stainless steel. |
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| US2474526A (en) * | 1940-06-15 | 1949-06-28 | Monsanto Chemicals | Picking of stainless steels |
| US2337062A (en) * | 1942-04-07 | 1943-12-21 | Solar Aircraft Co | Pickling solution and method |
| US2564549A (en) * | 1945-07-02 | 1951-08-14 | Albert R Stargardter | Pickling treatment |
| US2856275A (en) * | 1956-11-20 | 1958-10-14 | Amchem Prod | Chemical treatment of refractory metal surfaces |
| US3310435A (en) * | 1963-11-18 | 1967-03-21 | Dravo Corp | Process for continuous pickling of steel strip and regeneration of the contact acid |
| AU471215B2 (en) * | 1972-02-22 | 1976-04-15 | Seat belt retractor | |
| JPS549120A (en) * | 1977-06-24 | 1979-01-23 | Tokai Electro Chemical Co | Method of controlling acid cleaning liquid for stainless steel |
| DE3105508A1 (en) * | 1981-02-14 | 1982-09-02 | Metallgesellschaft Ag, 6000 Frankfurt | Stain and rust removal paste for metals |
| JPS5839234B2 (en) * | 1981-10-26 | 1983-08-29 | 住友金属工業株式会社 | Pickling and descaling method for steel wire rod |
| US4608091A (en) * | 1982-01-11 | 1986-08-26 | Enthone, Incorporated | Peroxide selective stripping compositions and method |
| DE3222532A1 (en) * | 1982-06-16 | 1983-12-22 | Arno 5042 Erftstadt Kuhlmann | Process and means for the acidic etching of austenitic stainless steels |
| FR2539140A1 (en) * | 1983-01-07 | 1984-07-13 | Ugine Kuhlmann | STABILIZATION OF AQUEOUS SOLUTIONS CONTAINING HYDROGEN PEROXIDE, FLUORHYDIC ACID AND METALLIC IONS |
| FR2551465B3 (en) * | 1983-09-02 | 1985-08-23 | Gueugnon Sa Forges | ACID STRIPPING PROCESS FOR STAINLESS STEELS AND ACID SOLUTION FOR IMPLEMENTING SAME |
| FR2560893B1 (en) * | 1984-03-09 | 1986-09-12 | Snecma | CHEMICAL STRIPPING BATH FOR HOT-RESISTANT ALLOY PARTS |
| DE3588013T3 (en) * | 1985-01-22 | 2002-06-06 | Ugine Sa | Process for acid pickling steel, especially stainless steel. |
| US5154774A (en) * | 1985-09-19 | 1992-10-13 | Ugine Aciers De Chatillon Et Gueugnon | Process for acid pickling of stainless steel products |
| FR2587369B1 (en) * | 1985-09-19 | 1993-01-29 | Ugine Gueugnon Sa | PROCESS OF ACID STRIPPING OF STAINLESS STEEL PRODUCTS |
| US5292374A (en) * | 1988-11-15 | 1994-03-08 | Maschinenfabrik Andritz Actiengesellschft | Process and plant for pickling stainless steel strip |
| DE3937438C2 (en) * | 1989-02-23 | 1998-01-29 | Wilfried Simmer | Steel pickling process |
| FR2657888B1 (en) * | 1990-02-08 | 1994-04-15 | Ugine Aciers | STRIPPING METHODS FOR STAINLESS STEEL MATERIALS. |
| US5354383A (en) * | 1991-03-29 | 1994-10-11 | Itb, S.R.L. | Process for pickling and passivating stainless steel without using nitric acid |
-
1991
- 1991-02-25 FR FR9102222A patent/FR2673200A1/en active Granted
-
1992
- 1992-02-24 DK DK92400471T patent/DK0501867T3/en active
- 1992-02-24 AT AT92400471T patent/ATE175452T1/en active
- 1992-02-24 ES ES92400471T patent/ES2127208T3/en not_active Expired - Lifetime
- 1992-02-24 DE DE69228080T patent/DE69228080T2/en not_active Expired - Lifetime
- 1992-02-24 EP EP92400471A patent/EP0501867B1/en not_active Expired - Lifetime
- 1992-02-24 FI FI920787A patent/FI99031C/en not_active IP Right Cessation
-
1993
- 1993-11-10 US US08/150,254 patent/US5690748A/en not_active Expired - Lifetime
-
1999
- 1999-03-12 GR GR990400772T patent/GR3029688T3/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| DE69228080T2 (en) | 1999-05-20 |
| FI920787A0 (en) | 1992-02-24 |
| US5690748A (en) | 1997-11-25 |
| ATE175452T1 (en) | 1999-01-15 |
| FI99031C (en) | 1997-09-25 |
| ES2127208T3 (en) | 1999-04-16 |
| FR2673200B1 (en) | 1995-03-03 |
| FR2673200A1 (en) | 1992-08-28 |
| GR3029688T3 (en) | 1999-06-30 |
| DE69228080D1 (en) | 1999-02-18 |
| EP0501867A1 (en) | 1992-09-02 |
| DK0501867T3 (en) | 1999-08-30 |
| FI920787A (en) | 1992-08-26 |
| FI99031B (en) | 1997-06-13 |
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