WO2011023319A1 - Procédé de décapage pour acier inoxydable - Google Patents

Procédé de décapage pour acier inoxydable Download PDF

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Publication number
WO2011023319A1
WO2011023319A1 PCT/EP2010/005040 EP2010005040W WO2011023319A1 WO 2011023319 A1 WO2011023319 A1 WO 2011023319A1 EP 2010005040 W EP2010005040 W EP 2010005040W WO 2011023319 A1 WO2011023319 A1 WO 2011023319A1
Authority
WO
WIPO (PCT)
Prior art keywords
pickling
hydrofluoric acid
concentration
hydrogen peroxide
rinsing
Prior art date
Application number
PCT/EP2010/005040
Other languages
German (de)
English (en)
Inventor
Siegfried Piesslinger-Schweiger
Olaf Boehme
Original Assignee
Poligrat Gmbh
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Poligrat Gmbh filed Critical Poligrat Gmbh
Priority to EP10745563A priority Critical patent/EP2470689A1/fr
Publication of WO2011023319A1 publication Critical patent/WO2011023319A1/fr

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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
    • 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
    • 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
    • C23G1/36—Regeneration of waste pickling liquors

Definitions

  • the invention relates to a method for the pickling treatment of stainless steel or stainless steel surfaces.
  • the inventive method is suitable for the surface treatment of all alloys and structural forms of stainless steel.
  • the inventive method allows the recycling of wastewater from the lo process.
  • the pickling treatment is usually carried out so that a top layer of material is chemically dissolved and removed in the pickling baths. As a result of this erosion, all contaminants contained on and in the removed material layer are removed.
  • Prior art pickling processes are based on the use of hydrofluoric acid, a secondary mineral acid such as nitric acid, sulfuric acid or phosphoric acid and an oxidizing agent such as nitric acid or hydrogen peroxide.
  • a secondary mineral acid such as nitric acid, sulfuric acid or phosphoric acid
  • an oxidizing agent such as nitric acid or hydrogen peroxide.
  • nitric acid this fulfills both the function of the secondary mineral acid and that of the oxidizing agent.
  • nitric acid is very disadvantageous in terms of environmental hazard and occupational safety.
  • Essential constituents of stainless steel pickling are hydrofluoric acid and a suitable oxidizing agent.
  • a secondary acid when using hydrogen peroxide in place of nitric acid.
  • the addition of this secondary acid serves the purpose of counteracting the lower stability of the hydrogen peroxide at higher concentration of dissolved metals in the pickling baths.
  • the present invention seeks to overcome the foregoing disadvantages of the prior art.
  • the aim of the invention is in particular a pickling process in which it is possible to work with the lowest possible concentration of hydrofluoric acid and with hydrogen peroxide without secondary acids, for example in the presence of a suitable stabilizer for hydrogen peroxide.
  • the method according to the invention should be applicable to all alloys and structural types of stainless steel.
  • the present invention is based on the finding that it is possible to achieve the objectives of the invention by means of a suitable pretreatment in the pickling process.
  • the inventors have found that for pre-treatment or activation of the pickling a solution containing hydrofluoric acid is suitable, the concentration of which is usually adjusted so that it is close to the concentration of the actual pickling bath, preferably even something about it.
  • hydrofluoric acid-containing (HF) solutions are used in a two-stage process - a pretreatment (activation) and the actual pickling.
  • HF hydrofluoric acid-containing
  • the hydrofluoric acid-containing solution in the first stage of the process essentially uses hydrofluoric acid (HF) at a concentration which can be close to (or equal to) the pickling bath concentration without the addition of H 2 O 2 .
  • the concentration of the hydrofluoric acid in the first stage is about 0.2 to 5 wt%, preferably 0.5 to 3 wt%. Since the first process step essentially serves for pretreatment or activation of the pickling material, no further components are required in this activation bath.
  • the person skilled in the art will be able to find a suitable concentration depending on the material to be treated and the hydrofluoric acid concentration in the following method step with simple experiments.
  • the concentration of hydrofluoric acid in the actual pickling process is then about 0.2 to 5 wt .-%, preferably 0.5 to 3 wt .-%.
  • the concentration of hydrogen peroxide in the pickling bath is usually 10 to 30% by weight, preferably 18 to 22% by weight, and more preferably about 20% by weight.
  • a suitable stabilizer may include, for example, urea. Urea can be used both alone and in conjunction with other stabilizers, such as ammonium ions. Other suitable stabilizers are, for example, alylidenediphosphonic acid. In addition, blends of urea and one or more alkanediphosphonic acids (including the salts) may generally be used for stabilization. A particularly suitable stabilizer is 1-hydroxyethane-1,1-diphosphonic acid. Stabilizers are disclosed in particular in EP-AI 903 081, which is incorporated herein by reference.
  • the stainless steel surfaces to be coated are usually subjected to a dipping time of 20 seconds to a maximum of 5 minutes in the first method step. No intermediate step such as rinsing is required before the dressing is introduced into the second process stage.
  • the second process stage is then initiated in a conventional manner but usually also without delay after the first process step.
  • About the pickling time results in a well controllable pickling attack without risk of damage by over-pickling. This has proved equally true for all alloys and microstructures of stainless steel. Only the concentration of hydrofluoric acid is to be adjusted to a certain extent of the stainless steel quality to be refined in order to adjust the speed of the pickling attack to the desired level.
  • the entry of hydrofluoric acid from the activation (pretreatment) in the pickling bath can be chosen so that the consumption of hydrofluoric acid in the pickling bath and the carry-over into the rinsing process are largely compensated. In the pickling bath, therefore, only the consumed and removed hydrogen peroxide must be supplemented. After the pickling bath is usually run in excess with hydrogen peroxide, the addition is not critical and does not require the analytical effort required for pickling baths according to the prior art.
  • the concentration of hydrofluoric acid for processing austenitic chromium-nickel steels is in the range of 1.5 to 3.0%, for processing ferritic steels at 0.5 to 1%. In the case of ferritic steels, one can even assume that the hydrofluoric acid baths used are no longer classified as toxic but merely as corrosive.
  • the concentration of hydrogen peroxide in the pickling baths is in the range of 10% to 30% by weight, preferably 20% by weight.
  • the concentration of stabilizer in the pickling bath is 2% by weight to 10% by weight, preferably 5% by weight to 8% by weight.
  • the inventive method operates at room temperature (maximum about 40 0 C), so that no complex heating and temperature control are required.
  • Example 1 Pickling bath for austenitic chromium-nickel steels Composition of the activating bath: 2.1% HF, balance water, activating time 3 min
  • Example 2 Pickling bath for chromium steels from 14% chromium content
  • Composition of the activation bath 1.0% HF, balance water, activation time 2 min.
  • Pickling bath composition 1.0% HF, 5.0% stabilizer, 20% H 2 O 2 , balance water
  • Example 3 Stainless steels with 9% to 13% chromium content Composition of the activation bath: 0.5% HF, balance water, activation time 2 min Pickling bath composition: 0.5% HF, 5.0% stabilizer, 20% H 2 O 2 , Rest water
  • the pickling baths according to the invention contain pollutants exclusively hydrofluoric acid and the dissolved metal salts of hydrofluoric acid, which are removed from the pickling bath in the rinsing water.
  • the treatment of the rinsing water is advantageously carried out with lime, which is stoichiometrically tuned to the amount of fluoride.
  • lime which is stoichiometrically tuned to the amount of fluoride.
  • the fluorides are precipitated to a concentration below 1 mg / l, the metals are largely converted into metal hydroxides and deposited as solids.
  • the neutralized rinse water can easily be used for the treatment of the lime milk or discharged into the sewage system, since it no longer contains salts such as nitrates, nitrites, sulfates or phosphates.
  • the freedom of salts opens up an advantageous solution for recycling the water: After neutralization, the rinsing water is recovered by evaporation and returned to the rinsing process as condensate. About the amount of recycled condensate is only the amount of compensation of the addition of hydrogen peroxide introduced into the pickling bath additional water. The thickened contents of the evaporator bottom are filtered, the fluorides and metal hydroxides are separated as a solid. The filtrate contains most of the Stabilizer and is returned to the pickling bath, so that the consumption of stabilizer is minimized.
  • the filter cake contains only metal hydroxides and offers optimal conditions for the economic recovery of the metals.
  • Rinsing water from a pickling bath with 50 g / l Fe and 10 g / l Cr contains 5% strength
  • Ni 300 mg / 1 Ni
  • the treatment was carried out by neutralizing with lime milk to pH 8-9, sedimentation and separation of the sludge by filtration. Fluoride and heavy metals were quantitatively removed. The ingredients of the stabilizer remained in the filtrate.

Landscapes

  • 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

La présente invention concerne un procédé de traitement de surface d'alliages et de formes structurales d'acier inoxydable, comprenant deux étapes, la première étant une étape de prétraitement ou d'activation, et la seconde étant une étape de décapage, une solution contenant de l'acide fluorhydrique étant employée dans les deux étapes.
PCT/EP2010/005040 2009-08-25 2010-08-17 Procédé de décapage pour acier inoxydable WO2011023319A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP10745563A EP2470689A1 (fr) 2009-08-25 2010-08-17 Procédé de décapage pour acier inoxydable

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE200910038795 DE102009038795A1 (de) 2009-08-25 2009-08-25 Beizverfahren für Edelstahl
DE102009038795.1 2009-08-25

Publications (1)

Publication Number Publication Date
WO2011023319A1 true WO2011023319A1 (fr) 2011-03-03

Family

ID=43050930

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2010/005040 WO2011023319A1 (fr) 2009-08-25 2010-08-17 Procédé de décapage pour acier inoxydable

Country Status (3)

Country Link
EP (1) EP2470689A1 (fr)
DE (1) DE102009038795A1 (fr)
WO (1) WO2011023319A1 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102013010080A1 (de) * 2013-06-14 2014-12-18 Poligrat Gmbh Verfahren zur Oberflächenbehandlung von Corten-Stahl
CN113740142B (zh) * 2020-05-27 2024-07-12 宝山钢铁股份有限公司 一种镀锌板基体氢含量的获取方法

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1657228A (en) * 1926-06-02 1928-01-24 Allegheny Steel Co Method of picking chromium-iron alloys
AT374508B (de) * 1982-07-01 1984-05-10 Ruthner Industrieanlagen Ag Verfahren zur aufarbeitung verbrauchter beizoder aetzloesungen auf der basis von salpeter-flussaeure
US5154774A (en) * 1985-09-19 1992-10-13 Ugine Aciers De Chatillon Et Gueugnon Process for acid pickling of stainless steel products
DE4142629A1 (de) * 1991-12-21 1993-06-24 Wurster Gerd Verfahren zum verdampfen von abwasser und/oder spuelwasser
EP0915185A1 (fr) * 1997-10-28 1999-05-12 Kawasaki Steel Corporation Procédé pour la fabrication de tÔles en acier austénitique inoxydable
DE19833990A1 (de) * 1998-07-29 2000-02-10 Metallgesellschaft Ag Beizmittel für Edelstähle
EP1050605A2 (fr) * 1999-05-03 2000-11-08 Henkel Kommanditgesellschaft auf Aktien Procédé de décapage d'aciers inoxydables sans acide nitrique et en présence d'ions chlorures
US6174383B1 (en) * 1995-11-28 2001-01-16 Eka Chemicals Ab Method at treatment of metals
EP1903081A2 (fr) 2006-09-19 2008-03-26 Poligrat Gmbh Stabilisateur de bains de polissage acides contenant du métal

Family Cites Families (5)

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Publication number Priority date Publication date Assignee Title
AT228137B (de) * 1960-06-10 1963-06-25 Othmar Ing Ruthner Verfahren zur Rückgewinnung der nach dem Beizen von Metallen im Spülwasser enthaltenen ausgeschleppten Beizsäure
SE381289B (sv) * 1973-06-21 1975-12-01 Nyby Bruk Ab Tvastegsbetningsforfarande
AT404030B (de) * 1995-02-15 1998-07-27 Andritz Patentverwaltung Verfahren zur beize von materialien aus stahl, insbesondere edelstahl
GB9807286D0 (en) * 1998-04-06 1998-06-03 Solvay Interox Ltd Pickling process
DE60215629T2 (de) * 2001-04-09 2007-09-06 AK Steel Properties, Inc., Middletown Verfahren zum beizen von rostfreiem stahl unter verwendung von wasserstoffperoxid

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1657228A (en) * 1926-06-02 1928-01-24 Allegheny Steel Co Method of picking chromium-iron alloys
AT374508B (de) * 1982-07-01 1984-05-10 Ruthner Industrieanlagen Ag Verfahren zur aufarbeitung verbrauchter beizoder aetzloesungen auf der basis von salpeter-flussaeure
US5154774A (en) * 1985-09-19 1992-10-13 Ugine Aciers De Chatillon Et Gueugnon Process for acid pickling of stainless steel products
DE4142629A1 (de) * 1991-12-21 1993-06-24 Wurster Gerd Verfahren zum verdampfen von abwasser und/oder spuelwasser
US6174383B1 (en) * 1995-11-28 2001-01-16 Eka Chemicals Ab Method at treatment of metals
EP0915185A1 (fr) * 1997-10-28 1999-05-12 Kawasaki Steel Corporation Procédé pour la fabrication de tÔles en acier austénitique inoxydable
DE19833990A1 (de) * 1998-07-29 2000-02-10 Metallgesellschaft Ag Beizmittel für Edelstähle
US20040053801A1 (en) * 1998-07-29 2004-03-18 Eckart Schonfelder Stripper for special steel
EP1050605A2 (fr) * 1999-05-03 2000-11-08 Henkel Kommanditgesellschaft auf Aktien Procédé de décapage d'aciers inoxydables sans acide nitrique et en présence d'ions chlorures
EP1903081A2 (fr) 2006-09-19 2008-03-26 Poligrat Gmbh Stabilisateur de bains de polissage acides contenant du métal

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
LUKE D ET AL: "THE PICKLING AND PASSIVATION OF STAINLESS STEELS", GALVANOTECHNIK, EUGEN G.LEUZE VERLAG, SAULGAU/WURTT, DE, 1 June 2006 (2006-06-01), pages 1369 - 1381, XP001500140, ISSN: 0016-4232 *
See also references of EP2470689A1 *

Also Published As

Publication number Publication date
EP2470689A1 (fr) 2012-07-04
DE102009038795A1 (de) 2011-05-05

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