EP0596273A1 - Product for pickling surfaces of chromium-nickel steel or chromium steel and its use - Google Patents

Product for pickling surfaces of chromium-nickel steel or chromium steel and its use Download PDF

Info

Publication number
EP0596273A1
EP0596273A1 EP93116251A EP93116251A EP0596273A1 EP 0596273 A1 EP0596273 A1 EP 0596273A1 EP 93116251 A EP93116251 A EP 93116251A EP 93116251 A EP93116251 A EP 93116251A EP 0596273 A1 EP0596273 A1 EP 0596273A1
Authority
EP
European Patent Office
Prior art keywords
acid
chromium
pickling
agent
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.)
Granted
Application number
EP93116251A
Other languages
German (de)
French (fr)
Other versions
EP0596273B1 (en
Inventor
Razmik Abedian
Siegfried Piesslinger-Schweiger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Poligrat GmbH
Original Assignee
POLIGRAT - HOLDING GmbH
POLIGRAT - Holding GmbH
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 - HOLDING GmbH, POLIGRAT - Holding GmbH, Poligrat GmbH filed Critical POLIGRAT - HOLDING GmbH
Publication of EP0596273A1 publication Critical patent/EP0596273A1/en
Application granted granted Critical
Publication of EP0596273B1 publication Critical patent/EP0596273B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

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
    • 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
    • C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
    • C23G1/08—Iron or steel
    • C23G1/088—Iron or steel solutions containing organic acids
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D1/00—Electroforming
    • C25D1/06—Wholly-metallic mirrors

Definitions

  • the invention relates to an agent for pickling the surface of chromium-nickel steels and chromium steels, which contains sulfuric acid, phosphoric acid or mixtures thereof and Fe (III) ions.
  • the invention further relates to the use of a corresponding agent in an electrochemical and / or chemical process for pickling the surface of chromium-nickel steels or nickel steels.
  • Pickling and cleaning agents for chromium-nickel and chromium steels known in the prior art usually contain an active acid and an inhibiting or oxidizing component. Sulfuric acid, hydrochloric acid and / or hydrofluoric acid are used as active components. Nitric acid is generally used as the inhibiting or oxidizing component.
  • the pickling process is used, among other things, to remove contaminants from foreign metals (e.g. ferrite contamination).
  • contaminants from foreign metals e.g. ferrite contamination
  • Pickling agents according to the prior art generally contain hydrofluoric acid as the active and nitric acid as the oxidizing component.
  • the nitric acid moreover inhibits the attack of the hydrofluoric acid on the metal surface, so that this attack is directed primarily towards the oxides and metallic impurities and thus the dissolution of the oxides is promoted.
  • a pickling agent is known from DE-A-3 742 367 in which the hydrofluoric acid is replaced by fluorosilicic acid.
  • a prerequisite for the effectiveness of this pickling agent is a content of 10 to 30% by weight of nitric acid. Although this agent does not have the toxicity of the pickling agents otherwise used in the prior art, there are various disadvantages when used.
  • the rinse water obtained when rinsing off the pickled surfaces contains, in addition to nitrate, poisonous nitrite, which requires extensive detoxification / removal as part of the proper treatment of the wastewater.
  • a method for pickling nickel copper alloys is known from US-A-947 067.
  • iron (III) salts are used in addition to sulfuric acid.
  • the pickling solution used consisting of a free acid and the iron salt, has the effect that the oxides of nickel and copper are removed from the surface of the metal and at the same time the precipitation of copper, which has detached from the metal surface, is prevented by nickel.
  • EP-A-0 501 867 discloses a process for the treatment of steels in which, among other things, sulfuric acid or phosphoric acid together with iron ions are proposed as pickling agent components. The main thing with the method is to keep the redox potential of the treatment bath at a certain value. According to the only embodiment, hydrogen fluoride with a concentration of 80 g / l is used as the acid.
  • a process for pickling stainless steel is known from EP-A-0 505 606, in which, in addition to sulfuric acid and iron 3 'ions, the HF concentration must be at least 40 g / l. In addition, H 2 0 2 is required as the oxidizing agent. Finally, the redox potential of the treatment solution must also be kept at a certain value in this process.
  • the problem of the present invention is to provide a means for pickling and / or cleaning metal surfaces, which avoids or reduces the environmental pollution and hazards caused by the means known in the prior art with nitric acid and hydrofluoric acid.
  • Such an agent should also meet the requirements for such agents when cleaning and pickling. It is important, among other things, that the effect of the agent largely affects the directs undesirable oxide deposits and impurities. The appearance and structure of the metallic surface should be largely preserved.
  • nitric acid and hydrofluoric acid can be completely dispensed with.
  • the agents according to the invention preferably contain the Fe (III) ions in the form of their water-soluble salts with a concentration of up to 5% by weight, preferably 0.5 to 3% by weight.
  • Suitable water-soluble salts are iron (III) sulfate, iron (III) citrate or iron (III) acetylacetonate.
  • the fluoroboric acid has proven itself in aqueous solution with a concentration of 0.1 to 5.0% by weight. It has surprisingly been found that a faster and more thorough pickling effect is achieved with fluoroboric acid than with fluorosilicic acid.
  • the agents according to the invention can also contain hydrofluoric acid (HF) in a concentration of up to 0.5% by weight, preferably 0.2 to 0.4% by weight. This increases the pickling effect. This is often necessary in particular for stainless steels with higher proportions of nickel, chromium and molybdenum, since these usually have scale layers that are more difficult to dissolve. Since the hydrofluoric acid is used here only in very low concentrations, the disadvantages of the prior art do not occur to the same extent as there. In particular, however, no addition of nitric acid is required. The product is therefore non-toxic in accordance with the Ordinance on Hazardous Substances.
  • HF hydrofluoric acid
  • the agent for pickling and / or cleaning metal surfaces usually contains an acid or acids and mixtures thereof in concentrations of 2 to 70% by weight, preferably 15 to 35% by weight.
  • These acids in addition to sulfuric acid, especially phosphoric acid and amidosulfonic acid, essentially serve to dissolve tarnishing colors in heat-affected zones and scale layers in the area of the weld seam.
  • polycarboxylic acids such as polyacrylic acid or polymethacrylic acid can also be used.
  • Derivatives of the abovementioned acids or polyacids can also be used, such as hexanoic acid diamide and succinic acid diamide and mixtures thereof.
  • chelating agents can improve the pickling effect of agents according to the invention.
  • Phosphonic acids in particular hydroxyethane-1,1-diphosphonic acid or morpholinomethane diphosphonic acid, preferably in a concentration of 0.1 to 5% by weight, can advantageously be used as chelating agents.
  • the agents according to the invention can contain an oxidizing agent for the oxidation of scale layers; these oxidizing agents are preferred in amounts of 1 to 3% by weight.
  • an oxidizing agent for the oxidation of scale layers these oxidizing agents are preferred in amounts of 1 to 3% by weight.
  • one or more nitro-substituted aromatic compounds having one or more NO 2 groups bonded to the aromatic ring nucleus in addition to a water-solubilizing group, likewise bonded to an aromatic nucleus, such as sodium m-nitrobenzenesulfonate or m-nitrobenzenesulfonic acid can be used.
  • the agents according to the invention can also contain the usual amounts of surfactants.
  • the agents according to the invention can be in liquid form as dipping and trickle stains but also thickened by a suitable thickening agent such as barium sulfate, aerosil, luminic acid, etc. as a spreadable or sprayable pickling paste.
  • a suitable thickening agent such as barium sulfate, aerosil, luminic acid, etc. as a spreadable or sprayable pickling paste.
  • the agents work particularly well in the temperature range from 10 ° C to 80 ° C.
  • Surfactants can also be present as further constituents in concentrations of 0.1-2% by weight.
  • the rest (to 100% by weight) then optionally consists of further strong acids - at least 10% by weight, for example phosphoric acid - and / or thickeners known per se.
  • the invention furthermore relates to the use of the agent according to the invention in an electrochemical and / or chemical process for pickling surfaces of chromium-nickel steels and chromium steels. It has proven to be particularly advantageous if an anodic current density of 0.2 to 30 A / dm 2 is used in an electrochemical process.
  • the method according to the invention can be used in particular for descaling metallic surfaces, and further electrochemical treatment steps such as electropolishing can follow.
  • the invention now provides an environmentally friendly and less hazardous agent for pickling and / or cleaning metallic surfaces.
  • a particular advantage of the agent according to the invention and of the method according to the invention is that a significant reduction in the pickling time can be obtained with regard to the required pickling effect.
  • Stainless steel sheets as before were treated with a composition according to DE 37 42 367 A1 (example 1).
  • the stainless steel sheets with a weld seam were pickled for 30, 60, 120 and 180 minutes at 23 ° C.
  • the mordant according to the prior art had the following composition.

Landscapes

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

Abstract

A product for pickling surfaces of chromium-nickel steels and chromium steels contains sulphuric acid, phosphoric acid or mixtures thereof and Fe(III) ions, the product additionally containing fluoboric acid. Using this product, it is possible to pickle surfaces of chromium-nickel steels and chromium steels in such a way that undesired oxide coatings, contaminations and tarnishing colours are removed. In the case of this product, the use of hydrofluoric acid or hydrofluoric acid in addition to nitric acid is unnecessary.

Description

Die Erfindung betrifft ein Mittel zum Beizen der Oberfläche von Chromnickelstählen und Chromstählen, welches Schwefelsäure, Phosphorsäure oder deren Mischungen und Fe(III)-lonen enthält. Weiterhin betrifft die Erfindung die Verwendung eines entsprechenden Mittels in einem elektrochemischen und/oder chemischen Verfahren zum Beizen der Oberfläche von Chromnickelstählen oder Nickelstählen.The invention relates to an agent for pickling the surface of chromium-nickel steels and chromium steels, which contains sulfuric acid, phosphoric acid or mixtures thereof and Fe (III) ions. The invention further relates to the use of a corresponding agent in an electrochemical and / or chemical process for pickling the surface of chromium-nickel steels or nickel steels.

Im Stand der Technik bekannte Beiz- und Reinigungsmittel für Chromnickel- und Chromstähle enthält gewöhnlich eine aktive Säure sowie eine inhibierende bzw. oxidierende Komponente. Als aktive Komponenten gelangen Schwefelsäure, Salzsäure und/oder Flußsäure zum Einsatz. Als inhibierende bzw. oxidierende Komponente dient in der Regel Salpetersäure.Pickling and cleaning agents for chromium-nickel and chromium steels known in the prior art usually contain an active acid and an inhibiting or oxidizing component. Sulfuric acid, hydrochloric acid and / or hydrofluoric acid are used as active components. Nitric acid is generally used as the inhibiting or oxidizing component.

Diese Mittel werden sowohl flüssig in Tauchbädern oder als Rieselbeizen als auch verdickt zu streich-oder sprühfähigen Pasten zur lokalen Schweißnahtbehandlung oder Behandlung großflächiger freistehender Werkstücke eingesetzt. Das Beizen der Oberfläche von Chromnickelstählen und Chromstählen ist die Voraussetzung für die gewünschte Korrosionsbeständigkeit dieser Werkstoffe.These agents are used both liquid in immersion baths or as trickle stains and thickened to form spreadable or sprayable pastes for local weld seam treatment or treatment of large, free-standing workpieces. Pickling the surface of chrome-nickel steels and chrome steels is the prerequisite for the desired corrosion resistance of these materials.

Der Beizvorgang dient unter anderem dazu, Verunreinigungen durch Fremdmetalle (z. B. Ferritkontamination) zu beseitigen. Darüberhinaus geht es darum, in Folge einer Wärmebehandlung oder beim Schweißen entstandenen Zunder oder Anlauffarben sowie organische Verunreinigungen zu beheben und eine metallisch reine Oberfläche zu schaffen. Diese ist die Voraussetzung dafür, daß sich anschließend aus dem Chromgehalt der Legierung und dem Sauerstoff der Umgebung eine geschlossene, korrosionsbeständige Chromoxidschicht auf der Werkstückoberfläche ausbilden kann. Erst diese bildet die Grundlage für die gewünschte Korrosionsbeständigkeit der Werkstoffe.The pickling process is used, among other things, to remove contaminants from foreign metals (e.g. ferrite contamination). In addition, it is a matter of eliminating scale or tarnishing as well as organic impurities as a result of heat treatment or welding and creating a clean, metallic surface. This is the prerequisite for the subsequent formation of a closed, corrosion-resistant chromium oxide layer on the workpiece surface from the chromium content of the alloy and the oxygen in the environment. Only this forms the basis for the desired corrosion resistance of the materials.

Beizmittel nach dem Stand der Technik enthalten in der Regel Flußsäure als aktive und Salpetersäure als oxidierende Komponente. Die Salpetersäure inhibiert darüberhinaus den Angriff der Flußsäure auf die Metalloberfläche, so daß sich dieser Angriff überwiegend auf die Oxide und metallischen Verunreinigungen richtet und somit die Auflösung der Oxide gefördert wird.Pickling agents according to the prior art generally contain hydrofluoric acid as the active and nitric acid as the oxidizing component. The nitric acid moreover inhibits the attack of the hydrofluoric acid on the metal surface, so that this attack is directed primarily towards the oxides and metallic impurities and thus the dissolution of the oxides is promoted.

Sowohl Flußsäure als auch Salpetersäure stellen bei ihrer Anwendung in Beizmitteln nach dem Stand der Technik eine besondere Gefährdung für Bedienungspersonal als auch die Umwelt dar. Deshalb ist deren Anwendung strengen gesetzlichen Auflagen hinsichtlich der Arbeitssicherheit aber auch der Umweltbelastungen unterworfen.Both hydrofluoric acid and nitric acid, when used in state-of-the-art pickling agents, pose a particular risk to operating personnel and the environment. Their use is therefore subject to strict legal requirements with regard to occupational safety and environmental pollution.

Es besteht ein steigendes Bedürfnis nach Chromstahl und Chromnickelstahl mit einer besonderen Korrosionsbeständigkeit. Diese Korrosionsbeständigkeit sollte aber durch ein Beizen erzielbar sein, bei dem sowohl die Gefährdung der Umwelt als auch des Bedienungspersonals minimiert wird.There is an increasing need for chromium steel and chromium-nickel steel with a special corrosion resistance. However, this corrosion resistance should be achievable by pickling, which minimizes both the risk to the environment and to the operating personnel.

Aus der DE-A-3 742 367 ist ein Beizmittel bekannt, in dem die Flußsäure durch Fluorkieselsäure ersetzt ist. Voraussetzung für die Wirksamkeit dieses Beizmittels ist aber ein Gehalt von 10 bis 30 Gew.-% Salpetersäure. Dieses Mittel weist zwar nicht die Giftigkeit der sonst im Stand der Technik verwendeten Beizmittel auf, jedoch ergeben sich beim Einsatz diverse Nachteile.A pickling agent is known from DE-A-3 742 367 in which the hydrofluoric acid is replaced by fluorosilicic acid. A prerequisite for the effectiveness of this pickling agent is a content of 10 to 30% by weight of nitric acid. Although this agent does not have the toxicity of the pickling agents otherwise used in the prior art, there are various disadvantages when used.

Bei der Anwendung dieses Mittels entstehen nämlich hochgiftige nitrose Gase, die eine sorgfältige Erfassung und Behandlung der Abluft sowie einen entsprechenden Schutz des Bedienungspersonals erforderlich machen. Darüberhinaus enthalten die beim Abspülen der gebeizten Oberflächen anfallenden Spülwässer neben Nitrat noch giftiges Nitrit, welches eine aufwendige Entgiftung/Entfernung im Rahmen der ordnungsgemäßen Behandlung der Abwässer erfordert.When using this agent, highly toxic nitrous gases are created, which require careful recording and treatment of the exhaust air and appropriate protection of the operating personnel. In addition, the rinse water obtained when rinsing off the pickled surfaces contains, in addition to nitrate, poisonous nitrite, which requires extensive detoxification / removal as part of the proper treatment of the wastewater.

Aus der US-A-947 067 ist ein Verfahren zum Beizen von Nickelkupferlegierungen bekannt. Bei diesem Beizverfahren werden neben Schwefelsäure Eisen(III)-Salze eingesetzt. Die verwendete Beizlösung aus einer freien Säure und dem Eisensalz bewirkt, daß die Oxide des Nickels und Kupfers von der Oberfläche des Metalls entfernt werden und zugleich die Ausfällung von Kupfer, welches sich von der Metalloberfläche abgelöst hat, durch Nickel verhindert wird.A method for pickling nickel copper alloys is known from US-A-947 067. In this pickling process, iron (III) salts are used in addition to sulfuric acid. The pickling solution used, consisting of a free acid and the iron salt, has the effect that the oxides of nickel and copper are removed from the surface of the metal and at the same time the precipitation of copper, which has detached from the metal surface, is prevented by nickel.

Die EP-A-0 501 867 offenbart ein Verfahren zur Behandlung von Stählen, bei dem als Beizmittelbestandteile unter anderem Schwefelsäure oder Phosphorsäure zusammen mit Eisenionen vorgeschlagen werden. Bei dem Verfahren kommt es vor allem darauf an, das Redox-Potential des Behandlungsbades auf einem bestimmten Wert zu halten. Nach dem einzigen Ausführungsbeispiel wird als Säure Fluorwasserstoff mit einer Konzentration von 80 g/I verwendet.EP-A-0 501 867 discloses a process for the treatment of steels in which, among other things, sulfuric acid or phosphoric acid together with iron ions are proposed as pickling agent components. The main thing with the method is to keep the redox potential of the treatment bath at a certain value. According to the only embodiment, hydrogen fluoride with a concentration of 80 g / l is used as the acid.

Aus der EP-A-0 505 606 ist ein Verfahren zum Beizen von rostfreiem Stahl bekannt, in dem neben Schwefelsäure und Eisen3'-lonen die HF-Konzentration mindestens 40 g/I betragen muß. Zusätzlich ist als Oxidationsmittel H202 erforderlich. Schließlich ist auch bei diesem Verfahren das Redox-Potential der Behandlungslösung auf einem bestimmten Wert zu halten.A process for pickling stainless steel is known from EP-A-0 505 606, in which, in addition to sulfuric acid and iron 3 'ions, the HF concentration must be at least 40 g / l. In addition, H 2 0 2 is required as the oxidizing agent. Finally, the redox potential of the treatment solution must also be kept at a certain value in this process.

Das Problem der vorliegenden Erfindung besteht darin, ein Mittel zum Beizen und/oder Reinigen von Metalloberflächen bereitzustellen, das die Umweltbelastungen und Gefährdungen durch die im Stand der Technik bekannten Mittel mit Salpetersäure und Flußsäure vermeidet bzw. vermindert.The problem of the present invention is to provide a means for pickling and / or cleaning metal surfaces, which avoids or reduces the environmental pollution and hazards caused by the means known in the prior art with nitric acid and hydrofluoric acid.

Ein solches Mittel soll aber zugleich den Anforderungen an derartige Mittel beim Reinigen und Beizen genügen. Hierbei kommt es unter anderem darauf an, daß die Wirkung des Mittels sich weitgehend auf die unerwünschten Oxidbeläge und Verunreinigungen richtet. Das Aussehen und die Struktur der metallischen Oberfläche soll dabei aber zugleich weitestgehend erhalten bleiben.Such an agent should also meet the requirements for such agents when cleaning and pickling. It is important, among other things, that the effect of the agent largely affects the directs undesirable oxide deposits and impurities. The appearance and structure of the metallic surface should be largely preserved.

Dieses Problem wird durch ein Mittel zum Beizen von Oberflächen von Chromnickelstählen und Chromstählen, welches Schwefelsäure, Phosphorsäure oder deren Mischungen und daneben Fe(III)-lonen enthält, gelöst, welches dadurch gekennzeichnet ist, daß es zusätzlich Fluorborsäure enthält.This problem is solved by a means for pickling the surfaces of chromium-nickel steels and chromium steels, which contains sulfuric acid, phosphoric acid or their mixtures and in addition Fe (III) ions, which is characterized in that it additionally contains fluoroboric acid.

Bei diesem erfindungsgemäßen Mittel kann auf Salpetersäure sowie Flußsäure vollständig verzichtet werden.With this agent according to the invention, nitric acid and hydrofluoric acid can be completely dispensed with.

Die erfindungsgemäßen Mittel enthalten die Fe(III)-lonen vorzugsweise in Form ihrer wasserlöslichen Salze mit einer Konzentration von bis zu 5 Gew.-%, vorzugsweise 0,5 bis 3 Gew.-%. Als wasserlösliche Salze eignen sich Eisen(III)-Sulfat, Eisen(III)-Citrat oder Eisen(III)-Acetylacetonat.The agents according to the invention preferably contain the Fe (III) ions in the form of their water-soluble salts with a concentration of up to 5% by weight, preferably 0.5 to 3% by weight. Suitable water-soluble salts are iron (III) sulfate, iron (III) citrate or iron (III) acetylacetonate.

Die Fluorborsäure hat sich in wäßriger Lösung mit einer Konzentration von 0,1 bis 5,0 Gew.-% bewährt. Es wurde überraschenderweise festgestellt, daß mittels der Fluorborsäure eine schnellere und gründlichere Beizwirkung erzielt wird als mit Fluorkieselsäure.The fluoroboric acid has proven itself in aqueous solution with a concentration of 0.1 to 5.0% by weight. It has surprisingly been found that a faster and more thorough pickling effect is achieved with fluoroboric acid than with fluorosilicic acid.

Neben der Fluorborsäure können die erfindungsgemäßen Mittel aber auch Flußsäure (HF) in einer Konzentration von bis zu 0,5 Gew.-%, vorzugsweise 0,2 bis 0,4 Gew.-%, enthalten. Dabei stellt sich eine Verstärkung der Beizwirkung ein. Dies ist häufig insbesondere erforderlich bei Edelstählen mit höheren Anteilen an Nickel, Chrom, sowie Molybdän, da diese in der Regel schwerer lösliche Zunderschichten aufweisen. Da die Flußsäure hier aber nur in sehr geringen Konzentrationen verwendet wird, treten die Nachteile des Standes der Technik nicht im gleichen Maße wie dort auf. Insbesondere ist aber auch kein Zusatz von Salpetersäure erforderlich. Das Produkt ist somit gemäß Gefahrstoffverordnung ungiftig.In addition to fluoroboric acid, the agents according to the invention can also contain hydrofluoric acid (HF) in a concentration of up to 0.5% by weight, preferably 0.2 to 0.4% by weight. This increases the pickling effect. This is often necessary in particular for stainless steels with higher proportions of nickel, chromium and molybdenum, since these usually have scale layers that are more difficult to dissolve. Since the hydrofluoric acid is used here only in very low concentrations, the disadvantages of the prior art do not occur to the same extent as there. In particular, however, no addition of nitric acid is required. The product is therefore non-toxic in accordance with the Ordinance on Hazardous Substances.

Üblicherweise enthält das Mittel zum Beizen und/oder Reinigen von Metalloberflächen eine Säure oder Säuren sowie deren Mischungen in Konzentrationen von 2 bis 70 Gew.-%, vorzugsweise von 15 bis 35 Gew.-%. Diese Säuren, neben der Schwefelsäure insbesondere Phosphorsäure und Amidosulfonsäure, dienen im wesentlichen zur Auflösung von Anlauffarben in Wärmeeinflußzonen und Zunderschichten im Schweißnahtbereich.The agent for pickling and / or cleaning metal surfaces usually contains an acid or acids and mixtures thereof in concentrations of 2 to 70% by weight, preferably 15 to 35% by weight. These acids, in addition to sulfuric acid, especially phosphoric acid and amidosulfonic acid, essentially serve to dissolve tarnishing colors in heat-affected zones and scale layers in the area of the weld seam.

Daneben können weitere anorganische und/oder organische Säuren in den erfindungsgemäßen Mitteln zum Einsatz gelangen. Es hat sich eine wirkungsmäßige Verbesserung der Mittel gezeigt, wenn zusätzlich 0,1 bis 30 Gew.-% substituierte oder unsubstituierte Carbonsäuren mit 1 bis 6 Kohlenstoffatomen oder Polycarbonsäuren verwendet werden. Von diesen Säuren gelangen vorzugsweise 0,1 bis 10 Gew.-% zum Einsatz. Bei den substituierten und unsubstituierten Carbonsäuren mit 1 bis 6 Kohlenstoffatomen handelt es sich beispielsweise um:

  • Zitronensäure, Oxalsäure, Ameisensäure, Gluconsäure, Maleinsäure, Weinsäure, Essigsäure, Propansäure, etc.
In addition, other inorganic and / or organic acids can be used in the agents according to the invention. An effective improvement of the agents has been shown if additionally 0.1 to 30% by weight of substituted or unsubstituted carboxylic acids with 1 to 6 carbon atoms or polycarboxylic acids are used. Of these acids, 0.1 to 10% by weight are preferably used. The substituted and unsubstituted carboxylic acids with 1 to 6 carbon atoms are, for example:
  • Citric acid, oxalic acid, formic acid, gluconic acid, maleic acid, tartaric acid, acetic acid, propanoic acid, etc.

Darüberhinaus können aber auch Polycarbonsäuren wie Polyacrylsäure oder Polymethacrylsäure zum Einsatz gelangen. Weiterhin können Derivate der vorstehend genannten Säuren bzw. Polysäuren verwendet werden, so wie Hexansäurediamid und Bernsteinsäurediamid und deren Mischungen.In addition, polycarboxylic acids such as polyacrylic acid or polymethacrylic acid can also be used. Derivatives of the abovementioned acids or polyacids can also be used, such as hexanoic acid diamide and succinic acid diamide and mixtures thereof.

Weiterhin kann die Anwesenheit von Chelatbildnern die Beizwirkung erfindungsgemäßer Mittel verbessern. Als Chelatbildner können vorteilhaft Phosphonsäuren, insbesondere Hydroxyethan-1,1-Diphosphonsäure oder Morpholinomethandiphosphonsäure, bevorzugt in einer Konzentration von 0,1 bis 5 Gew.-%, eingesetzt werden.Furthermore, the presence of chelating agents can improve the pickling effect of agents according to the invention. Phosphonic acids, in particular hydroxyethane-1,1-diphosphonic acid or morpholinomethane diphosphonic acid, preferably in a concentration of 0.1 to 5% by weight, can advantageously be used as chelating agents.

Darüberhinaus können die erfindungsgemäßen Mittel ein Oxidationsmittel zur Aufoxidation von Zunderschichten enthalten, bevorzugt sind diese Oxidationsmittel in Mengen von 1 bis 3 Gew.-%. Hierzu können erfindungsgemäß eine oder mehrere nitrosubstituierte aromatische Verbindungen mit einer oder mehreren N02-Gruppen gebunden an den aromatischen Ringkern nebst einer wasserlöslichmachenden Gruppe, ebenfalls gebunden an einen aromatischen Kern, wie beispielsweise Natrium-m-Nitrobenzolsulfonat oder m-Nitrobenzolsulfonsäure verwendet werden.In addition, the agents according to the invention can contain an oxidizing agent for the oxidation of scale layers; these oxidizing agents are preferred in amounts of 1 to 3% by weight. For this purpose, according to the invention, one or more nitro-substituted aromatic compounds having one or more NO 2 groups bonded to the aromatic ring nucleus in addition to a water-solubilizing group, likewise bonded to an aromatic nucleus, such as sodium m-nitrobenzenesulfonate or m-nitrobenzenesulfonic acid, can be used.

Die erfindungsgemäßen Mittel können darüberhinaus die üblichen Mengen an Tensiden enthalten.The agents according to the invention can also contain the usual amounts of surfactants.

Die erfindungsgemäßen Mittel können sowohl flüssig als Tauch- und Rieselbeize aber auch verdickt durch ein geeignetes Verdickungsmittel wie Bariumsulfat, Aerosil, Luminsäure, etc als streich- oder sprühfähige Beizpaste vorliegen. Die Mittel arbeiten besonders gut im Temperaturbereich von 10 ° C bis 80°C.The agents according to the invention can be in liquid form as dipping and trickle stains but also thickened by a suitable thickening agent such as barium sulfate, aerosil, luminic acid, etc. as a spreadable or sprayable pickling paste. The agents work particularly well in the temperature range from 10 ° C to 80 ° C.

Typischerweise setzen sich die erfindungsgemäßen Mittel wie folgt zusammen:

  • 15-35 Gew.-% Schwefelsäure oder Schwefelsäure/Phosphorsäuremischung
  • 0,5-3 Gew.-% Eisen(III)-Salze
  • 0,1-5,0 Gew.-% Fluorborsäure
  • und gegebenenfalls
  • 0,2-0,4 Gew.-% Flußsäure
The agents according to the invention are typically composed as follows:
  • 15-35% by weight sulfuric acid or sulfuric acid / phosphoric acid mixture
  • 0.5-3% by weight of iron (III) salts
  • 0.1-5.0 wt% fluoroboric acid
  • and if necessary
  • 0.2-0.4 wt% hydrofluoric acid

Als weitere Bestandteile haben sich bewährt (jeweils einzeln oder in Kombination):The following have also proven their worth (individually or in combination):

0,1-10 Gew.-% substituierte oder unsubstituierte Carbonsäuren mit 1 bis 6 Kohlenstoffatomen und/oder entsprechende Polycarbonsäuren0.1-10% by weight of substituted or unsubstituted carboxylic acids having 1 to 6 carbon atoms and / or corresponding polycarboxylic acids

0,1-5 Gew.-% Chelatbildner0.1-5% by weight chelating agent

1-3 Gew.-% Oxidationsmittel1-3% by weight of oxidizing agent

Als weitere Bestandteile können auch Tenside in Konzentrationen von 0,1-2 Gew.-% vorhanden sein. Der Rest (auf 100 Gew.-%) besteht dann gegebenenfalls aus weiteren starken Säuren - mindestens 10 Gew.-%, beispielsweise Phosphorsäure - und/oder an sich bekannten Verdickungsmitteln.Surfactants can also be present as further constituents in concentrations of 0.1-2% by weight. The rest (to 100% by weight) then optionally consists of further strong acids - at least 10% by weight, for example phosphoric acid - and / or thickeners known per se.

Gegenstand der Erfindung ist darüberhinaus die Verwendung des erfindungsgemäßen Mittels in einem elektrochemischen und/oder chemischen Verfahren zum Beizen von Oberflächen von Chromnickelstählen und Chromstählen. Als besonders vorteilhaft hat sich herausgestellt, wenn in einem elektrochemischem Verfahren mit einer anodischen Stromdichte von 0,2 bis 30 A/dm2 gearbeitet wird.The invention furthermore relates to the use of the agent according to the invention in an electrochemical and / or chemical process for pickling surfaces of chromium-nickel steels and chromium steels. It has proven to be particularly advantageous if an anodic current density of 0.2 to 30 A / dm 2 is used in an electrochemical process.

Das erfindungsgemäße Verfahren kann insbesondere zur Entzunderung von metallischen Oberflächen eingesetzt werden, wobei sich weitere elektrochemische Behandlungsschritte wie zum Beispiel Elektropolieren anschließen können.The method according to the invention can be used in particular for descaling metallic surfaces, and further electrochemical treatment steps such as electropolishing can follow.

Die Erfindung stellt nun ein umweltschonendes und die Gesundheit weniger gefährdendes Mittel zum Beizen und/oder Reinigen von metallischen Oberflächen bereit. Als besonderer Vorteil des erfindungsgemäßen Mittels bzw. des erfindungsgemäßen Verfahrens zeigt sich, daß hinsichtlich der erforderlichen Beizwirkung eine deutliche Verkürzung der Beizzeit erhalten werden kann.The invention now provides an environmentally friendly and less hazardous agent for pickling and / or cleaning metallic surfaces. A particular advantage of the agent according to the invention and of the method according to the invention is that a significant reduction in the pickling time can be obtained with regard to the required pickling effect.

Die Erfindung wird in den folgenden Beispielen näher erläutert.The invention is explained in more detail in the following examples.

In den folgenden Beispielen wurden jeweils 10 x 10 cm Edelstahlbleche, die über ihren Querschnitt eine Schweißnaht aufwiesen, mit unterschiedlichen Mitteln in unterschiedlicher Weise behandelt.In the following examples, 10 x 10 cm stainless steel sheets, which had a weld seam over their cross-section, were treated with different agents in different ways.

Beispiel 1example 1

Es wurde ein Edelstahlblech mit einer Schweißnaht (10 x 10 cm) jeweils 20, 30 und 40 Minuten bei 23 ° C in folgende Zusammensetzung eingetaucht:

  • Zusammensetzung
    Figure imgb0001
A stainless steel sheet with a weld seam (10 x 10 cm) was immersed for 20, 30 and 40 minutes at 23 ° C in the following composition:
  • composition
    Figure imgb0001

Es zeigte sich, daß sowohl die Schweißnaht als auch die Wärmeeinflußzone bereits nach 20 Minuten zunderfrei war.It was found that both the weld seam and the heat affected zone were free of scale after only 20 minutes.

Selbst bei einer 40minütigen Behandlung der metallischen Oberfläche wurde der Grundwerkstoff nicht angegriffen.Even with a 40-minute treatment of the metallic surface, the base material was not attacked.

Unter gleichen Bedingungen wurden mit der folgenden Lösung identische Ergebnisse erhalten.Under the same conditions, identical results were obtained with the following solution.

Zusammensetzung 2Composition 2

Figure imgb0002
Figure imgb0002

Beispiel 2Example 2

In die folgende Zusammensetzung wurden wiederum Edelstahlbleche (mit Schweißnaht) allerdings über 20 und 30 Minuten bei 40 °C getaucht.Stainless steel sheets (with weld seam) were again immersed in the following composition, however, at 40 ° C. for 20 and 30 minutes.

Zusammensetzung 3Composition 3

Figure imgb0003
Figure imgb0003

Auch bei diesem Beispiel zeigte sich, daß nach 20 Minuten die Schweißnaht und die Wärmeeinflußzone vollständig entzundert war. Trotz der höheren Temperatur von 40 °C wurde hier der Grundwerkstoff auch nach 30 minütiger Behandlung kaum angegriffen.This example also showed that after 20 minutes the weld seam and the heat affected zone were completely descaled. Despite the higher temperature of 40 ° C, the base material was hardly attacked even after 30 minutes of treatment.

VergleichsbeispielComparative example

Edelstahlbleche wie zuvor wurden mit einer Zusammensetzung gemäß der DE 37 42 367 A1 behandelt (Beispiel 1). Die Edelstahlbleche mit Schweißnaht wurden jeweils 30, 60, 120 und 180 Minuten bei 23 °C gebeizt.Stainless steel sheets as before were treated with a composition according to DE 37 42 367 A1 (example 1). The stainless steel sheets with a weld seam were pickled for 30, 60, 120 and 180 minutes at 23 ° C.

Das Beizmittel gemäß dem Stand der Technik hatte folgende Zusammensetzung.

Figure imgb0004
The mordant according to the prior art had the following composition.
Figure imgb0004

Selbst nach 30 und nach 60 Minuten konnte noch deutlich Zunder auf der Schweißnaht und der Wärmeeinflußzone beobachtet werden. Auch eine 180minütige Behandlung mit dieser Lösung nach dem Stand der Technik ergab noch etwas Zunderreste und Verfärbungen auf der Schweißnaht und der Wärmeeinflußzone.Even after 30 and 60 minutes, scale could still be clearly observed on the weld seam and the heat affected zone. Even a 180 minute treatment with this solution according to the prior art still showed some scale residues and discoloration on the weld seam and the heat affected zone.

Claims (13)

1. Mittel zum Beizen der Oberfläche von Chromnickelstählen und Chromstählen, welches Schwefelsäure, Phosphorsäure oder deren Mischungen und Fe(III)-lonen enthält, dadurch gekennzeichnet, daß es Fluorborsäure zusätzlich enthält.1. Means for pickling the surface of chromium-nickel steels and chromium steels which contains sulfuric acid, phosphoric acid or their mixtures and Fe (III) ions, characterized in that it additionally contains fluoroboric acid. 2. Mittel gemäß Anspruch 1, dadurch gekennzeichnet, daß die Fe(III)-lonen in Form wasserlöslicher Fe(III)-Salze mit einer Konzentration von bis zu 5 Gew.-% eingesetzt werden.2. Composition according to claim 1, characterized in that the Fe (III) ions are used in the form of water-soluble Fe (III) salts with a concentration of up to 5% by weight. 3. Mittel gemäß Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Fluorborsäure in wäßriger Lösung mit einer Konzentration von 0,1 bis 5,0 Gew.-% vorliegt.3. Composition according to claim 1 or 2, characterized in that the fluoroboric acid is present in aqueous solution with a concentration of 0.1 to 5.0 wt .-%. 4. Mittel gemäß einem der vorstehenden Ansprüche, dadurch gekennzeichnet, daß es Flußsäure (HF) in einer Konzentration bis zu 0,5 Gew.-% enthält.4. Agent according to one of the preceding claims, characterized in that it contains hydrofluoric acid (HF) in a concentration up to 0.5 wt .-%. 5. Mittel gemäß einem der vorstehenden Ansprüche, dadurch gekennzeichnet, daß es von 2 bis 70 Gew.-% Säure enthält.5. Agent according to one of the preceding claims, characterized in that it contains from 2 to 70 wt .-% acid. 6. Mittel gemäß Anspruch 5, dadurch gekennzeichnet, daß es weitere anorganische und/oder organische Säuren enthält.6. Composition according to claim 5, characterized in that it contains further inorganic and / or organic acids. 7. Mittel gemäß Anspruch 5, dadurch gekennzeichnet, daß es 0,1 bis 30 Gew.-% substituierte oder unsubstituierte Carbonsäuren mit 1 bis 6 Kohlenstoffatomen oder Polycarbonsäuren enthält.7. Composition according to claim 5, characterized in that it contains 0.1 to 30 wt .-% substituted or unsubstituted carboxylic acids having 1 to 6 carbon atoms or polycarboxylic acids. 8. Mittel gemäß einem der Ansprüche 1 bis 7, dadurch gekennzeichnet, daß es ein Oxidationsmittel enthält.8. Agent according to one of claims 1 to 7, characterized in that it contains an oxidizing agent. 9. Mittel gemäß Anspruch 8, dadurch gekennzeichnet, daß es als Oxidationsmittel eine oder mehrere nitrosubstituierte aromatische Verbindungen enthält.9. Composition according to claim 8, characterized in that it contains one or more nitro-substituted aromatic compounds as the oxidizing agent. 10. Mittel gemäß einem der Ansprüche 1 bis 9, dadurch gekennzeichnet, daß es Chelatbildner enthält.10. Agent according to one of claims 1 to 9, characterized in that it contains chelating agents. 11. Mittel gemäß einem der Ansprüche 1 bis 10, dadurch gekennzeichnet, daß es Tenside enthält.11. Agent according to one of claims 1 to 10, characterized in that it contains surfactants. 12. Verwendung eines Mittels nach einem der Ansprüche 1 bis 11 in einem elektrochemischen und/oder chemischen Verfahren zum Beizen der Oberfläche von Chromnickelstählen oder Nickelstählen.12. Use of an agent according to one of claims 1 to 11 in an electrochemical and / or chemical process for pickling the surface of chromium-nickel steels or nickel steels. 13. Verwendung nach Anspruch 12, in einem elektrochemischen Verfahren, das mit einer anodischen Stromdichte von 0,2 bis 30 A/dm2 arbeitet.13. Use according to claim 12, in an electrochemical process which operates with an anodic current density of 0.2 to 30 A / dm 2 .
EP93116251A 1992-11-02 1993-10-07 Product for pickling surfaces of chromium-nickel steel or chromium steel and its use Expired - Lifetime EP0596273B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4237021 1992-11-02
DE4237021A DE4237021C1 (en) 1992-11-02 1992-11-02 Means for pickling the surface of chromium-nickel steels and chrome steels and use of the agent

Publications (2)

Publication Number Publication Date
EP0596273A1 true EP0596273A1 (en) 1994-05-11
EP0596273B1 EP0596273B1 (en) 1998-05-06

Family

ID=6471947

Family Applications (1)

Application Number Title Priority Date Filing Date
EP93116251A Expired - Lifetime EP0596273B1 (en) 1992-11-02 1993-10-07 Product for pickling surfaces of chromium-nickel steel or chromium steel and its use

Country Status (5)

Country Link
EP (1) EP0596273B1 (en)
AT (1) ATE165876T1 (en)
DE (2) DE4237021C1 (en)
DK (1) DK0596273T3 (en)
ES (1) ES2114991T3 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004035861A1 (en) * 2002-10-15 2004-04-29 Henkel Kommanditgesellschaft Auf Aktien Pickling or brightening/passivating solution and process for steel and stainless steel
WO2005024099A1 (en) * 2003-09-05 2005-03-17 Poligrat Gmbh Electropolishing method
WO2008107082A1 (en) * 2007-03-05 2008-09-12 Poligrat Gmbh Method for the thermochemical passivation of stainless steel
EP3269844A1 (en) * 2016-07-11 2018-01-17 Beratherm AG Aqueous cleaning solution for removing blacking coverings on surfaces of stainless steels in contact with media and use thereof

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BR9401214A (en) * 1994-03-18 1995-10-24 Frimox Quimica Ltda Composition, solution and surface treatment process of ferrous materials
DE19833990A1 (en) 1998-07-29 2000-02-10 Metallgesellschaft Ag Mordant for stainless steels
DE10110823A1 (en) * 2001-03-07 2002-10-02 Bosch Gmbh Robert Process for removing material deposits that result from laser processing
DE102005055768A1 (en) * 2005-11-21 2007-05-24 Ralf Waldmann Method and means for the electrolytic cleaning and descaling of a metallic workpiece
DE102008021299A1 (en) * 2008-04-21 2009-10-29 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Catalyst for toxic hydrocarbon compounds and / or organic compounds and process for its preparation
DE102016210289A1 (en) 2016-06-10 2017-12-14 Henkel Ag & Co. Kgaa Process for the purification pretreatment of iron-containing components assembled by welding

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB891670A (en) * 1957-09-04 1962-03-14 English Electric Co Ltd Improvements in and relating to the removing of scale from silicon iron and other metals
US3785866A (en) * 1965-04-09 1974-01-15 Oakite Prod Inc Method for avoiding pitting in plating oxide-film-developing metals
JPS61235581A (en) * 1985-04-12 1986-10-20 C Uyemura & Co Ltd Scale remover and method for removing scale
JPS61276999A (en) * 1985-05-30 1986-12-06 Nippon Steel Corp Method for pickling steel sheet containing chromium
EP0505606A1 (en) * 1991-03-29 1992-09-30 Itb S.R.L. Process for pickling and passivating stainless steel without using nitric acid

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US947067A (en) * 1908-09-30 1910-01-18 Int Nickel Co Method of treating nickel-copper alloys.
US3010854A (en) * 1954-12-31 1961-11-28 Armco Steel Corp Pickling solution and method
DE3742367A1 (en) * 1987-12-14 1989-06-22 Pelox Chemietechnik Gmbh Co Kg Pickling and cleaning agent for metal surfaces
JPH0273983A (en) * 1988-09-07 1990-03-13 Nippon Parkerizing Co Ltd Acidic washing solution for aluminum
FR2673200A1 (en) * 1991-02-25 1992-08-28 Ugine Aciers METHOD FOR OVERDRAWING STEEL MATERIALS SUCH AS STAINLESS STEELS AND ALLIED STEELS.

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB891670A (en) * 1957-09-04 1962-03-14 English Electric Co Ltd Improvements in and relating to the removing of scale from silicon iron and other metals
US3785866A (en) * 1965-04-09 1974-01-15 Oakite Prod Inc Method for avoiding pitting in plating oxide-film-developing metals
JPS61235581A (en) * 1985-04-12 1986-10-20 C Uyemura & Co Ltd Scale remover and method for removing scale
JPS61276999A (en) * 1985-05-30 1986-12-06 Nippon Steel Corp Method for pickling steel sheet containing chromium
EP0505606A1 (en) * 1991-03-29 1992-09-30 Itb S.R.L. Process for pickling and passivating stainless steel without using nitric acid

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
DATABASE WPI Derwent World Patents Index; AN 87-018613 *
PATENT ABSTRACTS OF JAPAN vol. 11, no. 80 (C - 409)<2527> 11 March 1987 (1987-03-11) *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004035861A1 (en) * 2002-10-15 2004-04-29 Henkel Kommanditgesellschaft Auf Aktien Pickling or brightening/passivating solution and process for steel and stainless steel
US8192556B2 (en) 2002-10-15 2012-06-05 Henkel Kgaa Pickling or brightening/passivating solution and process for steel and stainless steel
WO2005024099A1 (en) * 2003-09-05 2005-03-17 Poligrat Gmbh Electropolishing method
WO2008107082A1 (en) * 2007-03-05 2008-09-12 Poligrat Gmbh Method for the thermochemical passivation of stainless steel
US8430973B2 (en) 2007-03-05 2013-04-30 Poligrat Gmbh Method for the thermochemical passivation of stainless steel
EP3269844A1 (en) * 2016-07-11 2018-01-17 Beratherm AG Aqueous cleaning solution for removing blacking coverings on surfaces of stainless steels in contact with media and use thereof

Also Published As

Publication number Publication date
ATE165876T1 (en) 1998-05-15
ES2114991T3 (en) 1998-06-16
DE59308502D1 (en) 1998-06-10
DK0596273T3 (en) 1999-02-15
DE4237021C1 (en) 1994-02-10
EP0596273B1 (en) 1998-05-06

Similar Documents

Publication Publication Date Title
DE2359021A1 (en) PICKLING SOLUTION AND METAL PICKLING METALS
EP1903081B1 (en) Stabiliser for acid, metallic polishing baths
DE1161740B (en) Process for pickling alloy steels
DE60102387T2 (en) METHOD FOR CONTINUOUS ELECTROLYTICIZING OF METALS USING AC-SUSTAINED CELLS
EP0596273B1 (en) Product for pickling surfaces of chromium-nickel steel or chromium steel and its use
EP2352860B1 (en) Method for treating stainless steel surfaces
DE2847267A1 (en) Pickling and/or chemical polishing of copper or its alloys - using aq. solns. contg. mineral acid, hydrogen peroxide, and aliphatic alcohol as stabiliser
DE3222532C2 (en)
DE10160318A1 (en) Process for pickling martensitic or ferritic stainless steel
DE1546124A1 (en) Surface treatment agents
DE9214890U1 (en) Agents for pickling and/or cleaning metal surfaces
DE2710459C2 (en) Process for electrolytic descaling of a metallic body and its application to alloy steel
DE1220699B (en) Pickling bath for stainless steel
DE10156624B4 (en) Method and pickling solution for cleaning deposits of a steel workpiece
DE1206262B (en) Process for deoxidizing the surface of metal objects by using alkali metal hydride
EP1100982B1 (en) Stripper for special steel
DE1908421C3 (en) Agent for removing copper-containing metal coatings from iron and steel surfaces
DE19624436A1 (en) Stainless steel strip surface treatment
DE4329290C2 (en) Process for the electrolytic cleaning of metallic parts and its application
EP0795627B1 (en) Etchant for stainless steel
EP0814180A1 (en) Process for treating stainless steel surfaces
DE1621611A1 (en) Process and solution for pickling copper alloys
DE2507059A1 (en) Degreasing and pickling iron articles - with acid baths contg. water-soluble aromatic nitro cpd. oxidising agents
DE3742367A1 (en) Pickling and cleaning agent for metal surfaces
DE2559289A1 (en) Descaling stainless steel using strongly acid aq. soln. - contg. sulphuric acid, nitric acid and hydrofluoric acid and thickener to form spreadable paste

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB IT LI LU NL SE

17P Request for examination filed

Effective date: 19940323

17Q First examination report despatched

Effective date: 19940705

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: POLIGRAT - HOLDING GESELLSCHAFT MBH

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: POLIGRAT GMBH

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE DK ES FR GB IT LI LU NL SE

REF Corresponds to:

Ref document number: 165876

Country of ref document: AT

Date of ref document: 19980515

Kind code of ref document: T

ITF It: translation for a ep patent filed

Owner name: STUDIO CIONI & PIPPARELLI

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REF Corresponds to:

Ref document number: 59308502

Country of ref document: DE

Date of ref document: 19980610

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2114991

Country of ref document: ES

Kind code of ref document: T3

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 19980623

ET Fr: translation filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19981007

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19981007

Ref country code: DK

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19981007

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19981007

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19981008

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19981008

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19981031

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19981031

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19981031

REG Reference to a national code

Ref country code: DK

Ref legal event code: T3

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
BERE Be: lapsed

Owner name: POLIGRAT G.M.B.H.

Effective date: 19981031

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19990501

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19981007

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

EUG Se: european patent has lapsed

Ref document number: 93116251.5

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19990630

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 19990501

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19990803

REG Reference to a national code

Ref country code: DK

Ref legal event code: EBP

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 19991113

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20051007