Nothing Special   »   [go: up one dir, main page]

EP1307609A2 - Continuous electrolytic pickling method for metallic products using alternate current supplied cells - Google Patents

Continuous electrolytic pickling method for metallic products using alternate current supplied cells

Info

Publication number
EP1307609A2
EP1307609A2 EP01961136A EP01961136A EP1307609A2 EP 1307609 A2 EP1307609 A2 EP 1307609A2 EP 01961136 A EP01961136 A EP 01961136A EP 01961136 A EP01961136 A EP 01961136A EP 1307609 A2 EP1307609 A2 EP 1307609A2
Authority
EP
European Patent Office
Prior art keywords
electrolytic
pickling method
electrolytic pickling
concentration
sec
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
EP01961136A
Other languages
German (de)
French (fr)
Other versions
EP1307609B1 (en
Inventor
L. Centro Sviluppo Materiali S.p.A. PACELLI
V. Centro Sviluppo Materiali S.p.A. FERRARI
Stefano Centro Sviluppo Materiali S.p.A. LUPERI
Mauro Centro Sviluppo Materiali S.p.A. CAMPIONI
Bruno Centro Sviluppo Materiali S.p.A. FERRI
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.)
Centro Sviluppo Materiali SpA
Original Assignee
Centro Sviluppo Materiali SpA
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 Centro Sviluppo Materiali SpA filed Critical Centro Sviluppo Materiali SpA
Publication of EP1307609A2 publication Critical patent/EP1307609A2/en
Application granted granted Critical
Publication of EP1307609B1 publication Critical patent/EP1307609B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25F—PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
    • C25F1/00—Electrolytic cleaning, degreasing, pickling or descaling
    • C25F1/02—Pickling; Descaling
    • C25F1/04—Pickling; Descaling in solution
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25F—PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
    • C25F1/00—Electrolytic cleaning, degreasing, pickling or descaling
    • C25F1/02—Pickling; Descaling
    • C25F1/04—Pickling; Descaling in solution
    • C25F1/06—Iron or steel

Definitions

  • the present invention relates to a continuous electrolytic pickling method for metallic products, in particular in Iron, Nickel, Titanium and alloys thereof, based on the use of alternate current supplied cells with electrolytic solution consisting of acid or neutral aqueous solutions.
  • pickling e.g. for the stainless steels, is actually carried out in order to eliminate the scale of thermal oxides which are generated during the hot- rolling and/or annealing treatments, and to dissolve the Chromium-depleted alloy layer (dechromized layer) therebelow.
  • This conventional method consists of three conceptually different steps: a first step of descaling, i.e., physico-chemical modification of the scale with the partial removal thereof; a second step of actual pickling, i.e. removal and solution of the residual scale and disposal of the sub-surface layer of dechromized alloy; and a third step, so-called of finishing, consisting in a surface passivation.
  • a first step of descaling i.e., physico-chemical modification of the scale with the partial removal thereof
  • a second step of actual pickling i.e. removal and solution of the residual scale and disposal of the sub-surface layer of dechromized alloy
  • finishing consisting in a surface passivation.
  • the step of descaling in most cases, is carried out by sandblasting with a hard grit which breaks up and partially removes the scale.
  • the step of descaling cannot be carried out by surface peening, which is not compatible with the quality of the finished product's surface.
  • thermochemical descaling which consists in immersing the material to be pickled in a bath of melted oxidizing salts (400°C-600°C) capable of altering the scale, increasing the degree of oxidation of the metals constituting the oxides.
  • Kolene baths eutectic of the NaOH-NaN0 3 -NaCl ternary system
  • electrolytic descaling by neutral sulphate solutions, with the partial modification of the oxidation states of the constituent metals of the scale and the entailed solution thereof.
  • the pickling step is generally carried out using highly oxidizing acid baths, capable of dissolving the sub-surface alloy layer (Cr-depleted for stainless steels) determining the detachment of the scale adhering thereto.
  • electrolytic cells capable of applying a continuous current density ranging from 3 A/dm 2 to 40 A/dm 2 to the material are used.
  • the finishing step aimed at forming a passivated protective film, when this is not carried out at the same time as the pickling step, is usually attained in baths having high redox potential. These baths contain the abovementioned acids and oxidizers at lower concentrations and with a lower content of the ions of the metals present in the metallic products to be pickled.
  • washing sections consisting of water jet systems equipped with rotary brushes are inserted. The function carried out by these systems is the removal of the pickling solution dragged by the strip, and the non- adhering scale particles deposed on the strip surface.
  • DE-A-19624436, WO 9826111, EP-A-763609 and JP95-130582 disclose pickling processes in acid solution, free from nitric acid, in presence of ferric ions with the use of alternate current supplied electrolytic cells (current density comprised between 0.5 A/dm2 and 250 A/dm2) .
  • DE-C-3937438 discloses a process in which direct current is employed for the reoxidation of the ferrous ions to ferric ions in a hydrochloric acid solution.
  • EP-A-838542 discloses a pickling process in an aqueous sodium sulphate solution, having a concentration between 10 g/1 and 350 g/1, in which the strip is vertically passed between pairs of counter electrodes, a direct current having a density between 20 A/dm2 and 250 A/dm2 being applied therebetween.
  • the main drawback of the process for the mechanical removal of the scale by sandblasting or peening lies in the difficulty of abating the dusts made of silica and metallic oxides particles, not to mention the high noise pollution of the surrounding working areas.
  • the baths of sulphuric and of hydrofluoric acid which use, instead of the nitric acid, systems having a high redox potential, entail a complex management in connection with the difficulties of maintaining the appropriate concentrations of reagents capable of ensuring the envisaged pickling kinetics.
  • the costs of the reagents e.g., of the stabilised hydrogen peroxide, are high, considering that a fraction of the metals accumulating in the solution react with the oxidizers, lowering the process effectiveness .
  • the present invention allows to overcome all of the abovementioned drawbacks, further providing other advantages which will hereinafter be made apparent.
  • an object of the present invention is to provide a pickling method for continuously cast products in steely in compliance of the UNI EU 74/20 norm, and in Nickel alloy and in Titanium, based on the use of alternate current supplied electrolytic cells in acid or neutral aqueous solutions.
  • an object of the present invention is a continuous electrolytic pickling method for steels, Nickel super alloys, Titanium and alloys thereof, characterised in that the material to be treated, for a time between 3 and 60 seconds, is immersed into or passes through at least one electrolytic cell with an electrolytic solution consisting of a neutral or acid aqueous solution, at a temperature between 20°C and 95°C, with at least one pair of electrodes connected to an alternate current power supply having a frequency ranging from 1 Hz to 1000 Hz, the electrolysis being carried out at a current density having an effective amplitude ranging from 10 A/dm2 to 250 A/dm2.
  • the frequency of the alternate current may range from 40 Hz to 70 Hz.
  • the electrolytic solution can be an aqueous solution, at a temperature between 20 °C and 95 °C, containing the following components having a concentration expressed in g/1: * sulphuric acid (H 2 S0 4 ) from 20 to 300, and optionally at least one among
  • the electrolytic solution is maintained at a temperature between 70 °C and 90 °C and comprises sulphuric acid at a concentration between 150 g/1 and 250 g/1, and, optionally, ferric ions (Fe +3 ) at a concentration of from 5 g/1 to 40 g/1.
  • the electrolytic solution is at a temperature between 70 °C and 90 °C, and comprises sulphuric acid at a concentration between 150 g/1 and 250 g/1 and at least one between hydrofluoric acid at a concentration between 5 g/1 and 50 g/1 and hydrochloric acid at a concentration between 5 g/1 and 50 g/1.
  • the electrolytic solution is at 70°C- 90 °C and comprises sulphuric acid at a concentration between 150 g/1 and 250 g/1.
  • the electrolytic solution may be a sodium sulphate (Na 2 S0 4 ) neutral aqueous solution having a concentration ranging from 25 g/1 to 300 g/1 at a temperature between 50 °C and 95°C.
  • Na 2 S0 4 sodium sulphate
  • pairs of adjacent electrodes are connected to two separate power supplies, so that the current lines outputted from a first electrode pair facing one side of the material to be treated, cross said material and close again on a second electrode pair, opposed to the first one and facing the other side of the material to be treated, defining a substantially X-shaped course.
  • electrodes facing one side of the material to be treated are connected to a power supply, so that the current lines which are outputted from said electrodes and cross the material, close again on other electrodes opposed to the first ones and facing the opposite side of the material to be treated, defining a course which is substantially orthogonal to said sides.
  • the electrolytic pickling -method according to the invention can be used for inducing a physical-chemical modification of the scale of the metallic oxides present onto the surface of the material to be pickled, a physical-chemical modification which, in the case of the stainless steels, occurs in a treatment time comprised between 1 sec and 10 sec.
  • the continuous electrolytic pickling method according to the present invention may be used in a step subsequent to that of the physical-chemical modification of the scale of metallic oxides present onto the surface of the material to be pickled.
  • this application of the pickling method according to the invention requires treatment times between 2 sec and 15 sec.
  • the electrolytic cells employable in the present invention may be vertical electrode or horizontal electrode cells, the former ones being preferable for the easy scavenging of the gas evolved by electrochemical reaction at made circuit.
  • the electrodes are made in materials resistant to the corrosive action of the baths employed.
  • the electrodes in the individual cell are connectable according to at least three schemes, reported by way of a non-limiting example in the attached Figs. 2, 3 and 4.
  • the electrodes may consist of an individual toroidal ring.
  • Another object of the present invention are the electrolytic cells characterised in that they have an electrode connection as indicated hereinafter and claimed in claims 8 and 9.
  • the AC flow induces an over voltage of the free corrosion potential on the surface of the alloy to be pickled, so as to reach thereon electrochemical potentials capable of fostering several oxidation-reduction reactions which involve both the alloy and the oxide layer thereabove, as well as the aqueous- solution.
  • the change in the oxidation state of the metals present in the surface oxides (in particular, Chromium for stainless steels) and the solution of the underlying metal are carried out.
  • water electrolysis with an intense production of Hydrogen and Oxygen, is carried out.
  • the dissolved Iron, in form of ferrous ion deriving from the solution of steel, is capable of fostering the reduction, according to the abovedescribed reaction, of all the Cr (VI) ions to Cr (III) ions, so that the Cr (VI) ions be absent from the solution.
  • the presence in the solution of the redox pair consisting of ferric and ferrous ions elevates the oxidizing power of the bath, providing the latter with passivating capabilities.
  • the voltage-current phase displacement assessed by electrode impedance spectroscopy, is such that at frequencies between 40 Hz and 70 Hz more than 90% of the current crossing the cell is in phase with the applied voltage (active component of the current) and it allows the abovementioned electrochemical reactions.
  • a mere 10% of the current is shifted 90° out of phase with respect to the voltage (reactive component of the current) it being employed, for the load, the discharge of the pseudo-condenser made by the double electric charge layer on the electrode surface.
  • the active component tends to decrease in favour of the reactive one, decreasing the fraction of the current fostering the electrochemical reactions required for the pickling.
  • the solution kinetics of the alloys to be pickled are high, particularly so, considering that the oxide is in no way pre-treated or conditioned prior to the in-cell electrolytic treatment.
  • Figure 1 shows the progress of the weight loss expressed in g/m 2 as a function of the time for the entire pickling treatment in a 200 g/1 H 2 S0 4 aqueous solution for a X 6 CrTi i2 (AISI 409) cold-rolled and annealed steel.
  • Figure 2 shows a first electrode configuration, in which electrodes 1 located at the same side of the strip N are alternately connected to the two terminals of a phase of a transformer. With this configuration, the electrodes 2 located at the side opposed to the strip are connectable to the same terminal of a phase of a transformer, connecting them to the corresponding ones on the other side.
  • Figure 3 shows a second configuration in which the electrodes 1 located in the same side of strip N are connected to the same terminal of one or more phases of one or more transformers, and the opposed electrodes 2 are connected to the other terminal of the corresponding phases of the transformers.
  • Figure 4 shows a third configuration in which the opposed electrodes of two adjacent pairs are connected to the two terminals of two separate single-phase transformers, so that the electric circuits of each single-phase transformer intertwine therebetween inside of strip N, defining an X-shaped- course.
  • the current is applied with the electrode configuration shown in figure 2.
  • the interelectrode gap is equal to 80 mm.
  • the in-tank solution is such as to maintain with the immersed strip surface a ratio not lower than lm 3 solution/m 3 strip and it is renewed upon reaching the limits set for the dissolved metals.
  • a current density equal to 60 A/dm 2 was set.
  • the treatment time i.e., the period in which the material is subjected to the action of the alternate current, was set at 15 sec, in connection with the strip speed and the electrode sizes.
  • FIG. 1 shows the diagram related to the weight losses of the steel subject of the example as a function of the treatment time and for two different current densities applied.
  • EXAMPLE 2 Pickling according to the invention of a cold-rolled and annealed AISI 430 strip (coil) The characteristics of the strip to be pickled are:
  • the current was applied with the electrode configuration shown in figure 2.
  • the interelectrode gap is equal to 80 mm.
  • the in-tank solution is such as to maintain with the immersed strip surface a ratio not lower than lm 3 solution/m 2 strip and it is renewed upon reaching the limits set for the dissolved metals .
  • the treatment time i.e., the period in which the material is subjected to the action of the alternate current, was set at between 5 sec and 25 sec, in connection with the strip speed and the electrode sizes
  • the weight loss attained at the end of the treatment was equal to about 40 g/m 2 of strip.

Landscapes

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

Abstract

Continuous electrolytic pickling method for steels, Nickel, superalloys, Titanium and alloys thereof, characterised in that the material to be treated , for a time comprised between 3 sec and 60 sec, is immersed into or passes through at least one electrolytic cell with an electrolytic solution consisting of a neutral or acid aqueous solution, at a temperature comprised between 20 °C and 95 °C, with at least one pair of electrodes connected to an alternate current power supply having a frequency ranging from 1 Hz to 1000 Hz, the electrolysis being carried out at a current density having an effective amplitude ranging from 10 A/dm2 to 250 A/dm2. The Figure depicts the progress of the weight loss of an AISI 409 (X6CrTi12) steel as a function of the application time of an embodiment of the pickling method according to the present invention.

Description

"CONTINUOUS ELECTROLYTIC PICKLING METHOD FOR METALLIC
PRODUCTS USING ALTERNATE CURRENT SUPPLIED CELLS"
DESCRIPTION The present invention relates to a continuous electrolytic pickling method for metallic products, in particular in Iron, Nickel, Titanium and alloys thereof, based on the use of alternate current supplied cells with electrolytic solution consisting of acid or neutral aqueous solutions. As it is known, pickling, e.g. for the stainless steels, is actually carried out in order to eliminate the scale of thermal oxides which are generated during the hot- rolling and/or annealing treatments, and to dissolve the Chromium-depleted alloy layer (dechromized layer) therebelow. This conventional method consists of three conceptually different steps: a first step of descaling, i.e., physico-chemical modification of the scale with the partial removal thereof; a second step of actual pickling, i.e. removal and solution of the residual scale and disposal of the sub-surface layer of dechromized alloy; and a third step, so-called of finishing, consisting in a surface passivation. The latter two steps are often carried out at the same time. In the state of the art, several ways for carrying out the step of descaling, depending on the type of oxide scale present in the metal at the end of metallurgical treatments, are known.
With regards to the oxide scale generated in the hot- rolling and annealing processes, the step of descaling, in most cases, is carried out by sandblasting with a hard grit which breaks up and partially removes the scale. For the cold-rolled products and the annealed stainless steel and/or Titanium, the step of descaling cannot be carried out by surface peening, which is not compatible with the quality of the finished product's surface.
Hence, different processes, capable of inducing a substantial modification of the oxides, facilitating the subsequent pickling process, are adopted.
To this end, the most widely adopted methods are as follows : a) thermochemical descaling, which consists in immersing the material to be pickled in a bath of melted oxidizing salts (400°C-600°C) capable of altering the scale, increasing the degree of oxidation of the metals constituting the oxides. In particular, Kolene baths (eutectic of the NaOH-NaN03-NaCl ternary system) at temperatures around 500 °C are the most widely adopted; b) electrolytic descaling by neutral sulphate solutions, with the partial modification of the oxidation states of the constituent metals of the scale and the entailed solution thereof. For both hot- and cold-rolled stainless steels and Titanium, the pickling step is generally carried out using highly oxidizing acid baths, capable of dissolving the sub-surface alloy layer (Cr-depleted for stainless steels) determining the detachment of the scale adhering thereto.
These baths mainly consist of mixtures of mineral acids, the most widely adopted thereamong being:
1) mixtures of nitric and hydrofluoric acid at temperatures generally between 60°C and 75°C; 2) mixtures of sulphuric, hydrofluoric, hydrochloric and phosphoric acids, with additions of elements having a high oxidizing power (sometimes used in mixtures) like, e.g., permanganates, persulphates, ferric chloride, ferric sulphate and hydrogen peroxide, at a temperature between 50 °C and 100°C; 3) hydrochloric or sulphuric acid with the addition of corrosion inhibitors for the pickling of unalloyed steels at temperatures comprised between 50 °C and 85°C. In some industrial plants, in order to increase the kinetics of the pickling step with all of the abovementioned mixtures, electrolytic cells capable of applying a continuous current density ranging from 3 A/dm2 to 40 A/dm2 to the material are used. The finishing step, aimed at forming a passivated protective film, when this is not carried out at the same time as the pickling step, is usually attained in baths having high redox potential. These baths contain the abovementioned acids and oxidizers at lower concentrations and with a lower content of the ions of the metals present in the metallic products to be pickled. In general, between each tank, and anyhow at the end of the line, washing sections consisting of water jet systems equipped with rotary brushes are inserted. The function carried out by these systems is the removal of the pickling solution dragged by the strip, and the non- adhering scale particles deposed on the strip surface.
To date, several processes, concerning the descaling step as well as the pickling step of stainless steels and of Titanium and alloys thereof, based on the employ of acid solutions free from -nitric acid, are known. In particular, processes for the pickling of stainless steels and of Titanium and alloys thereof based on the use of acid solutions, free from nitric acid, whose oxidizing power is provided by the presence of various elements, among which the ferric ions, the hydrogen peroxide, and the persulphates, are known.
In particular, DE-A-19624436, WO 9826111, EP-A-763609 and JP95-130582 disclose pickling processes in acid solution, free from nitric acid, in presence of ferric ions with the use of alternate current supplied electrolytic cells (current density comprised between 0.5 A/dm2 and 250 A/dm2) . DE-C-3937438 discloses a process in which direct current is employed for the reoxidation of the ferrous ions to ferric ions in a hydrochloric acid solution.
EP-A-838542 discloses a pickling process in an aqueous sodium sulphate solution, having a concentration between 10 g/1 and 350 g/1, in which the strip is vertically passed between pairs of counter electrodes, a direct current having a density between 20 A/dm2 and 250 A/dm2 being applied therebetween.
However, the known technologies, which are schematically reported hereto, entail significant environmental and working safety drawbacks, as well as drawbacks referring to the management of the pickling process in terms of control and costs thereof.
With regards to the descaling step, the main drawback of the process for the mechanical removal of the scale by sandblasting or peening lies in the difficulty of abating the dusts made of silica and metallic oxides particles, not to mention the high noise pollution of the surrounding working areas.
The chemical descaling carried out with melted salts proves particularly difficult to manage, due to the high temperature of the bath (400°C-600°C) as well as to the difficulty of disposing the washing solutions of the metallic product to be descaled at the end of the treatment. In fact, these washing solutions contain non- negligible quantities of hexavalent Chromium and of nitrites and nitrates.
The employ of baths containing nitric acid, for the pickling and the finishing steps, causes relevant environmental problems, for different reasons. Among the latter, the most important are:
A. difficulty of abating the highly polluting NOxs, evolved from the acid-metal reactions;
B. difficulty of complying with the existing norms for the environmental protection, for the disposal of spent solutions in connection with the high nitrate content thereof.
The baths of sulphuric and of hydrofluoric acid which use, instead of the nitric acid, systems having a high redox potential, entail a complex management in connection with the difficulties of maintaining the appropriate concentrations of reagents capable of ensuring the envisaged pickling kinetics.
Moreover, the costs of the reagents, e.g., of the stabilised hydrogen peroxide, are high, considering that a fraction of the metals accumulating in the solution react with the oxidizers, lowering the process effectiveness .
The present invention allows to overcome all of the abovementioned drawbacks, further providing other advantages which will hereinafter be made apparent.
In particular, an object of the present invention is to provide a pickling method for continuously cast products in steely in compliance of the UNI EU 74/20 norm, and in Nickel alloy and in Titanium, based on the use of alternate current supplied electrolytic cells in acid or neutral aqueous solutions. In fact, an object of the present invention is a continuous electrolytic pickling method for steels, Nickel super alloys, Titanium and alloys thereof, characterised in that the material to be treated, for a time between 3 and 60 seconds, is immersed into or passes through at least one electrolytic cell with an electrolytic solution consisting of a neutral or acid aqueous solution, at a temperature between 20°C and 95°C, with at least one pair of electrodes connected to an alternate current power supply having a frequency ranging from 1 Hz to 1000 Hz, the electrolysis being carried out at a current density having an effective amplitude ranging from 10 A/dm2 to 250 A/dm2. In particular, the frequency of the alternate current may range from 40 Hz to 70 Hz.
The electrolytic solution can be an aqueous solution, at a temperature between 20 °C and 95 °C, containing the following components having a concentration expressed in g/1: * sulphuric acid (H2S04) from 20 to 300, and optionally at least one among
* hydrofluoric acid (HF) from 5 to 50
* orthophosphoric acid (H3P04) from 5 to 200
* ferric ions (Fe+3) from 5 to 40. In the case of pickling of stainless steels, the electrolytic solution is maintained at a temperature between 70 °C and 90 °C and comprises sulphuric acid at a concentration between 150 g/1 and 250 g/1, and, optionally, ferric ions (Fe+3) at a concentration of from 5 g/1 to 40 g/1.
In the case of Nickel-base super alloys and for Titanium and alloys thereof, the electrolytic solution is at a temperature between 70 °C and 90 °C, and comprises sulphuric acid at a concentration between 150 g/1 and 250 g/1 and at least one between hydrofluoric acid at a concentration between 5 g/1 and 50 g/1 and hydrochloric acid at a concentration between 5 g/1 and 50 g/1. For carbon steels, the electrolytic solution is at 70°C- 90 °C and comprises sulphuric acid at a concentration between 150 g/1 and 250 g/1.
In another embodiment, for any application, the electrolytic solution may be a sodium sulphate (Na2S04) neutral aqueous solution having a concentration ranging from 25 g/1 to 300 g/1 at a temperature between 50 °C and 95°C.
In an embodiment of the present invention, pairs of adjacent electrodes are connected to two separate power supplies, so that the current lines outputted from a first electrode pair facing one side of the material to be treated, cross said material and close again on a second electrode pair, opposed to the first one and facing the other side of the material to be treated, defining a substantially X-shaped course.
In another embodiment of the present invention, electrodes facing one side of the material to be treated are connected to a power supply, so that the current lines which are outputted from said electrodes and cross the material, close again on other electrodes opposed to the first ones and facing the opposite side of the material to be treated, defining a course which is substantially orthogonal to said sides. The electrolytic pickling -method according to the invention can be used for inducing a physical-chemical modification of the scale of the metallic oxides present onto the surface of the material to be pickled, a physical-chemical modification which, in the case of the stainless steels, occurs in a treatment time comprised between 1 sec and 10 sec.
The continuous electrolytic pickling method according to the present invention may be used in a step subsequent to that of the physical-chemical modification of the scale of metallic oxides present onto the surface of the material to be pickled. In the case of the stainless steels, this application of the pickling method according to the invention requires treatment times between 2 sec and 15 sec.
The electrolytic cells employable in the present invention may be vertical electrode or horizontal electrode cells, the former ones being preferable for the easy scavenging of the gas evolved by electrochemical reaction at made circuit.
The electrodes are made in materials resistant to the corrosive action of the baths employed.
The electrodes in the individual cell are connectable according to at least three schemes, reported by way of a non-limiting example in the attached Figs. 2, 3 and 4.
In the case of opposed electrodes connected to the same terminal, the electrodes may consist of an individual toroidal ring. Another object of the present invention are the electrolytic cells characterised in that they have an electrode connection as indicated hereinafter and claimed in claims 8 and 9.
Among the most important advantages in the adoption of the present invention, the following may be mentioned: - provision of a descaling system capable of replacing currently employed technologies, minimising the problems connected to pollution and working safety; - provision of a pickling and finishing system to be carried out subsequently to the descaling treatment carried out with the currently adopted technologies, based on the use of solutions free from nitric acid capable of eliminating the environmental drawbacks connected to NOxs emissions;
- provision of a pickling and finishing system which does not require the employ of- substances having a high redox potential, like, e.g., ferric ions and peroxides, in order to provide the required oxidizing power to the solutions, solving the problems connected to the control of the in-tank reagents and to the related costs;
- provision of a pickling method capable of reuniting in a single stage the descaling, pickling and finishing steps, carrying out the entire pickling process with a single treatment system;
- provision of a pickling system capable of significantly reducing the times, and therefore the costs, of the treatment.
The positive effects of the adoption of the continuous pickling method according to the present invention may be explained in light of the following: the AC flow induces an over voltage of the free corrosion potential on the surface of the alloy to be pickled, so as to reach thereon electrochemical potentials capable of fostering several oxidation-reduction reactions which involve both the alloy and the oxide layer thereabove, as well as the aqueous- solution. Hence, the change in the oxidation state of the metals present in the surface oxides (in particular, Chromium for stainless steels) and the solution of the underlying metal are carried out. Moreover, water electrolysis, with an intense production of Hydrogen and Oxygen, is carried out.
These reactions, in increasing order of standard potential of the respective redox pairs, are: oxidation reactions of the constituent metals of the steel or of the Titanium and alloys thereof, or of the Nickel and alloys thereof
Ti → Ti2+ +2e
Cr → Cr3+ +3e Fe - Fe2+ +2e
Ni - Ni2+ +2e reactions involving the constituent metals of the thermal oxide scale of the alloy to be pickled
Fe2+ - Fe3+ +e Ti2+ → Ti3+ +2e
Ti3+ → Ti+ +e
Cr3+ → Cr6+ +3e water electrolysis reactions in acid solutions
4H30+4e - 2H2+4H20 6H20 → 02+4H30++4e in neutral solutions
4H20+4e → 2H2+40H"
40H" -» 0+2H20+4e The generation of chromates (hexavalent Cr) , by oxidation of the Chromium constituting the oxide scale, contributes to increasing the solution kinetics of the alloy and the oxidation of the ferrous ion to ferric ion according to the reactions
Cr207 2" + 6Fe2+ +14H+ -> 2CR3+ + 6Fe3+ +14H20 The dissolved Iron, in form of ferrous ion deriving from the solution of steel, is capable of fostering the reduction, according to the abovedescribed reaction, of all the Cr (VI) ions to Cr (III) ions, so that the Cr (VI) ions be absent from the solution.
For the stainless steels, the presence in the solution of the redox pair consisting of ferric and ferrous ions (E°=771 mV/SHE) elevates the oxidizing power of the bath, providing the latter with passivating capabilities. The voltage-current phase displacement, assessed by electrode impedance spectroscopy, is such that at frequencies between 40 Hz and 70 Hz more than 90% of the current crossing the cell is in phase with the applied voltage (active component of the current) and it allows the abovementioned electrochemical reactions. A mere 10% of the current is shifted 90° out of phase with respect to the voltage (reactive component of the current) it being employed, for the load, the discharge of the pseudo-condenser made by the double electric charge layer on the electrode surface. As the frequency increases, the active component tends to decrease in favour of the reactive one, decreasing the fraction of the current fostering the electrochemical reactions required for the pickling.
The alternation of Hydrogen-developing reactions, during the cathode polarization, and of Oxygen-developing reactions, during the anodic polarization, yields an intense descaling action, causingthe quick detachment of the oxide layer from the matrix.
The solution kinetics of the alloys to be pickled are high, particularly so, considering that the oxide is in no way pre-treated or conditioned prior to the in-cell electrolytic treatment.
So far, merely a general description of the present invention has been given. With the aidance of the figures and of the examples, having an explanatory yet not a limitative value, a more detailed description of specific embodiments thereof, aimed at making its objects, features, advantages and operation modes better understood, will hereinafter be provided.
Figure 1 shows the progress of the weight loss expressed in g/m2 as a function of the time for the entire pickling treatment in a 200 g/1 H2S04 aqueous solution for a X6CrTii2 (AISI 409) cold-rolled and annealed steel. Figure 2 shows a first electrode configuration, in which electrodes 1 located at the same side of the strip N are alternately connected to the two terminals of a phase of a transformer. With this configuration, the electrodes 2 located at the side opposed to the strip are connectable to the same terminal of a phase of a transformer, connecting them to the corresponding ones on the other side.
Figure 3 shows a second configuration in which the electrodes 1 located in the same side of strip N are connected to the same terminal of one or more phases of one or more transformers, and the opposed electrodes 2 are connected to the other terminal of the corresponding phases of the transformers. Figure 4 shows a third configuration in which the opposed electrodes of two adjacent pairs are connected to the two terminals of two separate single-phase transformers, so that the electric circuits of each single-phase transformer intertwine therebetween inside of strip N, defining an X-shaped- course. EXAMPLE 1
Pickling of a strip (coil) of cold-rolled and annealed
AISI 409LI.
The characteristics of the strip to be pickled are:
Pickling solution:
The current is applied with the electrode configuration shown in figure 2. The interelectrode gap is equal to 80 mm. At the outlet of the electrolytic cells a water jet system equipped with brushes, followed by a series of wringing rolls, was inserted. The in-tank solution is such as to maintain with the immersed strip surface a ratio not lower than lm3 solution/m3 strip and it is renewed upon reaching the limits set for the dissolved metals.
Assessing the loss due to currents closing again between the electrodes without involving the strip to be pickled to be <8%, a current density equal to 60 A/dm2 was set. The treatment time, i.e., the period in which the material is subjected to the action of the alternate current, was set at 15 sec, in connection with the strip speed and the electrode sizes.
The weight loss attained at the end of the treatment was equal to about 40 g/m2 of strip. Figure 1 shows the diagram related to the weight losses of the steel subject of the example as a function of the treatment time and for two different current densities applied. EXAMPLE 2 Pickling according to the invention of a cold-rolled and annealed AISI 430 strip (coil) The characteristics of the strip to be pickled are:
The current was applied with the electrode configuration shown in figure 2. The interelectrode gap is equal to 80 mm. At the outlet of the electrolytic cells a water jet system equipped with brushes, followed by a series of wringing rolls, was inserted. The in-tank solution is such as to maintain with the immersed strip surface a ratio not lower than lm3 solution/m2 strip and it is renewed upon reaching the limits set for the dissolved metals .
Assessing the load loss due to currents which close again between the electrodes without involving the strip to be pickled to be <8%, a current density equal to 75 A/dm2 was set.
The treatment time, i.e., the period in which the material is subjected to the action of the alternate current, was set at between 5 sec and 25 sec, in connection with the strip speed and the electrode sizes The weight loss attained at the end of the treatment was equal to about 40 g/m2 of strip.

Claims

1. A continuous electrolytic pickling method for steels, Nickel super alloys, Titanium and alloys thereof, characterised in that the material to be treated, for a time comprised between 3 sec and 60 sec, is immersed or travels through at least one electrolytic cell with an electrolytic solution consisting of a neutral or acid aqueous solution, at a temperature comprised between 20 °C and 95 °C, with at least one pair of electrodes connected to an alternate current power supply having a frequency ranging from 1 Hz to 1000 Hz, the electrolysis being carried out at a current density having an effective amplitude ranging from 10 A/dm2 to 250 A/dm2.
2. The electrolytic pickling method according to claim 1, wherein the frequency of the alternate current ranges from 40 Hz to 70 Hz.
3. The electrolytic pickling method according to claim 1 or 2, wherein the electrolytic solution is an aqueous solution, at a temperature comprised between 20 °C and 95 °C, containing the following components having concentrations expressed in g/1: sulphuric acid (H2S04) from 20 to 300, and optionally at least one among hydrofluoric acid (HF) from 5 to 50 orthophosphoric acid (H3PO4) from 5 to 200 ferric ion (Fe+3) from 5 to 40.
4. The electrolytic pickling method for stainless steels according to any one of the claims 1 to 3, wherein the electrolytic solution is maintained at a temperature between 70°C and 90°C and comprises sulphuric acid at a concentration comprised between 150 g/1 and 250 g/1, and, optionally, ferric ions (Fe+3) at a concentration of from 5 g/1 to 40 g/1.
5. The electrolytic pickling method for Nickel-base super alloys and for Titanium and alloys thereof according to claims 1 to 3, wherein the electrolytic solution is maintained at a temperature between 70 and 90 °C and comprises sulphuric acid at a concentration between 150 g/1 and 250 g/1 and at least one between hydrofluoric acid at a concentration between 5 g/1 and 50 g/1 and hydrochloric acid at a concentration between 5 g/1 and 50 g/1.
6. The electrolytic pickling method for carbon steel according to any one of the claims 1 to 3, wherein the electrolytic solution is maintained at 70°C-90°C and comprises sulphuric acid at a concentration between 150 g/1 and 250 g/1.
7. The electrolytic pickling method according to claim 1 or 2, wherein the electrolytic solution is a sodium sulphate (Na2S04) aqueous solution having a concentration ranging from 25 g/1 to 300 g/1 at a temperature between 50°C and 95°C.
8. The electrolytic pickling method according to any one of the claims 1 to 7, wherein pairs of adjacent electrodes are connected to two separate power supplies, so that the current lines, outputted from a first electrode pair facing one side of the material to be treated, cross said material and close again on a second electrode pair, opposed to the first pair and facing the other side of the material to be treated, defining a substantially X-shaped course.
9. The electrolytic pickling method according to any one of the claims 1 to 7, wherein electrodes facing one side of the material to be treated are connected to a power supply, so that the current lines, which are outputted from said electrodes and cross the material, close again on other electrodes opposed to the first ones and facing the opposite side of the material to be treated, defining a course which is substantially orthogonal to said sides of the material to be treated.
10. A use of the electrolytic pickling method according to claims 1 to 9, for inducing a physical-chemical modification of the scale of the metallic oxides present onto the surface of the material to be pickled.
11. The use of the electrolytic pickling method according to claim 10, for stainless steels, with a treatment time between 1 and 10 sec.
12. The use of the electrolytic pickling method according to claims 1 to 9, in a step subsequent to that of the physical-chemical modification of the scale of metallic oxides present onto the surface of the material to be pickled.
13. The use of the electrolytic pickling method according to claim 12 - in a step subsequent to that of the physical-chemical modification of the scale of metallic oxides present onto the surface of the material to be pickled - for stainless steels, with a treatment time comprised between 2 sec and 15 sec.
14. The use of the pickling method according to claims 1 to 13, combined to other conventional pickling systems.
15. Electrolytic cells, characterised in that they have an electrode connection as indicated in claim 8 or 9.
16. The continuous electrolytic pickling method, the use thereof, and the electrolytic cells as hereto disclosed, exemplified and claimed.
EP01961136A 2000-08-10 2001-08-06 Continuous electrolytic pickling method for metallic products using alternate current supplied cells Expired - Lifetime EP1307609B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
IT2000RM000456A IT1317896B1 (en) 2000-08-10 2000-08-10 CONTINUOUS ELECTROLYTIC PICKLING METHOD OF METAL PRODUCTS CONCELLS POWERED BY ALTERNATING CURRENT.
ITRM20000456 2000-08-10
PCT/IT2001/000435 WO2002012596A2 (en) 2000-08-10 2001-08-06 Continuous electrolytic pickling method for metallic products using alternate current supplied cells

Publications (2)

Publication Number Publication Date
EP1307609A2 true EP1307609A2 (en) 2003-05-07
EP1307609B1 EP1307609B1 (en) 2004-03-17

Family

ID=11454885

Family Applications (1)

Application Number Title Priority Date Filing Date
EP01961136A Expired - Lifetime EP1307609B1 (en) 2000-08-10 2001-08-06 Continuous electrolytic pickling method for metallic products using alternate current supplied cells

Country Status (9)

Country Link
US (1) US20040031696A1 (en)
EP (1) EP1307609B1 (en)
CN (1) CN1318652C (en)
AT (1) ATE262057T1 (en)
AU (1) AU2001282513A1 (en)
DE (1) DE60102387T2 (en)
ES (1) ES2220795T3 (en)
IT (1) IT1317896B1 (en)
WO (1) WO2002012596A2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014155341A1 (en) 2013-03-29 2014-10-02 Tenova S.P.A. Method for treating in continuous the surface of a laminate made of stainless steel in a solution based on sulfuric acid

Families Citing this family (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10160318A1 (en) * 2001-12-07 2003-06-18 Henkel Kgaa Process for pickling martensitic or ferritic stainless steel
DE102008057151A1 (en) * 2008-11-13 2010-05-27 Henkel Ag & Co. Kgaa Process for producing an electrolytically galvanized high strength steel sheet
CN102260899B (en) * 2010-05-25 2013-04-03 宝山钢铁股份有限公司 Method for removing scale on surface of titanium/titanium alloy strip
US20120168320A1 (en) * 2010-12-30 2012-07-05 Monique Chauntia Bland System and method for scale removal from a nickel-based superalloy component
JP6144006B2 (en) * 2011-01-17 2017-06-07 Ｊｆｅスチール株式会社 Method for producing stainless steel for fuel cell separator, stainless steel for fuel cell separator, fuel cell separator, and fuel cell
CN103014824A (en) * 2011-09-21 2013-04-03 李文志 Low carbon type alternating current electrochemical degreasing process method
ITMI20130494A1 (en) 2013-03-29 2014-09-30 Tenova Spa METHOD OF TREATING CONTINUOUSLY THE SURFACE OF A STAINLESS STEEL LAMINATE IN A CHLORIDRID ACID-BASED SOLUTION
DE102015202963A1 (en) * 2015-02-18 2016-08-18 Ulrich Schekulin Method and device for chemically removing material by opening edge structuring
CN107525062A (en) * 2017-08-23 2017-12-29 大唐东北电力试验研究所有限公司 A kind of thermal power plant's superheater tube sample dirt, which measures, determines system and method
CN107525061A (en) * 2017-08-23 2017-12-29 大唐东北电力试验研究所有限公司 A kind of power plant boiler boiler tube dirt, which measures, determines system and method
JP7177425B2 (en) * 2017-12-28 2022-11-24 株式会社日本科学エンジニアリング Electropolishing liquid for stainless steel
CN110592600A (en) * 2019-09-23 2019-12-20 中冶南方工程技术有限公司 Nitric acid-free pickling process for cold-rolled 430 ferrite stainless steel
CN110512217A (en) * 2019-09-23 2019-11-29 中冶南方工程技术有限公司 A kind of 201 austenitic stainless steel of cold rolling is without nitric acid acidwashing technique
CN110528009A (en) * 2019-09-23 2019-12-03 中冶南方工程技术有限公司 A kind of 304 austenitic stainless steel of cold rolling is without nitric acid acidwashing technique
KR102286367B1 (en) * 2019-11-11 2021-08-05 주식회사 포스코 Manufacturing method of stainless steel for polymer fuel cell seperator
CN111621840A (en) * 2020-05-26 2020-09-04 大连理工大学 Bipolar electrochemical removal method for iron pollution on surface of titanium alloy
KR102497442B1 (en) * 2020-11-25 2023-02-08 주식회사 포스코 Austenitic stainless steel for polymer fuel cell separator with improved contact resistance and manufacturing method thereof
CN113788520A (en) * 2021-10-08 2021-12-14 北京首钢吉泰安新材料有限公司 Iron-chromium-aluminum pickling process, wastewater treatment method and wastewater treatment device

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE19773E (en) * 1935-12-03 Euectrocleanuxg process
US2115005A (en) * 1936-10-15 1938-04-26 Samuel J Blaut Electrochemical treatment of metal
US2408424A (en) * 1940-06-15 1946-10-01 Monsanto Chemicals Pickling steels
US4214961A (en) * 1979-03-01 1980-07-29 Swiss Aluminium Ltd. Method and apparatus for continuous electrochemical treatment of a metal web
GB8517606D0 (en) * 1985-07-12 1985-08-21 Bekaert Sa Nv Cleaning by electrochemical pickling
US4813395A (en) * 1987-04-27 1989-03-21 Allied Corporation Two-cycle engine and method of operation
SU1723209A1 (en) * 1988-11-30 1992-03-30 Уральский научно-исследовательский институт трубной промышленности Method for electrochemical pickling of steel articles
JPH0726240B2 (en) * 1989-10-27 1995-03-22 ペルメレック電極株式会社 Electrolytic pickling or electrolytic degreasing method for steel sheet
AT399167B (en) * 1991-06-10 1995-03-27 Andritz Patentverwaltung METHOD AND DEVICE FOR ELECTROLYTICALLY STICKING CONTINUOUSLY CONTINUOUS ELECTRICALLY CONDUCTIVE GOODS
SE501561C2 (en) * 1993-05-09 1995-03-13 Swedish Pickling Ab Method and apparatus for machining stainless steel wherein the current is passed through the steel strip in its thickness direction
AT401183B (en) * 1995-02-15 1996-07-25 Andritz Patentverwaltung METHOD FOR REGENERATING ELECTROLYTES, ESPECIALLY NA2SO4 FROM STAINLESS STEEL, IN PARTICULAR STAINLESS STEEL TAPES
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
IT1302202B1 (en) * 1998-09-11 2000-07-31 Henkel Kgaa ELECTROLYTIC PICKLING PROCESS WITH SOLUTIONS FREE FROM ACIDONITRICO.
GB2358194B (en) * 2000-01-17 2004-07-21 Ea Tech Ltd Electrolytic treatment

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO0212596A2 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014155341A1 (en) 2013-03-29 2014-10-02 Tenova S.P.A. Method for treating in continuous the surface of a laminate made of stainless steel in a solution based on sulfuric acid

Also Published As

Publication number Publication date
WO2002012596A3 (en) 2002-04-25
CN1451058A (en) 2003-10-22
WO2002012596A2 (en) 2002-02-14
ATE262057T1 (en) 2004-04-15
CN1318652C (en) 2007-05-30
DE60102387T2 (en) 2005-03-24
US20040031696A1 (en) 2004-02-19
WO2002012596A9 (en) 2002-11-28
DE60102387D1 (en) 2004-04-22
IT1317896B1 (en) 2003-07-15
ITRM20000456A0 (en) 2000-08-10
AU2001282513A1 (en) 2002-02-18
EP1307609B1 (en) 2004-03-17
ES2220795T3 (en) 2004-12-16
ITRM20000456A1 (en) 2002-02-10

Similar Documents

Publication Publication Date Title
EP1307609B1 (en) Continuous electrolytic pickling method for metallic products using alternate current supplied cells
JP5768141B2 (en) Eco-friendly high-speed pickling process for producing low chromium ferritic stainless steel cold rolled steel sheets with excellent surface quality
KR100650961B1 (en) Process for electrolytic pickling using nitric acid-free solutions
JP6105167B2 (en) Pickling method of high chromium ferritic stainless cold rolled steel sheet
KR20120075345A (en) High speed pickling method for surface improvement of high chromium ferritic stainless cold steel strip
JP6031606B2 (en) High speed pickling process for producing austenitic stainless cold rolled steel sheet
EP0960221B1 (en) Method for pickling products of a metal alloy containing iron and of titanium and alloys thereof
JPH0827600A (en) Descaling method and device for stainless steel strip
JPH0357196B2 (en)
JP3792335B2 (en) Finishing electrolytic pickling method in descaling of stainless steel strip
EP1358367B1 (en) Continuous electrolytic pickling and descaling of carbon steel and stainless steel
JP2577619B2 (en) Method and apparatus for descaling alloy steel strip
KR101382934B1 (en) High Speed Pickling Process for Improving Corrosion Resistance of Austenitic Stainless Cold Strip
EP4056737A1 (en) Ionic liquid for pickling stainless steel and method for pickling stainless steel by using same
JP3873335B2 (en) Electrolytic descaling method for steel strip
EP2978878A1 (en) Method for treating in continuous the surface of a laminate made of stainless steel in a solution based on hydrochloric acid
JPH03243799A (en) High-speed electrolytically dissolving method for steel-based metal
JPH02173300A (en) Method for electrolytically descaling cold rolled stainless steel strip with neutral salt

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

17P Request for examination filed

Effective date: 20030207

AK Designated contracting states

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

AX Request for extension of the european patent

Extension state: AL LT LV MK RO SI

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

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 CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

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

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040317

Ref country code: BE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040317

Ref country code: CH

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040317

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040317

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040317

Ref country code: LI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040317

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040317

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040317

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT;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: 20040317

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REF Corresponds to:

Ref document number: 60102387

Country of ref document: DE

Date of ref document: 20040422

Kind code of ref document: P

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 FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040617

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040617

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040617

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

Ref country code: IE

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

Effective date: 20040806

Ref country code: LU

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

Effective date: 20040806

LTIE Lt: invalidation of european patent or patent extension

Effective date: 20040317

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

Ref country code: MC

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

Effective date: 20040831

NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2220795

Country of ref document: ES

Kind code of ref document: T3

ET Fr: translation filed
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

Effective date: 20041220

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

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

Ref country code: PT

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

Effective date: 20040817

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 16

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20160819

Year of fee payment: 16

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 17

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

Effective date: 20170806

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

Ref country code: GB

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

Effective date: 20170806

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 18

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: ES

Payment date: 20190924

Year of fee payment: 19

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20200821

Year of fee payment: 20

Ref country code: DE

Payment date: 20200819

Year of fee payment: 20

REG Reference to a national code

Ref country code: DE

Ref legal event code: R071

Ref document number: 60102387

Country of ref document: DE

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20211228

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

Ref country code: ES

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

Effective date: 20200807