WO2000033061A1 - Dispositif et procede de controle des processus de decapage de l'acier - Google Patents

Dispositif et procede de controle des processus de decapage de l'acier Download PDF

Info

Publication number
WO2000033061A1
WO2000033061A1 PCT/EP1999/009367 EP9909367W WO0033061A1 WO 2000033061 A1 WO2000033061 A1 WO 2000033061A1 EP 9909367 W EP9909367 W EP 9909367W WO 0033061 A1 WO0033061 A1 WO 0033061A1
Authority
WO
WIPO (PCT)
Prior art keywords
analysis
concentration
pickling bath
analysis vessel
given
Prior art date
Application number
PCT/EP1999/009367
Other languages
English (en)
Inventor
Paolo Giordani
Fabio Musiani
Ioannis Demertzis
Sandro Fortunati
Franco Mancia
Ezio Novaro
Original Assignee
Henkel Kgaa
Acciai Speciali Terni S.P.A.
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 Henkel Kgaa, Acciai Speciali Terni S.P.A. filed Critical Henkel Kgaa
Priority to EP99961037A priority Critical patent/EP1141686B1/fr
Priority to JP2000585647A priority patent/JP2002531700A/ja
Priority to MXPA01005464A priority patent/MXPA01005464A/es
Priority to CA002353387A priority patent/CA2353387A1/fr
Priority to DE69930001T priority patent/DE69930001T2/de
Publication of WO2000033061A1 publication Critical patent/WO2000033061A1/fr

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

Definitions

  • the invention consists in a device and in a method to control pickling processes for carbon steels, austenitic, ferritic and martensitic stainless steels, duplex steels and special alloys, in which said device automatically manages sampling of pickling baths and analysing of said samples in order to define (according to specific conductivity and potentiometric methodologies) critic process parameters and to restore desired concentrations of necessary chemicals in the pickling tanks.
  • the invention also permits to manage pickling conditions specific for the type of steel under treatment through definition of remotely activable operative procedures automatically recalling and realising the most apt operating conditions for pickling of the specific kind of material under treatment.
  • steel products such as plates, strips, tubes, rods
  • oxide layers are formed on the surface thereof which must be removed both to get proper final appearance as well as passivity and anticorrosive properties for the final product, and to allow further working.
  • Said superficial oxide layers are usually eliminated by a chemical treatment
  • the management of the process usually includes an occasional control of the pickling bath through manual titration of the acidity or measure of the conductivity of the solution and of its iron content (or of total metals, through measurement of bath density); it is also possible to measure the content in hydrofluoric acid by means of a specific ion selective electrode.
  • US patent 4,060,717 discloses the use of ions selective electrodes for fluorine and hydrogen ions to measure the concentration of nitric acid (or other strong acid) and of hydrofluoric acid in pickling baths containing nitric and hydrofluoric acids; the electric voltage data gathered by a control circuit are elaborated by a microprocessor to calculate the concentration of the two acids and to adjust relevant concentrations.
  • JP patent 55040908 discloses the determination of the hydrofluoric acid and of another strong acid (nitric, hydrochloric, sulphuric) through the determination with ion selective electrodes of the relevant anions after passing the solution through ion exchange membranes, in order to adjust the acids concentration.
  • US patent 5,286,368 measures the concentration of hydrofluoric acid in a mixture of nitric and hydrofluoric acids through the complexing ability of trivalent iron ions towards the fluorine ions, permitting to determine the concentration of the acids in the mixture.
  • the continuous automatic management of such pickling processes based on nitric acid though better than an occasional manual or automatic control performed, for instance, a few times per day, is not essential for the process in terms of quality of treated material, because of the functional characteristics of such baths; particularly, in the pickling of stainless steels, such baths usually have high nitric acid concentrations (about 12-15%) and hydrofluoric acid concentration of about 2-5%.
  • the high nitric acid concentration ensures at the same time both high acidity and almost constant oxidising power, making it possible to manage the process through occasional additions of chemicals. Moreover, the determination of acid concentration is sufficient to have an adequate control of the pickling ability of the bath.
  • the optimal conditions must be, therefore, continuously adjusted by means of oxidising agents, such as hydrogen peroxide. Moreover, the variation of the trivalent iron concentration indirectly influences also the concentration of the free acids present into the bath.
  • the criticity of nitric acid free pickling processes is obviously linked to the total iron amount dissolved per time unit, to the number of pickling tanks to be controlled, to the number of materials requiring different operative conditions and to the practical capability to ask for frequent manual additions of acids into the tanks.
  • the management of pickling processes for stainless steels such as those previously cited for continuous pickling plants of stainless steel strips or for high productivity automatic plants for rod processing, proved to be critic for the quality of the final product; it can also be non economic without the use of an automatic system for sampling, controlling and dosing of the reactants.
  • the control device and the method according to the present invention require the utilisation of specific skilfulness and analytical methods for a proper management of such processes.
  • a control device and a control method for nitric acid free pickling baths comprising means to take a sample of the bath to be analysed; means to analyse said sample in order to measure a number of parameters according to specific conductivity methodologies (to find out the concentration of hydrofluoric acid, of the sulphuric acid or of another inorganic strong acid) and potentiometric (to find out the concentrations of trivalent and bivalent iron) as well as the redox potential value of said sample and its temperature; restoring means, apt to calculate, according to the above measured values, the quantity of correction chemicals (preferably hydrofluoric acid, sulphuric acid and an oxidising agent) to be added to the pickling bath in order to restore at the desired level the value of said parameters and to actuate at least a device to add into said pickling bath said quantities of correction chemicals.
  • specific conductivity methodologies to find out the concentration of hydrofluoric acid, of the sulphuric acid or of another inorganic strong acid
  • potentiometric to find out the
  • Fig. 1 schematically shows a plant comprising an analysis device according to the invention
  • Fig. 2 shows a simplified scheme of an analysis device according to the invention
  • Fig. 3 schematically shows the analysis vessel CA of Fig. 2, comprising a conductivity measuring system and a preferred embodiment of the rinsing means of the vessel itself and of the measure electrode
  • Fig. 4 schematically shows the analysis vessel CA of Fig. 2, comprising a potentiometric measuring system and a preferred embodiment of the rinsing means of the vessel itself and of the measure electrode.
  • Fig. 1 schematically shows a plant comprising an analysis device according to the invention, comprising:
  • a plurality of reservoirs S each containing a solution at a given concentration of one of the correction chemicals (a strong mineral acid, preferably sulphuric acid, hydrofluoric acid and an oxidising agent, preferably but not necessarily hydrogen peroxide) to be added into one of the tanks V;
  • the correction chemicals a strong mineral acid, preferably sulphuric acid, hydrofluoric acid and an oxidising agent, preferably but not necessarily hydrogen peroxide
  • addition means enabling the analysis device A to control the addition into tanks V of correction chemicals contained in reservoirs S.
  • Fig, 1 components not interesting for the present description, such as valves, pumps, actuators, filtering and rinsing means, known per se, as well as other, if any, circuitry components are omitted.
  • the analysis device A comprises (Fig. 2) means to pick up from a vessel V a sample of the pickling bath; means to analyse it to measure, according to specific conductivity and potentiometric methodologies, the preset parameters (the strong mineral acid, for instance sulphuric acid, and the hydrofluoric acid concentrations, as well as the ones of trivalent and bivalent iron), the redox potential and the temperature of said diluted sample; means to calculate the amounts of correction chemicals to be sent from reservoirs S to tanks V to adjust said parameters and means to actuate the devices at the output of reservoirs S to send into the pickling bath the calculated amounts of said correction chemicals.
  • sulphuric acid will means any strong mineral acid.
  • the analysis devices (A1 , A2) are preferably divided, each one being specialised in only one of said analysis (measure of sulphuric acid and of hydrofluoric acid, respectively of iron ions concentrations).
  • the analysis devices (A1 , A2) can be managed by a logic unit of higher level, not shown in the figures, which can be placed "in loco" or in a remote site, connected to the analysis devices (A1 , A2) through bi-directional transmission means, known per se.
  • said analysis devices (A1 , A2) can be of the same model and comprise the analytical means apt to measure the concentration both of the acids (sulphuric and hydrofluoric) and of the iron ions.
  • Fig. 2 shows a simplified scheme of an analysis device A (A1 , A2) of Fig. 1 , comprising in combination relationship:
  • a sampling module C the sampling inputs of which I (11 , In) are in sequence connected to the permanent recycling piping among the pickling tanks V (V1 , ..., Vn; Fig. 1 ) and the analysis device A; at least a reservoir (not shown), in which the bath sample to be analysed is loaded, is provided inside the sampling module C;
  • dosing means D (D1 , D2) apt to draw the amounts of chemicals necessary to the analyses and to transfer the same into the analysis vessel CA, part of the dosing means D being apt to draw with low accuracy (from about 2 to about
  • the dosing means D with low and high accuracy are respectively grouped in two different functional units (D1 , D2).; • an analysis vessel CA, containing the measure electrodes (generically named EM in Fig. 2), receiving from sampling module C the bath sample to be analysed, from dosing means D the chemicals necessary for the analysis and from a reservoir W (not shown) the water (preferably having a conductivity lesser than 100 microsiemens) necessary to dilute said sample to a desired dilution ratio; in Fig.
  • an analysis vessel CA containing the measure electrodes (generically named EM in Fig. 2), receiving from sampling module C the bath sample to be analysed, from dosing means D the chemicals necessary for the analysis and from a reservoir W (not shown) the water (preferably having a conductivity lesser than 100 microsiemens) necessary to dilute said sample to a desired dilution ratio; in Fig.
  • a logic unit UL controlling and managing the analysis procedures, acquiring and elaborating the information from measure electrodes EM and actuating means to send into the pickling bath the solutions of the correction chemicals contained in the reservoirs S (Fig. 1 ).
  • the dosing means of functional unit D1 are peristaltic pumps with constant delivery, while the dosing means of functional unit D2 are syringes in antacid material (e.g. PES) operated by an electric stepping motor.
  • antacid material e.g. PES
  • the analysis device A also comprises means (hereinafter described with reference to Figures 3 and 4) permitting to rinse the analysis vessel CA and the measure electrodes EM after each measure with water and after a given number of measures with a chemical solution (preferably but not necessarily 10-20% hydrochloric acid), thus permitting to keep in optimal conditions the measure electrodes EM, to have reliable analytical data, to reduce to a minimum the maintenance interventions and to highly enhance the electrodes life.
  • a chemical solution preferably but not necessarily 10-20% hydrochloric acid
  • each type or family of materials to be pickled must be treated according to standard and characteristic parameters (hydrofluoric and sulphuric acids concentration, trivalent and bivalent iron ions concentration, ratio between trivalent and bivalent iron ions, hydrogen peroxide concentration, temperature of the sample to be analysed, and so on); in a preferred embodiment of the invention, the parameters characterising each working step as well as those concerning the operation of the analysis device A, which all permit to perform different analyses on pickling baths relating to the specific working step, are grouped into operating procedures biuniquely correlated with the material itself and stored in the logic unit UL, which are when necessary recalled according to the material to be pickled.
  • an operating procedure comprises at least the following information:
  • a further operative autocalibration procedure is stored in the logic unit UL which activates after a given number of analyses and comprises the functional steps of drawing from a container (preferably but not necessarily located in the reagent storage DR) a fixed amount of a standard solution having a known composition, of transferring it into the analysis vessel CA, of analysing it, of comparing the obtained analytical results with the known composition and of activating alarm signals if the deviation between obtained analytical results and known concentrations is larger than a desired value.
  • the logic unit UL can be connected to a central operative post and/or to a logic unit of higher level, by which it can be controlled and managed; as above said, this logic unit of higher level can be placed "in situ" or be remote.
  • the central post operator can modify the operative procedure performed by one or more of the logic units UL, activating the one pertaining to the activity to be initiated; the operator can also recall from one or more of the logic units UL an operating procedure, modify it and have it to be performed by the logic units UL and/or inputting a new operative procedure storing it in the logic units UL.
  • This determination is based on the principle that, in an aqueous solution formed by a mixture of a weak acid such as hydrofluoric acid and of a stronger acid such as sulphuric acid, the solution conductivity is practically equivalent to the one of the strong acid at the same concentration; the method also exploits (in a stage subsequent to a first conductivity measure on a bath sample duly diluted to measure the sulphuric acid concentration) the high affinity of hydrofluoric acid for a metal cation present in the solution as a salt of known concentration.
  • the salt anion most preferably come from a strong acid (e.g.
  • Such conductivity increase is, therefore, proportional to the concentration of hydrofluoric acid which, after a proper calibration, can be quantitatively measured.
  • Such salts can be, for instance, ferric nitrate, ferric chloride, aluminium nitrate, aluminium chloride; in a preferred embodiment of the invention a solution of ferric nitrate * 9H2 ⁇ is utilised, at a concentration of 750 g/l.
  • the sample dilution must be attentively evaluated as a function of the concentration of the acids present in the bath to be analysed; as a non-limiting example, for sulphuric acid concentrations up to 200 g/l and for hydrofluoric acid concentrations up to 60 g/l, dilution ratios from 1 :100 to 5:100, and preferably 4: 100, are deemed to be acceptable.
  • sample temperature after dilution with water Another variable essential for the obtainment of reliable results (which must be managed by the logic unit UL of the analysis device A) is the sample temperature after dilution with water; in fact, in the industry the water temperature can have considerable variations (usually between +5 and +40° C) according to the weather, to the water source and to the holding time in reservoir W.
  • the amount of ferric nitrate utilised during the titration must be such to ensure a full complexing of the hydrofluoric acid; in the considered system, for hydrofluoric acid concentration less than 60 g/l the ratio between the volume v3 of a solution of ferric nitrate * 9H2 ⁇ at 750 g/l and the volume v1 of the bath sample must be higher than 0,5 and preferably 1 .
  • the logic unit UL acquires the data L-i, L 2 , T and automatically find the concentration of the acids through the following calculations: • sulphuric acid concentration (g/l): a * L-i 2 + b • Li -c
  • Fig. 3 shows the characteristics of the conductivity cell CC, which specific form allows to minimise the negative effects due to the high viscosity of the solution and to facilitate the rinsing of the measure platinum plaques.
  • Said conductivity cell CC comprises a hollow body B, in glass and having a substantially cylindrical shape, containing two blackened platinum plaques EL; at the lower and upper parts of the hollow body B there are holes (F1 , F2) letting the sample to be analysed to circulate inside the hollow body B.
  • the hollow body B has a diameter of about 20 mm (and anyhow comprised between about 17 and 23 mm) and a height of about 40 mm (and anyhow comprised between about 35 and 45 mm); the EL plaques dimensions are about 10 x 5 mm (and anyhow between about 8 x 12 mm and about 3 x 7mm), the distance from one another being about 15 mm (and anyhow between about 12 and 18 mm).
  • the measure electric circuit (not shown) connected to the conductivity cell CC must work at high frequency (between 25 and 40 kHz).
  • the bivalent iron determination can be made through potentiometric analysis, by potassium permanganate titration according to the classic methodology.
  • the operative sequence requires: • pouring into the analysis vessel CA a given water volume v2, through the overflow pipe TP, to obtain a dilution ratio > 1 :50;
  • the trivalent iron is measured by iodometric titration, utilising however some specific attention to permit the use of an automatic device and the obtention of reliable and reproducible results.
  • analysis vessel CA • addition into analysis vessel CA (by means of dosing means D1 ) of a given non-critical volume of a lanthanum nitrate solution having a known concentration;
  • lanthanum salts can quantitatively release the ferric ion, generating powdery and non-sticking lanthanum fluoride precipitates, thus permitting the automatic management of the process with high reliability and very limited upkeeping.
  • This same result can also be achieved by adding to the system a complexing agent for the iron ion, which however can quantitatively release it during the subsequent reaction with potassium iodide; complexing agents such as EDTA can be fit for this purpose.
  • the potentiometric system comprises a measure electrode E (inert to the working environment) immersed in analysis vessel CA and a reference electrode R (preferably in glass, of the type Ag/AgCI) positioned outside said analysis vessel CA and in contact with the solution under measurement through a saline bridge, comprising an electrolyte (contained in a tank SR) which is made to continuously pass through a porous septum SP placed at an extremity of a small plastic tube T.
  • the continuous passage of the electrolyte through the septum SP is intended to consent the electric continuity; to avoid the contact between septum SP and the hydrofluoric acid of the pickling bath and to continuously renovate the electrolyte.
  • the measure electrode E is made from a body in antacid material bearing at one extremity a platinum plaque P, one of whose surfaces, mirror finished, faces downwards, thus preventing the salts deriving from the reaction products to be deposed on the measuring face of plaque P, fouling it.
  • the electrolyte preferably 3M potassium chloride
  • a 10% solution of glycerine of another compatible product having a viscosity at 20°C comprised between 1 ,15 and 1 ,45 centipoise, inert with respect to the working environment and functionally equivalent
  • glycerine of another compatible product having a viscosity at 20°C comprised between 1 ,15 and 1 ,45 centipoise, inert with respect to the working environment and functionally equivalent
  • the device according to the invention measure, before the determination of bivalent iron, the solution redox potential on the diluted pickling bath sample utilising the potentiometric system already described; the thus obtained value is very near ( ⁇ 20 mV) to the redox potential measured in the bath before its dilution.
  • the obtained value is compared with a range of values (usually comprised between 200 and 550 mV) stored into the logic unit UL to be utilised as a first signal of the correct operation of the system: if the measured value is outside of said range, the logic unit UL of the analysis device A stops the analysis procedure and sends an alarm.
  • the calibration of the potentiometric system is made at a given frequency (say, once per week) by redox potential measure on a standard solution of known potential (usually 468 mV).
  • the logic unit UL of an analysis device 1 after measuring the desired parameters on the pickling bath sample under analysis, calculates the amount of each of the solutions at known concentration of the correction chemicals (sulphuric acid, hydrofluoric acid and oxidising agent) contained in reservoirs S, said chemicals being opportunely added to the pickling bath to restore the desired composition values and actuates addition means (such as, for instance, dosing pumps or electrovalves) at the output of reservoirs S to send into the pickling bath said calculated amounts of the correction chemicals.
  • the correction chemicals sulphuric acid, hydrofluoric acid and oxidising agent
  • the logic unit UL must just calculate the actuating period of said addition means.
  • the logic unit UL calculates the actuating period s1 (in seconds) of the addition means sending into the pickling bath the oxidising reagent solution, by:
  • Fig. 3 schematically shows an exploded view of the analysis vessel CA of Fig. 2, comprising a measure system of conductivity type and a preferred embodiment of the rinsing means of analysis vessel CA and of measure cell CC.
  • Fig. 3 it is possible to see:
  • rinsing means (F, U) controlled by the logic unit UL, enabling the rinsing of analysis vessel CA and of the conductivity measure cell CC.
  • Fig. 4 schematically shows an exploded view of the analysis vessel CA of Fig. 2, comprising a potentiometric measure system as well as a preferred embodiment, similar to the one in Fig. 3, of the rinsing means of analysis vessel CA and of the measure electrodes.
  • Fig. 4 can be seen: • the potentiometric system, comprising the measure electrode E, the reference electrode R, positioned outside of the analysis vessel CA, and the saline bridge which in turn comprises an electrolyte contained in tank SR, continuously passing through a porous septum SP placed at one extremity of a small plastic tube T;
  • rinsing means (F, U) controlled by the logic unit UL, enabling the rinsing of analysis vessel CA, of the electrode E extremity and of the porous septum SP.
  • such rinsing means comprise a plurality of slits F placed along the upper edge of the analysis vessel CA and a nozzle U apt to rinse with a water spray the extremity of the measure electrode E and the porous septum SP, respectively the conductivity measure cell CC; in Figures 3 and 4, can also be seen the lid CP for the analysis vessel CA and means MS supporting the electrode E, the small tube T of the potentiometric system, the conductivity measure cell CC and the small tubes (not explicitly indicated in Figures 3 and 4) connecting the dosing means D (D1 , D2) with the analysis vessel CA; lid CP and supporting means MS will not be described, as known per se and anyhow not pertaining to present invention.
  • the analysis vessel CA, the measure electrode E and the porous septum SP are water rinsed after each analysis and washed with a chemical solution after a given number of analyses.
  • the logic unit UL fills with water analysis vessel CA through slits F up to have the tip of electrode E and the porous septum, respectively the conductivity measure cell CC immersed, picks up from a tank (preferably but non necessarily placed within the reagent's storage DR) an amount of product (preferably hydrochloric acid) necessary for said chemical washing and send it into analysis vessel CA; after a given period of time the logic unit UL empties analysis vessel CA and rinse it with water, to eliminate any trace of the chemical solution.
  • a chemical solution preferably 10- 20% hydrochloric acid
  • analysis vessel CA is filled with water through slits F and nozzle U, to avoid any fouling and/or damaging of the electrode E tip, of the porous septum SP, and of the conductivity measure cell CC. It is possible for an expert to modify and improve, as suggested by ordinary experience and by the natural technical evolution, the device for the control of pickling baths according to present description, still remaining within the scope of present invention.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Metallurgy (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
  • Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
  • Detergent Compositions (AREA)
  • Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
  • Coating With Molten Metal (AREA)
  • Spray Control Apparatus (AREA)

Abstract

La présente invention concerne un dispositif et un procédé de contrôle des processus de décapage de l'acier. Ce dispositif de contrôle comprend un moyen (C) pour prélever un échantillon du bain pour analyse; des moyens (CA, D, EM) pour analyser cet échantillon en vue de mesurer un certain nombre de paramètres selon des méthodes de conductivité et de potentiométrie spécifiques, ainsi que la valeur du potentiel d'oxydo-réduction des échantillons et sa température; des moyens de restitution, pouvant calculer, en fonction des valeurs mesurées ci-dessus, la quantité de produits chimiques correcteurs devant être ajoutés au bain de décapage afin de restituer au niveau souhaité la valeur de ces paramètres, et d'actionner au moins un dispositif pour ajouter dans le bain de décapage les quantités nécessaires de produits chimiques correcteurs. Les paramètres mesurés en fonction des méthodes de conductivité sont les concentrations d'acide sulfurique, d'acide hydrofluorique, ou d'un autre acide inorganique; les paramètres mesurés en fonction des méthodes potentiométriques sont les concentrations d'ions ferreux bivalents ou trivalents et de peroxyde d'hydrogène; les produits chimiques correcteurs étant l'acide sulfurique, un agent hydrofluorique, et un agent d'oxydation.
PCT/EP1999/009367 1998-12-02 1999-12-02 Dispositif et procede de controle des processus de decapage de l'acier WO2000033061A1 (fr)

Priority Applications (5)

Application Number Priority Date Filing Date Title
EP99961037A EP1141686B1 (fr) 1998-12-02 1999-12-02 Dispositif et procede de controle des processus de decapage de l'acier
JP2000585647A JP2002531700A (ja) 1998-12-02 1999-12-02 鋼の酸洗い工程を制御する装置と方法
MXPA01005464A MXPA01005464A (es) 1998-12-02 1999-12-02 Dispositivo y metodo para controlar los procesos de desoxidacion por bano acido del acero.
CA002353387A CA2353387A1 (fr) 1998-12-02 1999-12-02 Dispositif et procede de controle des processus de decapage de l'acier
DE69930001T DE69930001T2 (de) 1998-12-02 1999-12-02 Vorrichtung und verfahren zur regelung von stahlbeizen

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT1998MI002612A IT1303814B1 (it) 1998-12-02 1998-12-02 Apparecchiatura e metodo per controllare processi di decapaggio peracciaio.
ITMI98A002612 1998-12-02

Publications (1)

Publication Number Publication Date
WO2000033061A1 true WO2000033061A1 (fr) 2000-06-08

Family

ID=11381178

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP1999/009367 WO2000033061A1 (fr) 1998-12-02 1999-12-02 Dispositif et procede de controle des processus de decapage de l'acier

Country Status (9)

Country Link
EP (1) EP1141686B1 (fr)
JP (1) JP2002531700A (fr)
AT (1) ATE318408T1 (fr)
CA (1) CA2353387A1 (fr)
DE (1) DE69930001T2 (fr)
ES (1) ES2258863T3 (fr)
IT (1) IT1303814B1 (fr)
MX (1) MXPA01005464A (fr)
WO (1) WO2000033061A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002079544A1 (fr) * 2001-03-30 2002-10-10 Alcan International Limited Procede de commande de la concentration de solution dans une ligne de decapage de bande
WO2002081778A1 (fr) * 2001-04-09 2002-10-17 Ak Properties, Inc. Analyseur d'acide de liqueur de decapage
WO2004020700A1 (fr) * 2002-08-30 2004-03-11 Henkel Kommanditgesellschaft Auf Aktien Procede economique de retablissement du potentiel d'oxydation d'une solution de decapage

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2499000A (en) 2012-02-02 2013-08-07 Henkel Ag & Co Kgaa Aqueous acidic pickling solution with hydroxylamine accelerators
DE102020208769A1 (de) 2020-07-14 2022-01-20 Continental Teves Ag & Co. Ohg Elektromechanische Bremsvorrichtung
DE102021212879A1 (de) 2021-11-16 2023-05-17 Continental Automotive Technologies GmbH Elektromechanische Bremsvorrichtung

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1383637A (en) * 1973-07-18 1974-02-12 Centralec Soc Electrochemical cell for quantitative analysis
GB2000196A (en) * 1977-06-24 1979-01-04 Tokai Electro Chemical Co Controlling stainless steel pickling solution by hydrogen peroxide and sulphuric acid addition
JPH0666766A (ja) * 1992-08-20 1994-03-11 Mitsubishi Heavy Ind Ltd 鋼帯の酸洗浴中の鉄イオン濃度の測定方法
US5354383A (en) * 1991-03-29 1994-10-11 Itb, S.R.L. Process for pickling and passivating stainless steel without using nitric acid
JPH07128273A (ja) * 1993-11-02 1995-05-19 Mitsubishi Heavy Ind Ltd 酸洗液中の鉄イオン濃度測定装置
JPH07294509A (ja) * 1994-04-25 1995-11-10 Kawasaki Steel Corp 混合酸の分析方法および酸洗液の管理方法
JPH08160003A (ja) * 1994-12-05 1996-06-21 Nisshin Steel Co Ltd 酸洗液中の鉄イオン濃度測定方法
EP0769575A1 (fr) * 1995-10-18 1997-04-23 NOVAMAX ITB s.r.l. Procédé pour le décapage et la passivation d'aciers inoxydables sans acide nitrique
DE19543468A1 (de) * 1995-11-22 1997-05-28 Metallgesellschaft Ag Verfahren zum Entfernen von Oxidschichten von RSH-Stählen
WO1998015674A1 (fr) * 1996-10-07 1998-04-16 Solvay Interox Limited Solutions et procede pour le traitement de la surface de metaux

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1245594B (it) * 1991-03-29 1994-09-29 Itb Srl Processo di decapaggio e di passivazione di acciaio inossidabile senza acido nitrico
JPH0518926A (ja) * 1991-07-08 1993-01-26 Nisshin Steel Co Ltd 合金鉄鋼帯の酸洗処理用塩化鉄浴の成分濃度測定方法
JP3388325B2 (ja) * 1993-11-09 2003-03-17 義和 小林 自動滴定分析装置

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1383637A (en) * 1973-07-18 1974-02-12 Centralec Soc Electrochemical cell for quantitative analysis
GB2000196A (en) * 1977-06-24 1979-01-04 Tokai Electro Chemical Co Controlling stainless steel pickling solution by hydrogen peroxide and sulphuric acid addition
US5354383A (en) * 1991-03-29 1994-10-11 Itb, S.R.L. Process for pickling and passivating stainless steel without using nitric acid
JPH0666766A (ja) * 1992-08-20 1994-03-11 Mitsubishi Heavy Ind Ltd 鋼帯の酸洗浴中の鉄イオン濃度の測定方法
JPH07128273A (ja) * 1993-11-02 1995-05-19 Mitsubishi Heavy Ind Ltd 酸洗液中の鉄イオン濃度測定装置
JPH07294509A (ja) * 1994-04-25 1995-11-10 Kawasaki Steel Corp 混合酸の分析方法および酸洗液の管理方法
JPH08160003A (ja) * 1994-12-05 1996-06-21 Nisshin Steel Co Ltd 酸洗液中の鉄イオン濃度測定方法
EP0769575A1 (fr) * 1995-10-18 1997-04-23 NOVAMAX ITB s.r.l. Procédé pour le décapage et la passivation d'aciers inoxydables sans acide nitrique
DE19543468A1 (de) * 1995-11-22 1997-05-28 Metallgesellschaft Ag Verfahren zum Entfernen von Oxidschichten von RSH-Stählen
WO1998015674A1 (fr) * 1996-10-07 1998-04-16 Solvay Interox Limited Solutions et procede pour le traitement de la surface de metaux

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 018, no. 303 (P - 1751) 9 June 1994 (1994-06-09) *
PATENT ABSTRACTS OF JAPAN vol. 1995, no. 08 29 September 1995 (1995-09-29) *
PATENT ABSTRACTS OF JAPAN vol. 1996, no. 03 29 March 1996 (1996-03-29) *
PATENT ABSTRACTS OF JAPAN vol. 1996, no. 10 31 October 1996 (1996-10-31) *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002079544A1 (fr) * 2001-03-30 2002-10-10 Alcan International Limited Procede de commande de la concentration de solution dans une ligne de decapage de bande
WO2002081778A1 (fr) * 2001-04-09 2002-10-17 Ak Properties, Inc. Analyseur d'acide de liqueur de decapage
WO2004020700A1 (fr) * 2002-08-30 2004-03-11 Henkel Kommanditgesellschaft Auf Aktien Procede economique de retablissement du potentiel d'oxydation d'une solution de decapage

Also Published As

Publication number Publication date
MXPA01005464A (es) 2002-07-02
EP1141686A1 (fr) 2001-10-10
DE69930001D1 (de) 2006-04-27
DE69930001T2 (de) 2006-08-24
IT1303814B1 (it) 2001-02-23
ITMI982612A1 (it) 2000-06-02
ATE318408T1 (de) 2006-03-15
EP1141686B1 (fr) 2006-02-22
CA2353387A1 (fr) 2000-06-08
JP2002531700A (ja) 2002-09-24
ES2258863T3 (es) 2006-09-01

Similar Documents

Publication Publication Date Title
US4268397A (en) Method of treating waste water
RU2110618C1 (ru) Способ травления стали
US4152215A (en) Apparatus for controlling pH of culture solution for a living organism
US4182638A (en) Coating process with voltammetric sensing of the coating solution
EP1141686B1 (fr) Dispositif et procede de controle des processus de decapage de l'acier
ATE280851T1 (de) Verfahren zum beizen von rostfreien stählen ohne salpetersäure und in anwesenheit von chloridionen
US5259979A (en) Process for regeneration of cleaning compounds
US5286358A (en) Method of analyzing the complexing power of a pickling liquor
US5332446A (en) Method for continuous pickling of steel materials on a treatment line
US4897128A (en) Process of determining the zinc content of phosphating baths
JP2521215Y2 (ja) Ｃｏｄ自動測定装置
JPH05263279A (ja) ステンレス鋼帯の脱スケール用硝フッ酸浴の管理方法およびその連続脱スケール装置
US6475373B1 (en) Method of controlling NOx gas emission by hydrogen peroxide
Uchiyama et al. Measurement of homogeneous reaction rate by concentration-step, controlled potential electrolysis
KR830002447B1 (ko) 배수의 처리방법
JP2587282Y2 (ja) Ｃｏｄ測定装置
JPH083774A (ja) 鋼材の酸洗方法および酸洗装置
JP2000054167A (ja) 塩化第二鉄エッチング液の管理方法および装置
JPS55152180A (en) Method for regeneration of copper chloride etching solution
FI98764B (fi) Menetelmä näytteen kemiallisen hapen kulutuksen määrittämiseksi
JPH0874079A (ja) ステンレス鋼の硝フッ酸酸洗方法
JPH0673575A (ja) 塩浴液の管理方法
Dick Electroanalytical techniques: principles and applications
JPH1161465A (ja) 第二鉄イオンを含む過酸化水素溶液の濃度管理方法
JPH01262462A (ja) 液体の濃度測定方法並びに該方法を用いた自動濃度測定装置及び自動濃度制御装置

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): CA JP KR MX US ZA

AL Designated countries for regional patents

Kind code of ref document: A1

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

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
WWE Wipo information: entry into national phase

Ref document number: PA/a/2001/005464

Country of ref document: MX

ENP Entry into the national phase

Ref document number: 2353387

Country of ref document: CA

Ref country code: CA

Ref document number: 2353387

Kind code of ref document: A

Format of ref document f/p: F

ENP Entry into the national phase

Ref country code: JP

Ref document number: 2000 585647

Kind code of ref document: A

Format of ref document f/p: F

WWE Wipo information: entry into national phase

Ref document number: 1999961037

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 09857250

Country of ref document: US

WWP Wipo information: published in national office

Ref document number: 1999961037

Country of ref document: EP

WWG Wipo information: grant in national office

Ref document number: 1999961037

Country of ref document: EP