EP0448189A2 - Procédé de décapage d'objets en matériaux hautement alliés et appareil pour sa mise en oeuvre - Google Patents

Procédé de décapage d'objets en matériaux hautement alliés et appareil pour sa mise en oeuvre Download PDF

Info

Publication number
EP0448189A2
EP0448189A2 EP91250067A EP91250067A EP0448189A2 EP 0448189 A2 EP0448189 A2 EP 0448189A2 EP 91250067 A EP91250067 A EP 91250067A EP 91250067 A EP91250067 A EP 91250067A EP 0448189 A2 EP0448189 A2 EP 0448189A2
Authority
EP
European Patent Office
Prior art keywords
acid
pickling
threshold value
bath
predetermined threshold
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
EP91250067A
Other languages
German (de)
English (en)
Other versions
EP0448189A3 (en
EP0448189B1 (fr
Inventor
Klaus Pillmayer
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.)
Vodafone GmbH
Original Assignee
Mannesmann AG
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 Mannesmann AG filed Critical Mannesmann AG
Publication of EP0448189A2 publication Critical patent/EP0448189A2/fr
Publication of EP0448189A3 publication Critical patent/EP0448189A3/de
Application granted granted Critical
Publication of EP0448189B1 publication Critical patent/EP0448189B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
    • C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
    • C23G1/10—Other heavy metals
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
    • C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
    • C23G1/08—Iron or steel
    • C23G1/086—Iron or steel solutions containing HF

Definitions

  • the invention relates to a method for pickling workpieces made of high-alloy materials according to the preamble of the main claim.
  • workpieces made of high-alloy materials such.
  • Pickling may be required after hot working, such as extrusion or heat treatment, to remove the scale that has formed.
  • mixed acid which is usually operated in a temperature range from room temperature to 70 degrees Celsius, considerable amounts of nitrogen oxides (NO; NO2) are released in accordance with the material removal.
  • NO nitrogen oxides
  • the object of the invention is to provide an improved method for pickling workpieces made of highly different high-alloy materials, with which the officially defined limit values with regard to the permissible emission of nitrogen oxides are reliably undershot in a simple and space-saving manner with short pickling times and in continuous operation.
  • the advantage of the method can be seen in the fact that, on the one hand, an inexpensive chemical is used as the NO x acceptor, continuous operation of the pickling is possible and, in the normal case, the NO x content already detected in the area of origin is almost zero or at the detection limit (approx. 1 mg / m3).
  • the threshold value has been set to a level which, based on the evaluation of a large number of measurement records, is clearly related to the consumption of the added sulfamic acid.
  • This signal is sent to the Electric drive of a pump, which is arranged on a storage container for the liquid amidosulfonic acid, passed on, so that appropriate amounts of amidosulfonic acid can be supplied to the bath by means of a timer.
  • the advantage of the method is to be seen in the fact that in normal operation the NO x portion is at the detection limit due to the action of the amidosulfonic acid. is driven, ie is almost zero.
  • the elimination of the washing systems also means a not inconsiderable saving in water, which is reflected in low pickling costs per ton of pickled material.
  • a measurement in the chimney gave values ⁇ 1 ppm. This value must be related to the permissible limit of the TA-Luft of 780 ppm, which is valid at the delivery point to the environment, while the MAK value (maximum workplace concentration) is binding at the work place.
  • the pickling plant has a heatable pickling basin 1, shown here in cross section, which is filled with a mixed acid 2 consisting of nitric acid, hydrofluoric acid and water and in which, for example, a bundle of tubes 3 made of a high-alloy material for pickling is immersed.
  • the ascending, vaporous reaction products as indicated by the arrows 4, are sucked off together with the room air through the extraction channels 5,5 ', 5'',5''' arranged on the upper edge of the pickling tank 1.
  • the discharge channels 5,5 ', 5'',5''' are connected to lines 6,7, which, when combined, are fed to a washing system 8, shown schematically here.
  • a sensor 11 which is connected to a measuring device 12 and which continuously measures the residual traces of substances to be detected which are still present in the exhaust air. These records serve as documentation for the routine inspections of the Labor Inspectorate regarding the emission of pollutants.
  • Another sensor 13 is arranged on the exhaust air duct 5 ', in such a way that the tip of the sensor 13 is located directly in the vicinity of the bath level 14. The sensor 13 is connected via a line 15 to a measuring device 16 for determining the NO x content.
  • the measured actual value can, on the one hand, be displayed directly on a display device 17 or be fed to a control device 18, which forms a control signal in comparison with a predetermined threshold value.
  • This control signal is fed via a line 19 to the electric drive 20 of a pump (not shown here).
  • This pump is arranged on a reservoir 21 for the amidosulfonic acid, from which a line 22 leads to the pickling tank 1.
  • the operating team is required to lift the tube pack (s) 3 out of the pickling basin 1 in order to interrupt the pickling process and prevent further NO x formation.
  • FIG. 2 In the top view (FIG. 2) it can be seen that the sensor 13 is the most distant from the effect of the amidosulfonic acid supplied remote location is arranged. This ensures that the time span for the mixing of the amidosulfonic acid supplied with the mixed acid 2 present in the pickling tank 1 is taken into account.
  • the measurement sequence I shows the usual course of the NO x content with the diminishing effect of the added amidosulfonic acid.
  • the measured NO x content increases relatively quickly and when the predetermined threshold value 25 is reached, for example at 8 ppm, the pump 20 is switched on and an excess amount of amidosulfonic acid is added to the mixed acid. Since the effect of the amidosulphonic acid supplied does not immediately begin fully at all points in the pickling tank 1 due to the time required for thorough mixing, the NO x content initially rises further and here, for example, reaches 20 ppm as a peak point.
  • the measurement sequence II is intended to indicate the peculiarity of the pipe pickling system, in which it cannot be ruled out that a short-term increase in the NO x content in the detection area 13 is detected by an air bubble being released or by unusually violent bath movement. Since the peak value of this is still below the predetermined threshold value 25, pump operation is not triggered. This prevents that with a sufficient amount of amidosulfonic acid in the mixed acid bath, a locally increased NO x value causes a further supply of amidosulfonic acid.
  • the measurement sequence III shows an exceptional case which can occur if a particularly large tube packet with a high degree of scaling is used at the time the effect of the amidosulfonic acid has subsided.
  • the threshold 25th excess NO x levels peaked in the short term in the range 40 - 50 ppm and the cooldown is longer overall.
  • the defined switching pause for the pump is plotted on the time axis with x.
  • Example III now shows that the currently measured value is still above the threshold value 25 and the pump is consequently switched on again.
  • the warning limit 26 entered at approximately 78 ppm is a further threshold value, which is then of importance if the NO x portion should skyrocket to this value due to a pump failure.
  • a warning tone is triggered and the pickling process is interrupted by lifting the tube pack (s) 3 in order to prevent further NO x formation which may have a negative impact on health.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
EP91250067A 1990-03-14 1991-03-12 Procédé de décapage d'objets en matériaux hautement alliés et appareil pour sa mise en oeuvre Expired - Lifetime EP0448189B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4008567 1990-03-14
DE4008567 1990-03-14

Publications (3)

Publication Number Publication Date
EP0448189A2 true EP0448189A2 (fr) 1991-09-25
EP0448189A3 EP0448189A3 (en) 1993-07-14
EP0448189B1 EP0448189B1 (fr) 1996-05-22

Family

ID=6402418

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91250067A Expired - Lifetime EP0448189B1 (fr) 1990-03-14 1991-03-12 Procédé de décapage d'objets en matériaux hautement alliés et appareil pour sa mise en oeuvre

Country Status (3)

Country Link
EP (1) EP0448189B1 (fr)
AT (1) ATE138423T1 (fr)
DE (1) DE59107828D1 (fr)

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1621608A1 (de) * 1967-01-31 1971-06-03 Kunststofftechnik Gmbh U Co Ve Verfahren zum Abfangen von Stickoxyden
DE3412329A1 (de) * 1984-04-03 1985-10-10 Maschinenfabrik Andritz Ag, Graz Verfahren zum beizen von edelstaehlen, kupfer, buntmetallegierungen, sonderlegierungen, titan, zirkon, tantal usw. mittels salpetersaurer beizbaeder
EP0259533A1 (fr) * 1986-09-11 1988-03-16 Eka Nobel Aktiebolag Procédé pour diminuer l'emission d'oxydes de nitrogène à partir de liquides contenant de l'acide nitrique

Also Published As

Publication number Publication date
EP0448189A3 (en) 1993-07-14
DE59107828D1 (de) 1996-06-27
EP0448189B1 (fr) 1996-05-22
ATE138423T1 (de) 1996-06-15

Similar Documents

Publication Publication Date Title
DE69328139T2 (de) Verfahren zum Beizen und Passivieren von rostfreiem Stahl ohne Verwendung von Salpetersäure
DE69114265T2 (de) Verfahren zum Beizen und Passivieren von rostfreiem Stahl ohne Verwendung von Salpetersäure.
DE69606270T2 (de) Wässerige Lösung zur Kaltverfestigungsbehandlung von Stahlblechen
EP0972854B1 (fr) Procédé de dècapage d'acier inoxydable
DE4117382A1 (de) Verfahren zum regeln des ph-wertes einer sauren waschfluessigkeit
DE2227028C3 (de) Vorrichtung und Verfahren zur Behandlung giftiger Abfallstoffe
EP0448189B1 (fr) Procédé de décapage d'objets en matériaux hautement alliés et appareil pour sa mise en oeuvre
DE4103598C2 (fr)
EP0456271B1 (fr) Agent de nettoyage pour des installations d'eau potable
DE3110491C2 (de) Verfahren und Anlage zum Einengen eines in einem Kernkraftwerk anfallenden, Borsäure enthaltenden radioaktiven Abwassers
EP2359924B1 (fr) Dispositif d'absorption de gaz polluants
DE3412329C2 (fr)
DE2839506C2 (de) Verfahren zum Auswaschen saurer Gase aus Gasgemischen
DE3119444A1 (de) Verfahren zur stabilisierung des betriebes eines aus tantal oder einer legierung auf tantalbasis bestehenden saeuredigerierkessels
DE3205736A1 (de) Verfahren fuer die loesungsmittelbehandlung von insbesondere metallischem behandlungsgut
DE3000705C2 (de) Verfahren zum Aufrechterhalten der biologischen Aktivität und Adaptation der Biozönose einer biologischen Abluftnaßreinigungsanlage in Stillstandszeiten
DE3526055C1 (de) Verfahren zur Herstellung von Wasserstoff/Stickstoff-Schutzgas-Gemischen zum Glühen kaltgewalzter Stahlbänder
DE69023359T2 (de) Reinigungsverfahren für die Innenflächen von industriellen Apparaten aus Metall, z.B. aus Eisen oder Stahl.
AT377011B (de) Verfahren zum beizen von edelstaehlen, kupfer, buntmetallegierungen, sonderlegierungen, titan, zirkon oder tantal mittels salpetersaurer beizbaeder
DE3206205C2 (de) Verfahren zur Verhinderung oder Verringerung von Spannungsrißkorrosion
EP1513634B1 (fr) Procede permettant de reduire la corrosivite d'une eau de refroidissement ou de traitement
DE19706410A1 (de) Verfahren und Mittel zur Korrosionsschutzbehandlung wasserführender Metallsysteme
DE102006041482B3 (de) Verfahren zum Spülen einer Druckrohrleitung und Abwasserfördervorrichtung
DE102019111149B4 (de) Verfahren und Anlage zur Aufbereitung einer Sole für ein Schwebebecken
DE3301001C2 (de) Gär- und Lagerbehälter

Legal Events

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

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT CH DE ES FR GB IT LI SE

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT CH DE ES FR GB IT LI SE

17P Request for examination filed

Effective date: 19930621

17Q First examination report despatched

Effective date: 19940224

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT CH DE ES FR GB IT LI SE

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

Ref country code: IT

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

Effective date: 19960522

Ref country code: GB

Effective date: 19960522

Ref country code: FR

Effective date: 19960522

Ref country code: ES

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19960522

REF Corresponds to:

Ref document number: 138423

Country of ref document: AT

Date of ref document: 19960615

Kind code of ref document: T

REF Corresponds to:

Ref document number: 59107828

Country of ref document: DE

Date of ref document: 19960627

EN Fr: translation not filed
EN Fr: translation not filed
GBV Gb: ep patent (uk) treated as always having been void in accordance with gb section 77(7)/1977 [no translation filed]

Effective date: 19960522

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

Ref country code: CH

Payment date: 19970226

Year of fee payment: 7

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

Ref country code: CH

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

Effective date: 19980331

Ref country code: LI

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

Effective date: 19980331

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

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

Ref country code: AT

Payment date: 20010226

Year of fee payment: 11

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

Ref country code: SE

Payment date: 20010305

Year of fee payment: 11

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

Ref country code: AT

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

Effective date: 20020312

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

Ref country code: SE

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

Effective date: 20020313

EUG Se: european patent has lapsed

Ref document number: 91250067.5

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

Ref country code: DE

Payment date: 20030311

Year of fee payment: 13

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

Ref country code: DE

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

Effective date: 20041001