DE1217739B - Welding point cleaning on stainless steel - Google Patents
Welding point cleaning on stainless steelInfo
- Publication number
- DE1217739B DE1217739B DED39925A DED0039925A DE1217739B DE 1217739 B DE1217739 B DE 1217739B DE D39925 A DED39925 A DE D39925A DE D0039925 A DED0039925 A DE D0039925A DE 1217739 B DE1217739 B DE 1217739B
- Authority
- DE
- Germany
- Prior art keywords
- solution
- concentration
- cleaning
- corrosion
- metal oxide
- 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.)
- Pending
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F13/00—Arrangements for modifying heat-transfer, e.g. increasing, decreasing
- F28F13/18—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by applying coatings, e.g. radiation-absorbing, radiation-reflecting; by surface treatment, e.g. polishing
- F28F13/185—Heat-exchange surfaces provided with microstructures or with porous coatings
- F28F13/187—Heat-exchange surfaces provided with microstructures or with porous coatings especially adapted for evaporator surfaces or condenser surfaces, e.g. with nucleation sites
-
- 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
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F1/00—Tubular elements; Assemblies of tubular elements
- F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
- F28F1/12—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F1/00—Tubular elements; Assemblies of tubular elements
- F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
- F28F1/12—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
- F28F1/14—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending longitudinally
- F28F1/16—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending longitudinally the means being integral with the element, e.g. formed by extrusion
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F1/00—Tubular elements; Assemblies of tubular elements
- F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
- F28F1/12—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
- F28F1/24—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending transversely
- F28F1/26—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending transversely the means being integral with the element
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F13/00—Arrangements for modifying heat-transfer, e.g. increasing, decreasing
- F28F13/18—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by applying coatings, e.g. radiation-absorbing, radiation-reflecting; by surface treatment, e.g. polishing
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J19/00—Details of vacuum tubes of the types covered by group H01J21/00
- H01J19/28—Non-electron-emitting electrodes; Screens
- H01J19/32—Anodes
- H01J19/36—Cooling of anodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J2893/00—Discharge tubes and lamps
- H01J2893/0001—Electrodes and electrode systems suitable for discharge tubes or lamps
- H01J2893/0012—Constructional arrangements
- H01J2893/0027—Mitigation of temperature effects
Description
DEUTSCHESGERMAN
PATENTAMTPATENT OFFICE
AUSLEGESCHRIFTEDITORIAL
Int. CL: Int. CL:
C23gC23g
Deutsche Kl.: 48 al- 1/08 German class: 48 al- 1/08
Nummer: 1217739Number: 1217739
Aktenzeichen: D 39925 VI b/48 d2File number: D 39925 VI b / 48 d2
Anmeldetag: 26. September 1962Filing date: September 26, 1962
Auslegetag: 26. Mai 1966Opening day: May 26, 1966
Die Erfindung betrifft die Verwendung einer sauren, wäßrigen, zu 1 bis 50 Gewichtsprozent Fluoridionen, zu 1 bis 70 Gewichtsprozent Salpetersäure und zu 1 bis 6 Gewichtsprozent saure Metalloxyde, insbesondere Chromtrioxyde, enthaltenden Lösung zum Schweißstellenreinigen an nichtrostendem Stahl.The invention relates to the use of an acidic, aqueous, up to 1 to 50 percent by weight of fluoride ions, 1 to 70 percent by weight of nitric acid and 1 to 6 percent by weight of acidic metal oxides, in particular Chromium trioxide solution for cleaning welds on stainless steel.
Abrieb und Oxyde auf Gegenständen aus Chrom enthaltendem nichtrostendem Stahl werden durch Kontaktbehandlung mit Fluorwasserstoffsäure teilweise entfernt. Eine vollständige Entfernung wird durch die Bildung eines Schutzfilms aus sogenanntem Schwarzbrand oder Schwarzschutz verhütet, der den weiteren Säureangriff unterbindet.Abrasion and oxides on items made from stainless steel containing chromium are affected Contact treatment with hydrofluoric acid partially removed. A complete removal will be by forming a protective film of so-called black fire or black protection, which prevents the prevents further acid attack.
Salpetersäure allein reinigt nichtrostenden Stahl nicht. Die Zugabe von Salpetersäure zu Fluorwasserstoffsäure unterbindet oder verhütet jedoch die Bildung des Schwarzbrandes oder Schwarzschmutzes. Aus diesem Grunde sind Mischungen dieser Säuren weithin für den genannten Zweck verwendet worden.Nitric acid alone does not clean stainless steel. The addition of nitric acid to hydrofluoric acid prevents or prevents the formation of black fire or black dirt. the end for this reason mixtures of these acids have been widely used for the stated purpose.
Diese Mischungen wirken jedoch äußerst korrodierend auf nichtrostenden Stahl. Hierbei unterscheidet man zwei Arten von Korrosionswirkungen. Die erste ist gekennzeichnet durch einen allgemeinen Metallverlust, und diese Art wird im folgenden als »Korrosion« bezeichnet. Der zweiten Art von Korrosion unterliegen insbesondere nichtrostende Stähle, die einer Hochtemperaturbehandlung ausgesetzt waren. Wird nichtrostender Stahl einer Hochtemperaturbehandlung ausgesetzt, insbesondere lokal wie etwa beim Schweißen, so entsteht um den erhitzten Bereich herum ein hoher Temperaturgradient. Im Bereich hoher Temperatur reagieren der Kohlenstoff und das Chrom in dem Stahl und bilden Chromkarbid (Cr3C2). Diese Reaktion führt also zu einer Verringerung des Chromgehalts in dem erhitzten Bereich und um den erhitzten Bereich herum, wodurch die lokale Passivität vermindert wird. Der von Chrom entleerte Bereich ist einem übermäßigen korrodierenden, intergranular wirkenden Angriff durch eine Fluorwasserstoff-Salpetersäure-Mischung ausgesetzt, wie sie üblicherweise zur Reinigung nichtrostender Stähle verwendet wird. Diese intergranulare Durchdringung ist diejenige Art von Korrosion, mit der sich die Erfindung vorwiegend befaßt.However, these mixtures are extremely corrosive to stainless steel. A distinction is made here between two types of corrosion effects. The first is characterized by a general loss of metal, and this type is hereinafter referred to as "corrosion". The second type of corrosion is particularly susceptible to stainless steels that have been subjected to high temperature treatment. If stainless steel is subjected to high-temperature treatment, especially locally, such as during welding, a high temperature gradient is created around the heated area. In the high temperature range, the carbon and the chromium in the steel react to form chromium carbide (Cr 3 C 2 ). This reaction thus leads to a reduction in the chromium content in and around the heated area, thereby reducing the local passivity. The area devoid of chromium is exposed to excessive corrosive, intergranular action by a mixture of hydrofluoric acid and nitric acid, as is commonly used for cleaning stainless steels. This intergranular penetration is the type of corrosion with which the invention is primarily concerned.
Bei Anwendung der erfindungsgemäßen Lösung werden der intergranulare Angriff und die Korrosion wesentlich verringert. Besonders vorteilhaft ist es, Chromtrioxyd in dem Reinigungsmittel zu verwenden. When using the solution according to the invention, the intergranular attack and the corrosion significantly reduced. It is particularly advantageous to use chromium trioxide in the cleaning agent.
Es ist zwar eine Vielzahl von Behandlungsbädern für rostfreien Stahl bekannt, aber keines dieser Behandlungsbäder ist geeignet, Schweißstellen an Teilen Schweißstellenreinigung an nichtrostendem StahlWhile a variety of stainless steel treatment baths are known, none of these treatment baths are known is suitable for cleaning welds on parts of welds on stainless steel
Anmelder:Applicant:
The Dow Chemical Company,The Dow Chemical Company,
Midland, Mich. (V. St. A.)Midland, me. (V. St. A.)
Vertreter:Representative:
Dipl.-Ing. F. Weickmann,Dipl.-Ing. F. Weickmann,
Dr.-Ing. A. Weickmann,Dr.-Ing. A. Weickmann,
Dipl.-Ing. H. WeickmannDipl.-Ing. H. Weickmann
und Dipl.-Phys. Dr. K. Fincke, Patentanwälte,and Dipl.-Phys. Dr. K. Fincke, patent attorneys,
München 27, Möhlstr. 22Munich 27, Möhlstr. 22nd
Als Erfinder benannt:Named as inventor:
Earl Fredrick Morris, Tulsa, OkIa. (V. St. A.)Earl Fredrick Morris, Tulsa, OkIa. (V. St. A.)
Beanspruchte Priorität:
V. St. v. Amerika vom 27. September 1961
(140 997)Claimed priority:
V. St. v. America September 27, 1961
(140 997)
aus nichtrostendem Stahl zu reinigen, ohne daß Schwarzbrand auftritt.made of stainless steel to be cleaned without blackburn.
Die Verwendung von sauren Metalloxyden, z. B. Chromtrioxyd, als Zusatz zu Flußsäure ist aus der USA.-Patentschrift 2172 041 schon sehr lange bekannt; niemand hat aber bisher erkannt, daß man diese sauren Oxyde zu einer ganz bestimmten Säurekombination, nämlich der Kombination aus Fluorwasserstoffsäure und Salpetersäure zusetzen muß, um das seit langem gesuchte Mittel zum Behandeln von Schweißstellen an nichtrostenden Stählen zu erhalten, dasjenige Mittel nämlich, das keinen Schwarzbrand liefert.The use of acidic metal oxides, e.g. B. Chromium trioxide, as an additive to hydrofluoric acid is from the USA patent specification 2172 041 has been known for a very long time; but no one has yet recognized that one these acidic oxides to a very specific combination of acids, namely the combination of hydrofluoric acid and add nitric acid to the long-sought agent for treating To preserve welds on stainless steels, namely the means that does not prevent blackfire supplies.
Zur Lieferung der Fluoridionen kommen Fluorwasserstoffsäure, lösliche Fluoride, ζ. B. Ammoniumbifluorid, Natriumfluorid, Natriumhydrogenfiuorid, Kaliumfluorid, Kaliumhydrogenfluorid oder Mischungen von diesen in Frage.The fluoride ions are supplied by hydrofluoric acid, soluble fluorides, ζ. B. ammonium bifluoride, Sodium fluoride, sodium hydrogen fluoride, potassium fluoride, potassium hydrogen fluoride or mixtures of these in question.
Als saure Metalloxyde kommen wasserlösliche Metalloxyde in Frage, die in wäßriger Lösung die entsprechenden Säuren ergeben, z. B. Mangan-, Permangan-, Eisen-, Chrom-, Molybdän-, Wolfram-, Uran-, Vanadium-, Niob-, Tantalsäure und die Salze dieser Säuren, z. B. Manganate, Permanganate, Ferrate, Chromate usw., sofern sie in wäßrigen, sauren Medien löslich sind.As acidic metal oxides, water-soluble metal oxides come into question, those in aqueous solution corresponding acids result, z. B. manganese, permanganese, iron, chromium, molybdenum, tungsten, Uranic, vanadium, niobium, tantalic acid and the salts of these acids, e.g. B. Manganate, Permanganate, Ferrate, Chromates, etc., provided they are in aqueous, acidic media are soluble.
609 570/530609 570/530
Claims (1)
Korrosionsrate =Weight loss
Corrosion rate =
säure lag unter diesen Umständen also zwischen 1 und Permanganate, Chromate und Dichromate werdenAn optimal concentration range for chromium-wise a content of at least 16% chromium,
acidity under these circumstances was between 1 and permanganates, chromates and dichromates
Korrosionsschutz. Mehr Chromsäure war kostspielig, Es sei noch bemerkt, daß höhere Temperaturen in3%. Less chromic acid did not provide a significant 55 preferred within the scope of the invention.
Corrosion protection. More chromic acid was costly, it should be noted that higher temperatures in
halten werden, bis der gewünschte ReinigungseffektWhen carrying out the cleaning process 60 welded areas are to be cleaned, the objects to be cleaned can be immersed in the cleaning agent solution and the areas indicated there can be selected.
will hold until the desired cleaning effect
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14099761A | 1961-09-27 | 1961-09-27 |
Publications (1)
Publication Number | Publication Date |
---|---|
DE1217739B true DE1217739B (en) | 1966-05-26 |
Family
ID=30769156
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DED39925A Pending DE1217739B (en) | 1961-09-27 | 1962-09-26 | Welding point cleaning on stainless steel |
Country Status (3)
Country | Link |
---|---|
DE (1) | DE1217739B (en) |
FR (1) | FR1334216A (en) |
GB (1) | GB969119A (en) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2431671A1 (en) * | 1978-07-19 | 1980-02-15 | Pechiney Aluminium | Removing titaniferous incrustations from heat exchangers or reactors - by treatment with aq. liquor comprising hexa:fluosilicic acid and hydrofluoric acid |
DE3622505A1 (en) * | 1986-07-04 | 1988-01-14 | Pelox Chemietechnik Gmbh Co Kg | Pickling agent for iron and aluminium materials |
DE3825857A1 (en) * | 1988-07-29 | 1990-02-01 | Kernforschungsanlage Juelich | STAINLESS ACID FOR STAINLESS STEEL AND METHOD FOR RECONSTRUCTING USED STAINLESS ACID |
GB0204698D0 (en) * | 2002-02-28 | 2002-04-17 | British Nuclear Fuels Plc | Improvements in and relating to material testing |
GB2407585B (en) * | 2003-10-31 | 2005-12-14 | Stainless Restoration Ltd | Method of pickling internal surface(s) of a hollow stainless steel vessel |
FR2883575B1 (en) * | 2005-03-22 | 2007-10-19 | Airbus France Sas | STAINLESS STEEL STRIPPING SOLUTION AND STAINLESS STEEL STRIPPING METHOD |
CN107619727A (en) * | 2016-07-13 | 2018-01-23 | 上海蓝昌环境工程有限公司 | A kind of solid cleaner |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2172041A (en) * | 1937-10-07 | 1939-09-05 | Stephen F Urban | Pickling solution |
DE1077503B (en) * | 1952-11-01 | 1960-03-10 | Diamond Alkali Co | Use of crude chromic acid for pickling metals |
-
1962
- 1962-09-21 GB GB3598562A patent/GB969119A/en not_active Expired
- 1962-09-24 FR FR910217A patent/FR1334216A/en not_active Expired
- 1962-09-26 DE DED39925A patent/DE1217739B/en active Pending
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2172041A (en) * | 1937-10-07 | 1939-09-05 | Stephen F Urban | Pickling solution |
DE1077503B (en) * | 1952-11-01 | 1960-03-10 | Diamond Alkali Co | Use of crude chromic acid for pickling metals |
Also Published As
Publication number | Publication date |
---|---|
GB969119A (en) | 1964-09-09 |
FR1334216A (en) | 1963-08-02 |
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