US3257160A - Prevention of corrosion of wet metal articles - Google Patents

Prevention of corrosion of wet metal articles Download PDF

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Publication number
US3257160A
US3257160A US434839A US43483965A US3257160A US 3257160 A US3257160 A US 3257160A US 434839 A US434839 A US 434839A US 43483965 A US43483965 A US 43483965A US 3257160 A US3257160 A US 3257160A
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per liter
hydrazine
water
cyanide
methylene blue
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US434839A
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Zimmermann Max
Kallfass Herbert
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Bayer AG
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Bayer AG
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    • 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
    • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F11/00—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent
    • C23F11/08—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S204/00—Chemistry: electrical and wave energy
    • Y10S204/90—Effecting a change in isomerization by wave energy

Definitions

  • the present invention relates to the prevention of corrosion'of wet metal articles, and more particularly to a process for the wet preservation and corrosion protection of metal articles which are in contact with an aqueous phase and to preparations for such purposes.
  • hydrazine as a corrosion protective agent, for example in steam boilers, hot water plants, etc. is already known.
  • the effect of this compound is attributed to the reactivity which has long been known to exist between hydrazine and the oxygen dissolved in water.
  • hydrazine has an effect on the formation of a protective layer on metal surfaces. In-articlesmade of iron, this effect is explained by the formation of a very dense, firmly adhering layer of Fe O At normal temperature, the rate of reaction of hydrazine with oxygen is very low.
  • the effect of hydrazine as a corrosion protective agent, especially onbare metal surfaces leaves much to be desired, especially if chlorides or sulfates are dissolved in the water.
  • a further object of the present invention is to provide a method for the wet preservation and corrosion protection of metal articles which are in contact with an aqueous phase normally corrosive thereto, especially after prolonged contact therewith, using'a particular mixture of ingredients having a combined beneficial effect.
  • an aqueous phase such as an oxygen containing water and/or a salt containing water
  • FIGURE 1 shows the graph illustrating the reaction between. hydrazine and oxygen in a closed system over an extended period of time in the presence or absence of methylene blue.
  • FIGURE 2 shows a graph'illustrating the reduction in oxygen content by reason of the presence of hydrazine inthe presence or absence of methylene blue and/or a[ )4]-
  • FIGURE 3 shows a graph illustrating the reduction in oxygen content by reason of the presence of hydrazine in the presence or absence of methylene blue and/or Na [Co(CN)
  • N H per liter of water and methylene blue is added in quantities of 0.1 to mg. per liter water optionally in addition with water-soluble complex heavy metal cyanides in quantities of 0.1 to 10 mg. per liter water calculated on the heavy metal to the aqueous phase in contact with such metal articles.
  • methylene blue especially in combination with water-soluble complex heavy metal cyanides increases the protective action of hydrazine considerably, whereby the oxygen from the aqueous phase in question is removed effectively also at normal temperatures.
  • a good corrosion protection can also be achieved on bare metal surfaces, i.e. where a protective layer is not already present.
  • the corrosion amounts to about 0.1 to 0.5 g. iron per square meter per day the average rate of corrosion is reduced by the addition of methylene blue in combination with the complex heavy metal cyanides to the very favourable value of 0.005 g. Fe per square meter per day.
  • hydrazine is preferably applied in aqueous solution containing about 15% by weight of N H
  • a solution with this hydrazine content is referred to also was 24% hydrazine hydrate.
  • An aqueous hydrazine solution containing about N H which is obtained as azeotropic system on distilling mixtures of N2H4 and water is usually referred to as hydrazine hydrate.
  • Aqueous solutions containing about 15% N H can be handled and stored without danger and specific precautions.
  • FIGURE 1 The effect of methylene blue on the speed of reaction between hydrazine and oxygen is shown in FIGURE 1.
  • 200 mg. per liter of hydrazine in the form of a 24% hydrazine hydrate (aqueous solution containing about 15 N H and 5 g. per liter of water of methylene blue were added to a sample of water having an 0 content of 30 mg. per liter.
  • the reduction in oxygen with time was then measured in comparison with a sample to which only 200 g. per liter of hydrazine hydrate had been added.
  • the curves in FIGURE 1 show that with hydrazine activated with methylene blue-curve 2the oxygen content falls to 1 mg. per liter at the end of 20 hours.
  • the sample of water containing hydrazine without any additioncurve 1- shows only an inene blue/cobalt cyanide.
  • the combination of methylene blue with complex heavy metal cyanides has been found advantageous. Especially effective have been found to be the watersoluble complex cyanides of copper(I), Co(III), Ni(II), silver(I) and iron(II).
  • the complex cyanides are used in the form of their alkali metal and/ or ammonium compounds.
  • the heavy metal cyanides must be present in a form which has no oxidizing effect on hydrazine.
  • the complex-forming metals are therefore used in their lowest stage of oxidation, in which they are stable under normal conditions.
  • the effectiveness of hydrazine alone on the oxygen content of the water is improved.
  • the combination ofmethylene blue and the complex copper cyanides is applied advantageously, if water should be rendered free from oxygen in a very short time. Therefore the aforementioned combination of activating substances is preferably used in for example closed heating and cooling plants since in these cases the decomposition of hydrazine due to atmospheric oxygen diffusing into the water is kept within moderate limits and therefore a long lasting protection against corrosion is achieved without continuous addition of hydrazine.
  • the methylene blue/copper cyanide combination has a potentiating effect on the removal of oxygen by hydrazine
  • the corresponding deoxidation curve ob tained with the use of methylene blue and Na [Co(CN) lies above the deoxidation curve obtained with the use of methylene blue alonecurve 4.
  • the influence of the cobalt complex is enhanced, that of methylene blue diminished.
  • the results are similar when using a methylene blue/Na [Ni(CN) combination.
  • open systems e.g.
  • the calculated quantity of hydrazine preferably in the form of 24% hydrazine hydrate, to produce a concentration of 0.1 mg. per liter to 3000 mg. N H per liter in water is added to the supply or cooling water.
  • a concentration of about 0.1 mg. N H per liter is sufficient whereas in cooling water circuits it is preferable to have a concentration of about 300 mg. N H per liter.
  • Higher hydrazine contents are not harmful but are avoided for economical reasons.
  • the activating substances are preferably added in the form of aqueous solutions.
  • An adequate protective effect is achieved if methylene blue is present in quantities of 1 to 50 mg. per liter and, if desired, the heavy metal cyanide complexes in quantities of 0.01 to 10 mg. per liter of water, preferably in quantities of 0.1 to 5.0 mg. per liter calculated on the metal.
  • the present process can advantageously be used for the preservation under wet conditions and protection against corrosion of steam producing plants, hot water plants, circulating coolers and heat exchangers. It is especially advantageous that the preserving effect occurs already at temperatures at which only insufficient protection of the metal surfaces has hitherto been obtained by the usual methods, i.e. at temperatures of below C. or more precisely below the B.P. of water down to the freezing point.
  • the temperature range given above is no limitation of the new process for the hydrazine mixed with the aforesaid activating substances is applicable also to systems containing hot water or hot water and steam.
  • Example I Boiler tube rings of iron quality St. 35.29, after being annealed to remove stress and pickled, were kept for 14 days in an aqueous solution containing 200 mg. per liter of N H and 100 in. per liter of NaCl in Erlenmeyer flasks closed with rubber bungs.
  • an aqueous solution containing 200 mg. per liter of N H and 100 in. per liter of NaCl in Erlenmeyer flasks closed with rubber bungs.
  • the different samples containing increasing quantities of methylene blue of 0.1 to 0.5 mg. per liter manifested a diminution in corrosion, especially of pitting corrosion, which disappeared completely with addition of 5 mg. per liter.
  • a very thin and very stable protective layer was formed whereas the surface of the ring in Water to which no methylene blue had been added showed no protective layer.
  • Example 2 The effect of the combination of heavy metal cyanides and methylene blue and of methylene blue alone was investigated under the same experimental conditions as described in Example 1. Whereas the tube ring showed strong pitting corrosion when only 200 mg. per liter of N H and 100 mg. per liter of NaCl were added, the rings were still completely intact after 14 days when the hydrazine was activated with an addition of 5 mg. per liter of Co in the form of Na [Co(CN) and 5 mg. per liter of methylene blue or an addition of Cu in the form of Na [Cu(CN) and methylene blue or of Ni in the form of (NH [Ni(CN) and methylene blue or of methylene blue without the addition of cyanide. The strongest formation of protective coating was manifested by the ring in contact with the addition of the nickel complex.
  • Example 3 Boiler tube rings pretreated in the usual way were suspended in a condensate to which 200 mg. per liter of N H had originally been added and kept to stand uncovered in the air for 14 days.
  • the sample without addition of activator showed very strong hydroxide formation whereas the samples to which 5 mg. per liter of cobalt cyanide/methylene blue or 5 mg. per liter of nickel cyanide/methylene blue had been added showed practically no hydroxide formation. After 14 days, the rings still appeared as intact as at the beginning.
  • the average rate of corrosion was 0.0004 g. per square meter per day, compared with an average of 0.47 g. per square meter per day without the addition of activator.
  • the original N H content of 200 mg. per liter was reduced to 110 mg. per liter after 14 days if nickel cyanide/methylene blue was added. By passing air through for several days, the N H content could then be reduced to 30 mg. per liter and the pH to 7.0. The ring was at that point still intact. This addition of activator can thus in some circumstances provide protection against corrosion even with very low quantities of N H and at the same time it is no longer nearly so important to maintain a high pH.
  • Example 4 An open cooling circuit with fully desalted water to which 200 mg. per liter of N H 5 mg. per liter of Ni in the form of Na [Ni(CN) and 5 mg. per liter of methylene blue had been added showed no corrosion after several months of circulation if the slight consumption of hydrazine was compensated by occasional replacement and the pH maintained between 9 and 10.
  • Example 5 A heating circuit charged with normal salt-containing water and having an N H concentration of 100 mg. per liter and having an activator content of 0.5 mg. per liter of cobalt in the form of K [Co(CN) and containing 0.5 mg. per liter of methylene blue showed no corrosion after the summer break and could be put into operation again with this treated water.
  • Example 6 A steam boiler which had been put out of operation and which, to preserve it against wet conditions, was completely filled with condensate to which 100 mg. per liter of N H and 5 mg. per liter of Ni in the form of Na [Ni(CN)4] and methylene blue had been added, showed no sign of corrosion after being out of operation for 8 months.
  • the present invention relates to a method for the wet preservation and corrosion protection of metal articles such as those made of ferrous or cuprous metals in contact with an aqueous phase such as water containing oxygen and/or inorganic salts such as chlorides, sulfates and/or nitrates of the alkali and alkaline earth metals etc., which comprises providing in such aqueous phase which is in contact with the particular metal article, both hydrazine in an amount substantially between about 0.1 to 3000 mg. of N H per liter of water and methylene blue in an amount of substantially between about 0.1 to 50 mg. per liter of water.
  • an aqueous phase such as water containing oxygen and/or inorganic salts such as chlorides, sulfates and/or nitrates of the alkali and alkaline earth metals etc.
  • a water-soluble complex heavy metal cyanide is added in an amount calculated on the heavy metal substantially between about 0.01 to 10 mg. per liter of water.
  • the hydrazine is used in the form of hydrazine hydrate as e.g. in the form of substantially about a N H solution and the complex heavy metal cyanide is present preferably in an amount calculated on the heavy metal substantially between about 0.1 to 5 mg. per liter of water.
  • the addition of the methylene blue is combined with the addition of water-soluble complex metal mono-valent silver cyanide, the ammonium monovalent silver cyanide and mixtures thereof.
  • More specifically typical complex heavy metal cyanides include
  • the present invention represents an improvement in the method for the wet preservation and corrosion protection of predominantly iron containing metals in contact with the solution containing at least one of oxygen and salt which normally cause corrosion which improvement comprises-maintaining in such solution when 'in contact with the particular metal article a mixture of hydrazine and methylene blue preferably combined with the addition of a complex heavy metal cyanide in accordance with the foregoing.
  • the present invention relates to a preparation for the wet preservation and corrosion protection of metal articles in contact with the aqueous phase
  • a preparation for the wet preservation and corrosion protection of metal articles in contact with the aqueous phase such preparation comprising a mixture in an aqueous solution of hydrazine and methylene blue and optionally a complex heavy metal cyanide in amounts per liter as stated above.
  • preparations may be used which contain in aqueous solution a mixture of hydrazine in an amount substantially between about 0.1 to 3000 mg. N H per liter with substantially between about 0.1 to 50 mg. of methylene blue per liter of water and optionally with an addition of complex heavy metal cyanides inan amount substantially between about 0.01 to 10 mg. per liter calculated on the particular heavy metal.
  • the present invention relates to mixtures for the wet preservation and corrosion protection of predominantly iron containing metals in contact with the solution containing at least one of oxygen and inorganic salts, which normally cause corrosion which mixtures comprise per 1 kg. of hydrazine hydrate 24% 0.1 to 20 g. of methylene blue and optionally 0.1 to 5 g. of complex heavy metal cyanides calculated on the particular heavy metal, said particular heavy metals being selected from the group consisting of copper(I), cobalt(III), nickel(II), iron(II) and silver(I).
  • Method for the wet preservation and corrosion protection of metal articles in contact with an aqueous phase which comprises providing in such aqueous phase which is in contact with the particular metal article both hydrazine in an amount substantially between about 0.1 to 3000 mg. per liter of water and methylene blue in an amount substantially between about 0.1 to 50 mg. per liter of water.
  • said complex heavy metal cyanide is selected from the group consisting of alkali metal mono-valent copper cyanide, ammonium mono-valent copper cyanide, alkali metal trivalent cobalt cyanide, ammonium trivalent cobalt cyanide, alkali metal divalent nickel cyanide, ammonium divalent nickel cyanide, alkali metal divalent iron cyanide, ammonium divalent iron cyanide, alkali metal mono-valent silver cyanide, ammonium mono-valent silver cyanide and mixtures thereof.
  • the improvement which comprises maintaining in such solution when in contact with the particular metal articles a mixture of hydrazine in an amount substantially between about 0.1 to 3000 mg. of N H per liter of water, methylene blue in an amount substantially between about 0.1 to 50 mg. per liter of water and a complex heavy metal cyanide in an amount calculated on the heavy metal substantially between about 0.01 to 10 mg. per liter.
  • an aqueous phase which comprises a mixture containing in 24% hydrazine hydrate, 0.1 to 20 g. of methylene blue per kg. of 24% hydrazine hydrate and a complex heavy metal cyanide in an amount substantially between about 0.1 to 5 g. per kg. 24% hydrazine hydrate.
  • said complex heavy metal cyanide is selected from the group consisting of alkali metal mono-valent copper cyanide, ammonium mono-valent copper cyanide, alkali metal trivalent cobalt cyanide, ammonium trivalent cobalt cyanide, alkali metal divalent nickel cyanide, ammonium divalent nickel cyanide, alkali metal divalent iron cyanide, ammonium divalent iron cyanide, alkali metal monovalent silver cyanide, ammonium mono-valent silver cyanide, and mixtures thereof.
  • an aqueous phase which comprises a mixture in aqueous solution of hydrazine in an amount substantially between 0.1 to 3000 mg. N H, per liter of water and 0.1 to 50 mg. of methylone blue per liter of water.
  • said heavy metal cyanide is selected from the group consisting of alkali metal mono-valent copper cyanide, ammonium mono-valent copper cyanide, alkali metal trivalent cobalt cyanide, ammonium trivalent cobalt cyanide, alkali metal divalent nickel cyanide, ammonium divalent nickel cyanide, alkali metal divalent iron cyanide, ammonium divalent iron cyanide, alkali metal mono-valent silver cyanide, ammonium mono-valent silver cyanide and mixtures thereof.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
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  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
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  • Preventing Corrosion Or Incrustation Of Metals (AREA)
US434839A 1964-03-21 1965-02-24 Prevention of corrosion of wet metal articles Expired - Lifetime US3257160A (en)

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AT (1) AT252001B (xx)
BE (1) BE661452A (xx)
CH (1) CH458013A (xx)
DK (1) DK109885C (xx)
ES (1) ES310673A1 (xx)
GB (1) GB1104393A (xx)
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SE (1) SE308235B (xx)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4045253A (en) * 1976-03-15 1977-08-30 Halliburton Company Passivating metal surfaces
US4311599A (en) * 1980-11-12 1982-01-19 Nalco Chemical Company Reduced methylene blue for oxygen removal
EP1531193A3 (de) * 2003-09-30 2005-10-05 Henkel Kommanditgesellschaft auf Aktien Verfahren zur Entfernung von Sauerstoff aus Wasser
WO2006000364A1 (de) * 2004-06-25 2006-01-05 Elo-Chem Csm Gmbh Elektrolytisch regenerierbare ätzlösung

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1503220A (en) * 1975-03-17 1978-03-08 Chemed Corp Control of corrosion in aqueous systems by the use of an oxygen scavenger
FR2540854A1 (fr) * 1983-04-22 1984-08-17 Leuna Werke Veb Procede pour l'elimination de l'oxygene dissous dans l'eau
DE4304465C2 (de) * 1993-02-15 1995-01-05 Schilling Chemie Gmbh U Produk Verfahren zur Entfernung in Wasser gelösten Sauerstoffs, insbesondere in wasserführenden, geschlossenen Systemen
DE4409990A1 (de) * 1994-03-23 1995-09-28 Schilling Chemie Gmbh U Produk Verfahren zur Verhinderung der Korrosion von Metallen in wäßrigen Systemen
DE4427038C2 (de) 1994-07-29 1998-05-20 Schilling Chemie Gmbh U Produk Verfahren zur Entfernung in Wasser gelösten Sauerstoffes, insbesondere in wasserführenden, geschlossenen Systemen

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1260740A (en) * 1917-08-02 1918-03-26 William H Allen Treatment of iron and steel to prevent corrosion.
US2901437A (en) * 1955-05-03 1959-08-25 Wright Chem Corp Corrosion inhibiting composition
US3151087A (en) * 1957-12-09 1964-09-29 Nalco Chemical Co Corrosion inhibiting compositions and method

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1260740A (en) * 1917-08-02 1918-03-26 William H Allen Treatment of iron and steel to prevent corrosion.
US2901437A (en) * 1955-05-03 1959-08-25 Wright Chem Corp Corrosion inhibiting composition
US3151087A (en) * 1957-12-09 1964-09-29 Nalco Chemical Co Corrosion inhibiting compositions and method

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4045253A (en) * 1976-03-15 1977-08-30 Halliburton Company Passivating metal surfaces
US4311599A (en) * 1980-11-12 1982-01-19 Nalco Chemical Company Reduced methylene blue for oxygen removal
EP1531193A3 (de) * 2003-09-30 2005-10-05 Henkel Kommanditgesellschaft auf Aktien Verfahren zur Entfernung von Sauerstoff aus Wasser
WO2006000364A1 (de) * 2004-06-25 2006-01-05 Elo-Chem Csm Gmbh Elektrolytisch regenerierbare ätzlösung

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ES310673A1 (es) 1965-06-16
SE308235B (xx) 1969-02-03
CH458013A (de) 1968-06-15
BE661452A (xx) 1965-09-22
AT252001B (de) 1967-02-10
NL6503518A (xx) 1965-09-22
DK109885C (da) 1968-07-22
GB1104393A (en) 1968-02-28

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