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Abstract

Molybdate is a corrosion inhibitor for mild steel in near neutral and alkaline (pH 6 and above) simulated cooling water (SCW). However, it accelerates corrosion in acidic media (below pH 6). Nitrite can inhibit mild steel corrosion in SCW at pH 4·5 and above, but accelerates corrosion at pH 3. In near neutral and alkaline SCW, molybdate and nitrite act as a synergistic corrosion inhibitor for mild steel. In the acidic region between pH 3 and 4·5, the combination can decrease corrosion with a low concentration of molybdate and high concentration of nitrite. These concentrations depend on the relative amounts of molybdate and nitrite present in the system. A mechanism of action of molybdate and nitrite on mild steel corrosion in SCW is proposed, based on the experimental results.

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References

Bayes

A. L.

: US Patent No. 2147395, 1939.

Robertson

W. D.

: J. Electrochem. Soc., 1951, 98, 94.

Cartledge

G. H.

: Corrosion, 1968, 24, 223.

Sax

N. I.

: ‘Dangerous properties of industrial materials’, 113; 1957, New York, NY, Reinhold Publishing.

Pryor

M. J.

and Cohen

: J. Elect rochem. Soc., 1953, 100, 203.

Lizlovs

E. A.

: Corrosion, 1976, 32, 263.

Vukasovich

M. S.

: J. Less-Common Met., 1977, 54, 437.

Farr

J. P. G.

and Saremi

: Surf. Technol., 1982, 17, 199.

Farr

J. P. G.

, Seeney

A. M.

, BENTLEY

A. J.

, and EARWAKER

L. G.

: Surf. Technol., 1984, 23, 99.

10.

Farr

J. P. G.

, Saremi

, SEENEY

A. M.

, BENTLEY

A. J.

, and EARWAKER

L. G.

: Polyhedron, 1986, 5, 547.

11.

Mustafa

C. M.

: PhD thesis, University of Birmingham, Birmingham, UK, 1990.

12.

Farr

J. P. G.

and Saremi

: Proc. 4th Int. Conf. on Chemistry and Uses of Molybdenum, (ed. Barry

H. F.

and Mitchell

P. C. H.

), 128; 1982, Ann Arbor, MI, Climax Molybdenum Co.

13.

Vogel

A. I.

: ‘A text-book of quantitative inorganic analysis’, 785; 1971, London, Longman.

14.

Sakashita

and Sato

: Corros. Sci., 1977, 17, 473.

15.

Uhlig

H. H.

: ‘Corrosion and corrosion control’, 85; 1967, London, Wiley.

16.

Vukasovich

M. S.

and Farr

J. P. G.

: Polyhedron, 1986, 5, 551.

17.

Cotton

F. A.

and Wilkinson

: ‘Advanced inorganic chemistry’, 951; 1972, London, Interscience Publishers.

18.

Wicox

G. D.

, Gabe

D. R.

, and WARWICK

M. E.

: Corros. Rev., 1986, 6, 328.

19.

Jospeh

and Perret

: Corros. Sci., 1967, 7, 553.

20.

Ogura

and Ohama

: Corrosion, 1984, 40, 47.

Corrosion behaviour of mild steel in moderately alkaline to acidic simulated cooling water containing molybdate and nitrite

Abstract

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