Conclusions
The reference material 316L SS was found to be highly
susceptible to crevice attack in the paper machine white
water environment. A remarkable crevice corrosion
resistance was observed for nickel-based alloys. Alloy
C-276 and alloy 59 exhibit superior performance in this
medium. With the increase in pH and temperature, the
crevice corrosion resistance was found to be improved
on comparison with 316L SS. The increased resistance to
crevice attack exerted by nickel alloys can be attributed
to the stabilisation of the passive ®lms formed on the
surface by the speci®c alloying elements Cr, Ni and Mo,
as revealed by XPS results. The passive layer contains
Cr2O3 in the inner layers and Cr(OH)3 as the major
constituent in the outermost layer. The presence of Mo
and its oxides further establishes its role in increasing the
corrosion resistance. The nickel concentration beneath
the passive layer was also found to be increased due to
anodic segregation, which can aid intermetallic com-
pound formation. This intermetallic layer, along with
the passive ®lm enriched with stable MoO4
2) species,
resulted in reduced anodic dissolution, providing an
enriched source of oxide-forming metallic species di-
rectly beneath the passive ®lm and hence improvement
in the corrosion resistance of the nickel alloys.
Acknowledgements One of the authors (K.S.K.D) acknowledges
the CSIR, New Delhi, for ®nancial assistance and Dr. Santhanu
Bera, WSCL, BARC facilities, Kalpakkam, for his help in ac-
quiring XPS data.
References
1. Wensley DA (1987) Paper machine corrosion. In: ASM
Handbook: Corrosion. American Society for Metals, Metals
Park, Ohio, pp 13: 1186±1190
2. Shaw BA, Moran PJ, Gartland P (1993) Crevice corrosion of a
nickel-based super alloy in natural and chlorinated seawater.
In: Proceedings of the 12th International corrosion congress,
vol. 3B. NACE, Houston, pp 1915±1927
3. Shreir LL, Jarman RA, Burstein (1994) Corrosion metal/en-
vironmental reactions. Butterworth-Heinemann, London
4. Bowers DF, McFarland T (1984) Tappi J 67: 86
5. Muhonen JM (1974) Pulp and paper industry corrosion
problems. NACE, Houston, p 75
6. Geller A, Gottsching L (1982) Tappi J 65: 97
7. Bowers DF (1978) Tappi J 61: 57
8. Dayal RK, Parvathawarthani N, Gnanamoorthy JB (1983) Br
Corros J 18: 184
9. Old®eld JW, Sutton WH (1978) Br Corros J 13: 13
10. Old®eld JW, Sutton WH (1980) Br Corros J 15: 31
11. Garner A (1984) J Pulp Paper Sci 10: J51
12. Leckie HP, Uhlig HH (1966) J Electrochem Soc 113: 1261
13. Fontona MG (1987) Corrosion engineering. McGraw-Hill,
Singapore
14. Heubner U, Rocbel M, Wallis F (1989) Werkst Korros 40: 40
15. Hibner EL, Ross RW (1983) Corrosion/83. NACE, Houston,
p 163
16. Brooks AR, Clayton CR, Doss K, Lu YC (1986) J Electro-
chem Soc 133: 2459
17. Sugimoto K, Sawada Y (1977) Corros Sci 17: 425
18. Childs PE, Laub LW, Wagner JB (1971) Proc Br Ceram Soc
19: 21
19. Halada GP, Clayton CR, Herman H (1995) J Electrochem Soc
142: 74
20. Olefjord I, Marcus P (1982) Surf Interface Anal 4: 23
21. Rossi A, Elsener B (1993) XPS study of passive ®lms on
stainless steel in neutral solutions. In: Proceedings of the 12th
International corrosion congress, vol 3B. NACE, Houston,
pp 2120±2130
22. Tullin C, Jungstrom EL (1989) Energy Fuels 3: 284
23. Johnson O (1975) Chem Scr 8: 162
24. Asami K, Hashimoto K, Shimodaira S (1976) J Jpn Inst
Metals 40: 438
25. Grunert W, Stakheev AY, Feldhans R, Anders K,
