Abstract
In the present work it is aimed to study the corrosion behaviour of two types of stainless steel alloys (one ferritic and two austenitic) in molten Li2CO3- Na2CO3- K2CO3 mixture. This mixture is of interest in corrosion studies because of its low melting point (397°C) and good electrical properties. In this investigation the following techniques of measurements are used: (i) open circuit-potential, (ii) galvanic current, (iii) impedance, (iv) atomic absorption spectroscopy for the determination of the amount of metals dissolved in the melt (v) corrosion tests, carried out on the oxide scales formed during the oxidation of stainless steel alloys in carbonate melt. In this melt the electrode Ag/AgCl was used as a reference electrode. In molten carbonates, the oxide ions originate by self-dissociation according to the equilibrium CO3 2− ↔ CO2 + O2−. The oxide ions, O2−, and carbonate ions, CO3 2−, play an important role in the oxidation process of these alloys and their passivation in the carbonate melt. As previously mentioned in references it can be assumed that the oxide scales formed on the alloy surface consist mainly of LiCrO2 and LiFeO2. The cathodic path of the corrosion process may be the reduction of CO2 and/or CO3 2−. The resistance of alloys against corrosion in melt increases with the increase of temperature. This may be due to the increase of concentration of O2− and CO2, enhancing both the anodic and cathodic reactions. The activation energy was calculated and found to be 91.496, 23.412 and 37.956 kJ/mol for the alloys 1, 2 and 3 respectively. The above mentioned techniques of measurements showed that the oxide scales of the austenitic stainless steel alloys (2, 3) are more passive and protective than of ferritic stainless steel alloy (1). This means that the resistance against corrosion, in the carbonate melts, of austenitic stainless steel alloys is higher than that of ferritic one.
Similar content being viewed by others
References
J. M. King, Jr., Final Report, NASA CR, 134599, FCR-0237 (1977).
Quarterly Status Report for period Jan. 1–March 31, 1977, contract. No.31–109–38–3952, Institute of Gas technology, Chicago, Ill.
R. B. Swaroop, J. W. Sim and K. Kinoshita, J. Electrochem. Soc. 125(11) (1978) 1799.
R. A. Donado, L. G. Marianowski, H. C. Maru and J. R. Selman, ibid. 131(11) (1984) 2535.
Idem., ibid. 131(11) (1984) 2541.
O. P. Penyagina, I. N. Ozeryanaya, N. D. Shamanova and B. B. Antonov, Tr. Inst. Electrochim., Ural Nauchn. Tsetr, Akad. Nauk SSSR 26 (1978) 48.
R. T. Coyle, T. M. Thomas and G. Y. Lai, in High Temp. Corros. Energy Syst. Proc. Symp. 672, 1984, edited by M. F. Rothman (Metall. Soc. AIME. Werrendal, PA 1985).
K. Nakagawa, T. Isozaki, S. Kihara and B. Gijustu, 36(7) (1987) 438.
H. Kiyoshi, Y. Takatoshi, Y. Takehiko, F. Yutaka and O. Keizou, Zairyo to Kankyo 40(2) (1991) 130.
N. Tatsuo, Y. Kohichi and U. Isamu, in Proc. Electrochem. Soc. 1993, 93 (Proceedings of the Third International Symposium on Carbonate Fuel Cell Technology, 1993, p. 264).
H. Yokokawa, N. Sakai, T. Kawada and M. Dokiya, J. Electrochem. Soc. 140(12) (1993) 3565.
J. P. T. Vossen, L. Plomp, J. H. W. De Wit and G. Rietveld, ibid. 142(10) (1995) 3327.
C. G. Lee, H. Nakano, T. Nishina, I. Uchida and S. Kuroe, ibid. 145(8) (1998) 2747.
S. Sendroff and A. Brenner, ibid. 101 (1954) 31.
J. O. M. Bckris, G. J. Hills, D. Inman and L. Young, J. Sci. Inster. 33 (1956) 438.
S. N. Flengas and E. K. Rideal, Proc. Roy. Soc. A233 (1956) 443.
S. N. Flengas and T. R. Ingraham, Canad. J. Chem. 35 (1957) 1139.
J. P. T. Vossen, A. H. H. Janssen and J. H. W. De Wit. J. Electrochem. Soc. 143(1) (1996) 58.
J. P. T. Vossen, R. C. Makkus and J. H. W. De Wit, ibid. 143(1) (1996) 66.
M. D. Ingram, B. Baron and J. Janz, Electrochim. Acta 11 (1966) 1629.
L. Young, “Anodic Oxidation Films” (Academic Press, London, New York, 1961) p. 11257.
Z. Szlarska-Smialowska and R. W. Steehle, J. Electrochem. Soc. 12 (1974) 1393.
A. M. Bekheet, M. M. Hefny, A. A. Mazhar and M. S. El-Basiouny, Ann. Chem. (Rome) 73 (1983) 63.
M. S. El-Basiouny, A. M. El-Kot and M. M. Hefny, Corrosion 36 (1980) 244.
U. R. Evans “The Corrosion and Oxidation of Metals” (Edward Arnold, London, England, 1960) p. 898.
T. Bunzo and O. Takeo, Hyomen Gijutu 43(3) (1992) 233.
Q. W. Walter, Corros. Sc. 26(9) (1986) 681.
M. Azzi and J. J. Rameau, ibid. 30 (1990) 439.
J. P. T. Vossen, P. C. H. Ament and J. H. W. De Wit, J. Electrochem. Soc. 143(7) (1996) 2272.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Salih, S.A., El-Masri, A.N. & Baraka, A.M. Corrosion behaviour of some stainless steel alloys in molten alkali carbonates (I). Journal of Materials Science 36, 2547–2555 (2001). https://doi.org/10.1023/A:1017954720772
Issue Date:
DOI: https://doi.org/10.1023/A:1017954720772