Transition from External to Internal Oxidation of Single Phase Binary Alloys


Article Preview

It is shown from the oxidation results that, for Fe-Cr, Ni-Cr, Co-Cr binary alloys with and without internal Cr2O3 precipitations after exposure, continuous external Cr2O3 scales formed on their surfaces, especially at the initial stage. It is therefore suggested that the transitions of oxidation for these alloys take place from externally to internally. There are two types of transitions for alloys: (1) the transition from temporary external oxidation to internal oxidation; and (2) the transition from permanent external oxidation to internal oxidation. The thermodynamic conditions for these transitions have been analyzed, and the criterion for prediction of the minimum solute concentration of a binary solid solution alloy required for the second transition has been derived. It is also suggested that the external oxide scale is an important factor to determine the formation of pure solvent metal nodules on the surfaces.



Materials Science Forum (Volumes 522-523)

Edited by:

Shigeji Taniguchi, Toshio Maruyama, Masayuki Yoshiba, Nobuo Otsuka and Yuuzou Kawahara




Y. D. He et al., "Transition from External to Internal Oxidation of Single Phase Binary Alloys", Materials Science Forum, Vols. 522-523, pp. 45-52, 2006

Online since:

August 2006




[1] C. Wagner, Z. Elektrochem., 63(7) (1959), 772-782.

[2] C. Wagner, J. Electrochem. Soc., 99(10) (1952), 369-380.

[3] G. Wang, B. Gleeson and D.L. Douglass, Oxid. Met., 35 (1991), 317-332.

[4] Y.D. He, Z.W. Li, and W. Gao, Mater. High Temp., 18S (2000), 17-22.

[5] W. Gao, Z.W. Li, and Y.D. He, Mater. High Temp., 18S (2000), 23-30.

[6] D.R. Wang, Y.D. He, S. Li, and W. Gao, J. Chin. Soc. Corr. Protect., 22(2) (2002), 79-83.

[7] W. Gao, Z.W. Li, Z. Wu, S. Li and Y.D. He, Intermetallics, 10, (2002), 263-270.

[8] P. Kofstad, Nonstoichiometry, Diffusion and Electrical Conductivity in Binary Metal Oxides, Wiley & Sons, New York, (1972).

[9] J. Stringer, Mater. Sci. Eng., A120 (1989), 129-137.

[10] Y.D. He, Z.F. Huang, H.B. Qi, D.R. Wang, Z.W. Li, and W. Gao, Mater. Lett., 45 (2000), 75-85.

[11] Y.D. He, H.B. Qi, X. Bai, D.R. Wang, Z.W. Li, C.H. Xu, and W. Gao, High Temp. Mater. Process., 19(2) (2000), 71-77.

[12] S. Guruswamy, S.M. Park, J.P. Hirth, and R.A. Rapp. Oxid. Met., 26(1986), 77-100.

[13] D.L. Douglass, Oxid. Met., 44(1/2) (1995), 81-111.