J. H. Devan, P. Tortorelli
1993
Citations
0
Influential Citations
90
Citations
Quality indicators
Journal
Corrosion Science
Abstract
Iron aluminide alloys containing 16–40 at% aluminum and 0–5 at% chromium were tested in H2S-H2-H2O gas mixtures at 800°C and in air at 800–1000°C. Results were compared with those for developmental FeCrAl alloys. Alloys containing 18% or more aluminum were highly resistant to H2S-H2-H2O gas mixtures, and the corrosion behavior did not change significantly with aluminum concentrations above 18%. A 20 at% Al level was found to be critical for sustained oxidation resistance of binary FeAl alloys in air at 900°C and above. However, the addition of 5 at% Cr at the 16 at% Al level reduced the oxidation rate in air to that of alloys containing ≥20% Al. Corrosion rates of iron aluminides were comparable to FeCrAl alloys in air but were significantly lower than Cr-containing alloys in H2S-H2-H2O. The respective corrosion processes operative for iron aluminides in mixed gas and air are discussed in terms of the observed alloying effects.