Sulfidation behavior of Fe–40Al sheet in H2–H2S mixtures at high temperatures

The sulfidation behavior of a 200 μm thick Fe–40at.%Al sheet has been investigated at temperatures between 973 K and 1273 K in H2–H2S mixtures with H2S contents of 0.052–9.7vol%. The Fe–40Al sheet exhibited excellent sulfidation resistance at temperatures below 1073 K in all the H2S–H2 mixtures. This may be attributed to the formation of a thin alumina film on the surface of the Fe–40Al sheet during sulfidation, identified by AES analysis. At temperatures higher than 1173 K, the Fe–40Al sheet also exhibited good sulfidation resistance in the 0.052%H2S–H2 mixture, and there was only a slight increase in mass gain with temperature. This compares favorably with Fe–20Cr–11Al (in at.%) foil which was severely sulfidized even at 973 K in the 0.052%H2S–H2 mixture, and showed markedly increased mass gain with increased H2S content and temperature.