Corrosion of iron-aluminium alloys in gaseous atmosphere containing hydrogen chloride and hydrogen sulphide at 600 and 700°C.

<title/> The corrosion of two binary iron-aluminium alloys was compared in gaseous CO2-H2-HCl-H2S and CO2-H2 mixtures at 600 and 700°C. In each environment, the Fe-14Al alloy resisted corrosion due to the formation of a protective alumina scale. The Fe-4Al alloy corroded more rapidly in the CO2-H2-HCl-H2S atmosphere than in the CO2-H2 atmosphere at both temperatures. The corrosion products comprised thick outer layers of iron oxide, porous inner layers of mixed iron-aluminium oxide and internal precipitates of aluminium oxide. Sulphur was detected near the scale/alloy interface and the increase in corrosion rate was attributed to the presence of chlorine and sulphur. [ABSTRACT FROM AUTHOR]