Metal dusting of Fe-Al alloys at 600℃ in CO-H2-H2O gas mixtures

摘要

The metal dusting of binary iron aluminium alloys with aluminium contents from 5 torn45 at% was investigated at 600 ℃ in CO-H2-H2O gas mixtures with 0.2% H2O and COrncontents of 15, 25 and 50 vol.% (aC > 1). Thermogravimetric analysis, light-opticalrnmicroscopy, X-ray diffraction analysis and scanning electron microscopy werernperformed. First results show that with increasing Al content of the alloy, a decreasingrncarburisation rate was observed. This results can be interpreted by the formation of arnthin alumina scale on the high Al-containing alloys. Furthermore, an effect of surfacernpreparation was also observed. The grinding samples show faster mass gain thanrnpolishing. It can be explained by the deformation during the sample preparation. As arnconsequence there is the difference in the kinetics of surface control reaction.rnThermodynamic calculations by using the software Thermo-Calc were performed inrnorder to support the experiments. Further work will be carried out with respect tornpreoxidation and orientation dependence of the metal dusting attack.