Biomass-fired power generation

KCl-Induced Corrosion of an FeCrAl Alloy at 600 °C in O2 + H2O Environment: The Effect of Pre-oxidation

“…The amount of CrO 4 2-peaked at 9 h. Since scale spallation was not observed, the decrease in CrO 4 2-after [9 h implies that the chromate has decomposed. The deviations from the stoichiometry of Reaction (1) found after 72 and 168 h are attributed to the small amounts of K ?…”

“…A Dionex ICS-90 system was used to establish the amount of water-soluble anions (CrO 4 2-, Cl -) on the sample surface after exposure. The anions were analysed with an IonPac AS4A-SC analytic column and 1.8 mM Na 2 CO 3 /1.7 mM NaHCO 3 as the elution.…”

“…The stoichiometric relationship between K ? , Cl -and CrO 4 2-on the sample surface after 1, 9 and 24 h (see Table 2) indicates that KCl reacts with chromia in the oxide scale according to:…”

“…The deviations from the stoichiometry of Reaction (1) found after 72 and 168 h are attributed to the small amounts of K ? , Cl -and CrO 4 2-that remained on the surface, resulting in relatively large measurement errors.…”

“…This is due to an aggressive environment that contains e.g. alkali salts and water combined with metal temperatures up to *550°C [1][2][3][4][5][6][7][8][9]. At such relatively low temperatures, chromia-forming alloys, such as FeCr and FeCrNi steels, are currently being used [10].…”