The oxidation of Fe3Al–(0, 2, 4, 6%)Cr alloys at 1000°C

Degradation of Aluminide Layers During Cyclic Oxidation of Ferritic 430 Stainless Steel

“…figure 7 and EDS detects both Fe and Cr atoms, as shown in figure 5b. These results are consistent to be reported by Lee et al that Fe and Cr atoms from the aluminide layer could give a contribution to support a formation of the α-Al2O3 layer [10]. Both Fe and Cr are well known to accelerate the transformation of -Al2O3 to α-Al2O3 [17][18][19].…”

“…This result is evident with SEM observation of surface morphology of the aluminized specimens after 30 cycles, as shown in figure 6. The EDS analysis clearly reveals in figure 3b that the α-Al2O3 scale contains a small amount of dissolved Fe-atoms because the solubility of Fe-atoms in the Al2O3 is about 5% at 1000 °C [10]. Perez et al reported that at the oxidation temperature of approximately 950 °C the formation of Cr2O3 was restricted by the formation of volatile CrO3 [16].…”

“…Some studies report that the FeAl and Fe3Al alloys without Cr show a decrease in oxidation resistance at 1000 °C [8,9]. Lee et al reported that the addition of 2-4 % Cr first decreases the oxidation resistance of Fe3Al alloys, but then increases it with further addition of Cr (up to 6 %) [10]. Chromium was found to be the most effective element in improving the high temperature ductility of FeAl and Fe3Al [11].…”

Enhanced High Temperature Corrosion Resistance in Advanced Fossil Energy Systems by Nano-Passive Layer Formation

“…It is possible that the adsorption of oxygen or sulfur is more favorable on certain grains do to their orientation. Graupner et al 17 observed a similar grain boundary dependence in a study on the oxidation of low index FeAl. The authors report that the rate of oxygen uptake at 500°C in UHV varied with grain orientation, FeAl(110) being about 2 order of magnitude slower than that of FeAl(100).…”

“…A similar mechanism was cited by Kai et al 16 as being responsible for the formation of iron sulfides on iron aluminum alloys in a sulfidizing environment at 700-900°C. In an oxidizing environment, Lee et al 17 showed that an aluminum-and chromium-depleted region developed beneath an external Al 2 O 3 scale on Fe 3 Al oxidized at 1,000°C. Shebany and Douglass 18 pre-oxidized several iron, nickel and cobalt alloys to develop a protective oxide scale prior to exposure in sulfur vapor.…”