A Comparison of the Oxidation and Nitridation Properties of Selected Chromia- and Alumina-Forming Alloys at 800 °C

Abstract Three FeCrAl alloys and two chromia-formers (a stainless steel, a Ni-base alloy) have been exposed in four environments (dry air, air + 20% H 2 O, O Ar 95% N 5% ) for 168 h at 800 °C. The corroded samples were investigated by SEM/EDS, XRD gravimetry, the formation of CrO (OH) (g) was measured as function time using denuder technique. Fe-base alloy formed Cr-rich protective oxide scale dry wet but suffered break-away oxidation Ar. In contrast, extensive NiO internal chromia O. All three alumina scales Kanthal APMT severely nitrided environment due to defects associated with RE-rich inclusions which allowed nitrogen enter alloy. Cr-lean EF101 EF100 did not suffer nitridation all.