A series of conventional Fe- and Ni- base, chromia- and alumina- forming alloys, and a
newly developed creep-resistant, alumina-forming austenitic (AFA) steel were evaluated
in metal dusting environments with a range of water vapor contents. Five 500h
experiments have been performed at 650°C with different water vapor contents and total
pressures. Without water vapor, the Ni-base alloys showed greater resistance to metal
dusting than the Fe-base alloys, including AFA. However, with 10-28% water vapor,
more protective behavior was observed with the higher-alloyed materials and only small
mass changes were observed. Longer exposure times are in progress to further
differentiate performance.
Keywords: metal dusting, Ni-base alloys, Fe-base alloys, oxidation testing, AFA alloys