Effect Of Co Addition On The High-Temperature Oxidation Behavior Of Oxide-Dispersion-Strengthened Fecral Alloys

The effect of Co addition on the high-temperature oxidation behavior of oxide dispersion-strengthened (ODS) FeCrAl alloys was investigated at 1000 ?C in air. Exclusively ?-Al2O3 scale formed on the surfaces of alloys containing 5 wt.% Al, and Y segregation was observed at the grain boundaries of Al2O3 scale. The solute Y in the Fe12Cr5Al-ODS (wt.%) alloy substrate was decreased by Co addition, thus limiting Y segregation at grain boundaries of the Al2O3 scale. The diminished Y segregation was inferred to cause grain size coarsening, which accounted for the slower oxidation kinetics of 5Al alloys with Co addition.