Effect of Rare-Earth Elements on High-Temperatures Oxidation Resistance of Fe-20Cr-5Al Alloy Foils

摘要

The oxidation behavior of 50 μm thick Fe-20 mass/100 Al alloy foils containing small amounts of Y, La, Ce, Pr, Nd or Sm was examined by a cyclic oxidation test at 1373 and 1473 K in air. The addition of rare-earth elements Decreased the growth rates of both the Al_2O_3 scale, which grew until Al in the foil had been depleted, and the Cr_2O_3 Scale, which formed between the Al_2O_3 scale and the substrate after the depletion of Al. The segregation of the rare-earth Elements to the Al_2O_3 grain boundaries was observed with a transmission electron microscope equipped with an energy- Dispersive X-ray spectrometer.