Cyclic-oxidation of Al2O3-forming heat-resistant alloys with small amounts of sulfur and yttrium at 1473K

The cyclic-oxidation of Fe-20Cr-4Al alloys with 0.1 mass% sulfur, and 0.05, 0.1 and 0.5 mass% yttrium was studied up to 5cycles (1 cycle=18.0ks) in oxygen at 1473K by mass change measurements, observation of surface appearance of the alloys, X-ray diffraction, scanning electron microscopy and electron probe X-ray microanalysis. Mass changes of all the alloys increased with increasing number of cycles, and that of 0.5Y alloy decreased compared with the other alloys after 5cycles.