High-temperature oxidation of heat-resistant alloys with small amounts of sulfur and reactive elements (Y, Hf) for 1800ks at 1273K

Abstract

High-temperature oxidation of heat-resistant alloys with small amounts of sulfur and reactive elements (Y, Hf) was studied for 1800ks in air at 1273K by mass change measurements, observation of surface appearance of the alloys, X-ray diffraction, scanning electron microscopy and electron probe X-ray microanalysis. Mass change of the alloy with 7ppm of sulfur showed low value because of marked spalling of the oxide film on the alloy. Mass changes of the other alloys with sulfur increased with increasing sulfur up to 491ppm of sulfur. Mass changes of the alloys with sulfur and yttrium were 4.3-5.1×10^-3kg/m². Mass changes of the alloys with sulfur and hafnium were 2.3-5.2×10^-3kg/m².