Spalling of oxide scale on Al₂O₃-forming heat-resistant alloys cooled in liquid nitrogen or air

Abstract

Spalling of oxide scale on Al₂O₃-forming heat-resistant alloys cooled in liquid nitrogen or air was studied by mass change measurements, observation of surface appearance of the alloys, X-ray diffraction, scannig laser microscopy, scannig electron microscopy and electron probe microanalysis. The mass changes of 104ppmS alloy at 1473K, of 104 and 1300ppmS alloys at 1573K, and of 53 and 1300ppmS alloys at 1673K showed big different values by the two cooling media of liquid nitrogen and air. On the other hand, the mass changes of the other alloys, except 24 and 53ppmS alloys, showed each similar values by the two cooling media after oxidation at 1473K.