Oxidation and Hot Corrosion of Ni-Cr- and Co-Cr-Base Alloys Containing Rare Earth Oxide Dispersions.
Final rept. 3 Aug 70-3 Aug 71,
BATTELLE MEMORIAL INST COLUMBUS OHIO COLUMBUS LABS
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The effects of rare earth oxide REO dispersions, Y2O3, and CeO2, on the oxidation and hot corrosion characteristics and mechanisms of Ni-Cr- and Co-Cr-base alloys were studied. Primary emphasis was directed toward a detailed investigation of Ni-20woCr-3vo REO and Co-21woCr-3vo REO alloys prepared by attritor milling, and preliminary oxidation results were obtained on Co-Cr-Al-Y2O3 alloys. It was found that REO particles had four effects on the oxidation behavior of Ni-Cr and Co-Cr alloys 1 They promote the selective oxidation of chromium to form a continuous protective Cr2O3 scale 2 The rate of growth of Cr2O3 is reduced compared with particle-free alloys 3 Cr2O3 oxide scale growth is inward in dispersion alloys compared with outward growth in particle-free alloys 4 Oxide scale adhesion is improved. A kinetic analysis was developed to account for the oxidation behavior and a model of scale growth is presented. Author
- Properties of Metals and Alloys