Polycrystalline samples of were oxidized in air in the 900 to 1400°C temperature range. The oxidation was parabolic with parabolic rate constants, kp, that increased from to as the temperature increased from 900 to 1400°C, respectively, which yielded an activation energy of 370 ± 20 kJ/mol. The scale that forms was dense, adhesive, resistant to thermal cyclings and layered. The outer layer was pure (rutile), and the inner layer consisted of mixture of and . The results are consistent with a model in which growth of the oxide layer occurs by the inward diffusion of oxygen and the simultaneous outward diffusion of titanium and carbon. The presence of small volume fractions (≈ 2%) of in were found to have a deleterious effect on the oxidation kinetics.