Fig. (8) Surface states of three of the HfC-containing cobalt-based samples after oxidation (here after 50h at 1200°C): Co-25Cr-0.25C-3.7Hf alloy (A), of the Co-25Cr-0.50C-3.7Hf alloy (B) and of the Co-25Cr-0.50C-7.4Hf alloy (C).