Cast cobalt-based, nickel-based and iron-based alloys are widely used for numerous applications, and notably their chromium–rich versions are often considered in different domains, among them aeronautics for which chromium allows the alloys well resisting against high temperature oxidation and corrosion. Carbon can be added in great quantities to these alloys in order to obtain high fractions of chromium carbides to achieve high levels of hardness and of good resistance against wear phenomena. In service the wear-solicited materials or coatings may reach high temperatures, because friction-induced heating. They can be then affected by oxidation by hot gases and their resistance to this deterioration needs to be better known, especially for versions of such alloys obtained by classical foundry way for which this was seemingly not extensively studied. The aim of the present work is precisely to study the behaviour in high temperature oxidation in air of chromium carbides – rich alloys based on cobalt, nickel and iron, elaborated by conventional casting. Finally all these hard alloys very rich in carbon, mainly present as carbides but also as graphite in some cases, displayed a rather good resistance against oxidation by air at temperatures as high as 1200°C and under. Except the three carbon-richest iron alloys exposed to the very high temperature of 1200°C, the behaviour of the alloys was rather good at least during 50 hours, as shown by the presence of external chromia (but, it is true, more or less mixed with other not so protective oxides). The low chromium contents in matrix, due to the consumption of a great part of this element when the numerous carbides formed during solidification, was obviously corrected during high temperature oxidation by an enrichment of the matrix with Cr coming from the carbides dissolving deeper and deeper (carbide-free zone development). The presence of graphite in the C-richest cobalt-based and nickel-based alloys did not provoke a catastrophic oxidation although this free carbon especially exposed to oxidation may generate great volumes of COx gases able to perturb the continuity of the growing external protective scale. To finish one can also notice that the most external parts of these alloys are replaced by carbide-free zones which are much softer than the carbides-rich bulk alloys. This can be a problem to maintain a good wear resistance on surface.