Investigation on the mechanism of deteriorated oxidation resistance of Ti(C0.7,N0.3)-304ss cermet doped with Y during the early oxidation stage

Abstract

The high-temperature oxidation resistance of the Ti(C0.7,N0.3)-304ss cermets during the early oxidation stage was deteriorated by adding Y. The outward diffusion of Fe atoms was improved with Y addition, and a Fe-rich outer oxide layer was generated on the surface. Impurities at phase boundary act as barriers to suppress the diffusion of Fe and O atoms; while they were purified by Y atoms, and the barriers were destroyed. As a result, the oxidation resistance deteriorated. The apparent activation energy of the cermets declined from 207.18 KJ/mol to 149.97 KJ/mol by doping with Y.