Carbon addition by solid carburizing was performed for Mo and Mo-Ti alloys. The Vickers hardness tests was performed for these samples. The Vickers hardness tests estimated the hardness of a sample. The hardness distribution was investigated from the sample surface to the piece thickness direction of a sample. Existence, size and identification of precipitate was examined by TEM and EDX.
The hardness of Mo added carbon was of the same grade compared with that of the recrystallized ones. The hardness of Mo-Ti added carbon alloys was higher than that of the recrystallized ones. The precipitate has not been checked in Mo. However the precipitate was able to be checked in Mo-Ti alloys. The precipitate was TiC. The increase in a hardness of Mo-Ti alloys added carbon was due to precipitation hardening. In the case of Mo-Ti alloys, there is possibility of internal carburizing.