Thermodynamic modeling in reduced activation steels

Reduced Activation (RA) martensitic steels of the 9/11 CrWVTa type are promising candidates for fusion reactor applications as long as they exhibit good mechanical properties-similar to those of commercial martensitic steels of the 9/12CrMo(NbV) type-and satisfy design criteria related to the behavior under irradiation. A contribution on thermodynamic modeling in RA steels is presented. The current status of the development of a thermodynamic database in the framework of the CALPHAD approach is reported. Thermodynamic calculations concerning RA alloys are discussed which can be helpful to interpret experimental observations on phase relationships, phase compositions, transition temperatures, etc.