Ni-based Superalloy Development for VHTR - Methodology Using Design of Experiments and Thermodynamic Calculation

In this work, to develop novel structural materials for the IHX of a VHTR, a more systematic methodology using the design of experiments (DOE) and thermodynamic calculations was proposed. For 32 sets of designs of Ni-Cr-Co-Mo alloys with minor elements of W and Ta, the mass fraction of TCP phases and mechanical properties were calculated, and finally the chemical composition was optimized for further experimental studies by applying the proposed . The highly efficient generation of electricity and the production of massive hydrogen are possible using a very high temperature gas-cooled reactor (VHTR) among generation IV nuclear power plants. The structural material for an intermediate heat exchanger (IHX) among numerous components should be endurable at high temperature of up to 950 .deg. C during long-term operation. Impurities inevitably introduced in helium as a coolant facilitate the material degradation by corrosion at high temperature. This work is concerning a methodology of Ni-Cr-Co-Mo based superalloy developed for VHTR using the design of experiments (DOE) and thermodynamic calculationsmethodology