Xiang Zhang presented his research at 2016 ANS Winter Meeting and Nuclear Technology Expo
The title of the Xiang’s presentation and paper (co-authored by Dr. Van Tung Phan) is: “Microstructural creep, fatigue and creep-fatigue modeling of Nickel-based superalloy Inconel 617 at high temperature”.
Abstract:
Inconel 617 is a solution strengthened nickel-based alloy which has been considered as one of the leading structural material for the intermediate heat exchangers (IHX) in very high temperature reactor (VHTR). In order to gain understanding of the creep and fatigue deformation mechanisms and their inter- actions in alloy 617 operating in the VHTR environment, a com- putational model that operates at the microstructural scale has been developed for creep, fatigue and creep-fatigue modeling of alloy 617. This model is based on an isothermal, large de- formation crystal plasticity finite element (CPFE) formulation and idealizes the deformation in the crystal lattice as collective glide and climb of dislocations. A recently developed glide resistance evolution equation by the authors that can capture the intermediate softening observed in both fatigue and creep- fatigue cycles of Inconel 617 at high temperature is adopted for the dislocation glide formulation. Dislocation climb is incorporated to account for the interactions between dislocations and local point defects at high temperature. The CP equations are solved incrementally as the constitutive relationship in the context of FE analysis on fully resolved microstructure reconstructed from experiment data. Model parameters are calibrated and verified using experimental tests.