Recent progress in the microstructurally-based creep modelling of Ni-based alloy 617
Sprache des Vortragstitels:
Englisch
Original Tagungtitel:
6th International ECCC Creep & Fracture Conference
Sprache des Tagungstitel:
Englisch
Original Kurzfassung:
Solid solution strengthened (SSS) Ni-based superalloys, such as A617, show superior creep resistance at 700°C. They are promising candidates to raise the efficiency of future thermal power plants or turbines in aircrafts. Apart from SSS, the creep strength in A617 stems from ?? and carbide precipitates. In this work, a microstructurally-based creep model for A617 is presented. Mobile dislocations in the model interact with fine grain-interior precipitates, and grain boundaries act as dislocation sources/ sinks. The model is capable of simulating creep curves and time-torupture (TTR) diagrams based on the evolution of mobile dislocations. At lower stresses, the accuracy of modelled
TTR can be improved by adding a share of diffusion creep to dislocation creep. The simulated evolution of dislocation densities is realistic compared to the literature data. The reduction of area of ruptured samples was included within a damage factor, enabling the consideration of sample toughness.