About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
Environmentally Assisted Cracking: Theory and Practice
|
Presentation Title |
Modelling Environmentally Assisted Cracking (EAC) in Ni-based Superalloys |
Author(s) |
Sakina Rehman |
On-Site Speaker (Planned) |
Sakina Rehman |
Abstract Scope |
Ni-based turbine discs form a surface oxide layer when exposed to high temperatures and corrosive reagents. Growth of the oxide layer results in a γ´ precipitate depleted region at the oxide-matrix interface due to preferential transport of oxide-forming elements to the growing surface oxide. A mean-field model has been developed to predict the γ´ precipitate depletion zone in RR1000. Initial particle size distributions are divided into a series of discrete size classes, corresponding to the equilibrium phase fraction of γ´. A multicomponent diffusion driven growth-rate law is formulated to determine the dissolution rate of each discrete particle size class. The model is validated and agrees well with experimental depletion zone data. It is found that the γ` precipitates dissolve faster at the surface, and the rate of dissolution increases as the temperature approaches the solvus temperature. Increasing the solute concentration lead to a decreased dissolution rate of γ´ precipitates. |
Proceedings Inclusion? |
Planned: |
Keywords |
Modeling and Simulation, Copper / Nickel / Cobalt, High-Temperature Materials |