About this Abstract |
Meeting |
Superalloys 2024
|
Symposium
|
Superalloys 2024
|
Presentation Title |
D-2: Gamma Prime Precipitation in the Cast and Wrought AD730 Superalloy |
Author(s) |
Jerome Blaizot, Laurane Finet, Aurelien Chabrier, Alexandre Fornara, Matthieu Fage, Roufeida Remichi, Mickael Dade, Michel Perez |
On-Site Speaker (Planned) |
Laurane Finet |
Abstract Scope |
AD730® is a γ-γ' polycrystalline superalloy which has been recently developed for future engine turbine discs. The γ' precipitation influences mechanical properties at the service temperature but also the kinetics of recrystallization during forging process. Consequently, a deep understanding and monitoring of γ' precipitation is required at each stage of the industrial process. The objective of this work is to understand the precipitation mechanism, determine the evolution of γ' size during cooling and isothermal heat treatments, and calibrate a model for the nucleation and growth of γ' during the ingot-to-billet conversion. The experimental analysis showed that water quenching at a cooling rate of 100 °C/s after a solution treatment at 1160 °C led to a fine and homogeneous γ' precipitation for which the average circle radius ranges from 10 nm to 20 nm. Then, samples were heat treated between 1000 °C and 1080 °C with various holding times to characterize and quantify the size of precipitates. The results were compared to the precipitation modeling using the in-house software PreciSo, a multi-class, Kampmann-Wagner Numerical precipitation model based on classical nucleation and growth theories. Even if the simulations of precipitation during isothermal heat treatments start with the correct initial radius, coarsening appears to occur slower than predicted by the simulations. This discrepancy is attributed to one simulation parameter, the diffusivity of solute elements, which needs to be improved to obtain a better fit with experimentations. |
Proceedings Inclusion? |
Definite: At-meeting proceedings |