About this Abstract |
Meeting |
Materials Science & Technology 2020
|
Symposium
|
Advanced Steel Metallurgy
|
Presentation Title |
Modelling of Precipitation and Grain Growth in Ti-Nb Microalloyed Steels |
Author(s) |
Alexis Graux, Sophie Cazottes, M. Perez, M. Bugnet, Damien Fabregue |
On-Site Speaker (Planned) |
Damien Fabregue |
Abstract Scope |
To achieve high mechanical properties in microalloyed steels, fine precipitates are used to control grain growth during heat treatments. Thus, it is of prime importance to be able to predict the austenite grain growth kinetic coupled with precipitation. The model described has been used in Ti-Nb microalloyed steels. After a careful characterization of the precipitation state by SEM and TEM, a thermodynamic based model has been developed. The solubility product was determined by CALPHAD database and then a model based on the classical nucleation and growth theory was implemented to be able to describe the evolution of (Ti,Nb)C size distributions during isothermal heat treatments. The calculated precipitate size distributions were coupled to a simple grain growth model based on Zener pinning accounting for the pressure due to the whole precipitate size distribution. The obtained grain growth kinetics are in good agreement with the experimental obtained ones after different heat treatments. |