| About this Abstract |
| Meeting |
2024 TMS Annual Meeting & Exhibition
|
| Symposium
|
High Performance Steels
|
| Presentation Title |
Engineering Non-equilibrium L12-NiAl Phase to Form a Nano-precipitate Strengthened Austenitic Steel |
| Author(s) |
Colin A. Stewart, Edwin A. Antillon, Keith E. Knipling, Patrick G. Callahan, David J. Rowenhorst |
| On-Site Speaker (Planned) |
Colin A. Stewart |
| Abstract Scope |
Using integrated computational materials engineering (ICME), we have developed a novel series of FCC Austenitic steels with estimated yield strengths over 180 ksi through the formation of three nano-scale precipitate phases: (i) insoluble FCC Cu particles, (ii) ordered intermetallic NiAl precipitates, and (iii) carbides. Age hardenability was evaluated by microindentation, and the precipitation sequences were assessed by atom-probe tomography across a range of ageing time steps, temperatures, and compositions. A non-equilibrium L12 phase was identified as a precursor to strengthening B2-NiAl nano-precipitates, assessed by combined atom-probe tomography and TEM. The formation of this L12 structure was also predicted via density functional theory calculations. The synergistic alloying additions that enable the formation of this non-equilibrium phase will be discussed, as well as how the precipitation pathways can change across the design space. In particular, we will discuss combining this fundamental understanding of the precipitation with ICME tools to predict material behavior. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
ICME, Iron and Steel, Phase Transformations |