| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Nanostructured Materials in Extreme Environments III
|
| Presentation Title |
Nanoscale Compositional Homogenization by Severe Plastic Deformation-Induced Twinning for Achieving Desensitization in Stainless Steel |
| Author(s) |
Kasturi Narasimha Sasidhar, Robert Ulfig, Kumar Sridharan |
| On-Site Speaker (Planned) |
Kasturi Narasimha Sasidhar |
| Abstract Scope |
We report the use of ultrasonic nanocrystalline surface modification (UNSM), a high strain-rate surface peening technology for rapid de-sensitization of austenitic stainless steels at room temperature. Transmission electron microscopy investigation of the UNSM-treated samples revealed that the UNSM treatment triggered nano-scale deformation twinning in the austenite matrix. Atom probe tomography (APT) measurements in the vicinity of the sensitization-induced grain boundary chromium carbides revealed that this deformation twinning facilitated a nano-scale homogenization of the Cr-content in the austenite matrix. As a result, the lowest Cr-content in the austenitic matrix was raised from 7 at. % in the as-sensitized condition to ~12 at. % in the UNSM-treated sample, higher than the threshold Cr content of ~11-12% required for passivation. Detailed analysis of the spatial distribution of the Cr-concentration in terms of APT crystallography and Cr-carbide precipitate morphology suggests that atomic transport across {111} twin-planes during deformation is responsible for the compositional homogenization. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Surface Modification and Coatings, Characterization, Iron and Steel |