| About this Abstract |
| Meeting |
2024 TMS Annual Meeting & Exhibition
|
| Symposium
|
Additive Manufacturing: Process-induced Microstructures and Defects
|
| Presentation Title |
Multiscale Gradient Strengthening of Additively Manufactured Low Alloy Martensitic Steel |
| Author(s) |
Ankita Roy, Abhijeet Dhal, Roopam Jain, Priyanka Agrawal, Shreya Mukherjee, Rajiv Mishra, B. A McWilliams, Clara Mock, K C Cho |
| On-Site Speaker (Planned) |
Ankita Roy |
| Abstract Scope |
Alloys showing polymorphic phase transitions at different temperatures provide an excellent opportunity for the creation of gradient microstructure within a single build in additive manufacturing. With the aim of developing a gradient in microstructure, low alloy AF9628 steel was manufactured using Directed Energy Deposition (DED). It was observed that the high quenching rates lead to the formation of untempered martensite in the last laid layer while high volume energy density associated with DED thermally affected approximately eight pre-laid layers leading to the formation of tempered martensite. Microscale-XRD analysis shows the varying fraction of martensite and retained austenite with varying build height and subsequent thermal cycles. Our investigation reveals that the variation in microstructure ultimately leads to the variation in strengthening mechanisms that are operative at different heights. The in-situ thermal cycles resulted in a combination of a range of high strength (1.7-2.0 GPa) and ductility (16-22%) within a single build. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Additive Manufacturing, Iron and Steel, Phase Transformations |