About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
|
Symposium
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Chemistry and Physics of Interfaces
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Presentation Title |
J-11: Compositional and Interfacial Effects on Stabilization of BCT Phase in Electron-beam Welded Low-alloy Steel |
Author(s) |
Grayson Nemets, Ching-Heng Shiau, Zhongxia Shang, Elliot Hanel Marrero, Jasmyne Emerson, Maria Okuniewski, Janelle Wharry |
On-Site Speaker (Planned) |
Grayson Nemets |
Abstract Scope |
This talk explores the compositional and interfacial effects on phase changes in electron-beam (EB) welded low-alloy steels during heat treatment. This talk will focus on SA508 low-alloy steel produced via powder metallurgy with hot isostatic pressing (PM-HIP). EB welding induces the formation of brittle BCT martensite, but subsequent heat treatments may be able to normalize the microstructure. However, TEM EDS data shows heterogeneous distribution of alloying elements in tempered areas after heat treatment. In addition, weld-induced amorphous MnSi precipitates are observed, often coupled with BCT grains. These precipitates crystallize with more aggressive heat treatment. HR-TEM imaging reveals that these precipitates exert outward pressure on the lattice parameter of their adjacent BCT martensite-like grains near the precipitate-grain interface. 4D-STEM reveals uneven stress distributions within these BCT phases. The combination of these chemical and interfacial effects stabilize the BCT phase within the weld line, reducing the effectiveness of normalizing heat treatment. |
Proceedings Inclusion? |
Planned: |
Keywords |
Iron and Steel, Nuclear Materials, Powder Materials |