About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
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Symposium
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Additive Manufacturing: Advanced Characterization with Synchrotron, Neutron, and In Situ Laboratory-scale Techniques II
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Presentation Title |
Investigating the Ferrite-to-Austenite Solidification Competition in Stainless Steel Laser Welds with Time-resolved X-ray Diffraction |
Author(s) |
Joseph W. Aroh, Seunghee A. Oh, Rachel E. Lim, Benjamin J. Gould, Andrew C. Chuang, P. Chris Pistorius, Anthony D. Rollett |
On-Site Speaker (Planned) |
Joseph W. Aroh |
Abstract Scope |
It is generally accepted that high solidification rates result in a shift from primary ferrite to primary austenite solidification mode in stainless steels with low Cr/Ni equivalency ratios based on differences in dendrite tip growth kinetics between the two phases. This understanding was tested with high-speed synchrotron x-ray diffraction measurements during in situ laser melting and re-solidification of various stainless steels. A large-area detector was employed to capture complete Debye-Scherrer rings at a high spatiotemporal resolution allowing laser scan velocities to range from 0.01 – 0.5 m/s. The time-resolved diffraction patterns were correlated with ex situ microstructural characterization of the sectioned melt tracks to understand how the solidification sequence results in the final microstructure. This analysis is the first to directly link the in situ characterization of liquid-solid phase transformation kinetics with the various solidification microstructures that occur in laser welds as a function of both solidification rate and composition. |
Proceedings Inclusion? |
Planned: |
Keywords |
Solidification, Phase Transformations, Additive Manufacturing |