About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
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Symposium
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30 Years of Nanoindentation with the Oliver-Pharr Method and Beyond
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Presentation Title |
Hardening Relationship with Hydrogen and Dislocation Structure in FeCr Alloys by In Situ Nanoindentation |
Author(s) |
Jing Rao, Subin Lee, Gerhard Dehm, Marķa Jazmin Duarte Correa |
On-Site Speaker (Planned) |
Jing Rao |
Abstract Scope |
Hydrogen embrittlement is a critical issue commonly observed in metallic materials. Here we use a novel in situ set-up built in-house for electrochemical backside hydrogen charging during nanoindentation on ferritic FeCr alloys with high hydrogen diffusivity and low solubility to investigate their changes in mechanical response. A hardening effect, independent of the grain orientation, occurs while the elastic modulus remains constant during hydrogen charging at different conditions. The relative hardness variation follows an initial linear increase with increased hydrogen content until hydrogen absorption and desorption reach a steady state. This hardening effect is verified by an enhanced dislocation density in the cross-section underneath the nanoindentation imprints by transmission electron microscopy and modeled accordingly. A higher chromium content results in a more pronounced hardening effect at the corresponding hydrogen saturation level, suggesting that the substitutional chromium atoms act as flat trapping sites for hydrogen retarding its diffusion and increasing its solubility. |
Proceedings Inclusion? |
Planned: |
Keywords |
Characterization, Mechanical Properties, Iron and Steel |