| About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
Corrosion and Environmental Degradation: Theory and Practice
|
| Presentation Title |
Revisiting Mechanisms for Hydrogen-Assisted Fracturing of Ni-Fe-Cr Alloys |
| Author(s) |
Kaori Miyata Kawano |
| On-Site Speaker (Planned) |
Kaori Miyata Kawano |
| Abstract Scope |
The susceptibility of Ni-Fe-Cr alloys to hydrogen-assisted fracturing was evaluated through tensile tests with hydrogen charging, and the dislocation structures affected by hydrogen were characterized. TEM images of the dislocations affected by hydrogen showed that hydrogen transforms the configuration of the dislocations from a planar one, with edge dislocations, to a screw-like one consisting of dipoles and loops. Meanwhile, the stacking fault energy (SFE) determined by the separation between the partial dislocations suggested that hydrogen reduces the SFE by up to 30%. The mechanisms by which hydrogen alters the behavior of the dislocations are elucidated in terms of hydrogen trapping within the dislocation cores. The energy of hydrogen trapping within the dislocation cores was calculated based on the difference between the SFEs with and without hydrogen. The compositional dependence of hydrogen embrittlement and the hydrogen trapping energy can be expressed as functions of the average density of the 3d electrons. |