| About this Abstract |
| Meeting |
Materials Science & Technology 2020
|
| Symposium
|
Environmentally Assisted Cracking: Theory and Practice
|
| Presentation Title |
Hydrostatic Instability as the Underlying Mechanism of Hydrogen Embrittlement
|
| Author(s) |
Michael F. McGuire |
| On-Site Speaker (Planned) |
Michael F. McGuire |
| Abstract Scope |
Fundamental progress on understanding hydrogen embrittlement has been hindered by controversy over the mechanism. In this study the seemingly overlooked effect of a large hydrogen-induced lattice expansion in the densely dislocation-populated fracture process zone is predicted from first principles and confirmed experimentally. The stress relaxation caused by the hydrogen-induced expansion adjacent to the critical point is shown to be sufficient to cause a hydrostatic instability at the critical point of maximum hydrostatic stress, leading to stepwise brittle failure as the Treska failure criterion is exceeded. The mechanistic model is then tested against numerous known characteristics of hydrogen embrittlement. |