About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
Environmentally Assisted Cracking: Theory and Practice
|
Presentation Title |
Evaluation of the Responsible Hydrogen Embrittlement Mechanism in Martensitic Steels by Advanced Microstructural Characterization |
Author(s) |
Tom Depover, Kim Verbeken, Margot Pinson |
On-Site Speaker (Planned) |
Tom Depover |
Abstract Scope |
This work investigates the susceptibility to hydrogen embrittlement (HE) of martensitic steels. Thermal desorption spectroscopy shows that the main H trapping sites are dislocations and high angle grain boundaries (HAGBs). In-situ bending tests reveal that H causes a transition towards a cleavage fracture, paired with a significant ductility loss explained by hydrogen enhanced decohesion (HEDE), indicating that H at HAGBs play an important role. Next, Al is gradually added as well. For an optimal Al/C ratio, a very thin ferritic film on the PAGBs is formed significantly increasing the ductility in air. When testing in H, the microfilm causes a delay in fracture, since fracture propagation is redirected along the interface resulting in intergranular fracture. The responsible mechanism is an interplay between HEDE and hydrogen enhanced localized plasticity (HELP). Hence, an optimal Al/C ratio in martensitic steels offers the opportunity to increase the HE resistance by inventive grain boundary engineering. |
Proceedings Inclusion? |
Planned: |
Keywords |
Mechanical Properties, Characterization, Environmental Effects |