About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Steels in Extreme Conditions
|
| Presentation Title |
Understanding the Role of Microstructure on the Sub Critical Crack Growth Rate and Crack Path in X65 Pipeline Steels |
| Author(s) |
Elisabeth Kuebel, Aeriel Leonard, Ramgopal Thodla |
| On-Site Speaker (Planned) |
Elisabeth Kuebel |
| Abstract Scope |
The crack growth behavior of two X65 pipeline steels was characterized by employing electron microscopy and electron back scatter diffraction to understand the role of microstructure on fracture behavior and subcritical crack growth (SCGR) rate. Samples were extracted from both seamless (4742) and seam-welded (4740) pipes. Fatigue crack growth tests were performed under various conditions (increasing, decreasing, and constant ΔK) to see the influence of loading parameters before and after hydrogen was introduced to the material. Two different methods were utilized for hydrogen uptake: high pressure hydrogen gas environment and cathodically charging before mechanical testing. It was found that the loading profiles had a strong influence on the crack path and SCGR rate. At constant ΔK crack propagation mainly occurred along high angle grain boundaries. At fast loading rates CG alternated between intergranular and transgranular propagation where there was a high amount of highly deformed grains. |
| Proceedings Inclusion? |
Planned: |