About this Abstract |
| Meeting |
MS&T26: Materials Science & Technology
|
| Symposium
|
Fracture of Steels: New Approaches to Modeling and Experimental Characterization
|
| Presentation Title |
Delamination in Charpy Impact Testing of Vintage Pipeline Steels: Implications for Fitness‑For‑Service Assessments |
| Author(s) |
Areeba Essani, Milan Agnani, Ernest Lever |
| On-Site Speaker (Planned) |
Areeba Essani |
| Abstract Scope |
The U.S. natural gas transmission pipeline network requires reliable fitness‑for‑service assessments to ensure safe operation. These assessments depend on accurate material strength and fracture toughness data to evaluate structural integrity. However, evaluating toughness in vintage pipeline steels presents unique challenges due to microstructural heterogeneity. Instrumented Charpy impact tests were conducted on vintage pipeline steels at different temperatures. These steels are prone to centerline segregation, resulting in splitting or delamination during impact testing, leading to artificially high impact energies. Such elevated impact energies can be observed across a range of temperatures, obscuring the ductile‑to‑brittle transition behavior and complicating the correlation of Charpy impact results with fracture toughness. Mechanistic and probabilistic approaches are developed to understand and identify delamination during impact testing and to quantify its influence on measured toughness, providing improved interpretation of Charpy data in the context of fitness‑for‑service evaluations of pipeline infrastructure. |