About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
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| Symposium
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Understanding Corrosion-Related Cracking
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| Presentation Title |
Understanding the Role of Microstructure on the Sub Critical Crack Growth Rate and Crack Path in Pipeline Ferritic Stainless Steels
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| Author(s) |
Elisabeth Kuebel, Aeriel Leonard, Ramgopal Thodla |
| On-Site Speaker (Planned) |
Elisabeth Kuebel |
| Abstract Scope |
The crack growth behavior of two ferritic stainless steels: 4740 and 4742 was characterized in a high-pressure hydrogen gas environment. Samples were extracted from both seamless and seam-welded pipes and subjected to various loading profiles including increasing, decreasing, and constant ΔK. A methodology employing electron microscopy (scanning, transmission) and electron back scatter diffraction was utilized to understand the role of microstructure on the fracture behavior and subcritical crack growth (SCGR) rate. It was found that the loading profiles had a strong influence on the crack path and SCGR rate. Electron microscopy showed that the localization of strain and grain orientation controlled the crack path where at constant ΔK crack propagation mainly occurred along high angle grain boundaries where there was a localization of strain. At fast loading rates CG alternated between intergranular and transgranular propagation where there was a high amount of highly deformed grains. |