| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Environmentally Assisted Cracking: Theory and Practice
|
| Presentation Title |
Investigation of Laboratory versus In-service Sensitization Effects on Corrosion Fatigue Performance of AA5456-H116 |
| Author(s) |
Allison Akman, David Schrock, Jenifer (Warner) Locke |
| On-Site Speaker (Planned) |
Allison Akman |
| Abstract Scope |
AA5xxx alloys are utilized in marine applications, but corrosion resistance and environment assisted cracking properties can be degraded by the precipitation of anodic β-phase (Al<sub>3</sub>Mg<sub>2</sub>) along grain boundaries (sensitization) during in-service thermal exposure. This research aims to understand corrosion fatigue (CF) performance by comparing laboratory and in-service sensitized AA5456-H116 microstructures at three sensitization levels (DoS). Crack growth rates (da/dN) will be compared over a range of stress intensity ranges (ΔK), stress ratios (R), and fatigue loading frequencies. For the same ΔK and R, CF testing of T-L oriented fracture mechanics samples shows that laboratory sensitized microstructures exhibit a higher da/dN than those sensitized in-service at the same DoS. Quantification of grain boundary β-phase coverage and degree of recrystallization via SEM will attempt to correlate microstructural changes with da/dN differences. Gallium-embrittled intergranular fracture surfaces reveal particles covering a highly sensitized microstructure, whereas a low DoS has little to no particles present. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |