| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Environmental Degradation of Additively Manufactured Materials
|
| Presentation Title |
Exceptional Localized Corrosion Resistance of Ni-Based Alloy 625 Processed by Directed Energy Deposition Additive Manufacturing in Concentrated Chloride Environments |
| Author(s) |
Karthikeyan Hariharan, Andrew D. Iams, James S. Zuback, Todd A. Palmer, Narasi Sridhar, Rashed M. Alazemi, Gerald S. Frankel, Eric J. Schindelholz |
| On-Site Speaker (Planned) |
Karthikeyan Hariharan |
| Abstract Scope |
Alloy 625 is a Ni-Cr-Mo-Nb solid solution strengthened alloy known for its superior elevated temperature mechanical properties and excellent corrosion resistance. However, it is susceptible to localized corrosion in concentrated chloride environments. Studies have shown that alloy 625 processed by directed energy deposition (DED-625) exhibits enhanced localized corrosion resistance in dilute chloride environments. However, there is a dearth of understanding of its behavior in concentrated chlorides. In this work, we report a significant improvement in localized corrosion resistance of DED-625 in 7.6M LiCl solution at 50oC compared to the wrought counterpart. We attribute the exceptional localized corrosion resistance of the DED alloy to the refined distribution of nitrides during the DED process. Nb,Ti-rich MN-type nitrides larger than 1μm that were present in the wrought material served as pit initiation sites and likely degraded the corrosion resistance. Refinement of those precipitates by DED rendered them less deleterious to the corrosion process. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Additive Manufacturing, Environmental Effects, |