About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advanced Welding, Joining, and Bonding of Structural Steels
|
| Presentation Title |
Graded Transition Steel Joints for Mitigating Galvanic Embrittlement in Acid Gas Geothermal Environments |
| Author(s) |
Ting Roy, Kamel Ben BenNaceur, Megumi Kawasaki, Mari Takahashi, Chihiro Furusho, Anil Singh, Indranil Roy |
| On-Site Speaker (Planned) |
Kamel Ben BenNaceur |
| Abstract Scope |
Coupling corrosion-resistant alloys (CRAs) with low-alloy steels (LAS) can generate galvanic currents in acid-gas, enhanced-geothermal, and super-hot-rock environments, promoting hydrogen generation, uptake, and hydrogen-assisted embrittlement. This work introduces a graded transition joint (GTJ) designed to mitigate these risks by replacing abrupt dissimilar-metal interfaces with controlled compositional and microstructural gradients. GTJs are fabricated using powder-metallurgy routes, including high-pressure torsion (HPT) of graded powders and CIP/HIP consolidation, with hybrid additive-manufacturing approaches also considered. Processing and alloy chemistry are optimized for full density, metallurgical bonding, diffusion control, microcrack resistance, CRA corrosion performance, and LAS structural integrity. TEM and HAADF-STEM characterization relates grain refinement, grain-boundary structure, and residual stress to hydrogen transport and cracking behavior. A proposed Galvanic Potential Gradient Index (GPGI) quantifies electrochemical transitions across the joint, guiding GTJ composition, geometry, and microstructure for improved reliability in hydrogen-sensitive energy infrastructure. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Nanotechnology, Powder Materials, Joining |