| About this Abstract |
| Meeting |
2024 TMS Annual Meeting & Exhibition
|
| Symposium
|
Additive Manufacturing Fatigue and Fracture: Towards Rapid Qualification
|
| Presentation Title |
Can the Retained Austenite in Nitrogen-Atomized Additively Manufactured 17-4PH Stainless Steel Improve the Environmental Crack Resistance? |
| Author(s) |
Mark R. Stoudt, James S Zuback, Andrew W Iams |
| On-Site Speaker (Planned) |
Mark R. Stoudt |
| Abstract Scope |
While exceptional weldability makes SS17-4PH appropriate for additive manufacturing (AM) applications, AM processing often promotes significant localized composition variations and phases that are uncommon in wrought material. Wrought SS17-4PH consists of δ-ferrite stringers in a precipitation-hardenable martensite matrix, but when AM processed from nitrogen-atomized powder, the microstructure becomes a mixture of martensite and meta-stable retained austenite that persists after post-build heat treatment. The question is whether appropriate heat treatment can stabilize the more ductile austenite so that strain-induced transformation to martensite reliably enhances the fracture toughness under conditions that promote hydrogen embrittlement. Slow strain rate tensile tests, performed under controlled hydrogen fugacity at different strain rates in an acidified chloride environment, were used to investigate this possibility. This presentation will provide some insight regarding how post-build heat treatments can be developed that exploit the microstructural differences in AM material and improve the overall performance of this important industrial alloy. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Additive Manufacturing, Mechanical Properties, Characterization |