| About this Abstract |
| Meeting |
MS&T23: Materials Science & Technology
|
| Symposium
|
Additive Manufacturing of Metals: Microstructure, Properties and Alloy Development
|
| Presentation Title |
Laser Powder Directed Energy Deposition of 17-7 PH Stainless Steel |
| Author(s) |
Alex L Barbosa, Fabio E Mariani, Rodrigo G Dourado da Silva, Piter Gargarella, Reginaldo T Coelho, Kahl D. Zilnyk, Antonio J Ramirez |
| On-Site Speaker (Planned) |
Kahl D. Zilnyk |
| Abstract Scope |
Precipitation hardening (PH) stainless steels are some of the most employed ferrous alloys in additive manufacturing, but most studies are focused on martensitic grades. Comparatively, semi-austenitic PH steels have higher corrosion resistance and yield strength, combined with higher machinability. This last property is due to the matrix being austenitic before the final heat treatments, making them suitable for hybrid manufacturing processes (e.g. DED followed by milling). However, their microstructures are extremely dependent on the thermal history. Single tracks of 17-7 PH semi-austenitic stainless steel were deposited by Laser Powder Directed Energy Deposition using 24 different parameter combinations (laser power and speed, powder feed rate). The bead height, the substrate dilution rate and the δ-ferrite fraction were analyzed. The results show a complex, non-linear relationship with process parameters. Numerical heat transfer simulations and thermodynamic calculations show that the solidification mode changes from ferritic to austenitic when the thermal input is reduced. |