|About this Abstract
|Materials Science & Technology 2020
|Additive Manufacturing: Alloy Design to Develop New Feedstock Materials
|Optimization of Nitrogen-Atomized 17-4 Stainless Steel Feedstock for AM Processing
|Carelyn E. Campbell, James Zuback, Mark Stoudt
|On-Site Speaker (Planned)
|Carelyn E. Campbell
Wrought martensitic precipitation hardened stainless steel, 17-4 PH, is widely used in the aerospace and marine industries when high strength and corrosion resistance are needed. Additively manufactured (AM) nitrogen-atomized 17-4 parts often have unexpected properties that result in poor performance, primarily as the nitrogen acts as an austenite stabilizer and the desired martensitic matrix microstructure is not achieved. This work focuses on optimizing the feedstock composition within the composition specification to control the influence of the nitrogen on the AM part. The current alloy specification allows for significant composition variation in the Cr, Ni, Cu, and Nb contents. The Cr and Ni contents are optimized with respect to the solubility of nitrogen at the processing temperatures and influence on the martensitic start temperature. The Cu and Nb contents are optimized to maximize the precipitation strengthening during aging. The models are validated using experimental results from AM nitrogen-atomized powder 17-4 parts.