About this Abstract |
Meeting |
MS&T22: Materials Science & Technology
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Symposium
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Additive Manufacturing of Metals: Microstructure, Properties and Alloy Development
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Presentation Title |
Laser Powder Bed Fusion of Ultra-High Strength Steel from Gas Atomized Powders |
Author(s) |
Thinh Huynh, Kevin Graydon, Nemanja Klejstan, Marko Knezevic, Brandon McWilliams, Kyu Cho, Yongho Sohn |
On-Site Speaker (Planned) |
Thinh Huynh |
Abstract Scope |
A novel ultra-high strength steel alloy was gas atomized to produce powder feedstock for the fabrication of components via laser powder bed fusion (LPBF). Charge alloys were inductively melted with Argon shrouding at a superheating temperature of 1800 °C and subsequently gas atomized using Argon gas at a pressure of 2 MPa. LPBF optimization was performed as a function of laser power and scan speed, and relative density above 99 % was obtained using 200 W and 800 mm/s. The as-fabricated LPBF specimens consisted of supersaturated austenite primed for quench and temper martensitic transformation. Changes in the as-built microstructure and phase constituents were documented as a function of laser scan speed using electron microscopy and x-ray diffraction. Tensile properties and hardness were examined to assess the alloy’s mechanical behavior as functions of various heat treatments along with correlated microstructural development. |