High temperature air oxidation behavior of Hastelloy X processed by Electron Beam Melting (EBM) and Selective Laser Melting (SLM)

The microstructure and oxidation behavior of Laser Beam Melted, Electron Beam Melted and wrought Hastelloy X were studied at 950 degrees C in dry air, 50 h cycles, up to 1000 h. The variability of processing parameters and powder compositions strongly impacted the oxidation and spallation behavior. The alloys with high Mn and Si were associated with higher oxidation rates, finer Cr2O3 grain microstructure and increased spallation was observed for the alloys with large elongated grain microstructures (aspect ratio of 10 +/- 3).