Microstructural Evolution of One and Two step Heat Treatments on Electron Beam Powder Bed Fusion Fabricated Haynes 282

Haynes 282 was found to be an ideal candidate in industrial gas turbine engine applications due to high temperature creep resistance and strength. As a promising fabrication method, additive manufacturing (AM) has emerged as a cost- and material-efficient method to produce near net shape. However, it proves difficult to manufacture desired microstructures, especially when compared to conventional processing methods. One way to achieve desired microstructures and properties in AM builds is to use post-process heat treatments. In this study, we investigated the microstructural evolution of a Haynes 282 pyramidal build subjected to a one-step and a two-step aging treatment. A systematic study of both the as-fabricated and heat-treated samples was performed using scanning electron microscopy, electron backscattered diffraction, and Vickers hardness mapping. The mechanism governing the microstructural evolution from the as-fabricated state to the aged state will be discussed.