| Abstract Scope |
While conventionally manufactured 17-4PH exhibits a broadly martensitic structure, binder jet printed (BJP) 17-4PH has a complex microstructure composed of porosity, retained γ-austenite, retained δ-ferrite, martensite, and carbides. Such microstructural differences suggest that the hydrogen-material interactions behavior of BJP 17-4PH will likely differ from that of CM 17-4PH, but studies to-date assessing the hydrogen uptake, trapping, and diffusivity in BJP 17-4PH are highly limited. The objective of this study is to evaluate the HEAC behavior of BJP 17-4PH in two temper conditions (H900 and H1025) after undergoing hot isostatic press and solution annealing treatments. Thermal desorption spectroscopy measurements conducted on hydrogen pre-charged 17-4PH specimens from each condition reveal a critical influence of this BJP-induced composite microstructure, resulting in higher hydrogen uptake, complex trapping behavior, and dramatically lower diffusivity. The implications of these results are then assessed in the context of mechanisms for hydrogen-assisted cracking. |