Lee, D.-H., Zhao, Y., Lee, S. Y., Ponge, D., & Jägle, E. A. (2022). Hydrogen-assisted failure in Inconel 718 fabricated by laser powder bed fusion: The role of solidification substructure in the embrittlement. Scripta Materialia, 207, 114308. https://doi.org/10.1016/j.scriptamat.2021.114308
Abstract:
The influence of hydrogen on the mechanical behavior of Inconel 718 fabricated by laser powder-bed-fusion was investigated through a series of tensile experiments. Samples subjected to two different post-fabrication heat treatments, viz. direct aging (DA) and homogenization plus aging (HA), were tested. Detailed microstructural characterization showed that a solidification substructure including a high density of dislocations and precipitates prevails in the DA sample while the HA sample is free from such a substructure. The DA sample exhibited a comparatively higher strength, but a lower resistance to hydrogen embrittlement. By recourse to a statistical analysis of the hydrogen-assisted cracks, the severe hydrogen embrittlement of the DA sample was proven to be due to the significant portion of H-assisted intergranular cracks that occurred without the aid of slip localization. These results are discussed in terms of the changes in microstructure upon heat treatments, and their influences on the H trapping sites.
License type:
Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
Funding Info:
This research / project is supported by the A*STAR - Structural Metal Alloys Programme
Grant Reference no. : A18B1b0061