Zheng, L., Shen, L., Wang, Y., Wang, H., Zhao, Y., Ramamurty, U., & Hu, J. (2026). Effect of the Solutionizing Temperature on the Strength and Hydrogen Embrittlement Resistance of the Laser Powder Bed Fused Inconel 718 Superalloy. Corrosion Science, 113642. https://doi.org/10.1016/j.corsci.2026.113642
Abstract:
Laser powder bed fusion (LPBF) enables the fabrication of complex, high-performance Inconel 718 (IN718) components with unique non-equilibrium microstructures that are characterized by cellular substructures, elemental segregation, and Laves phase formation. Applications of LPBF IN718 with high strength in hydrogen-rich environments are limited by their low hydrogen embrittlement (HE) resistance. Keeping this in view, we examine the role of solutionizing temperature on the strength and HE resistance of solutionized and double aged (SA) LPBF IN718 with the aid of slow strain rate tensile (SSRT) tests that are conducted in air as well as in situ hydrogen charging conditions. Results reveal that solutionizing at a relatively low-temperature of 980 ℃ (LSA) enhances strength while maintaining HE resistance comparable to the as-built alloy, owing to retained dislocation cellular networks decorated with the Laves phases and nanoscale γ'/γ'' precipitates that promote uniform hydrogen distribution and suppress strain localization. In contrast, high-temperature solutionizing at 1150 ℃ (HSA) results in the dissolution of cellular structures and recrystallization and grain growth that leads to a microstructure with coarse equiaxed grains. The latter facilitate rapid hydrogen diffusion along their boundaries, which results in severe intergranular cracking. These findings demonstrated that controlled, lower-temperature solutionizing enables a balanced optimization of strength and HE resistance in LPBF-produced precipitation-strengthened superalloys, providing valuable guidance for the post-processing design of materials intended for applications in hydrogen-rich environments.
License type:
Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
Funding Info:
There was no specific funding for the research done