Passive behavior of laser directed energy deposited Inconel 718 after homogenization and aging heat treatment

• Published in: Corrosion science Vol. 205; p. 110439
• Main Authors: Zhang, Yufeng, Yu, Jun, Lin, Xin, Guo, Pengfei, Yu, Xiaobin, Zhang, Shaoli, Liu, Jianrui, Huang, Weidong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.08.2022
• Subjects: Additive manufacturing; Inconel 718; Ions transportation; Laser directed energy deposition; Passive film; Ions transportation; Passive film; Additive manufacturing; Laser directed energy deposition; Inconel 718
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2022.110439

Microstructure and passive behavior of laser directed energy deposited Inconel 718 after homogenization and aging heat treatment were investigated. The deposit microstructure mainly consists of γ phase and (γ + γ″) phases after homogenization and homogenization + aging treatment, respectively. Both heat-treated samples present a similar trend on passive behavior within the potential ranging. However, compared to homogenization treatment, the passive film of the deposit exhibits a lower electrochemical stability after homogenization + aging treatment, which is caused by the accelerated ions transportation through the interface between γ″ phase and passive film. •The microstructure of laser directed energy deposited (LDED) Inconel 718 after homogenization (H-LDED Inconel 718) and “homogenization + aging” (HA-LDED Inconel 718) mainly consists of γ phase and (γ + γ″) phases, respectively.•Both H-LDED and HA-LDED Inconel718 perform a similar trend on the passive behaviors and produce analogous compositions of the passive films within the potential ranging.•The ions transportation is facilitated by the interface between γ″ phase and passive film, leading to a lower stability of the passive film formed on HA-LDED Inconel 718.