Journal of Materials Research and Technology (Jan 2024)

Comparative study on mechanical properties and high temperature oxidation behaviour of Hastelloy X and Inconel 718 fabricated by laser directed energy deposition

  • Guanghao Gong,
  • Zifan Wang,
  • Xueyun Du,
  • Fei Weng,
  • Huijun Yu,
  • Zhihuan Zhao,
  • Chuanzhong Chen

Journal volume & issue
Vol. 28
pp. 2624 – 2635

Abstract

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The high temperature oxidation resistance is crucial to assure the reliability of nickel-based superalloy parts serving at elevated temperature. Hastelloy X is a solid solution strengthening superalloy featured by decent mechanical properties and excellent high temperature oxidation resistance, having the potential to replace the commonly used nickel-based superalloy Inconel 718 in appropriate high-end manufacturing fields. In this work, a comparative study on mechanical properties and high temperature oxidation behaviour of Hastelloy X and Inconel 718 fabricated by laser directed energy deposition was carried out. Under the same processing parameters, the as-built Hastelloy X consisted of columnar and cellular γ phase with dispersed carbides, but Inconel 718 contained columnar γ phase with dispersed carbides and γ′ phase. At ambient temperature, Hastelloy X showed better ductility but inferior strength and hardness. Additionally, the isothermal oxidation tests at 1000 and 1100 °C demonstrated that the oxidation kinetics curves of both as-built superalloys followed the parabolic law. Hastelloy X owned a better high temperature oxidation resistance, which could be attributed to the uniformly distributed dense Cr2O3 and the relatively slight exfoliation of oxides in the oxide scales.

Keywords