Additive manufacturing of 18% nickel maraging steels: Defect, structure and mechanical properties: A review

This paper reviews the latest research progress in the additive manufacturing (AM) process of 18% nickel maraging steels, which involves laser-based powder bed fusion (L-PBF), laser-based directed energy deposition (L-DED), and wire arc additive manufacturing (WAAM). The emphasis is on the defects, structure, and mechanical properties of the additive manufactured 18% nickel maraging steels. At first, this article outlines the influences of the processing parameters of AM techniques on the defects formed in the fabricated parts, in terms of the L-PBF and WAAM. The macrostructure and microstructure characteristics of as-built and heat-treated 18% nickel maraging steel are then described in detail. Later, the mechanical properties of as-built and heat-treated 18% nickel maraging steel are assessed, such as their tensile, hardness, impact toughness, and fatigue performances. Finally, future directions for work on the AM of 18% nickel maraging steel are provided.