Additive manufacturing of steels: a review of achievements and challenges

N. Haghdadi, M. Laleh, M. Moyle, S. Primig
Journal of Materials Science 56 (2021) 64-107. (OPEN ACCESS)

This paper our first AUSMURI grant review paper.

Additive manufacturing (AM), also commonly known as 3D printing, has recently gained huge interest in both academia and industry, with its market value expected to reach $21 billion by the end of 2020. While the early successful adoption of AM for metals has been for Ti-alloys and Ni-based superalloys, AM has been successfully expanded to other metallic systems over time, including steels. Various groups of metals and alloys can now be processed via AM, with steels currently accounting for about 1/3 of all publications in the metals AM literature.

Appreciating the unique microstructural characteristics of AM steels compared to the conventionally processed steels, and despite considerable progress made in understanding these microstructural features, there was a lack of overview on how these will potentially result in advanced properties. The current review intends to fill this gap by providing a comprehensive review of the unique properties of AM steel currently reported in the literature. We focus on mechanical and corrosion properties of AM steels, and compare them to what has been achieved via conventional processing. We focus the most popular steels in the AM context, i.e., austenitic stainless steels (with the vast body of literature on 316L) and Maraging/Precipitate Hardening steels, but also review the AM of a variety of other types of steels that have been processed by AM so far including ferritic-martensitic steels, carbon bearing tool steels, oxide dispersed strengthened (ODS) steels and transformation/twinning induced plasticity (TRIP/TWIP) steels.