Elucidating the impact of oxide dispersion chemistry on mechanical and corrosion behavior of austenitic steels fabricated via laser powder bed fusion

Laser powder bed fusion (L-PBF) enables the fabrication of oxide dispersion strengthened (ODS) stainless steels with refined microstructures, yet the effects of oxide chemistry and dispersion on mechanical and corrosion performance remain unclear. Here, a process-microstructure-property framework is established by combining tailored powder chemistry with controlled oxide incorporation. Si- and Mn-free 316 L powders were designed to suppress amorphous oxide formation, while Y 2 O 3 nanoparticles were uniformly anchored via a hetero-agglomeration strategy. During L-PBF, Y 2 O 3 exhibited matrix-dependent reactions: amorphous Y-Si-O phases formed in conventional 316 L, whereas crystalline, semi-coherent YCrO 3 precipitates developed in the Si- and Mn-free alloy. This transition in oxide phase and interface structure, together with a near-fully dense microstructure (~99.9%), fundamentally altered both mechanical and electrochemical behavior. The crystalline YCrO 3 reinforcements led to sustained tensile strength of ODS alloy, in contrast to the reduced performance associated with amorphous oxides. EIS tests and XPS analyses revealed that the Y 2 O 3 addition globally enhances passivation kinetics by promoting a protective Cr 2 O 3 -rich film. These results demonstrate that mechanical and electrochemical performance in L-PBF ODS stainless steels is governed by the synergistic effects of alloy chemistry and oxide crystallinity, offering a viable pathway for designing high-strength, corrosion-resistant ODS alloys via additive manufacturing.