Pitting susceptibility of 316L stainless steel manufactured via LPBF: A 2k factorial design approach

Abstract

The influence of additive manufacturing (AM) on the pitting corrosion resistance of 316L stainless steel remains disputed, with conflicting reports attributing differences to porosity and microstructural heterogeneities. In this work, the pitting susceptibility of 316L produced by laser powder bed fusion (AM 316L) and wrought (W) 316L was systematically assessed using a 2 3 factorial design of experiments, a first for this problem. Pitting potential (E pit ) measured by potentiodynamic polarization, was used as the performance metric, while NaCl concentration and temperature were varied as environmental factors. AM 316L exhibited markedly higher resistance, with an average E pit ≈ 518 mV, compared to ≈ 37 mV for W 316L. Increasing the NaCl concentration and temperature reduced E pit in both materials, with temperature exerting a more potent effect. Interactive effects revealed that AM 316L was more sensitive to these environmental factors than W 316L, a previously unreported observation. The results provide statistically robust evidence that AM enhances baseline pitting resistance of 316L. However, it also highlights the increased vulnerability of AM microstructures under aggressive chloride and thermal conditions.

The authors' abstract, as published at the source. Results in Materials, 2026 · DOI ↗