Cleanability and Electrochemical Corrosion Assessment of Laser Powder Bed Fusion 316 L Stainless Steel for Food‐Processing Equipment: A Multi‐Parameter Surface Approach

ABSTRACT

Laser powder bed fusion (LPBF) enables complex 316 L stainless‐steel food‐processing components, but surface finishing affects both cleanability and corrosion. Wrought (WR), as‐built (AB), mechanically polished (MP), and electropolished (EP) surfaces were compared using topography, wettability, whey‐protein fouling and alkaline cleaning, hygienic endpoints, and polarization in 3.5 wt% NaCl. AB had the largest valley volume and developed area, retained the most protein after cleaning, and had the highest corrosion current density. Cleaning efficiency ranked MP (97.3%) > WR (95.5%) > EP (94.7%) > AB (91.4%). EP had the lowest corrosion current density (0.190 ± 0.020 μA cm ⁻² ) and highest operational breakdown potential (0.483 ± 0.012 V vs. SCE), whereas WR had a lower breakdown potential than AB. Thus, defect‐rich surfaces can impair both functions, but the cleanability and electrochemical optima differ. LPBF food‐contact surfaces require joint qualification, with corrosion metrics providing complementary surface‐state information rather than stand‐alone prediction of cleaning efficiency.