Effects of femtosecond laser texturing on the corrosion and stress corrosion cracking resistances of the 316L austenitic stainless steel additively manufactured by binder jet printing

Abstract

The impact of femtosecond laser texturing (FLT) on the corrosion and stress corrosion cracking (SCC) behavior of binder jet printed (BJP) 316L stainless steel, both in its as-printed form and after hot isostatic pressing (HIP), is investigated. Hierarchical micro- and nano-surface architectures were produced using FLT through 200, 400, and 800 laser passes, corresponding to low-, medium-, and high-depth textures, respectively. The latter two resulted in superhydrophobic surfaces, while the low-depth texture imparted superhydrophobicity to BJP 316L but only hydrophobicity to BJP+HIP 316L. Compared to the low-depth textures, the medium- and high-depth textures significantly reduced the adhesion of corrosive media. Cyclic potentiodynamic polarization tests showed that FLT enhanced localized corrosion resistance in BJP 316L but diminished it in BJP+HIP 316L. Corrosion rates correlated directly with increasing surface roughness, following the order 200 < 400 < 800 passes. Crucially, medium-depth FLT markedly improved SCC resistance in BJP 316L. Post-FLT, the SCC performance of BJP 316L matched that of their HIP-treated counterparts. These findings demonstrate that FLT is a promising post-processing strategy to bolster both localized corrosion and SCC resistance in additively manufactured 316L stainless steel.