Micro-Capillary Electrochemical and Microscopic Investigations of Massive and Individual Micrometer-Sized Powder Particles of Stainless Steel 316L

摘要

Material properties, corrosion, and metal release from stainless steel powders are important factors toassess any occupational health hazards. This paper elucidates the corrosion behavior of stainless steelparticles (inert-gas-atomized AISI 316L powders sized < 45m, polished and non-polished) comparedwith corresponding massive low-sulfur bulk sheet material. Electrochemical measurements using amicrocapillary technique are compared with ex-situ optical and scanning electron microscopy imagingand electron dispersive X-ray spectroscopy elemental analysis on the same area of individual particles.Non-polished 316L particles were significantly more passive compared to polished massive sheet andpolished particles that in general showed a similar corrosion behavior. Corrosion was not induced bybulk compositional differences but could be attributed to surface inhomogeneities. The results are inagreement with the high passivity of non-polished particles in macroscopic studies, an effect caused byan unique surface oxide, characterized in part I of this paper series.