Transcripción del resumen del autor. The pitting corrosion behavior of Type 304 (UNS S30400) stainless steel (SS) under an electrolyte droplet with a layer of silica particles on the surface was investigated using a Kelvin probe. Droplets of 2.5 M magnesium chloride (MgCl2) solution were placed on an electrophoretically silica-coated steel surface and exposed to a constant low relative humidity. As a result of water evaporation, the chloride concentration increased and pitting corrosion initiated, which was detected by a sudden drop in open-circuit potential. Metastable pits repassivated slower under the silica particle layer than on bare stainless steel. Pits on silica-coated Type 304 SS initiated within a narrow chloride concentration and time range unlike pits on bare Type 304 SS. Pit growth rate was not influenced by the silica layer, but the particles acted as diffusion barrier. A mechanism for pit growth under a layer of inert particles was proposed.

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