The study has demonstrated that a stable microcrystalline
Cr2O3 film could be formed on stainless steel 316 L by
immersion of steel samples in a CrO3-based electrolyte. The
film is composed of Cr2O3 grains of sizes ranging from 30
to 150 nm. The oxide film has a bilayered structure in which
the topmost layer is composed of chromium hydroxide or
oxy-hydroxide, followed by an inner part of Cr2O3 phase.
The thickness of the film was estimated to be 50 nm.