Semiconductivities of passive films formed on stainless steel bend under erosion-corrosion conditions

Semiconductivities of passive films at a stainless steel bend in sand-containing NaCl solution under erosion-corrosion (E-C) conditions were investigated by Mott-Schottky analysis. It is demonstrated that higher donor densities and faster diffusivities of point defects within passive film appear at the extrados of the bend. X-ray photoelectron spectroscopy (XPS) analysis reveals that the passive layer at the extrados of bend contains less Fe3O4 and Fe2O3. The semiconductivities of passive films are strongly dependent on the hydrodynamic characteristics at the bend.