“…The structures obtained by PEO under various experimental conditions were characterized by XPS, SEM, XRD, and EDS analyses. The feasibility was proved of employing PEO in NaAlO 2 aqueous solution using a pulsed unipolar power supply for ceramic-like aluminum oxide films preparation, with thicknesses in the range of 20-50 µm, and a high content of Al 2 O 3 on the surface of austenitic stainless steels.Coatings 2020, 10, 318 2 of 16 by reducing acids, such as sulfuric acid [3,4]. Stainless steel 316L grade is the low carbon version of stainless steel 316.Due to its properties, AISI 316 steel is used in many areas, such as construction of exhaust manifolds, furnace parts, heat exchangers, jet engine parts, evaporators, chemical processing equipment, nuclear equipment, valve and pump parts, and parts that are exposed to marine environments [5][6][7][8].…”