Effect of Gamma Radiation on the Electrochemical Behavior of AISI 8620 Steel Coated with Diamond-Like Carbon

Equipment degradation caused by corrosion has become frequent in pressurized water-based nuclear reactors (PWR). The radiation and adverse conditions encountered in the primary circuit of these reactors degrade most non-metallic materials. The growing search for materials with high corrosion resistance, stability and durability has intensified in recent years with a view to improving these industrial systems. In this context, a steel with industrial application AISI 8620 was coated with Diamond-Like Carbon (DLC). The coating was made by the plasma-enhanced chemical vapor deposition (PECVD) technique and subsequently irradiated with gamma rays. The morphology and physicochemical characterizations of the steel surfaces coated with the DLC film were evaluated by atomic force microscopy (AFM), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and Raman scattering spectroscopy. The electrochemical behavior was evaluated by using electrochemical impedance spectroscopy. The analysis indicated increased corrosion potential and a higher charge transfer resistance for coated and irradiated steel.