EFFECT OF SLIGHTLY ACID PH WITH OR WITHOUT CHLORIDE IN RADIOACTIVE WATER ON THE CORROSION OF MARAGING-STEEL

This study was carried out to ascertain the behavior of maraging steel used in the tanks of French plants for reprocessing radioactive water which may contain chloride ions at pH 3. The rest or corrosion potent ials can be either in the transpassive or active regions due to the pr esence of radiolytic species. The corrosion current and potential depe nd on the pH and intermediates formed on the surface in the active reg ion; therefore, maraging steel behavior was studied by cyclic voltamme try without and with electrode rotation and different acid pH which pr ovide an indication of mechanisms, modification of local pH and transi ent formation. In the passive-transpassive region, breakdown and poros ity in the oxide appear with or without chloride, according to electro chemical impedance spectroscopy. In presence of chloride, the corrosio n kinetics were obtained by cyclic voltammetry and electrochemical imp edance spectroscopy. The anodic and cathodic areas of maraging steel c orroded by pitting were shown using the Scanning Reference Electrode T echnique.