The Tribocorrosion Behaviour and its Mechanisms of Type 304L Stainless Steel in Nitric Acid Media

An enhanced understanding of the interaction of wear and corrosion interaction of type 304L SS in various nitric acid concentrations is essential to avoid any failure of the component in a nuclear reprocessing plant. Therefore, the present work is focused on investigating the tribocorrosion behaviour and mechanism of type 304L stainless steel (SS) in different concentrations of 3, 6, 8, and 11.5 M nitric acid simulating a nuclear reprocessing environment. The open circuit potential sliding results revealed that the cathodic potential shift depends on the nitric acid concentrations. The intermittent sliding test demonstrated faster repassivation kinetics in the wear track between the successive sliding contacts as the increase in nitric acid concentration. At higher nitric acid concentration, the regeneration of oxide film in the contact region reduces friction and wear. Thus, the specific wear rate increases in the order of 11.5 < 8 < 6 < 3 M HNO3. The tribocorrosion material degradation mechanism of type 304L SS in nitric acid for nuclear reprocessing application is described.