Further insights into the mechanisms involved in the corrosion of 316L(N) austenitic steel in oxygenated liquid sodium at 550 °C. (1st April 2020)

• Record Type: Journal Article
• Authors: Rivollier, Matthieu; Courouau, Jean-Louis; Tabarant, Michel; Blanc, Cécile; Jomard, François; Giorgi, Marie-Laurence
• Is Part Of: Corrosion science. Volume 165(2020)
• Publication Date: 2020-04-01
• Subjects: A. Stainless steel -- C. High temperature corrosion -- Interfaces -- Oxidation; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2019.108399
• Languages: English
• ISSNs: 0010-938X

Abstract

Graphical abstract: Highlights: Austenitic steel is immersed in liquid Na containing O at 550 °C from 239 to 7704 h. NaCrO2 and M6 C (M = Mo and Fe) are formed for all immersion times. Cr depletion is observed nearby the surface and in the vicinity of grain boundaries. NaCrO2 is dissolved until the saturation of liquid Na in Cr is reached. The Cr solubility is higher than that of pure Cr due to the presence of dissolved O. Abstract: 316 L(N) austenitic steel was corroded at 550 °C in liquid sodium containing 200 μg g −1 dissolved oxygen from 242 h to 7704 h. NaCrO2 is formed for all immersion times, O and Na from liquid metal and Cr from steel. The oxidation front is located at the chromite / steel interface and in the steel grain boundaries. M6 C carbides (M = Mo and Fe) are also formed, C from liquid sodium. NaCrO2 is dissolved until the saturation of liquid sodium in Cr is reached. The Cr solubility is higher than that of pure Cr due to the presence of dissolved oxygen.