Evaluation of corrosion behavior on Mn-Cr austenitic steels using 0.1 M HCl solution

Article history: One of the attractive low activation steels is the austenitic Mn-Cr steel from the view point of waste disposal because of few long- lived nuclides. In this paper, three types of Mn-Cr austenitic steels were fabricated by vacuum induction furnace. Then plates with 10 mm thickness were produced by hot-rolling. The physical metallurgy of these steels was studied by the corrected Schaeffler diagram, X-ray and electron diffraction patterns. The corrected Schaeffler diagram and X-ray diffraction (XRD) results showed that the matrix of these steels is a single γ-phase structure. Also, the corrosion behaviour in 0.1M HCl solution was evaluated by open- circuit potential, Tafel polarization, and electrochemical impedance spectroscopy (EIS). The results of Tafel polarization experiments showed that corrosion current density of all three Cr-Mn steels is in the range of 10 -4 A cm -2 , which indicates their appropriate resistance in this acidic environment. The Nyquist plots showed that polarization resistance decreases from the first to the third Cr-Mn steels. This trend is due to the increase in corrosion current density which corresponds to Tafel polarization curves.