Corrosion behavior of Fe25Mn6Si5Cr shape memory alloys modified with rare earth in a NaCl solution

The corrosion behavior of the Fe25Mn6Si5Cr based alloys containing various contents of rare earth (RE) in 3.5 wt% NaCl aqueous solution was investigated by using potentiodynamic polarization measurement and immersion tests. A conventional three-electrode cell was employed, in which a saturated calomel electrode (SCE) was used as reference, and a large platinum foil served as the auxiliary electrode. Electrochemical tests were carried out in a glass cell filled with ∼200 ml of aqueous solution maintained at room temperature. The results indicate that the corrosion resistance of alloy 2# with 0.16 wt% RE, which is below the concentration limit for its solid-solution in matrix is remarkably improved.