Corrosion behavior of shape memory stainless steel in acid media

The corrosion behavior of three Fe–Mn–Si–Cr–Ni–(Co) shape memory stainless steels (SMSS) in 0.5 M H2SO4 solution was studied through electrochemical and immersion tests. The test results were compared with that of a type 304 (SS 304) austenitic stainless steel. The three SMSSs exhibited a passive behavior in 0.5 M H2SO4 solution; however, their anodic behavior in the active dissolution region was markedly different. The passive current densities of the SMSSs were similar to that of SS 304, although the critical anodic current required for passivation was higher. The corrosion rate of the SMSSs was much higher than that of SS 304. It was observed that the amount of Cr and Mn plays an important role in the corrosion behavior of SMSSs. The best corrosion behavior in acid media was shown by the SMSS that contained the highest amount of Cr and the lowest amount of Mn.

Research highlights
► The corrosion behavior of three Fe–Mn–Si–Cr–Ni–(Co) shape-memory stainless steels (SMSSs) in acid media was compared with that of a type 304 (SS 304) austenitic stainless steel.
► Electrochemical and immersion tests in 0.5 M H2SO4 solution.
► The Fe–Mn–Si–Cr–Ni–(Co) SMSSs present a high corrosion rate in the corrosion potential region.
► The protectiveness of the anodic passive film formed on SMSSs is similar to that of SS304.
► The Cr and Mn content plays an important role in the corrosion behavior of the SMSSs.