Enhanced corrosion resistance of austenitic Fe‐Mn‐C TWIP steel by cerium(III) in 1 M hydrochloric acid pickling solution

The influence of rare earth Ce3+ ions on the corrosion behaviour of Fe-Mn-C TWIP steel in 1 M hydrochloric acid solution was studied by electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). Electrochemical corrosion tests showed that Ce3+ can significantly reduce corrosion deterioration up to 1.0 mM. Beyond that level the corrosion rate increases till a steady value. Surface film resistance increases with time evolution until 24 h, then decreases and stabilises. High corrosion protection of steel surface after 24 h exposure to the acidic solution containing the optimal Ce3+ ion concentration is revealed by SEM investigations.