Corrosion Behavior of Four Kinds of Stainless Steels in Chloride-containing Simulated Condensate from Blast Furnace Gas Pipeline

Corrosion behaviors of 316L, 2205, 254SMo and 2507 stainless steels(SS) in simulated condensate solution with different concentrations of chloride from blast furnace gas pipeline were studied by electrochemical impedance spectroscopy, potentiodynamic polarization curve and cyclic polarization curve. The results showed that the charge transfer resistance of 316L, 2205, 254SMo and 2507 SS decreased with increasing the concentration of Cl-. 2507 SS had the largest charge transfer resistance and 316L SS had the lowest among these four SS. The polarization curves showed that no passivation region existed and the corrosion current density was very high for 316L SS. Obvious passivation region existed and showed better corrosion resistance for 254SMo and 2507 SS. The returned segment of the cyclic polarization curves of 254SMo and 2507 SS changed reversely along the original ones, indicating the strong repairing ability of the destroyed passive film. However, the reverse scan current of 2205 SS was always larger than its obverse scan current, indicating relatively worse repairing ability of the passivated film.