Acta Metallurgica Sinica (English Letters) ›› 2010, Vol. 23 ›› Issue (6): 431-438.DOI: 10.11890/1006-7191-106-431

• Research paper • Previous Articles     Next Articles

Effect of chloride ions on 316L stainless steel in cyclic cooling water

Zuojia LIU1, Xuequn CHENG1,Shengjie LU2, Xiaogang LI1   

  1. 1) Key Laboratory of Corrosion and Protection (Ministry of Education of China), University of Science and Technology Beijing, Beijing 100083, China
    2) Equipment and Power Department, Shijiazhuang Refine & Chemical Company Limited, SINOPEC,Shijiazhuang 050032, China
  • Received:2010-04-22 Revised:2010-08-20 Online:2010-12-25 Published:2010-12-14
  • Contact: Xiaogang LI

Abstract: The effect of Cl- on the 316L stainless steel in simulated cooling water has been studied using polarization curves, electrochemical impedance spectroscopy (EIS), Mott-Schottky plot and scanning electron microscopy (SEM) techniques. Cl- concentrations vary from 200 to 900 mg/L. Results reveal that the corrosion resistance increases with the decrease of Cl- concentration in simulated cooling water. The increase of Cl-concentration leads to the shift of the corrosion potential towards the positive direction. Mott-Schottky curves show that in the passive film, Cr2O3 and FeO at the inner layer exhibit P-type but Fe2O3 and CrO3 (CrO42-) N-type semiconductive properties. The SEM/EDX data demonstrate that elements such as Fe, O, C, Si and Cl as well as the presence of calcium and aluminum are presented on the surface of the metal.

Key words: Polarization curve, EIS, Mott-Schottky plot, SEM/EDX, Simulated cyclic cooling water