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

Zuojia LIU 1),Xuequn CHENG 1),Shengjie Lü 2) and Xiaogang LI* 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

摘 要：The effect of Cl- on the 316L stainless steel in simulated cooling water has been studied using polarization curves,electrochemical impedance spectroscopy （EIS）,MottSchottky 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.

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