Corrosion Behavior of 316L Stainless Steel with Different Pretreatment Processes in a High-concentration Chloride Environment

Addressing the perchloride corrosion environment of the coastal industry，the effects on the corrosion behavior and properties of the 316L stainless steel in 3.5wt% NaCl solution by three pretreatments i.e.，the bright solution treatment，the environmental protection pickling and the HNO₃+HF pickling are systematically studied by means of the potentiodynamic polarization and the electrochemical impedance spectroscopy together with the weight loss method etc.The research outcomes reveal that all the three pre-treatment processes are capable of improving the corrosion resistance of the 316L stainless steel to a certain extent，among them，the bright solid solution treatment can make the 316L stainless steel have the lowest corrosion current density and corrosion rate as well as the best corrosion resistance，and this superior corrosion resistance is attributed to the steel’s single austenitic microstructure and more uniform distribution of the passivating elements after pre-treatment.