Study On Electrochemical Behavior Of316L Stainless Steel In Borate Buffer Solution

316L stainless steel is the main material equipment in first circuit water of nuclear power because of its resistance to corrosion. Austenitic stainless steel is sensitive to stress corrosion cracking (SCC). This work was focused on the corrosion mechanism of316L stainless steel in the high temperature and high pressure water environment, the relationship between resistance to corrosion and microstructure was studied. The formation mechanism of passive film and electrochemical behavior of316L stainless steel were investigated at room temperature and high temperature and high pressure, respectively.. The main results are as follows:The good intragranular distribution form of carbide in316L stainless steel was benefit to the increasing of resistance to corrosion. There are more∑3in the grain boundary structure, and high density in the{001} in the large grain. Orientation map showed that small grain boundary structure appeared strong texture grain split.The result of the electrochemical behavior of316L stainless steel in room temperature and atmospheric pressure environment showed that the temperature had a obviously influence on the corrosion resistance, and the stable passive film formed on316L stainless steel surface in the temperature range from35℃to85℃. The polarization resistance decreased with the solution temperature increasing. A stable passive film formed on316L stainless steel surface in the range from-0.1V to0.5V. The results of electrochemical impedance spectroscopy (EIS) showed that the passive film of316L stainless steel in the0.3V was more compact and stable. The passive film was a p-type semiconductor.The results of XPS showed that Fe was in the form of FeO and Fe2O3at room temperature and Fe2O3and FeOOH at high temperature condition. Cr was in the form of Cr and Cr2O3at room temperature and Cr(OH)3at high temperature condition. The stability of the passive film was reduced at high temperature. Electrochemical experimental results showed that pitting corrosion sensitive of316L stainless steel with stress was higher than that of without stress. The passive film formed at at room temperature is more stable of than in high temperature.