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利用电化学极化曲线和临界点蚀温度测量方法,对比研究316NG和321不锈钢在3.5％的NaCl溶液中的抗点腐蚀性能.实验结果表明:所有测试温度下(室温、40℃、60℃、80℃)316NG的点蚀击穿电位(Eb)均显著高于321不锈钢;随着温度升高,316NG和321不锈钢的Eb显著下降,抗点蚀性能变差;3.5％NaCl溶液中316NG和321不锈钢的临界点蚀温度(CPT)分别为20.1℃和3.9℃.从电化学角度看,在模拟海洋环境下,316NG的抗点蚀性能显著优于321不锈钢.扫描电镜下在321不锈钢的点蚀坑中观察到TiN或TiC颗粒存在,致使抗点蚀性能降低.“,”The pitting corrosion of 316NG stainless steel and 321 stainless steel in the 3.5％ NaCl solution was studied by using the electrochemical polarization curves and electrochemical critical pitting temperature test.The results showed that the pitting potential of 316NG was markedly higher than that of 321 at all the test temperatures (room temperature,40℃,60℃ and 80 ℃).The pitting potential of 316NG and 321 dropped sharply when the test temperature increased,which demonstrated that the pitting resistance became worse.The critical pitting temperature (CPT) of 316NG and 321 were 20.1 ℃ and 3.9℃ respectively.From the perspective of electrochemistry,the pitting corrosion resistance of 316NG was apparently better than that of 321 in the simulated marine environment.The particles of TiN or TiC could be observed in the corrosion pits by using scanning electron microscopy (SEM),which led to a decrease of the pitting resistance.