摘要
研究了000Cr25Ni20奥氏体不锈钢在不同温度和不同浓度硝酸中的腐蚀电化学行为,发现随着硝酸浓度和温度的升高,000Cr25Ni20不锈钢在溶液中的自腐蚀电位向过钝化区移动,钝化区范围变小。钝化电位下,000Cr25Ni20不锈钢的电化学阻抗谱呈容抗特征,容抗弧半径较大;同一外加钝化电位下硝酸浓度对阻抗谱的影响不明显;在钝化/过钝化过渡区,伴随晶间腐蚀的出现,阻抗谱在低频段出现感抗特征,随着钝化膜极化阻值的急剧减小,高频段的容抗半径大幅度减小。
The electrochemical corrosion behavior of 000Cr25Ni20 austenitic stainless steel in nitric acid solution at different temperatures and in different concentrations were investigated.The results showed that the free corrosion potential of 000Cr25Ni20 stainless steel was shifted towards to transpassive zone and the range of the passive zone reduced with the rise of both nitric acid concentration and temperature.At passive potential,a capacitive loop with great value of radius appeared in the electrochemical impedance spectroscopy（EIS）.The influence of nitric acid concentration on the EIS was not obvious at the same passive potential.In passive/transpassive transition zone,with intergranular corrosion occurred,a inductive loop appeared at low frequency area.The radius of the capacitive loop at high frequency decreased sharply because of the impedance value of passive film severely decreasing.
出处
《腐蚀与防护》
CAS
北大核心
2010年第12期939-941,965,共4页
Corrosion & Protection
关键词
000Cr25Ni20不锈钢
硝酸
电化学
钝化
000Cr25Ni20 stainless steel
nitric acid
electrochemical corrosion
passivation
