摘要
采用动电位极化测量技术研究在一定氯离子存在下硝酸盐对LY12CZ硬铝合金点蚀发生、发展行为的影响.试验认为,硝酸盐在浓度较低时没有钝化作用,使铝合金电位从钝化区向活化区过渡,但它使再钝化电位提高,在一定的钝化条件下,可促进氧化膜的修复;当硝酸盐浓度大于某一数值时,铝的点蚀电位明显增加,能有效抑制点蚀发生.这一值的大小与介质中存在的氯离子含量有关.
The influence of nitrate on the pit nucleation and growth on aluminum alloy in sodium chlorine solution was investigated by potentiodynamic techniques. At low concentration, nitrate changed the potential from passive to active region. But, it shifted the repassivation potential towards positive direction. When aluminum alloy was being passive, nitrate could repair the passive film of aluminum. At higher concentration, nitrate shifted the pitting and repassivation potential towards positive direction, which indicated the suppression of pit nucleation and propagation. The big or small of concentration has a bearing on concentration of chlorion.
出处
《装备环境工程》
CAS
2004年第3期32-35,共4页
Equipment Environmental Engineering
关键词
腐蚀
点蚀
再钝化
电位
corrosion potential
pitting potential
repassivation potential
