利用电化学方法研究纯镁在薄液膜下的腐蚀行为Ⅱ-薄液膜对纯镁腐蚀阳极过程的影响  

CORROSION OF PURE MAGNESIUM UNDER THIN ELECTROLYTE FILMS Ⅱ-INFLUENCE OF THIN ELECTROLYTE FILMS ON ANODIC PROCESS OF PURE MAGNESIUM CORROSION

作　　者：陈崇木[1] 张涛 邵亚薇[1,2] 孟国哲 王福会 李晓刚[2,3] 董超芳[3] 

机构地区：[1]哈尔滨工程大学材料科学与化学工程学院腐蚀与防护实验室,哈尔滨150001 [2]中国科学院金属研究所金属腐蚀与防护国家重点实验室,沈阳110016 [3]北京科技大学腐蚀与防护中心,北京100083

出　　处：《腐蚀科学与防护技术》2009年第2期97-100,共4页Corrosion Science and Protection Technology

基　　金：国家自然科学基金项目(50601007)

摘　　要：利用电化学噪声研究了纯镁在不同厚度薄液膜下的腐蚀行为.结果表明:与本体溶液相比,薄液膜对纯镁腐蚀的阳极过程有使点蚀的孕育速度减缓作用的同时还有使点蚀生长的概率增加的作用;薄液膜下纯镁表面产生的亚稳态点蚀生长成稳态点蚀的概率比本体溶液下的大.点蚀孕育速度比点蚀生长概率对阳极过程的影响更大;这导致了薄液膜下纯镁腐蚀的阳极过程减缓.Corrosion behavior of pure magnesium under thin electrolyte films was investigated by means of electrochemical noise （EN）. Based on shot noise theory and stochastic theory, the EN results were quantitatively analyzed by using the Weibull and Gumbel distribution function, respectively. The experimental results revealed that thin electrolyte film had two opposite effects on anodic process of pure magnesium corrosion. On one hand, the pit initiation rate was retarded. The frequency of corrosion events under electrolyte film was greatly lowered compared to that in bulk solution. On the other hand, the pit growth probability was increased. The metastable pit induced by thin electrolyte film on pure magnesium had a higher probability to become larger pit cavity than that in bulk solution. Pit initiation rate had greater influence on the anodic process than pit growth probability, which led to the inhibition of the anodic process of pure magnesium with the decreasing of thin electrolyte film thickness.

关 键 词：纯镁 薄液膜 腐蚀 电化学噪声 随机分析 

分 类 号：TG172.3[金属学及工艺—金属表面处理]