NaCl薄液膜下不锈钢腐蚀行为研究  

CORROSION BEHAVIOR OF STAINLESS STEEL UNDER NaCl ELECTROLYTE THIN FILM

作　　者：唐晓[1] 王佳[1] 李亚坤[1] 孙玉平 

机构地区：[1]中国海洋大学化学化工学院,青岛266100 [2]山东省高密市城南中学,高密261500

出　　处：《腐蚀科学与防护技术》2009年第3期227-229,共3页Corrosion Science and Protection Technology

基　　金：国家自然科学基金(40706031)

摘　　要：利用Kelvin探针参比电极技术和电化学阻抗方法研究了不锈钢在不同厚度NaCI薄液膜下的腐蚀行为．结果表明：在0．35％NaCl液膜厚度7～90μm范围内，随着液层厚度的增大，不锈钢在薄液膜下腐蚀的氧扩散控制特征越显著，而且氧还原反应极限电流逐渐降低；3．5％NaCI薄液膜下阻抗测得的溶液电阻随着液膜增厚而首先迅速降低然后趋于平稳；在液层较厚时（425～120μm）随着液层厚度的减小，腐蚀速度受氧扩散控制逐渐增大；液层厚度减薄至40～120μm区间，由于阳极反应受抑制和阴极反应加速的共同影响腐蚀速度会出现极小值；液层厚度非常薄（20μm以下）时由于电流分布不均匀抑制了氧还原，腐蚀速度很低．Corrosion behavior of stainless steel under a NaC1 electrolyte thin film was studied by using Kelvin probe and EIS as well as measuring cathodic limit current densities, polarization resistance of the steel and solution resistance beneath different films. Results showed that beneath thin films of 0. 35% NaC1 with thickness 7 - 90 μm, the oxygen control characterization became obvious and the cathodic limit current density of stainless steel increased with decreasing thickness of the electrolyte. For 3.5% NaC1 thin films, solution resistance decreased dramatically and then kept stable with increase of film thickness; with the film thickness decreased from 425 μm to 120 μm ,corrosion rate first increased because of the oxygen diffusion ,then in the range of 40 -120 μm,corrosion rate exhibited a minimum because the anodic reaction was inhibited, however, the cathodic reaction was accelerated, and a non-uniformly distributed corrosion current induced very low corrosion rate when the thickness of electrolyte below 20 μm.

关 键 词：大气腐蚀 薄液膜 EIS 极化曲线 Kelvin探针 

分 类 号：TG172.6[金属学及工艺—金属表面处理]