阴极保护下缝隙内的电位分布

POTENTIAL DISTRIBUTION INSIDE A CATHODICALLY PROTECTED CREVICE

实验测量了稀NaCl溶液中阴极保护下的模拟缝隙内低碳钢的电极电位分布 ,研究了缝口控制电位、溶液电导率和缝隙厚度对电位分布的影响。结果表明在实验条件下缝隙内的电位梯度随极化时间的延长而减小 ;溶液电导率和缝隙厚度的增大以及缝口控制电位的负移都可使缝隙内电位负移 。

Potential distributions inside a cathodically protected crevice configurated by a top plate and segmented mild steel electrodes were measured in diluted NaCl solutions. The effects of the control potential, solution conductivity and crevice thickness on the potential distribution were studied. The results showed that the potential gradient inside the crevice decreased with elapse of polarization time. In general, the more negative the control potential was and the greater the solution conductivity and crevice thickness were, the more negative the potential inside the crevice was. However, when the control potential was over negative, the cathodic polarization of the steel electrodes in the depth of the crevice might be less than that under a moderate control potential because of hydrogen evolution.