采用分段电极测量阴极保护下矩形模拟剥离涂层底部Q345钢的电位和电流的分布。研究扰动、溶液氧含量和溶液初始pH值对缝内阴极极化行为的影响。结果表明,扰动作用能够迫使本体溶液中的氧进入缝内,降低缝内Q345钢的阴极极化程度。在低电导率溶液中,扰动作用能够在缝内诱发明显的氧浓差腐蚀电池,加剧缝底部Q345钢的腐蚀。本体溶液氧含量以及溶液初始pH值对缝内Q345钢的最终阴极极化水平影响很小。
Potential and current distributions in a cathodically polarized crevice between a simulated dis- bonded coating and segmented Q345 steels were measured in this paper. The effects of agitation, oxygen concentration and pH value of initial solution on cathodic polarization behavior were studied. The results showed that agitation forced the oxygen in bulk solution to enter the crevice, thus degrading cathodic polariza- tion level of Q345 steels in crevice. In low conductivity solution, agitation caused oxygen concentration cells in crevice, and aggravated corrosion at the rear of crevice. The oxygen concentration and initial solution pH had little influence on the final cathodic polarization level of Q345 steels beneath the simulated disbonded coating.
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