Abstract: A simulated occluded corrosion cell (OCC) was used to study the chemical changes within corrosion cracks or crevices of mild steel (A3) in 0.01 mol·L-1 NaCl solution at 50 掳C . It was found that as anodic currents passing the cell, the pH value fell quickly at the beginning while slowly after it reached about 6, which was proportional to the quantity of passing electricity. Meanwhile the Cl- migrated into occluded cell. The Cl- migration was proportional to the time of current flowing, and a linear relation also existed between Cl- migration per mm2 of anode area per hour and current intensity, while for each mol Cl- migrated almost always 1.5～1.6 F of electricity passed. This relationship did not change whatever the current density and the time were.

摘要： 用模拟闭塞电池恒电流实验研究了低碳钢(A3钢)在0.o1mo·L~(-1)NaCl溶液中闭塞区内化学状态的变化.对内试件通入阳极电流后,闭塞区内溶液pH值随时间的延长和电量的增加而迅速下降,当pH值约为6之后下降缓慢,pH值与电量的对数呈直线关系.CI~-向闭塞区内电迁移,每迁入Cl~-1 mol需要电量1.5～1.6F(法拉第),该关系不随时间长短和电流密度大小而变化.