四探针技术测碳钢在混凝土及混凝土模拟溶液中的局部区域腐蚀行为

摘要

采用自制原位腐蚀测试装置，对碳钢在含NaCl的混凝土模拟溶液和混凝土环境中的方阻和腐蚀深度进行连续监测，并对不同区域的腐蚀行为进行了分析。结果表明：在模拟溶液中由于氯离子的直接均匀作用，碳钢表面各区域的腐蚀情况基本相同，腐蚀过程三个阶段的方阻和腐蚀深度都遵循二项式曲线规律；而在混凝土环境中各区域的腐蚀情况不同，部分区域腐蚀动力学规律与模拟溶液中的相同，而部分区域的第一阶段方阻和腐蚀深度符合直线规律；第二、三阶段符合二项式曲线规律。采用方阻法可获得腐蚀过程的动力学规律。%Sheet resistance and corrosion depth of carbon steel were continuously monitored in simulated concrete solution and concrete with NaC1 by a self-designed in-situ corrosion measurement system. The corrosion behavior in different regions was analyzed. The results show that corrosion of different regions on the surface of carbon steel in the, solution was basically the same because of the direct and uniform function of chloride ion, meanwhile sheet resistance and corrosion depth followed binomial law in three stages of corrosion process. Nevertheless the corrosion of different regions in concrete was different. In some regions, the corrosion kinetics was the same as that in the solution, and in others sheet resistance and corrosion depth agreed with linear law in the first stage, then binomial law in the second and third stage. The kinetics of corrosion process would be acquired by sheet resistance method.