混凝土模拟液中碳素钢-不锈钢连接时的腐蚀规律

Corrosion behavior of carbon steel coupled with stainless steel in concrete simulation solution

为了探明混凝土中普通碳素钢与不锈钢搭配使用时的腐蚀规律,使用含氯离子的混凝土模拟液模拟氯盐污染混凝土环境,测试分析了一系列不锈钢、碳素钢试件的动电位极化曲线(CP)、电化学阻抗谱(EIS)和零电阻电流(ZRA)。研究结果表明:连接不锈钢的碳素钢腐蚀速度明显加快,工程应用时宜采取绝缘措施以降低腐蚀风险;碳素钢-碳素钢之间由于锈蚀程度不同也存在电偶腐蚀,但相比不锈钢-碳素钢连接其腐蚀速度较慢且腐蚀规律不太稳定;在氧气含量一定情况下,受腐蚀产物的影响试件后期腐蚀速度普遍减小。

To reveal the corrosion regularity of ordinary carbon steel coupled with stainless steel in concrete, the concrete simulation so- lutions containing chloride ions were used to simulate the chloride econtaminated concrete.The corrosion behaviors of the specimens were assessed by different electrochemical measurement techniques such as potentiostatic cyclic polarization （CP）, electrochemical impedance spectroscopy （EIS） and zero-resistance ammetry （ZRA）.Thetest results show that a significant increase in corrosion activity happensfor the carbon steel coupled with stainless steel specimens compared with that for others, therefore, some isolation measurements are needed to avoidthis galvanic corrosion.Galvanic corrosion also occurs in the coupled carbon steels with different corrosion levels,but it isn＇t as strong and stable as that occurs in carbon steels coupled with stainless steels.When the oxygen is limited,the corrosion rate slows down in the later period affected by the corrosion products.