大气预锈对混凝土模拟液中低合金钢筋腐蚀行为的影响

Influence of Atmospheric Pre rusting on Corrosion Behavior of Low Alloy Rebar in Simulated Concrete Pore Solution

关键词:  预锈  低合金钢筋  混凝土模拟液  电化学阻抗谱  背散射电子图像

Key words:  pre rusting  low alloy rebar  simulated concrete pore solution（SCPS）  electrochemical impedance spectroscopy(EIS)  BSE image

摘要:

通过电化学阻抗谱(EIS)、背散射电子(BSE)图像与能谱分析(EDS)研究了大气预锈对低合金钢筋和普通低碳钢筋在混凝土模拟液中氯盐腐蚀行为的影响.结果表明：大气预锈作用影响2种钢筋钝化膜的生成；氯盐侵蚀后，大气预锈作用降低了低碳钢筋的耐蚀性，但低合金钢筋的耐蚀性不受预锈作用影响，原因是低合金钢筋基体与氧化皮间的缝隙内形成了致密的富Cr锈层，抑制了氯盐对钢筋基体的进一步侵蚀.

Abstract:

The influence of atmospheric pre rusting on the chloride induced corrosion behaviors of low alloy(LA) rebar and conventional low carbon(LC) rebar in simulated concrete pore solution(SCPS) was investigated using electrochemical impedance spectroscopy(EIS) and surface analysis techniques(BSE images and EDS analysis). The results indicate that, the formation of passive film for both rebars is slightly influenced by pre rusting and the reduced corrosion resistance of LC rebar can be observed after chlorides attack. However, the long term chloride induced corrosion behavior of LA rebar is not affected by pre rusting. The main reason is that compact Cr enriched corrosion products are gradually formed for LA rebar, thus fill the crevice between rebar substrate and prevent from the further attack by chlorides.