钼酸钠对钢筋在氯离子混凝土模拟液中腐蚀行为的影响  

Influence of Sodium Molybdate on Electrochemical Behavior of Steel Rebar in 5% NaCl Saturated Ca(OH)_2 Solution Simulating Concrete Pores

作　　者：周欣[1,2] 杨怀玉[1] 王福会[1] 

机构地区：[1]中国科学院金属研究所金属腐蚀与防护国家重点实验室,沈阳110016 [2]辽宁科技学院冶金工程系,本溪117022

出　　处：《腐蚀科学与防护技术》2010年第4期343-347,共5页Corrosion Science and Protection Technology

基　　金：国家科技支撑计划资助项目(2007BAB27B03-3)

摘　　要：利用动电位极化曲线、交流阻抗技术及Mott-Schottky曲线等方法,研究了钼酸钠对钢筋在5%NaCl混凝土模拟液中的电化学腐蚀行为和表面钝化膜性能的影响.结果表明：随钼酸钠浓度增大,缓蚀效率逐渐增加,对钢筋的腐蚀有较好地抑制作用,药剂在钢筋表面的吸附可有效屏蔽氯离子的侵蚀作用;Mott-Schottky结果表明,在-0.5~0.1 VSCE范围内,混凝土模拟液中钢筋表面钝化膜Cs-c2-E曲线呈正线性相关,表明钢筋表面钝化膜为n型半导体,且随钼酸钠浓度增大,钢筋钝化膜载流子密度逐渐减小,钝化膜稳定性增强,耐蚀性逐步提高;钝化膜致密性分析表明,随钼酸钠浓度增大,钝化膜致密性增加,抗氯离子腐蚀能力增强.By means of polarization curve measurement,electrochemical impedance spectrum（EIS）,and Mott-Schottky analysis technique,the effect of sodium molybdate on the corrosion behavior of and the performance of passive film formed on steel rebar in 5% NaCl saturated Ca（OH）2 solution was investigated.This solution was a simulated solution existed in concrete pores.The results indicated that the inhibition efficiency increased with the increasing concentration of sodium molybdate,which acted as a good inhibitor for steel rebar in alkaline solution containing 5% NaCl through retarding main anodic process.The overall inhibition behavior of sodium molybdate could be attributed to the stability adsorption film formed on the metal surface through the competitive adsorption with Cl-.Mott-Schottky（M-S）measurements in the range of potential from-0.5 VSCE to 0.1 VSCE showed that the curves of C-2sc-e followed a linear M-S relationship with a positive slope,suggesting the passive film formed on steel rebar surface was an n-type semi-conductor.Moreover,with increasing concentration of inhibitor,the carrier density in passive film decreased,indicating that the passive film formed on steel rebar surface in the presence of sodium molybdate was more compact and stable than that in the absence of inhibitor,and therefore,the corrosion resistance of passive film was enhanced.

关 键 词：钼酸钠 钢筋腐蚀 缓蚀作用 钝化膜 

分 类 号：TG174.4[金属学及工艺—金属表面处理]