热镀锌钢在模拟混凝土孔隙液中电化学腐蚀行为  

Electrochemical corrosion behaviors of hot-dip galvanized steel in simulated concrete pore solutions

作　　者：徐玉野[1] 王全凤[1] 罗漪[1] 

机构地区：[1]华侨大学土木工程学院,福建泉州362021

出　　处：《福州大学学报（自然科学版）》2008年第3期424-429,442,共7页Journal of Fuzhou University(Natural Science Edition)

基　　金：福建省自然科学基金资助项目(E0410023);福建省青年科技人才创新资助项目(2007F3064);华侨大学科研基金资助项目(07BS405)

摘　　要：采用电化学阻抗法研究了不同pH值、不同氯离子浓度条件下热镀锌钢在模拟混凝土孔隙液中的电化学腐蚀行为,建立了两种腐蚀等效电路模型,分析了腐蚀参数的变化规律.结果表明:当饱和Ca(OH)2溶液受到严重碳化(pH<11)时,热镀锌钢在该体系中会发生析氢反应,耐腐蚀性能降低;当饱和Ca(OH)2溶液受到较小程度的碳化(11.5≤pH<12.5)反而更有利于热镀锌钢的进一步钝化,耐腐蚀性能提高,pH=12.0时的年腐蚀率最小,仅为0.59μm/a,而pH=12.5时的年腐蚀速率约为1.21μm/a;当饱和Ca(OH)2溶液未碳化(pH=12.5)且NaC l浓度不超过0.5%时,热镀锌钢在该体系中所形成的钝化膜的耐蚀性能较好,不会发生析氢反应;随着碳化程度的增大,氯离子对热镀锌钢腐蚀作用加剧.The electrochemical corrosion behaviors of hot- dip galvanized （HDG） steel in simulated concrete pore solutions for different pH values and with variable concentration of chloride ions were investigated by electrochemical impedance spectroscopy （EIS） measurements. Two equivalent circuit models corresponding to the corrosion processes were proposed and the evolution features of the electrochemical parameters were analyzed. The results show that： when the saturated Ca（OH） 2 solution was carbonized seriously （pH 〈 11 ）, the hydrogen evolution reaction is happened and the corrosion resistance is decreased ; a minor carbonization of the saturated Ca（OH） 2 solution （ 11.5≤ pH 〈 12.5 ） induces further passivation of the metal surface and the corrosion resistance is enhanced： the corrosion rate of HDG steel in pH 12.0 is minimal, around 0.59 μm/a, whereas that in pH 12.5 is approximate 1.21μm/a; when the saturated Ca（OH）2 solution was not carbonized （pH = 12.5） and the NaCl concentration was not greater than 0.5%, the corrosion resistance of the obtained passivation films on the surface of HDG steel in this system is better and the hydrogen evolution reaction doesn＇ t occur; with the increase in carbonization of the saturated Ca （OH）2 solution, the corrosion rate of HDG steel is also increased by chloride ions.

关 键 词：热镀锌钢 模拟混凝土孔隙液 电化学阻抗谱 腐蚀行为 

分 类 号：TU528[建筑科学—建筑技术科学] TG174[金属学及工艺—金属表面处理]