海工混凝土微孔隙环境中钢筋的腐蚀电化学行为  

Electrochemical Behavior of Steel Corrosion in Microporous Environment of Marine Concrete

作　　者：文成 田玉琬 王贵 胡杰珍 WEN Cheng;TIAN Yu-wan;WANG Gui;HU Jie-zhen(School of Mechanical and Power Engineering//Guangdong Marine Equipment and Manufacturing Engineering Technology Research Center,Guangdong Ocean University,Zhanjiang 524088,China)

机构地区：[1]广东海洋大学机械与动力工程学院//广东省海洋装备及制造工程技术研究中心,广东湛江524088

出　　处：《广东海洋大学学报》2022年第2期126-134,共9页Journal of Guangdong Ocean University

基　　金：国家自然科学基金(51801033)。

摘　　要：【目的】钢筋的氯致腐蚀问题是限制海工混凝土结构耐久性的主要因素,本研究旨在探索钢筋在氯离子环境中的真实腐蚀机理,为海工混凝土耐久性评估提供理论基础。【方法】设计新型微溶液电解池,模拟海工混凝土微孔隙环境,采用循环伏安、极化曲线和交流阻抗谱方法研究该环境中钢筋的腐蚀速率和电化学规律,并与传统本体溶液、实际混凝土结构中的钢筋腐蚀作对比。【结果】微溶液和本体溶液中钢筋的腐蚀热力学行为一致;溶液体积大于1 mL时钢筋腐蚀动力学行为变化不大,但溶液体积低至100μL后钢筋腐蚀速率大幅下降;微溶液中钢筋溶出的Fe^(2+)离子相对较多,导致阳极反应的平衡电极电位正移、阳极极化阻滞作用加强,腐蚀速率下降。【结论】传统本体溶液电化学测试方法评估钢筋腐蚀速率时出现过评估,而新型微溶液电解池与实际钢筋腐蚀动力学相关性更好。【Objective】The chloride-induced corrosion of steel reinforcement is the main reason limiting the durability of marine concrete structures.This study aims to explore the real corrosion mechanism of steel reinforcement in the chloride environment,in order to provide a theoretical basis for the evaluation of marine concrete durability.【Method】A new micro solution cell was designed in this work,and cyclic voltammetry,polarization curves,and electrochemical impedance spectroscopy tests were performed to study the corrosion rate and electrochemical behavior of steel reinforcement in this environment,which was then compared with corrosion of reinforcing steel in the conventional bulk solution and actual concrete structures.【Result】The thermodynamic behavior of steel corrosion in the micro solution is consistent with that in bulk solution;When the solution volume is larger than 1 mL,the dynamic behavior of steel corrosion changed little,while the corrosion rate decreased significantly when the solution volume is as low as 100μL;The higher equilibrium electrode potential of the anodic reaction and the strengthened anodic polarization,caused by Fe^(2+)enrichment in the micro solution,are responsible to this decrease in corrosion rate.【Conclusion】The traditional electrochemical tests in the bulk solution tends to overestimate the corrosion rate of steel reinforcement,and the new methods in the micro solution has better correlation with the corrosion kinetics of actual steel reinforcement.

关 键 词：钢筋 腐蚀速率 孔隙 微溶液 电化学 

分 类 号：P75[天文地球—海洋科学] TG174.4[金属学及工艺—金属表面处理]