Feng Lijuan, Yang Huaiyu, Cui Xin, Chen Di, Li Guofu
Shandong Peninsula Engineering Research Center of Comprehensive Brine Utilization, Weifang University of Science and Technology Shouguang Weifang 262700 P. R. China
State Key Laboratory for Corrosion and Protection, Insititute of Metal Research, Chinese Academy of Sciences Shenyang 110016 P. R. China.
RSC Adv. 2018 Feb 9;8(12):6507-6518. doi: 10.1039/c7ra13045g. eCollection 2018 Feb 6.
In order to mitigate the corrosion of steel rebar in concrete, a new environmentally friendly corrosion inhibitor formula (WKI) was designed and the corrosion inhibitive effects of WKI on steel rebar were studied by gravimetric method, electrochemical impendence spectroscopy (EIS), potentiodynamic polarization and Mott-Schottky scanning in simulated concrete pore solution. Furthermore, surface analysis and quantum chemical calculations were conducted in order to illustrate the corrosion inhibitive mechanism. The results indicate that WKI exhibits excellent corrosion inhibitive activities on steel rebar in simulated concrete pore solution. By the presence of WKI, local corrosion was significantly suppressed and no pitting could be detected during the whole experimental period. The total corrosion resistance was increased from 5469 Ω cm to 64 440 Ω cm and the corrosion current density was reduced from 3.23 μA cm to 0.21 μA cm for the sample immersed in the corrosion medium for 7 d with WKI. The corrosion potential of the steel rebar electrode moved to a higher level and the charge transfer resistance increased, indicating that the anti-corrosion properties of the steel rebar were enhanced. The corrosion inhibitive mechanism of WKI can be attributed to the fact that it can promote the formation of a passive film and reduce its defect concentration its adsorption and interaction with the metal surface, consequently inhibiting the corrosion of steel rebar caused by chloride ions.
为减轻混凝土中钢筋的腐蚀，设计了一种新型环保缓蚀剂配方（WKI），并通过失重法、电化学阻抗谱（EIS）、动电位极化和在模拟混凝土孔隙溶液中的莫特-肖特基扫描研究了WKI对钢筋的缓蚀效果。此外，还进行了表面分析和量子化学计算以阐明缓蚀机理。结果表明，WKI在模拟混凝土孔隙溶液中对钢筋表现出优异的缓蚀活性。由于WKI的存在，局部腐蚀得到显著抑制，在整个实验期间未检测到点蚀。对于在含有WKI的腐蚀介质中浸泡7天的样品，总耐蚀性从5469Ω·cm增加到64440Ω·cm，腐蚀电流密度从3.23μA/cm²降低到0.21μA/cm²。钢筋电极的腐蚀电位向更高水平移动，电荷转移电阻增加，表明钢筋的防腐性能得到增强。WKI的缓蚀机理可归因于它能促进钝化膜的形成并降低其缺陷浓度，以及它与金属表面的吸附和相互作用，从而抑制氯离子引起的钢筋腐蚀。
