模拟酸性海洋大气环境中锌缓蚀剂的研究  

Corrosion Inhibitor for Zinc in Simulated Acidic Marine Atmosphere

作　　者：徐婷 张阔[1,2] 杜敏 XU Ting;ZHANG Kuo;DU Min(Key Laboratory of Marine Chemistry Theory and Technology,Ministry of Education,Ocean University of China,Qingdao 266100,China;School of Chemistry and Chemical Engineering,Ocean University of China,Qingdao 266100,China)

机构地区：[1]中国海洋大学海洋化学理论与工程技术教育部重点实验室,山东青岛266100 [2]中国海洋大学化学化工学院,山东青岛266100

出　　处：《表面技术》2020年第11期33-40,共8页Surface Technology

基　　金：国家自然科学基金(52071302)。

摘　　要：目的针对锌在海洋大气环境中的腐蚀状况,筛选有效的缓蚀复配体系,进一步研究多聚磷酸钠和硫脲的缓蚀剂复配体系在模拟酸性海洋大气环境中对锌的腐蚀影响,探讨复配体系对锌的缓蚀机理。方法利用失重法评价复配体系在不同温度、不同浓度下的缓蚀性能,并利用强极化曲线法、电化学阻抗法和X射线光电子能谱法(XPS)探讨其缓蚀机理。结果在40℃时,pH=4、0.3 mol/L的NaCl溶液中,质量比1∶4的多聚磷酸钠和硫脲复配缓蚀剂能够有效抑制锌和热镀锌的腐蚀,缓蚀率分别达到92.19%和91.39%。该复配缓蚀剂对锌在气相环境中的腐蚀同样具有良好的抑制作用。电化学测试结果表明,在25、40、60℃时,缓蚀率随浓度的升高而增加;在80℃时,缓蚀率随浓度的增大而减弱。通过表面成分分析发现,添加复配缓蚀剂后,在锌表面出现了N、S、P三种新元素。结论多聚磷酸钠和硫脲的复配体系是混合抑制型缓蚀剂。复配缓蚀剂中的多聚磷酸钠能够在锌表面形成保护性薄膜。硫脲属于小分子有机物,容易吸附在锌的表面,所以它能填充膜的间隙,并与锌紧密地结合在一起。多聚磷酸钠和硫脲共同作用可以使锌表面形成更致密、更稳定的膜,从而增强对锌的保护作用。The work aims to select effective corrosion inhibitor compound system for the corrosion status of zinc in marine atmosphere to further study the effect of sodium phosphate polymer and thiourea compound corrosion inhibitor on zinc in simulated marine atmosphere and explore the corrosion inhibition mechanism of compound system for zinc.The corrosion inhibition performance of the compound system at different temperature and concentrations was evaluated by weight loss method.Besides,the strong polarization curve method,electrochemical impedance method and X-ray photoelectron spectroscopy(XPS)were used to explore the corrosion inhibition mechanism.At 40℃,in 0.3 mol/L NaCl solution with pH=4,the sodium polyphosphate and thiourea compound corrosion inhibitor with a mass ratio of 1∶4 could effectively inhibit the corrosion of zinc and hot-dip galvanizing,and the corrosion inhibition rates respectively reached 92.19%and 91.39%.The compound inhibitor also had a good inhibition effect on the corrosion of zinc in gas phase environment.The electrochemical test showed that the inhibition rate increased with the increasing concentration at 25,40 and 60℃.While at 80,the inhibition rate decreased as the concentration increased.Through the analysis on surface component,three elements of N,S and P appeared on the surface after the compound inhibitor was added.This compound system of sodium phosphate polymer and thiourea is a mixed inhibition type corrosion inhibitor.Sodium polyphosphate is able to form a protective film on the surface of zinc;and thiourea is a small-molecule organic substance that is easily adsorbed on the surface of zinc,so it can fill the gaps and bind tightly with zinc.The joint action of sodium polyphosphate and thiourea can make the zinc surface form a denser and more stable film,thereby enhancing the protection of zinc.

关 键 词：酸性海洋大气环境 多聚磷酸钠 硫脲 锌 协同效应 

分 类 号：TG174.42[金属学及工艺—金属表面处理]