单宁酸复配缓蚀剂的成膜特性及缓蚀性  

Tannic acid compound as a corrosion inhibitor: film-forming characteristics and corrosion resistance

作　　者：方涛 张博威 张展 王怡 彭光春 黄康 张天翼 FANG Tao;ZHANG Bo-wei;ZHANG Zhan;WANG Yi;PENG Guang-chun;HUANG Kang;ZHANG Tian-yi(Corrosion and Protection Center,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学新材料技术研究院

出　　处：《工程科学学报》2019年第12期1527-1535,共9页Chinese Journal of Engineering

基　　金：国家自然科学基金资助项目（50701006,51271031）;国家重点基础研究发展计划资助项目（2014CB643300）

摘　　要：单宁酸由于环保、价格低的特点在金属保护方面应用广泛,然而单一利用单宁酸作为缓蚀剂取得的效果有限,有研究表明盐类与缓蚀剂复配可以改善缓蚀剂的缓蚀效果.在此基础上进行单宁酸复配缓蚀剂的研究,采用两种复配剂氯化铁、钼酸钠分别与单宁酸(TA)缓蚀剂进行复配,研究其对碳钢Q235的缓蚀效果.通过硫酸铜点滴实验、浸泡实验、电化学实验对比氯化铁、钼酸钠分别与单宁酸复配后在碳钢表面的成膜特性及缓蚀效果.硫酸铜点滴液变色时间随着单宁酸中氯化铁和钼酸钠两种化合物浓度的升高出现先增加后降低的趋势;浸泡实验可以看出在单宁酸中加入氯化铁和钼酸钠后,碳钢表面仅出现个别点蚀坑;根据电化学测试结果,对比加入氯化铁前后单宁酸缓蚀剂对碳钢的缓蚀效果,发现两者的电荷转移电阻由2698变为3711Ω·cm2,腐蚀电流密度由2.734降为1.902μA·cm^−2.加入钼酸钠后,电荷转移电阻和腐蚀电流密度存在明显的增加与下降,电荷转移电阻由2698变为5100Ω·cm2,腐蚀电流密度由2.734降为0.714μA·cm^−2.在单宁酸中添加氯化铁和钼酸钠都能改善单宁酸的缓蚀效果,其中单宁酸与钼酸钠复配的缓蚀效果更好.Tannic acid(TA)is widely used to protect metals from corrosion because it is environmentally friendly and inexpensive.However,the single effect of TA used as corrosion inhibitor has been widely investigated and studies focusing on the corrosion inhibition effect have been limited.Some studies have proven that the addition of a compound corrosion inhibitor can considerably improve the corrosion inhibition efficiency of an inhibitor,and this method can be applied to TA.The corrosion inhibition effect of the combination of two compounds,FeCl3 and Na2MoO4,with TA was analyzed on carbon steel Q235.Copper sulfate drip test,soaking test,and electrochemical test were used to compare the film-forming characteristics and corrosion inhibition effect of the combination of FeCl3 and Na2MoO4 with TA on carbon steel surface.The discoloration time of copper sulfate droplets initially increases and subsequently decreases with the increase in the concentrations of FeCl3 and Na2MoO4 in TA.At the end of the soaking test,fewer pits are observed on the surface of carbon steel following the addition of FeCl3 and Na2MoO4 to the TA inhibitor.Based on the results of the electrochemical tests,the corrosion inhibition effects of the TA inhibitor on carbon steel before and after the addition of FeCl3 were compared.The results reveal that the charge transfer resistance of the two inhibitors increases from 2698 to 3711Ω·cm2,and the corrosion current density decreases from 2.734 to 1.902μA·cm^−2.A clear increase and decrease in the charge transfer resistance and corrosion current density,respectively,are observed once Na2MoO4 is added.Further,the charge transfer resistance increases from 2698 to 5100Ω·cm2,and the corrosion current density decreases from 2.734 to 0.714μA·cm^−2.The following conclusions can be drawn from these results:the addition of FeCl3 or Na2MoO4 to TA can both improve the corrosion inhibition effect of TA;the compound system of TA and Na2MoO4 exhibits a better corrosion inhibition effect compared with the compoun

关 键 词：单宁酸 低碳钢 复配 转化膜 耐蚀性 电化学 

分 类 号：TG174.42[金属学及工艺—金属表面处理]