A sandwich-like structure hybrid coating of cold galvanizing coating/polydopamine on hot-dip galvanized steel with enhanced adhesion and corrosion resistance  

作　　者：LI JiWen GAO NingJie ZHANG WanYu XU Long NWOKOLO Kenneth Izuchukwu WU Hao LIU FuChun HAN En-Hou 

机构地区：[1]Key Laboratory of Nuclear Materials and Safety Assessment,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China [2]School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China [3]Institute of Corrosion Science and Technology,Guangzhou 510530,China [4]Jihua Laboratory,Foshan Guangdong Province,Foshan 528000,China

出　　处：《Science China(Technological Sciences)》2023年第8期2381-2395,共15页中国科学（技术科学英文版）

基　　金：supported by the Ling Chuang Research Project of China National Nuclear Corporation(Grant No.E041F212Z1)。

摘　　要：This study aims to enhance the adhesion strength and anti-corrosion performance of the cold galvanizing coating(CGC)applied on the hot-dip galvanized steel(HDG).Polydopamine(PDA)is deposited on the HDG surface with different time ranges and as an interlayer between CGC and HDG through covalent immobilization.The surface morphology and the covalent interaction between PDA/HDG are exhibited by scanning electron microscope(SEM),atomic force microscopy(AFM)and X-ray photoelectron spectroscopy(XPS).The pull-off adhesion tests before and after neutral slat spry tests show an enhanced dry adhesion strength and less adhesion loss of the hybrid CGC/PDA coated HDG compared with the direct CGC coated HDG.In addition,open circuit potential(OCP)reveals that the corrosion protection performance of the hybrid CGC/PDA coated HDG increases by 200%(up to 201 d)and the corrosion density icorrattaining about 4.45×10^(-7)A/cm^(2).Electrochemical impedance spectroscopy(EIS)measurements and X-ray diffraction(XRD)analysis confirm that the precipitate of the stable chelation formed by PDA and Zn^(2+)between CGC and HDG substrate can also improve the corrosion protection performance.Such a strategy of strengthening adhesion and forming the chelate compound at the HDG surface promises a new route to corrosion protection of CGC on HDG.

关 键 词：DOPAMINE zinc-rich coatings hot-dip galvanized steel corrosion protection chelate compound 

分 类 号：TG174.4[金属学及工艺—金属表面处理]