Corrosion Behavior of Hot-dip Galvanized Advanced High Strength Steel Sheet in a Simulated Marine Atmospheric Environment

Kai Zhang, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
2019 International Journal of Electrochemical Science  
This paper describes a study of the corrosion behavior and mechanism of 1000MPa grade hot-dip galvanized steel in a simulated marine atmospheric environment with neutral salt spray tests at different times. Subsequent weight loss measurements, electrochemical measurements, confocal scanning laser microscopy (CSLM), scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) were used. The results demonstrated that with neutral salt spray
more » ... ral salt spray (NSS) time elapsing, the corrosion appearance evolved from pitting corrosion to severe uniform corrosion. At the initial time, flocculent corrosion products were predominant and were mainly made up of Zn(OH)2 and ZnO. Then, the corrosion products became compact, and at this period, the corrosion rate was at a lower level, indicating that the compact products prevented the diffusion of reactive ions and were protective for the matrix. Clcould combine with the zinc oxides and accelerate the dissolution of the protective products; ZnCl2 and Zn5(OH)8Cl2 · H2O were the main corrosion products. Zn5(CO3)2(OH)6 develops after an extensive period of salt spray. Eventually, the compact corrosion products diminished, and the matrix was exposed and corroded.
doi:10.20964/2019.02.13 fatcat:nskjqpbrp5b2fa476ugzryxlmm