GD-OES and electrochemical study of Ce containing conversion layers of hot dip galvanised and by Sendzimir process continuously hot dip galvanised steel plates

摘要

The present work is focused on the conversion layers of hot dip galvanised and continuously hot dip galvanised steel sheets produced by ISD DUNAFERR, Co., Ltd. The conversion coatings on the galvanised steel plates were produced by dipping the plates into solutions of rare earth salts for different immersion periods. The applied rare earth salts were, cerium nitrate and cerium chloride, respectively. The corrosion resistance of the treated plates was tested by DC polarisation measurements and electrochemical impedance spectroscopic method (EIS). The most promising conversion layers were subjected to special corrosion test modelling the effect of the squeezing of plates or coils during storage and delivering and the humidity, simultaneously. The qualitative properties of the corroded surface were tested by glow discharge optical emission spectroscopy (GD-OES).