Preparation of silane film on the surface of cold rolled steel for corrosion protection

The γ-aminopropyltriethoxysilane film was deposited on differently pretreated cold rolled steel(CRS) using the immersion technique.The corrosion resistance of the silane film was investigated in 3.5% NaCl solution,using Tafel polarization and electrochemical impedance spectroscopy(EIS).The morphologies of the silane film before and after corrosion testing in 3.5% NaCl solution were characterized through scanning electron microscope(SEM).The results indicate that uniform and compact silane film could be formed on the CRS when the surface of CRS was pretreated in 0.10%CeCl3 or 0.10%NaOH,especially in the the former solution.The prepared film led to the large increase in polarization resistance and therefore the evident decrease in corrosion current density.The morphology of the silane film on the CRS remained nearly unchanged before and after corrosion.