Electrochemical impedance spectroscopy of scribed coated steel after salt spray testing

摘要

In the present study, various representative models of finite length diffusion impedance were examined, in order to find the optimum description for dissolved oxygen diffusion, during corrosion of scribed coated steel in cyclic salt spray conditions, at 6, 8 and 12-week intervals. Modified restricted diffusion fitted the experimental data after 6 and 8 weeks and modified restricted or modified transmissive could fit the data after 12 weeks, accompanied by a decrease in corrosion resistance. Oxygen would diffuse through the porous corrosion layer and reduce on the magnetite layer, lying on top of the electrode surface.