Corrosion-rate-simulation of Seel in Wet & Dry Repeat Test on the Basis of the New Equation Relevant to Oxygen Reduction Limitting Current.

Abstract

Constant i_abs or δ^≠ has been determined at eight electrolyte film salt concentration c, on basis of the following equation ; 1/i_lim＝i_abs/（1＋δ/δ^≠）, where i_lim is the cathodic limitting current of oxygen reduction, δ is the thickness of electrolyte thin film formed on cathode, and i_abs or δ^≠ is a constant inherent in c.
Provided that the wet corrosion rate of steel under drying process is proportional to the limitting reduction current due to oxygen in atmosphere, i_lim has been simulated as a function of c which is the good indicator of drying process state on corroding steel surface.
The i_lim simulation obtained from ten c agrees fairly well with the corrosion rate of steel in wet&dry repeat corrosion test measured by electrochemical impedance method reported by Nishikata et al.