Study On The Corrosion Behavior Of Electric Galvanized Steel By Means Of EIS And EN Method

The paper were used by Ctrl I EIS and EN methods studied the corrosion behavior of galvanized steel in NaCl solution.For local corrosion process of cathode and anode process was establieshed electric double layer capacitor and Faraday impedance are separation of the separation of the equivalent circuit model is complete.Verified by polarization impedance spectrum under the rationality of the model.The results show that the electric galvanized steel corrosion in NaCl solution is divided into four stages.Initial stage of immersion for passivation of zinc corrosion.Anodic reaction is dissolved,Cathodic reaction is oxygen through the passivation membrane diffusion to the reduction of zinc,Rn as high as 18000 ? at this time.Soak 24h-96 h for zinc sacrifice protection iron matrix phase.Anodic process is dissolved,passivation of zinc layer on the zinc cathode process is iron on oxygen reduction.The stage of Rn in 8000 ?-10000 ? platform.For 120 h to mixed corrosion stage.Anodic reaction is dissolved passivation of zinc layer of zinc and iron on the substrate dissolved,iron matrix is cathodic reaction on the oxygen reduction.OCP rapidly rising from 1.050 V to0.800 V,Rn dropped to 4000 ?.PI and W in the previous basic remains the same,in the120 h rise suddenly,and discrete degree also suddenly become bigger.Soak over 144 h for the iron substrate from corrosion stage.Anodic reaction is dissolved iron on the matrix,the cathode reaction is iron on oxygen reduction.OCP rose to 0.600 V,Rn in around 4000?.The complete separation of the equivalent circuit model is set up,simpleand feasible.Is expectd to find application in the local corrosion system.