2006 Volume 92 Issue 11 Pages 667-675
Cathodic protection distance at the shear cut edge of zinc coated steel sheet is an important parameter for the lifetime of the steel material. However, cathodic protection distance is variable for electrolyte thickness, electric conductivity and so on. It is difficult to quantify the cathodic protection distance under various environmental conditions. So it is useful to estimate the cathodic protection distance by numerical analysis.
Most of numerical analysis models for galvanic corrosion use a polarization curve measured in a bulk electrolyte solution. However, under thin layer electrolytes, the cathodic current density strongly depends on the electrolyte thickness and the polarization curve shifts by salt concentration. So we developed the numerical analysis model that the polarization curve is calculated by the electrolyte thickness and NaCl concentration.
We investigated the cathodic protection distance in NaCl solution for several thicknesses and concentrations by numerical analysis. Moreover, we estimated the cathodic protection distance in the drying process of NaCl solution on the shear cut edge of zinc coated steel sheet.