Enhanced predictive corrosion modeling of crevice evolution at e‐coat defects under cyclic climate conditions

E‐coated galvanized steel sheets are widespread parts of the automotive industry. Hence, the undermining of the organic coating due to defects is a crucial issue. The delamination of an e‐coating is simulated for different cyclic climate conditions using the finite element method to predict the corrosion behavior over several weeks. A semiempirical mixed potential theory model is developed incorporating the time‐of‐wetness, the temperature, and the effect of corrosion products. Furthermore, the spatial orientation of the sheets is considered in the simulation. The trends of experimental delamination widths of corrosion tests are well described by the simulation.