Effect of Zinc Coating on Cosmetic Corrosion in Automotive Body Panel

The corrosion of three-coated electrogalvanized steel (EG) and cold-rolled steel sheet (CR) has been investigated to evaluate their potential for outer side panels of automobile. It was found that, in the salt test, the average width of blisters on the three-coated EG was larger than that on CR. However, in the cyclic corrosion test, which is considered to simulate the actual dry and wet corrosion environment more accurately, CR showed less corrosion resistance, while EG showed high corrosion resistance, that is, no blisters or rust were found on the three-coated EG.