Properties of New Organic-Silicate Composite Coated Steel Sheet for Automotive Outer Panel

In response to the increasing demand for organic-silicate composite coated steel sheet with bake hardenability, we developed EZN-UCII, which allowed the coating to be cured in the temperature range where bake hardenability could be maintained. It was said that improved perforation corrosion resistance of automotive body panels was achieved through the development of EZN-UCII. In recent years, the most important objective with respect to the corrosion resistance of automotive body panels has been to improve cosmetic corrosion resistance of the outer panel. The cosmetic corrosion resistance can be improved by applying an organic-silicate composite coating on Zn-Ni plated steel sheet. EZN-UCII, however, could not be applied to the automotive outer panel because the inferior appearance of the cationic e-coat made it worthless for use on the exposed side of the outer panel. In response to the call for an organic-silicate composite coated steel sheet with excellent appearance of cationic e-coat, we developed a new product, EZN-UCIV. EZN-UCIV also provides excellent corrosion resistance, weldability, anti-powdering property and paintability equivalent to EZN-UCII.