Development of Two-Layered Zn-Fe Alloy Electroplated Steel Sheet-New Coated Steel Sheet for Automotive Body

There is an urgent need to develop a now type of coated steel, which will meet the requirements for high strength steel and protection against corrosion caused by chipping. According to the results of various improvement studies on the composition of coating layers and their properties, the low Zn/Fe ratio on the surface layer should show good paintability.

By sequence of studies we have developed a two layered Zn-Fe alloy electroplated steel sheet with excellent corrosion resistance, and optimum press formability and paintability compared to cold rolled sheet.

Finally, we have confirmed the effectiveness of a newly developed electroplated sheet through corrosion tests of an actual auto body and have succeeded in applying the new steel to the mass production line.