Development of Corrosion Resistant Electrogalvarized Steel Including Small Amounts of Co and Cr

Abstract

In order to develop the electrogalvanized steel with high corrosion resistance, conventional electrogalvanizing bath was modified with an addition of Co and Cr compounds. This newly developed coated steel is called FZ. FZ is produced by conventional electrogalvanizing process using a composite electrolyte containing small amount of cobalt and chromium ions. The corrosion resistance of the product is twice as high as the conventional electrogalvanized steel. The other properties such as formability and weldability are quite the same as conventional one. Chromate-treated and phosphate-treated products are also manufactured and their corrosion resistance and paint adhesion are excellent as well.