| 摘要 |
PURPOSE:To remarkably enhance the corrosion resistance of the title sheet without deteriorating the productivity and work efficiency by plating a sheet in a zine bath contg. a specified amt. of special metals, etc. and by heating the plated layer to alloy the zinc. CONSTITUTION:A steel sheet is plated in a zine bath contg. Al 3%, Mg and/or Mn; 0.01-5% and other inevitable metals, and the plated layer is heated to alloy the zinc. The addn. of Al enhances the adherence of the plated layer, and Al>3% makes alloying difficult. The addn. of Mn remarkably enhances the corrosion resistance of the plated sheet, yet Mn<0.01% results in insufficient corrosion resistance, and Mn>5% is uneconomical. The alloyed zinc effectively contributes to formation of stable zinc hydroxide controlling corrosion resistance. The Fe compsn. in the plated layer is regulated to the range of 7-30 wt%. By this method alloying is easily carried out without deteriorating the productivity and work efficiency compared to conventional chromate treatment. |
