| 摘要 |
PURPOSE:To obtain a surface treated steel plate high in corrosion resistance, by subjecting a steel plate to immersion plating in a bath prepared by dispersing a specific amount of a Cr source fine particle in a Zn or a Zn-Al alloy plating bath. CONSTITUTION:One kind of a fine particle with a particle size of 3mum or less comprising metal chromium, chromium oxide, a chromium base alloy or a Cr source forming said chromium compounds after added to a plating bath is contained in a molten Zn or a molten Zn-Al alloy plating both in an amount of 0.1-20wt% as metal chromium. In this prepared molten plating bath, a steel plate subjected to preliminary treatment is immersed to obtain a molten Zn plated steel plate. By this method, the corrosion resistance, processability or the like of the Zn or the Zn-Al alloy plated steel plate are enhanced. |
