| 摘要 |
PURPOSE:To offer excellent rust resistance, by performing Ni plating of specific thickness, and forming a chromate film of specific thickness on said plating. CONSTITUTION:On high nickel-iron alloy steel, Ni plating of 1-10g/m<2> as Ni is performed, and, a chromate film of 5-100mg/m<2> as the quantity of Cr is formed on said plating. In case when the Ni plating is <=1g/m<2>, a uniform plating film is not obtained, and on the other hand, even if it exceeds 10g/m<2>, corrosion resistance and weldability of a product are not elevated so much. As for the chromate treatment, when the quantity of Cr is <=5mg/m<2>, its corrosion resistance is insufficient, and on the other hand, in case when it exceeds 100mg/ m<2>, its adhesiveness drops and an electric conduction at welding is degraded. |
