| 摘要 |
PURPOSE:To obtain a Zn-Ni alloy electroplated steel sheet having stable quality by adding an adequate amt. of ammonium salt to a Zn-Ni alloy plating soln. thereby adjusting the content of Ni as desired and suppressing the intrusion and deposition of an oxide. CONSTITUTION:An adequate amt. of ammonium salt such as ammonium chloride is added to a plating soln. consisting essentially of zinc chloride and nickel chloride to adjust the content of Ni during alloy plating within an 8-20wt% range and to deposit alloy plating consisting mainly of gamma-(NiZn3) phase in the stage of electroplating a Zn-Ni alloy on the surface of a steel sheet by using said plating soln. This plating bath has preferably 10-50% molar concn. per cent of Ni<2+>/Ni<2+>+Zn<2+> and 1.5-5.8pH. The ammonium salt is added in the rate from about 0.5mol/l until solubility is attained. The intrusion of an unavoidable oxide having a yellowish brown color and bluish purple color in the deposited layer is obviated by the above-mentioned method.
|
