| 摘要 |
A method for manufacturing an electrolytically chromated steel sheet, comprising the steps of: subjecting a steel sheet intermittently to a plurality of runs of cathodic electrolytic chromate treatment in an acidic electrolytic chromating solution. At least one of these plurality of runs of cathodic electrolytic chromate treatment is carried out at a high electric current density within the range of from 75 to 200 A/dm<2>, to form on at least one surface of the steel sheet a chromating film comprising a metallic chromium layer as a lower layer having numerous granular projections over the entire surface thereof, and a hydrated chromium oxide layer as an upper layer. The electrolytically chromated steel sheet manufactured in accordance with the method of the present invention is excellent in a secondary paint adhesion and a weldability, and has a satisfactory surface hue. |
