| 摘要 |
PURPOSE:To improve treating property with phosphate, and to increase adhesion and corrosion resistance of paint film, by performing plastic working, including bending and tension, of the surface of galvanized steel sheet prior to the treatment with phosphate. CONSTITUTION:Galvanized steel sheet having 0001 face of crystal zinc is treated with phosphate prior to the painting so as to improve the painting property such as adhesion etc. to the paint film to be made subsequently. Prior to the treatment with phosphate, plastic working including 0.05-5% bending and tension as plastic extension is performed with a tension leveler. By this working, new crystal faces composed of faces 10-10 which are a little more highly activated than faces 0001 are exposed divergently in several mu unit thereby forming uniform and dense phosphate film by the following phophate treatment. Said coating is painted to form painted steel sheet having high adhesion to paint film and excellent corrosion resistance. |
