| 摘要 |
PURPOSE:To improve the corrosion resistance of steel sheet surface, by compund- plating of the surface of steel sheet with zinc and a plastic compound in a molecular state. CONSTITUTION:The surface of a steel sheet is cleaned successively by alkali degreasing, hot water washing, water washing, pickling, water washing, and drying, it is then put into a vacuum vessel, where it is treated by ion bombardment in Ar gas stream. Thereafter, pure zinc particles are heated in a tungsten resistance boat to be evaporated, simultaneously, a plastic compound, e.g., polyethylene, polypropylene, polycarbonate etc., is heated in another tungsten resistance boat to be evaporated. Hereby, compound-plating film composed of zinc and a plastic compound is deposited from the vapors on the surface of the steel sheet. The plating layer forms a semiconductor layer of combination of molecular zinc and a molecular plastic compound continuously from the surface of the steel sheet to the surface of the plating layer. Because the plating layer itself possesses semiconducting property without losing metallic properties in spite of having high insulating property over the whole layer, it is excellent in corrosion resistance as a sacrificial anticorrosion plating. |
