| 摘要 |
PURPOSE:To form an alloy plating layer having a composition uniform in the plane and thickness directions by separately vaporizing plural metals having different vapor pressure, joining the vapors through vapor ducts respectively having a movable throttle part and depositing the vapors through a flow straightening plate. CONSTITUTION:In the vapor deposition chamber 1 having an evacuating port 7, the Zn and Mg having different vapor pressures are simultaneously vaporized, and the vapors are deposited on the surface of a steel sheet 2 traveling through seal rolls 3 and 4 to form a Zn-Mg alloy plating layer. In this device for applying alloy plating by vapor deposition, the Zn and Mg are respectively heated by a heater H in exclusive vaporization vessels 8 and 9, and vaporized. The vapors are led by the vapor ducts 10 and 11 connected respectively to the vaporization vessels 8 and 9, and the flow rates are controlled by the movable throttle parts 13 and 14 to the rates corresponding to the alloy composition. Both vapors are joined in a joining duct 12, and supplied to the vapor deposition part through the flow straightening plate 15 confronted with the surface to be vapor-deposited. By this method, a Zn-Mg alloy plating layer having specified contents of the Zn and Mg having different vapor pressures and having the composition uniform in the plane and thickness directions is formed. |
