| 摘要 |
PURPOSE:To make the thickness of the metal coating uniform and to improve the appearance and the moisture-resisting property of the coating by a method wherein the body coated with the metal by hot dipping is subjected to ultrasonic cleaning in a heating medium at a temperature not lower than the melting point of the coating metal. CONSTITUTION:After pulling out the coated body from a molten metal bath, the body is immersed into the heating medium such as palm oil which is heated at a temperature of not lower than the melting point of the coating metal. While remelting the coating metal on the surface of the body by the immersion, ultrasonic vibration is applied to the heating medium, whereby such contaminants as chlorides and oxides are removed from the surface of the coated body and an excess of deposit can be removed, so that the thickness of the metal coating is controlled appropriately. In addition, since a film palm oil or the like is formed, the surface of the metal coating is prevented from decoloration due to oxidation during heating. |
