| 摘要 |
PURPOSE:To prevent defective plating adhesion and defective alloying in the stage of subjecting a steel strip to molten Zn hot dipping by subjecting said steel strip to the Zn hot dipping through a surface cleaning device, an electroplating device and a reduction type heating furnace and further regulating the coating weight of the molten Zn then alloying the plating Zn. CONSTITUTION:After a steel strip 1 is passed through a surface cleaning device 2 consisting of a degreasing tank 3, a rinsing tank 4, a pickling tank 5 and a rinsing tank 6, it is plated with Fe, Ni, etc. by electroplating in the electrolytic cell 8 of an electroplating device 7. This is passed through a rinsing tank 9, and a drying and heating device 16 then through a reduction type heating furnace 10, where the strip 1 is heated to activate its surface; thereafter, the steel strip is passed through the inside of a Zn hot dipping bath cell 12, whereby it is subjected with the Zn hot dipping. This is pulled up and the excess plating Zn is removed with a regulating device 13 for the coating weight of the molten Zn such as gas wiper nozzle, after which part of the plating Zn is alloyed with an alloying heat treating device, if necessary. |
