| 摘要 |
In a process for phosphating composite metals containing steel and zinc surfaces using phosphating solutions based on zinc phosphate by the dipping process, in order to achieve satisfactory formation of the phosphate layer, the composite metals are subjected to preliminary dipping for a maximum of 30 seconds in a phosphating solution based on zinc phosphate in order to initiate the formation of the phosphate layer, and are then conveyed to the main dip-phosphating zone. It is advantageous to spray the composite metals with a phosphating solution based on zinc phosphate while they are being conveyed from the preliminary to the main dip-phosphating zone, and it is advisable to limit the duration of the conveying and thus of the spraying treatment to a maximum of 30 seconds. |
