A kind of metal galvanized passivation method and the purposes of chelating agent

Abstract

The metal galvanizing passivation method of the present invention is mainly applied in the field of metal surface galvanizing, especially in the galvanizing and passivation of metal parts. The invention provides a metal galvanizing passivation method which combines the cooling and passivation steps into one. The steps are as follows: put the metal parts into the zinc pot, galvanize in the high-temperature molten zinc solution, and then galvanize the high-temperature The parts are transferred to the integrated cooling and passivation pool, and the passivation reaction and cooling steps are completed at the same time. After the surface temperature of the galvanized parts is reduced to 50-90 ° C, the galvanized parts are removed, dried quickly, and directly packaged and moved to the outdoor. On the one hand, the two-in-one metal galvanizing passivation method simplifies the metal galvanizing process, greatly improves the production efficiency of the process, reduces equipment energy consumption, and shortens the production cycle; on the other hand, it also reduces the passivation process. The dripping of liquid saves the cost of raw materials and is conducive to the expansion of production scale. At the same time, the use of chelating agent as the passivator of phytic acid can keep the original color of zinc in the passivated galvanized parts, and can avoid stains caused by the residual passivation droplets.

Description

technical field [0001] The present invention relates to the method for metal surface galvanizing and passivation and the application of chelating agent in the field of metal galvanizing, specifically a kind of metal galvanizing passivation method using chromium-free passivation solution containing chelating agent for passivation and Application of chelating agent in the field of passivation of metal galvanizing. Background technique [0002] The current conventional galvanizing process usually includes the following steps: put the metal parts into a zinc pot with high-temperature molten zinc for hot-dip galvanizing, after the galvanizing is completed, transfer the galvanized parts to cooling water for cooling, and then place the cooled The galvanized parts are transferred to a special passivation tank for passivation reaction, and a passivation film is formed on the surface of the galvanized parts. Finally, the passivated galvanized parts are dried by natural drying or heati...

AI Technical Summary

Problems solved by technology

This long-term passivation process must be completed indoors, otherwise the ideal passivation layer may not be obtained due to environmental factors such as rain, which greatly affects the efficiency of the entire galvanized passivation production process

Of course, it is possible to use common methods such as heating to accelerate the passivation reaction, but simple heating may cause the zinc layer to burst, and it is impossible to prepare a dense, firm and good-looking passivation layer. The reason why the conventional galvanized passivation process is usually cooled first and then passivated

There is no suitable solution in the art to solve this technical problem

[0007] In addition, when the passivation operation is performed after cooling in the traditional process, the temperature of the galvanized parts will be further reduced. In winter, it is usually necessary to assist other means such as drying to speed up the drying process, which makes the galvanizing process more complicated

[0008] There are also many metal galvanized passivation methods that use different passivation solutions to make the passivation layer white or brightly colored, and a small amount of passivation solution may remain on the surface of the metal parts, which may cause stains

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