How to clean the galvanized sheet without flowers?

There are two kinds of hot-dip galvanized zinc flowers: one is normal zinc flowers, and the other is non-flower galvanized sheet. In the previous hot-dip galvanized products, because the lead in the zinc liquid could not be refined, there would always be some shiny phenomena on the surface. Therefore, in our old concept, hot-dip galvanized has a lot of flowers. With the development of the automotive industry, if hot-dip galvanized auto sheets need to be painted, the sequins will affect the coating. Later, after reducing the lead content in zinc ingots and zinc liquid to tens of ppm, we can produce products with no or little shiny stone. The following editor will introduce you to the flowerless galvanized sheet.

Flowless galvanized sheet mainly refers to a special production process. Usually, the lead in the zinc can is controlled at a certain level, or the strip steel is removed from the zinc can and then subjected to special treatment, such as small light treatment or spraying zinc powder, to control the light within a certain range. When cleaning the flowless galvanized sheet, an emulsion should be used, which can not only reduce the rolling force, but also ensure the quality of the surface of the flowless galvanized sheet. According to the cleaning principle of the galvanized steel sheet, dirt can be eradicated from the surface of the steel sheet through the process of wetting, soaking, wrapping and stripping the cleaner.

When using the emulsion, not only the emulsion can be used, but additives can be added to the emulsion to improve the performance, so that the lubricant can form a network-like adsorption film on the metal surface to ensure the quality of the galvanized steel strip on the surface of the emulsion, so that it can have a certain degree of toughness and compressive strength when used in the future. Since the polar molecules in the emulsion have a large adsorption force on the metal surface, the additives improve the rolling performance of the emulsion on the one hand and ensure the rolling stability.

Zinc particles appear on the surface of the hot-dip galvanized sheet, that is, those small rough particles that are not smoothed, which not only affects the appearance, but also affects the use. The reason for the formation of such particles is that during the production process of the flowless galvanized sheet, the machine will agitate and float too much bottom slag, and it will adhere to the surface of the hot-dip galvanized sheet, and due to the high production temperature, the bottom slag will float. In addition, the bottom scum floats in the zinc solution.

If the aluminum content is too high, it is considered that aluminum and zinc have good affinity, so they are bound and attached to the surface of the galvanized sheet, and the elimination of zinc particles can also be treated by prescribing the correct medicine. For example, the bottom scum is often treated to keep the galvanized environment clean; the bath temperature of the flowerless galvanized sheet should not be too high, and it should be kept at 440 ° C~ 450 ° C. The aluminum content in the zinc bath should not be too high, and it should be kept at about 0.1%.

In addition, please note that if the storage time is too long, it will increase the oxidation effect, etc. In short, as long as the zinc particles are strictly produced, they can be eliminated. A thicker edge is formed on the surface of the flowerless galvanized sheet, which means that the edge of the zinc layer of the flowerless galvanized sheet is thicker than the middle part, which becomes a thicker edge defect, which is not conducive to strip coiling. The thick edge is divided into high-speed thick edge and low-speed thick edge. The reason for the formation of thicker edge is due to improper adjustment of the angle of the air knife during galvanizing, which leads to blowing and the formation of turbulence. It can be eliminated by properly adjusting the strength of the air knife.