alvanized strip is the cold or hot rolled, long and narrow strip of steel coated with different levels of raw materials called (zinc, aluminum). Hot dip galvanized coating with uniform, strong adhesion, long life and other advantages. Hot-dip galvanized strip matrix and the molten bath complex physical and chemical reactions, the formation of corrosion-resistant zinc-iron alloy layer closely. Alloy layer and pure zinc layer, strip matrix integration. Therefore, its strong corrosion resistance.
The first stage
The entire volume of strip pickling decontamination, to the surface bright and clean.
second stage
① hot-dip zinc: pickling, ammonium chloride or zinc chloride solution or ammonium chloride and zinc chloride mixed solution tank cleaning. Then into the hot dipping tank for galvanizing.
② hot dip galvanized: pickling, ammonium chloride or zinc chloride solution or ammonium chloride and zinc chloride mixed aqueous solution tank cleaning, into the continuous annealing furnace into the galvanized tank, galvanized.
③ straight galvanized: Pickling, into the continuous annealing furnace into the galvanized tank, galvanized.
The third phase
Galvanized steel plate after storage, galvanized layer according to customer demand, generally not less than 50g / square meters, of which any sample shall not be less than 48g / square meter.
Post-treatment of galvanized steel strip includes three aspects, passivation, pre-phosphating and oiling. The first passivation of galvanized steel strip can improve the surface structure of zinc coating and gloss, improve the corrosion resistance of galvanized coating and service life, and can improve the coating and the substrate metal bonding force. Passivation treatment mainly chromate passivation. In the passivation solution to add some activators, such as fluoride, phosphoric acid or sulfuric acid, resulting in thicker chromate film after passivation. When the passivation solution of fluoride can reduce the surface tension of the steel, accelerate the film reaction, and can increase the role of chemical polishing, the passivation film is fine and bright.
The effect of galvanized steel strip meets the modern requirements and is now widely used as a building material. Galvanized steel strip has many years of no rust, corrosion-resistant features, it can be done from the adverse external environment, always maintain its own performance and appearance. In the process of using galvanized steel strip, in order to improve its working efficiency and its own characteristics, the galvanized steel strip can be post-processed to make its performance even better.