Shandong Longfa Group Co., Ltd.
ADD: Dianzi Industrial Zone , Boxing county,Binzhou City ,Shandong Province,China
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The most common phosphating treatment method for galvanized sheet
When this aqueous solution is sprayed onto the surface of the galvanized sheet, a film formation reaction occurs, and the reaction formula is:
GeneratedZnHP04、Zn3(P04)2It is deposited on the surface of the galvanized layer to form a phosphate film.
In order to promote the progress of the phosphating treatment, an accelerator such as Zn(N03)2, NaNO3, and a catalyst sodium fluoride are often added to the treatment liquid. At the same time, the temperature of the phosphating solution is strictly controlled at about 20 °C, and the pH value is controlled within the range of >3.
The phosphatized galvanized sheet is coated with a 1.5 to 2.0 g/m2 phosphating film on its surface to give a uniform silver-gray surface.