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Introduction to the method of removing the galvanized layer of packaging steel strip
by：Hongmei
2021-03-15
Introduction to the method of removing the galvanized layer of packaging steel strip
The removal of the zinc layer mainly adopts the chemical solution soaking method. Since zinc is easy to dissolve in the acid solution, soaking in the chemical solution is also the main method. Alkaline solutions can also be used for workpieces made of copper or brass as the base material. The method for removing zinc by chemical solution immersion is simple, easy to operate, and low cost, so most zinc removal uses this method. However, in some special cases, electrolysis is also used, but it is rarely used. Therefore, the formulation of the electrolysis method is rarely introduced.
(1) Solution formula and process conditions for removing zinc coating by chemical method
In the process of chemical soaking, if too much surfactant is entrained on the surface of the plated parts, the acid solution will produce more foam. In this case, 1%-2% nitric acid can be added to play the role of oxidation and defoaming. Alkaline solution is mainly used for the removal of galvanized layers of high-carbon steel substrates and elastic parts, which can prevent over-corrosion and hydrogen penetration. It can also be used for the removal of zinc from copper and copper alloy workpieces.
(2) The method of removing the galvanized layer by electrolytic method. Since the galvanized layer can be easily removed by the chemical soaking method, the electrolytic method is rarely used, because the electrolytic method needs to add an electrolytic device, which is not economical Therefore, it is generally not recommended, but it can be used when necessary. For example, a certain factory uses the following electrolytic solution formula and process conditions when removing the galvanized layer on copper and brass workpieces.
The removal of the zinc layer mainly adopts the chemical solution soaking method. Since zinc is easy to dissolve in the acid solution, soaking in the chemical solution is also the main method. Alkaline solutions can also be used for workpieces made of copper or brass as the base material. The method for removing zinc by chemical solution immersion is simple, easy to operate, and low cost, so most zinc removal uses this method. However, in some special cases, electrolysis is also used, but it is rarely used. Therefore, the formulation of the electrolysis method is rarely introduced.
(1) Solution formula and process conditions for removing zinc coating by chemical method
In the process of chemical soaking, if too much surfactant is entrained on the surface of the plated parts, the acid solution will produce more foam. In this case, 1%-2% nitric acid can be added to play the role of oxidation and defoaming. Alkaline solution is mainly used for the removal of galvanized layers of high-carbon steel substrates and elastic parts, which can prevent over-corrosion and hydrogen penetration. It can also be used for the removal of zinc from copper and copper alloy workpieces.
(2) The method of removing the galvanized layer by electrolytic method. Since the galvanized layer can be easily removed by the chemical soaking method, the electrolytic method is rarely used, because the electrolytic method needs to add an electrolytic device, which is not economical Therefore, it is generally not recommended, but it can be used when necessary. For example, a certain factory uses the following electrolytic solution formula and process conditions when removing the galvanized layer on copper and brass workpieces.
