Hot-dip galvanizing auxiliary plating solution process indicator
Author: Robby
Composition of auxiliary plating solution: The main components of hot-dip galvanizing auxiliary plating solution include zinc chloride (ZnCl₂) and ammonium chloride (NH₄Cl). These components play an important role in the hot-dip galvanizing process. The role of zinc chloride is to activate the surface of the steel substrate and promote the reaction between zinc and steel substrate; ammonium chloride helps to reduce the oxidation of the workpiece in the dip plating process.
Temperature: The temperature control of the auxiliary plating solution is very important. Generally controlled between 60 ℃ and 85 ℃. The purpose of increasing the temperature is to increase the solubility of zinc chloride and ammonium chloride to ensure that an excellent zinc coating is obtained. For hanging plating production, the temperature is controlled at 45℃ to 65℃; for blow plating production, the temperature is controlled at 65℃ to 75℃.
pH: The pH value of the auxiliary plating solution should be controlled between 4 and 5.5. pH control is critical to the effectiveness of the auxiliary plating, too low or too high a pH value will affect the stability of the auxiliary plating solution and its effectiveness.
Iron salt content: The iron salt content in the auxiliary plating solution should be controlled at a low level, generally requiring FeCl₂<1g/L. Excessive iron salt content will lead to an increase in zinc slag, which will affect the quality of the galvanized layer. In actual production, iron salt content needs to be tested and controlled regularly to ensure production quality.