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　　Galvanized steel pipe are widely used in building steel structures, automobile manufacturing, machinery manufacturing, bridge construction, container keel, ship manufacturing and other fields due to their excellent corrosion resistance, deep processing formability, paint and weldability, as well as good surface quality and comprehensive mechanical properties.

　　A layer of metal or alloy is deposited on the surface of the product through the electrolysis process of metal ions to change the physical and chemical properties of the product surface, so that the galvanized steel pipe has the characteristics of wear resistance, decoration and impact resistance. In addition, it can also coat a specific coating according to the special requirements of the specific product, such as light energy and electromagnetic coating, Q195 Schedule 80 Seamless Galvanized Steel Pipe which can fully expand the galvanized steel pipe.

　　The galvanized steel pipe processing and electroplating process mainly includes pretreatment, electroplating and post-treatment. The quality of the coating depends on the electroplating process of the material, and the electroplating process is affected by many factors. Six factors are summarized as follows:

　　1. Zinc content: The higher the purity of zinc, the narrower the brightness range; when the purity of zinc is too low, the brightness range will be wider. Galvanized steel pipes will take longer to reach the required thickness of zinc layer, which will lead to higher iron content in zinc plating layer.

　　2. Sodium hydroxide: Sodium hydroxide has dual effects on the reaction. When the content of sodium hydroxide is too high, burning phenomenon is easy to occur during high temperature operation. When the content of sodium hydroxide is too low, the dispersibility of solution is poor, which will reduce the quality of zinc layer.

　　3. Iron content: When the iron content is too high, the iron content in the coating will correspondingly be more, which will lead to the inadequate brightness of passive film; and the low iron content will lead to the lower iron content in the galvanized coating, reduce the corrosion resistance of galvanized pipe, and lead to olive color on the surface of automobile plate.

　　4. Brightener: The brightener used now is composed of ZF-100A and ZF-100B. The former concentration is too high to enhance the brittleness of the coating, while too low to cause the coating in the low current zone to be sparse, resulting in non-uniform passivation.

　　5. Temperature: High temperature in the process of electroplating will lead to the decrease of Solution Dispersion ability, the increase of iron content in the coating, and the non-uniform passivation; and when the reaction temperature is too low, the high current density zone will easily burn, the brittleness of the coating is greater and the deposition rate is slower.

　　6. Cathode moving speed: In the process of electroplating, the cathode must be kept in a moving state. If the moving speed is too fast, the coating in the high current density area will be rough; and if the moving speed is too slow, airflow may occur, resulting in the uneven coating of materials.

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