1. Conceptual analysis
Hot dip galvanizing is an effective method of metal corrosion prevention. It involves melting zinc ingots at high temperatures, adding some auxiliary materials, and then immersing metal structural components in a galvanizing tank to attach a layer of zinc to the metal components, thus achieving the purpose of corrosion prevention. The advantage of hot-dip galvanizing is its strong anti-corrosion ability, good adhesion and hardness of the galvanized layer, thus achieving the purpose of anti-corrosion.
Cold galvanizing: It is a process of electroplating zinc with a small amount of zinc, only 10-50g/m2, which uses electrolysis to attach a layer of metal film to the surface of metal or other material parts. The process of forming a uniform, dense, and well bonded metal layer can prevent corrosion, improve wear resistance, conductivity, reflectivity, and enhance aesthetics.
2. Differences in reaction modes
Hot dip galvanizing is a chemical treatment that belongs to electrochemical reactions Hot dip galvanized pipe is produced by reacting molten metal with iron substrate to form an alloy layer, thereby combining the substrate and coating
Cold galvanizing is a physical treatment that only involves brushing a layer of zinc on the surface, so the zinc layer is prone to peeling off. Hot dip galvanizing is commonly used in construction
3. Differences in processes
Hot dip galvanizing is the process of immersing a workpiece in a molten zinc solution for a certain period of time after degreasing, pickling, dipping, and drying, and then removing it. Cold galvanizing is the process of using electrolytic equipment to remove oil and acid from workpieces, placing them in a solution composed of zinc salts, and connecting the negative electrode of the electrolytic equipment; Place a zinc plate opposite the workpiece and connect it to the positive electrode of the electrolysis equipment. Connect the power supply and use the directional movement of current from the positive electrode to the negative electrode to deposit a layer of zinc on the workpiece.
4. Difference between galvanized products
Hot dip galvanizing has a finer and brighter appearance than cold dip galvanizing, and the coating is uniform. However, in terms of zinc layer thickness, hot-dip galvanizing is several tens of times thicker than cold dip galvanizing. The anti-corrosion performance is also dozens of times higher than that of electroplated zinc. Hot dip galvanizing, also known as hot-dip galvanizing, is a method of removing oil and rust from steel workpieces, presenting a surface free of dirt and infiltration, and immediately immersing them into a pre heated and melted zinc plating tank to form a layer of zinc coating on the surface of the workpiece.
Cold galvanizing is the process of hanging workpieces that have also undergone oil and rust removal, presenting a clean and wet appearance, onto the cathode in a specialized electroplating tank, and using zinc as the anode. Connect the DC power supply, the zinc ions on the anode migrate to the cathode, and discharge on the cathode to coat the workpiece with a layer of zinc. The coating of hot-dip galvanizing is relatively thick, usually 30-60 microns, and the coating has high anti-corrosion ability. Electrogalvanizing results in a smooth and even surface of the workpiece, but due to the relatively thin coating, the anti-corrosion time for electroplating is generally within 5-30 microns. They are used for rust prevention of indoor components, such as chassis bottoms, panels, small-sized fasteners, etc. In suburban environments, the standard hot-dip galvanized anti rust thickness can be maintained for more than 50 years without the need for repair; In urban or coastal areas, the standard hot-dip galvanized anti rust layer can be maintained for 20 years without the need for repair.
5. Difference in usage
Hot dip galvanizing: Suitable for long-term rust prevention of steel parts used in outdoor work, such as highway fences, power towers, large-sized fasteners, and other relatively "rough" workpieces. The earlier iron water pipes were also hot-dip galvanized
Electrogalvanizing: Used for rust prevention of indoor components such as chassis bottoms, panels, and small-sized fasteners.
