1. Hot dip galvanizing. Zinc has excellent corrosion resistance. Galvanizing is a method of sacrificing anode to maintain cathode metal. The service life depends on its corrosion degree and corrosion speed, as well as the resistance thickness of zinc coating. The zinc layer thickness of hot-dip galvanizing is usually above 65um(455g/m2). The bonding surface of zinc and iron forms a layer of zinc-iron alloy, which improves the adhesion of zinc layer. The atmospheric exposure test of hot-dip galvanized layer in different environments was carried out on foreign bridge frames. According to the test results, hot dip galvanizing can meet the service life requirements of cable bridge. Hot dip galvanized steel bridge has been widely used at home and abroad because of its excellent corrosion resistance and high performance-price ratio. Thin-walled members with large slenderness ratio. When hot galvanizing is not easy to deform, it is necessary to think about the structure of cable bridge and galvanizing skills. Corrosion, forming a large area of coating foaming and peeling. Other coatings have poor ultraviolet resistance and are usually not suitable for field use. Specific questions can be consulted, Shanghai Changpeng Metal Products.
2. Apply antirust paint. As for the large structural parts of the bridge, due to the limitations of zinc pot, electroplating bath and oven, they can only be treated with antirust paint. This of course has the characteristics of low cost and convenient use; But the corrosion resistance is poor. Short life, heavy maintenance workload, usually not suitable for use. The aluminum alloy pallet has been used in China. Regardless of the high humidity in coastal areas and the salt in areas containing sulfur dioxide gas. The cable tray is made of aluminum alloy, and the natural exposure experimental results show that the steel cable tray has remarkable corrosion resistance. Especially in selective anodic aluminum oxide corrosion is very good. Specific questions can be consulted, Shanghai Changpeng Metal Products.
3. Galvanizing. Compared with hot dip galvanizing, bridge electro-galvanizing has simple process and low cost. There are no special requirements for cable bridge structure. After passivation treatment, the maintenance performance of electro-zinc coating is significantly improved. The zinc coating is usually around 12/zm. Therefore, it is not suitable for occasions with high requirements for corrosion resistance life. Specific questions can be consulted, Shanghai Changpeng Metal Products. There are clear regulations on the selection, thickness, adhesion and corrosion resistance test of the coating, and the selection of planning objectives and content requirements are also different. There are many manufacturers producing galvanized pallets in China now. When they participate in helping customers, they use the above skill standards differently. In order to improve the corrosion resistance of galvanized layer, zinc-nickel alloy electroplating or high passivation treatment after zinc plating can be selected.
4. Electrostatic spraying. PVC material is usually powder coating, polyester powder or antiseptic powder. The coating thickness is about 100/ 1rn. Electrostatic spraying has beautiful appearance, chemical corrosion resistance and outstanding function. However, compared with the metal coating, the adhesion strength is lower and the clean and wear-resistant particles are worse.