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1. Weathering steel: Steel with superior corrosion resistance compared to ordinary structural steel is known as weathering steel. It generally contains metals such as phosphorus, copper, nickel, chromium, and titanium, which form a protective layer on the metal surface to enhance its corrosion resistance. Its low-temperature impact toughness is also better than that of ordinary structural steels. The standard is \"Weathering Steel for Welded Structures\" (GB4172-84). 2. Hot-dip galvanizing: Hot-dip galvanizing involves immersing rust-removed steel components in molten zinc at a temperature of around 600°C, so that a zinc layer is formed on the surface of the steel components. The thickness of this zinc layer must be no less than 65 μm for thin plates with a thickness of 5 mm or less, and no less than 86 μm for thicker plates. Thus achieving the purpose of corrosion prevention. The advantages of this method are a long service life, a high degree of industrialization in production, and stable quality. Therefore, it is widely used in outdoor steel structures that are heavily affected by atmospheric corrosion and are difficult to maintain. Such as a large number of transmission towers, communication towers, etc. Profiled steel sheets and similar components used in lightweight steel structure systems, which have become increasingly common in recent years. Hot-dip galvanizing is also widely used for corrosion protection. The first step in hot-dip galvanizing is acid washing to remove rust, followed by cleaning. If these two processes are not carried out thoroughly, it will create risks for corrosion prevention. So it must be dealt with thoroughly. For steel structure designers, it is necessary to avoid designing components with mating surfaces, so as to prevent incomplete pickling or residual acid in the gaps between those surfaces. This causes yellow liquid to flow on the galvanized surface. Hot-dip galvanizing is carried out at high temperatures. For tubular members, their ends should be left open. If both ends are sealed, the air inside the tube will expand, causing the end plates to burst and resulting in safety accidents. If one end is sealed, the flow of zinc liquid is hindered, and it tends to accumulate inside the tube. 3. Thermal spray aluminum (zinc) composite coating: This is a long-lasting corrosion protection method that offers comparable corrosion resistance to hot-dip zinc coating. The specific procedure is to first perform sandblasting on the surface of the steel components to remove rust, revealing a metallic shine and creating a rough surface. The continuously fed aluminum (zinc) wire is then melted using an acetylene-oxygen flame, and blown onto the surface of the steel components with compressed air to form a honeycomb-shaped aluminum (zinc) coating layer (with a thickness of approximately 80μm to 100μm). Finally, the capillaries are filled with coatings such as epoxy resin or neoprene paint to form a composite coating. This method cannot be used for working on the inner wall of tubular components; therefore, both ends of such components must be hermetically sealed to prevent corrosion of the inner wall. The advantage of this process is its strong adaptability to component dimensions, with almost no restrictions on the shape and size of the components. Locks as large as those at Gezhouba are also constructed using this method. Another advantage is that the thermal influence of this process is localized and confined, thus preventing thermal deformation. Compared to hot-dip galvanizing, this method has a lower level of industrialization; sandblasting and aluminum (zinc) coating require heavy labor, and the quality is also prone to being affected by the operator’s mood swings. 4. Coating method: The corrosion resistance of the coating method is generally inferior to that of long-term corrosion prevention methods. Therefore, it is more commonly used in indoor steel structures or in outdoor steel structures that are relatively easy to maintain. Its cost per use is low, but the maintenance cost is high when used outdoors. The first step in applying the coating method is rust removal. A high-quality coating depends on thorough rust removal. Therefore, for coatings with high requirements, sandblasting or shot blasting is generally used to remove rust, expose the luster of the metal, and eliminate all rust and oil stains. The coating applied on-site can be manually derusted. The choice of coating should take the surrounding environment into account. Different coatings have varying tolerances to different corrosion conditions. Coatings generally consist of a primer layer and a topcoat layer. The primer contains a high amount of powder and little binder. The film formed is rough, with strong adhesion to steel and good bonding with the topcoat. Topcoats contain a high proportion of binders, form a glossy film, protect the primer from atmospheric corrosion, and resist weathering. There is an issue of compatibility between different coatings; when using different coatings one after another, it is important to pay attention to their compatibility. Applying the coating requires appropriate temperature (between 5~38°C) and humidity (relative humidity not exceeding 85%). The construction environment for applying the coating should have low dust levels, and there should be no dew on the surface of the components. It must not be exposed to rain within 4 hours after painting. The coating is usually applied 4 to 5 times. The total thickness of the dry paint film is 150 μm for outdoor projects and 125 μm for indoor projects, with an allowable deviation of 25 μm. On the seaside, at sea, or in an atmospherically highly corrosive environment, the total thickness of the dry paint film can be increased to 200–220 μm. 5. Cathodic protection method: A more reactive metal is applied to the surface of the steel structure to replace it and prevent corrosion. It is commonly used in underwater or underground structures.