What causes the anti-corrosion coating of steel structure joints to fail first?

The anti-corrosion coating on steel structure joints may fail before other surfaces due to the following reasons: 1. Stress concentration: The joints are subjected to greater forces, which makes stress concentration more likely to occur, leading to cracks or peeling of the coating. 2. Construction quality: The construction at the joint areas is relatively complex; uneven coating or insufficient thickness can affect the protective effectiveness of the coating. 3. Environmental factors: The joint areas are often in a connected state, and there may be gaps that allow water and pollutants to accumulate, accelerating the corrosion process. 4. Mechanical damage: During installation or maintenance, the joint areas are more prone to mechanical impact or friction. 5. Temperature difference changes: Due to the structural characteristics of various nodes, they may have different coefficients of thermal expansion, and temperature differences can lead to the cracking of the coating. All these factors can cause the anti-corrosion coating of steel structure joints to fail earlier than that of other areas. .

The main reasons why the anti-corrosion coatings on steel structure joints fail earlier than those on other surfaces include the following: stress concentration. Stress concentration at the joints causes the coatings to crack and peel off easily. Complex geometric shapes: The geometry of the nodes is complex, making it difficult to apply a uniform coating and leading to the formation of weak points. Welding effects: The heat-affected zone resulting from welding can alter the material properties and reduce the adhesion of the coating. Mechanical damage: During installation and use, the joints are prone to mechanical damage, which can damage the coating. Environmental factors: Moisture and corrosive substances tend to accumulate at the nodes, accelerating the degradation of the coating. Difficulty in coating application: It is difficult to apply the coating at joints, and it is hard to ensure the thickness and quality of the coating. Fatigue and vibration: The joints are subjected to more fatigue and vibration, leading to cracks and peeling of the coating. Difficult to maintain: Maintenance at the nodes is inconvenient, making effective inspection and repair challenging. Solution: Design optimization: reduce stress concentration. Surface treatment: Ensure the surface is clean and has the appropriate roughness. High-quality coating: Use a coating with strong adhesion and corrosion resistance. Construction quality control: Ensure the coating is uniform and meets the required thickness. Regular maintenance: Check and repair the coating in a timely manner. Through these measures, the service life of the node coating can be effectively extended.