Corrosion Causes and Anticorrosion Methods for Aluminum Alloy in High-speed Trains

The body and hook-beam structure of high-speed trains are manufactured using aluminum alloy, known for its advantages such as low density, high strength-to-weight ratio, good corrosion resistance, and excellent low-temperature performance. By replacing traditional steel materials with aluminum, the weight of the train body is significantly reduced, leading to lower energy consumption, reduced environmental pollution, and creating both economic and social benefits.

However, aluminum and aluminum alloys have highly reactive chemical properties. Despite forming a dense oxide film when exposed to oxygen in the environment, providing better corrosion resistance than ordinary steel, corrosion can still occur when aluminum alloy is used in high-speed trains. Corrosive water sources, including splashing, atmospheric condensation, and water evaporating from the ground during parking, can disrupt the oxide film. Corrosion in aluminum alloy used in the body of high-speed trains mainly manifests as uniform corrosion, pitting corrosion, crevice corrosion, and stress corrosion, making it a complex process influenced by both environmental factors and alloy properties.

There are various methods for anticorrosion of aluminum alloy, such as applying anticorrosive coatings to effectively isolate the aluminum alloy substrate from the external environment. A typical anticorrosive coating is epoxy resin primer, widely used for its good water resistance, strong substrate adhesion, and compatibility with various coatings.

However, compared to physical rust prevention methods, a more effective approach is the chemical passivation treatment. After passivation treatment of aluminum and aluminum alloys, product thickness and mechanical precision remain unaffected, and there are no changes in appearance or color. This method is more convenient and provides a more stable and corrosion-resistant passivation film compared to traditional anticorrosive coatings. The passivation film formed through aluminum alloy passivation treatment is more stable and has higher corrosion resistance than traditional anticorrosive coatings, with the added benefit of self-repair functionality.

Our chromium-free passivation solution, KM0425, is suitable for passivating aluminum materials, aluminum alloys, and die-cast aluminum products, enhancing their corrosion resistance. It is a new and high-quality product for general-purpose passivation of aluminum materials. Formulated with organic acids, rare earth materials, high-quality corrosion inhibitors, and a small amount of high-molecular-weight passivation accelerators, it is acid-free, non-toxic, and odorless. Compliant with current environmental RoHS standards, using this passivation solution ensures that the passivation process does not damage the original color and dimensions of the workpiece while significantly improving the resistance of aluminum materials to salt spray.

Post time: Jan-25-2024