As a core component of automotive cooling systems, the surface treatment process of corrugated radiator tubes plays a decisive role in improving their corrosion resistance. While corrugated structures increase heat dissipation area, their complex geometry also makes them susceptible to moisture, salt, and corrosive media residue, creating localized corrosion environments. By scientifically selecting surface treatment processes, a dense protective layer can be constructed between the metal substrate and the external environment, slowing down the corrosion process from multiple dimensions, including physical barrier, chemical passivation, and electrochemical protection, significantly improving the durability and reliability of the corrugated radiator tube.
Electroplating processes deposit a metal coating on the surface of the corrugated radiator tube, forming a physical barrier layer to resist corrosion. For example, zinc plating utilizes zinc's reactivity, preferentially sacrificing itself to protect the iron substrate in corrosive environments. Even if the coating is scratched, zinc's "self-healing" ability can still slow down rust propagation. For copper corrugated radiator tubes, nickel plating prevents copper oxidation and the formation of verdigris while maintaining high thermal conductivity, ensuring that heat dissipation efficiency is not affected. The uniformity of the electroplating layer is crucial for covering complex corrugated structures. Electrolysis parameters must be controlled to ensure complete coverage of grooves and edges, preventing weak areas from becoming corrosion initiation points.
Chemical conversion coating technology generates a dense passivation film through a chemical reaction between the metal surface and a specific solution, enhancing corrosion resistance. For example, aluminum corrugated radiator tubes often employ anodizing, forming an alumina film in a sulfuric acid environment using an applied current. This film is highly hard, wear-resistant, and effectively isolates oxygen and moisture, significantly improving the stability of aluminum alloys in humid environments. For steel corrugated radiator tubes, phosphating treatment generates a phosphate conversion film on the surface. This porous film serves as an adsorption substrate for subsequent coatings and also possesses a certain degree of corrosion resistance, forming a dual protection.
Coating technology constructs a dual physical and chemical protective barrier by spraying or impregnating organic coatings onto the surface of the corrugated radiator tube. Epoxy resins, polyurethanes, and other coatings possess excellent adhesion and chemical corrosion resistance, effectively blocking corrosive media such as salt spray and acid rain. To address the unique characteristics of corrugated structures, multi-layer composite coating technology has become mainstream: the base coat uses a zinc-rich coating, preferentially corroding the zinc layer using cathodic protection principles; the intermediate coating uses epoxy micaceous iron oxide to enhance shielding; and the top coat uses fluorocarbon resin to give the corrugated radiator tube excellent weather resistance and UV resistance. This "triple protection" system significantly extends the service life of the corrugated radiator tube in harsh environments.
Surface treatment processes improve the corrosion resistance of corrugated radiator tubes not only by enhancing the material's inherent corrosion resistance but also by indirectly improving the corrosive environment through optimized surface conditions. For example, polishing reduces surface roughness, minimizing moisture and salt retention; brushing guides liquid flow by creating regular textures, preventing localized liquid accumulation. Furthermore, surface treatment eliminates residual stress generated during metal processing, reducing the risk of stress corrosion cracking and further enhancing the reliability of the corrugated radiator tube.
The surface treatment process for automotive corrugated radiator tubes needs to be selected specifically based on the application environment and material properties. In coastal areas or high-salt-spray environments, hot-dip galvanizing or multi-layer composite coating processes should be prioritized; for high-temperature conditions, ceramic coatings or high-temperature resistant paints are more advantageous; while in the cooling systems of precision electronic equipment, anodizing or electrophoretic coating processes can meet the dual requirements of insulation and corrosion resistance. By scientifically matching surface treatment processes with application scenarios, the corrosion resistance of corrugated radiator tubes can be maximized, providing a reliable guarantee for the efficient operation of automotive cooling systems.
