In marine environments, ships are exposed to harsh conditions such as high salinity, humidity, and ultraviolet rays for a long time, and corrosion issues have become a key factor affecting the structural safety and service life of ships. Therefore, how to effectively improve the corrosion resistance of ships during the manufacturing process is an important issue that cannot be ignored in ship design and construction.



Firstly, material selection is the foundation for improving the corrosion resistance of ships. Modern shipbuilding widely uses high-strength corrosion-resistant steel, stainless steel, aluminum alloys, and composite materials. For example, the underwater part of the hull usually selects shipboard weathering steel with excellent resistance to seawater corrosion; the superstructure can use aluminum alloys to reduce weight and improve resistance to atmospheric corrosion. In addition, glass fiber reinforced plastics (FRP) and other new composite materials are widely used in the manufacturing of small ships or special-purpose ships due to their excellent chemical corrosion resistance.



Secondly, coating protection is one of the most commonly used corrosion prevention methods. During the manufacturing process, ships are coated with multi-layer protective coatings such as anti-rust primer, intermediate paint, and topcoat. These coatings not only isolate the metal from the corrosive medium but also improve the aesthetics and weather resistance of the hull. In recent years, with increasingly strict environmental regulations, non-toxic and environmentally friendly anti-fouling coatings have gradually become the mainstream trend, such as self-polishing anti-fouling paint (SPC) and biodegradable coatings, which can effectively prevent the attachment of marine organisms and reduce environmental pollution.



In addition, cathodic protection technology is an important measure to improve the corrosion resistance of ships. Cathodic protection is divided into two methods: sacrificial anode and impressed current. Sacrificial anodes such as zinc and aluminum-based alloys are installed in key parts of the hull, which corrode preferentially through electrochemical reactions to protect the main structure; while impressed current methods are suitable for large ships, which protect the entire hull by adjusting the potential with an external power source.



Finally, optimizing structural design can also effectively reduce local corrosion. For example, avoiding dead ends where water accumulates, using rounded corners for transitions, and reasonably arranging drainage holes can reduce water vapor retention and lower the risk of corrosion. At the same time, strengthening daily maintenance and regular inspections, such as using ultrasonic thickness gauges to monitor the corrosion of the hull and making timely repairs, are also important means to extend the service life of ships.



In summary, improving the corrosion resistance of ships requires a comprehensive approach from material selection, coating protection, cathodic protection, and structural design. With the advancement of technology and the enhancement of environmental awareness, in the future, shipbuilding will focus more on green, intelligent, and sustainable development while improving corrosion resistance.