Marine specialized paint coating is not just a layer of "paint", but a "system integration" composed of multiple processes and layers of different functional coatings. Its core goal is to resist the extremely harsh corrosion factors of the marine environment.

The marine environment poses an extremely severe challenge to hydraulic cylinders, with the main threats coming from:

1. High salt content: Seawater and marine atmosphere contain a large amount of chloride ions, which can easily penetrate ordinary coatings, causing severe electrochemical corrosion and pitting of the base metal.
2. High humidity: The continuous humid environment provides necessary conditions for corrosion.
3. UV radiation: Strong sunlight can degrade many organic coatings (such as ordinary epoxy resins), causing powdering, loss of gloss, and cracking.
4. Mechanical damage: Wear: Friction between the piston rod and the seal when the oil cylinder extends and retracts. ·Impact: Collision with floating ice, other equipment, or marine organisms during lifting, transportation, or operation.
5. Chemical erosion: May come into contact with oil, hydraulic oil, and other chemicals on drilling platforms.
6. Wet dry alternation: Oil cylinders in tidal or splash zones undergo continuous wet dry cycles on their surfaces, which is the most severely corroded area.

A typical high-performance coating system for marine hydraulic cylinders typically uses a "bottom center surface" composite coating system, with each layer playing an irreplaceable role.

function: This is the cornerstone of the entire coating system, determining the adhesion and long-term rust prevention ability between the coating and the substrate.

Process: Usually, Sa 2.5 or Sa 3 sandblasting treatment is used to thoroughly remove rust, oxide scale, and all impurities, expose the natural color of the metal, and form roughness, providing a strong "anchoring" effect for the coating.

Common type: epoxy zinc rich primer.

• Function: Cathodic protection: Zinc powder serves as a sacrificial anode, and even if there are minor scratches on the coating, zinc will preferentially corrode, thereby protecting the underlying steel substrate.
• Barrier protection: The dense paint film blocks the penetration of water vapor and oxygen.
• Strong adhesion: forms an extremely strong bond with the sandblasted steel surface.

Common type: thick paste epoxy cloud iron intermediate paint.

• Function: Increase coating thickness: Build a physical barrier called "film thickness", typically requiring a total dry film thickness of 250 μ m to 400 μ m or even higher for the entire coating system. Without sufficient thickness, the protection life cannot be discussed.
• Shielding effect: The sheet-like mica iron oxide is like countless small mirrors, stacked layer by layer, greatly extending the penetration path of corrosive media and enhancing the barrier protection effect.
• Connecting the past and the future: Enhancing the adhesion between primer and topcoat.

Common types: polyurethane topcoat or fluorocarbon topcoat.

• Function: Weather resistance and UV resistance: These are the most important functions of topcoats. It can maintain color and luster for a long time, without powdering or cracking, and protect the underlying coating from UV damage.
• Chemical resistance: resistant to salt spray, oil pollution, and chemical erosion.
• Wear resistance: Provides good surface hardness, resisting friction and slight collisions during piston rod expansion and contraction. Aesthetics and Identification: Provide standardized colors (such as yellow, white, etc.) for warning and aesthetic purposes.

1. Extremely high salt spray resistance: usually requires a neutral salt spray test of>3000 hours, which is the most basic entry-level requirement.
2. Comply with strict international standards: Must meet globally recognized marine anti-corrosion standards such as NORSOK M-501 (Norwegian Petroleum Industry Standard), ISO 12944 (C5-M Marine Corrosion Environment Level), etc.
3. System compatibility: The base, middle, and topcoat must come from the same system or be verified to be compatible for use, ensuring good interlayer adhesion and avoiding compatibility issues such as "biting the bottom".
4. Professional construction and inspection: From surface treatment, environmental temperature and humidity control, film thickness measurement to adhesion testing, each process must be strictly carried out in accordance with specifications and inspected by a third party.

·The oil cylinder substrate is first electroplated with hard chromium to obtain an extremely hard, smooth, and wear-resistant surface.

·Then spray the above-mentioned marine specific paint system on the hard chromium layer.

·Advantage: Strong alliance. The hard chrome layer provides ultimate wear resistance and mechanical damage protection, even if the surface paint is scratched, the hard chrome layer below can still provide excellent corrosion protection. The paint layer provides comprehensive resistance to environmental corrosion and UV protection.

The hydraulic cylinder marine special paint coating is a composite coating system designed to resist extreme corrosion environments in the ocean, consisting of high-performance primer, high shielding intermediate paint, and high weather resistant topcoat. It ensures the safe and reliable operation of hydraulic cylinders on offshore platforms for more than 15-20 years through a triple mechanism of cathodic protection, barrier shielding, and weather resistance, combined with strict construction standards. It is often combined with metal protective layers such as electroplated hard chromium to form a dual protection system that combines rigidity and flexibility.

Interested in learning more about industry trends and solutions? Contact Melody: sale@gyhydraulic.com/WhatsApp +8615852701381