The marine environment can be called the "invisible killer" of deck cranes - high salt spray, high humidity, intense ultraviolet rays, coupled with salt residue and mechanical wear caused by the impact of waves, which can easily lead to the corrosion of the deck crane's metal structure and electrical system failure, which not only shortens the service life of the equipment, but also directly threatens the safety of marine operations. As a service provider specializing in the R&D and sales of deck telescopic knuckle boom cranes, we deeply understand the critical importance of anti-corrosion performance for marine equipment. Today, we will introduce to you how to improve the anti-corrosion measures of our deck crane machinery and extend the life of our lifting machinery from material selection to design, production, and scheduled maintenance.
What are the threats to deck cranes from the marine environment?
Salt spray corrosion:
Chloride ions in seawater are highly corrosive, which will destroy the oxide film on the metal surface and cause pitting and crevice corrosion deep into the metal, especially in the welds, bolts, and other parts of the marine crane.
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Damp and heat corrosion
The marine climate is humid, and the temperature difference between day and night in some sea areas is significant, which can easily lead to condensation on equipment surfaces, providing conditions for the diffusion of corrosive media and accelerating metal corrosion.
02
Mechanical wear + corrosion superposition
Wave impact and ship bumps will cause the ship crane's structural parts to rub against each other and damage the surface protective layer; at the same time, dust, sand, and gravel in marine operations will aggravate wear, exposing the metal matrix directly to the corrosive environment.
03
Special Media Corrosion
In offshore waters, ports, or chemical carrier operations, additional corrosion threats, such as industrial exhaust gases and chemical residues, may also be encountered, further testing the equipment's anti-corrosion capabilities.
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Anti-corrosion Solution for YFM Deck Telescopic Jib Crane
1. Selection of Corrosion-Resistant Substrate
The substrate is the foundation of anti-corrosion. The core structural components of our deck telescopic folding crane (such as the telescopic arm, folding arm, and legs) are all made of specialized corrosion-resistant steel, including weathering steel and high-strength stainless steel. Among them, weathering steel contains alloy elements such as copper, chromium, and nickel, which can form a dense oxide rust layer on the surface to prevent further penetration of corrosive media. For special applications such as chemical transport ships and offshore platforms, 316L stainless steel is also selected, offering superior resistance to chloride-ion corrosion and better adaptation to harsher operating environments.
2. Design and Process: Surface Pre-treatment
Even the best coating will quickly peel if applied to a rough, dirty surface. Therefore, our deck telescopic foldable boom cranes undergo a rigorous surface pre-treatment process before painting.
First, the equipment surface is flushed with a high-pressure water jet (paired with neutral detergent) to remove dust, grease, and salt residue from transportation.
For equipment purchased in coastal areas, an additional "salt neutralization" step is added - key areas are wiped with a 5% citric acid solution to obliterate residual chloride ions.
Rust removal classified by degree of rust: The deck cranes provided by YFM are treated with sandblasting to Sa2.5 level, completely removing rust and scale, with surface roughness controlled between 40-80μm, thereby enhancing the adhesion of the coating to the substrate and altogether avoiding later coating peeling and detachment.
3. Design and Technology: Multi-layer composite coating system
After surface pretreatment, a multi-layer coating is immediately applied to form a "physical isolation barrier." Our company adopts an industry-leading "primer + intermediate coat + top coat" composite coating system, with each layer having a clear functional purpose.
Primer: Enamel rich in zinc powder: As the first layer of protection, the enamel rich in zinc powder not only provides a physical barrier against corrosive media but also sacrifices the zinc powder through "cathodic protection" to protect the steel substrate. Even minor coating damage can prevent rapid substrate rusting. The dry film thickness is controlled between 60 and 80 μm to ensure adequate protection.
Midcoat: Epoxy iron oxide intermediate coating: It serves as a bridge between the primer and topcoat, enhancing the thickness and mechanical strength of the layer, and improving impact and wear resistance; meanwhile, iron oxide pigments can further block the penetration of moisture and oxygen, extending the overall service life of the coating. The dry film thickness is approximately 80-100μm.
Topcoat: Aliphatic polyurethane topcoat. As the outer protective layer, it offers excellent weather resistance and UV aging resistance, and resists corrosion from salt mist and humidity. In addition, the topcoat surface is smooth and self-cleaning, reducing the adhesion of salt and dust. For different sea areas, we can also customize topcoats in various colors. Generally, gray is selected for nearshore operations due to its strong resistance to pollution, while orange is used for offshore operations for its high visibility, or according to customer requirements.
4. Design & Craftsmanship: Focus on Details with Specialized Anti-Corrosion Design for Key Components
Corrosion of deck cranes often starts from detailed components. Therefore, the YFM team has implemented specialized enhanced designs for corrosion-prone key parts.
Welds and Bolted Connections: Welds are treated with "smooth grinding + additional anti-corrosion mastic" to avoid crevice corrosion; the inner walls of bolt holes are coated with anti-rust grease, and stainless steel gaskets + anti-corrosion sealants are used after bolt installation to prevent salt from entering the thread gaps.
Articulation Joints of Telescopic Boom & Folding Boom: A dual-protection system of "anti-corrosion rubber strips + stainless steel protective covers" is adopted to reduce coating damage caused by friction and wear; meanwhile, dustproof and waterproof sealing caps are added at the oil injection ports of the articulation joints to avoid lubricating oil contamination and the ingress of corrosive media.
Connection Between Outrigger Base & Deck: An additional polyurea waterproof layer is applied. Polyurea materials have excellent anti-corrosion and impact resistance, which can effectively isolate the contact surface between seawater and the metal base of the outriggers. At the same time, drainage holes are provided at the connection points to prevent long-term corrosion caused by water accumulation.
Electrical System: All electrical control cabinets adopt an IP65-rated waterproof and dustproof design, and wiring interfaces use sealed waterproof connectors; key electrical components (such as sensors and controllers) are selected from marine-grade anti-corrosion models to ensure stable operation in high-salt-fog environments.
5. Long-Term Guarantee: Regular Maintenance & Anti-Corrosion Upgrades
Even with a comprehensive factory anti-corrosion design, regular post-maintenance can further extend the equipment's anti-corrosion service life.
Daily Maintenance: Rinse the equipment surface with fresh water weekly to remove salt fog residues; check for coating damage or peeling, and repair promptly with special repair paint if problems are found.
Regular Inspection: Test coating thickness and adhesion every 6 months to ensure coating performance meets standards; derust and repaint key parts, such as bolted connections and welds, every year.
In harsh marine environments, the anti-corrosion performance of deck telescopic folding cranes directly determines the equipment's service life, operational safety, and operating costs. The deck telescopic folding cranes provided by YFM Company feature a full-process, high-standard anti-corrosion system from base material selection through post-maintenance. They can not only meet the operational needs of ordinary cargo ships and fishing boats but also satisfy the stringent requirements of special scenarios such as offshore platforms and chemical tankers.
One-stop marine machinery factory in China
If you'd like to learn about customized anti-corrosion solutions for deck telescopic folding jib cranes in different marine scenarios, please feel free to contact our professional team for one-on-one exclusive consulting services.
Contact person: Megy Hu
Email:megyhu@yfm-crane.com
WhatsApp: +17612748600