——Laser cladding technology enables the full life cycle performance upgrade of marine engineering equipment

I. Industry challenges and core needs

Marine engineering equipment is exposed to high salt spray corrosion, biological attachment, high pressure shock and extreme temperature difference environment for a long time, resulting in failure problems such as wear, corrosion and fatigue cracks in key components. According to statistics, about 60% of the cost of ship maintenance comes from surface damage repair, while traditional repair technologies (such as surfacing and electroplating) have defects such as large thermal deformation, low bonding strength and short coating life712.

Aiming at the pain points in this field, our company takes laser cladding technology as the core, combines synchronous powder feeding process and customized alloy powder, and provides a full process service from old parts repair to new product pre-strengthening, helping key components such as ship propulsion systems, deck machinery, and hull structures to achieve a disruptive upgrade of 5-10 times increase in wear resistance, extended salt spray corrosion resistance life to 15 years, and “high temperature stability exceeding 800℃”.

Ⅱ. Classification of core components and surface treatment requirements

1. Propulsion system

Propeller and propulsion shaft:

Requirements: anti-cavitation (linear speed ≥ 30m/s), seawater corrosion resistance (Cl⁻ concentration 3.5%), and anti-biological attachment.

Technical solution: laser cladding Cr3C2-NiCr composite coating, hardness HRC 55-60, bonding strength ≥ 400MPa, passed ASTM G48 salt spray test and DNVGL-RP-0416 marine engineering certification.

Turbocharger blades:

Requirements: high temperature resistance (600-800℃), resistance to sulfide oxidation (sulfur fuel environment).

Technical solution: Inconel 625 nickel-based alloy is used, with a temperature resistance of 1000℃ and a 70% reduction in sulfide oxidation rate.

2. Deck machinery

Anchor gear/winch drive shaft:

Requirements: anti-abrasive wear (sand and gravel impact), anti-micro-wear (alternating load).

Technical solution: gradient cladding WC-10Co-4Cr coating, surface hardness HRC 65, bottom FeCrNiMoB buffer layer, impact toughness increased by 3 times.

Hydraulic cylinder inner wall:

Requirement: resistance to seawater penetration corrosion, restore sealing surface accuracy (Ra≤0.8μm).

Technical solution: coaxial powder feeding laser cladding 316L stainless steel + nano Al2O3 reinforcement layer, porosity ≤1%, pitting resistance increased by 4 times.

3. Hull and special structure

Ballast bulkhead/seawater valve:

Requirement: anti-microbial corrosion (SRB bacteria), electrochemical corrosion resistance (potential difference control).

Technical solution: cold spray Ta (tantalum) coating, concentrated hydrochloric acid corrosion resistance life of more than 10 years, in line with NORSOK M-001 standard.

LNG tank lining:

Requirement: resistance to -162℃ low temperature brittleness, resistance to methane penetration.

Technical solution: laser cladding nickel-based alloy + ceramic fiber reinforcement layer, thermal expansion coefficient matching 9Ni steel, low-temperature impact energy ≥100J.

III. Laser cladding technology advantages and material system

1. Những ưu điểm kỹ thuật cốt lõi

Metallurgical-grade bonding: dilution rate ≤5%, bonding strength reaches more than 95% of the substrate, completely solving the problem of traditional electroplating peeling.

Micron-level precision: six-axis robot with coaxial powder feeding to achieve 0.1mm-level repair of complex curved surfaces (such as three-dimensional contours of propeller blades).

Low-temperature process: substrate heat-affected zone ≤0.3mm, avoiding thermal deformation of aluminum alloy hull structures (such as superstructures).

2. Material selection and performance adaptation

IV. Full-process service and quality control

1. Old parts repair process

Damage assessment:

Use industrial endoscope to detect micro cracks in propulsion shaft, and 3D scanning to reconstruct propeller geometry (accuracy ±0.05mm).

Thiết kế quy trình:

Match materials and parameters based on the working condition database (including 2000+ ship cases), such as power (2-6kW), powder feeding rate (10-50g/min).

Triển khai tại chỗ:

The mobile laser cladding workstation supports on-site operations at the dock and is equipped with a powder recovery system (utilization rate ≥90%).

Post-processing certification:

Electrolytic polishing (Ra≤0.4μm) + penetrant flaw detection (ASTM E1417) + salt spray test (3000 hours).

2. Quy trình gia cố sơ bộ sản phẩm mới

Marine diesel engine crankshaft: substrate 42CrMo + cladding Stellite 6 coating, surface hardness HRC 55, fatigue life increased to 20,000 hours (original 12,000 hours).

Submersible pressure hull: titanium alloy substrate + laser cladding Ta (tantalum) corrosion resistant layer, resistant to 1000m deep sea pressure, passed DNV GL submersible certification.

V. International cooperation cases and benefits

1. Nordic cruise propulsion shaft repair

Problem: The propeller shaft was reduced by 2mm in diameter due to cavitation, and the cost of a single replacement was 1.2 million euros.

Solution: Laser cladding Cr3C2-NiCr coating (thickness 3mm), the cavitation rate after repair was reduced to 0.1mm/year.

Result: The repair cost is only 20% of the new part, and it has been certified by Lloyd’s Register.

2. Strengthening of storage tanks for LNG carriers in the Middle East

Requirement: methane penetration resistance and low-temperature brittleness of the lining at -162℃.

Solution: New product pre-cladding nickel-based alloy + ceramic fiber layer, thermal stress reduced by 40%, and service life extended to 25 years.

Benefits: Customers’ annual operation and maintenance costs reduced by US$1.8 million, and carbon emissions reduced by 35%.

VI. Technical commitment and future direction

As a trusted surface engineering partner in the global marine engineering field, we promise:

Zero geopolitical restrictions: Adhere to the ITAR compliance framework, and provide services covering major shipbuilding bases such as Europe, Southeast Asia, and the Middle East.

Intelligent upgrade: Develop AI-driven laser cladding robots, monitor the morphology of the molten pool in real time, and dynamically optimize power and powder feeding rate.

Green manufacturing: Reduce metal resource consumption by 70% through remanufacturing, and help customers achieve IMO 2030 carbon reduction targets.

Let every giant ship move forward steadily in the stormy waves – we use innovative technology and extreme craftsmanship to protect the reliability and economy of marine equipment.