GNEE 5083 H116 Marine Grade Aluminium Alloy Plate (DNV Certified) is a high-strength, corrosion-resistant aluminum alloy designed specifically for shipbuilding and offshore applications. It combines outstanding seawater corrosion resistance, superior weldability, and excellent fatigue strength under DNV-approved manufacturing and quality control processes. This alloy is widely used in hulls, superstructures, decks, offshore platforms, and other structural marine components where durability, safety, and weight reduction are critical.
Introduction
Aluminium alloy 5083 is among the most commonly used grades in marine industries. When processed to the H116 temper and accompanied by DNV (Det Norske Veritas) certification, it becomes a trusted choice for commercial ships, naval vessels, and offshore structures.
The H116 temper indicates the material has been strain-hardened and partially annealed, providing enhanced toughness and optimized proof strength for marine use.
DNV certification ensures full compliance with classification society requirements for traceability, quality assurance, and mechanical performance.
Key Features
Exceptional resistance to seawater and marine atmospheres
High tensile strength and superior fatigue performance compared to standard marine alloys
Excellent weldability with GMAW (MIG), GTAW (TIG), and resistance welding methods
High ductility and toughness, even at low temperatures
Lightweight compared with steel, reducing vessel weight and improving fuel efficiency
DNV certification ensures quality, traceability, and compliance with marine class rules
Suitable for both new vessel construction and repair/retrofit projects
Primary Applications
Ship and boat hulls (commercial, naval, offshore support vessels)
Decks and superstructures
Rigid inflatable boats (RIBs) and small aluminium craft
Offshore platforms, topsides, and walkways
Buoyancy chambers, pontoons, and marine tanks
Corrosion-resistant structural panels and stiffeners
Cryogenic and low-temperature marine equipment
Chemical Composition (Typical wt%)
| Element | Range (%) |
|---|---|
| Aluminum (Al) | Balance |
| Magnesium (Mg) | 4.0 – 4.9 |
| Manganese (Mn) | 0.4 – 1.0 |
| Chromium (Cr) | 0.05 – 0.25 |
| Iron (Fe) | ≤ 0.4 |
| Silicon (Si) | ≤ 0.4 |
| Copper (Cu) | ≤ 0.1 |
| Zinc (Zn) | ≤ 0.25 |
| Titanium (Ti) | ≤ 0.15 |
| Other (each) | ≤ 0.05 |
| Other (total) | ≤ 0.15 |
Complies with EN 573 and ASTM specifications. Actual composition may vary slightly based on manufacturer requirements.
Mechanical Properties (Typical-H116 Temper)
| Property | Typical Value |
|---|---|
| Tensile Strength (Rm) | 305 – 350 MPa |
| Yield Strength (Rp0.2) | ≥ 215 MPa |
| Elongation (A50) | ≥ 10 – 12% |
| Hardness (Vickers) | ~80 – 95 HV |
| Fatigue Strength (10⁷ cycles) | ~80 – 120 MPa |
| Density | 2.66 g/cm³ |
| Modulus of Elasticity | 69 GPa |
Temper Definition and Processing
The H116 temper is specifically developed for marine-grade aluminum. It indicates that the material has been strain-hardened and stabilized to enhance mechanical strength and improve resistance to stress corrosion cracking.
Plates are typically stabilized through low-temperature annealing or natural aging.
Welding may slightly reduce strength in heat-affected zones; use DNV-approved welding procedures.
Post-weld cleaning and surface preparation help maintain corrosion resistance.
Physical & Thermal Properties
| Property | Value |
|---|---|
| Melting Range | 590 – 640 °C |
| Thermal Conductivity (20 °C) | ~121 W/m·K |
| Electrical Resistivity (20 °C) | 0.047 ×10⁻⁶ Ω·m |
| Coefficient of Thermal Expansion (20–100 °C) | 23.6 µm/m·K |
Production Standards & Certification
Standards: EN AW-5083 (EN 573 / EN 755), ASTM B209 / B928, ISO 6361
Certification: DNV material certification verifying compliance with classification rules for marine aluminum plates
Documents Provided:
EN 10204 3.1 / 3.2 certificates
Mill Test Reports (MTR)
DNV approval letters
Welding Procedure Specifications (WPS)
Non-destructive testing (NDT) records (where required)
Dimensional Range & Supply Forms
| Form | Thickness Range | Typical Width | Typical Length |
|---|---|---|---|
| Plate | 3 mm – 200 mm | up to 2.5–4.0 m | up to 12 m (custom cut) |
| Sheet | 0.5 mm – 6 mm | up to 2.5 m | Coil or cut-to-length |
| Heavy Plate | 80 mm – 200 mm | Limited by mill | As per order |
Larger thicknesses may require specialized rolling or forging equipment.
Welding, Fabrication & Surface Treatment
Welding: MIG/TIG and submerged arc welding are commonly used. Recommended filler metals: ER5356 or ER5183 for strength and corrosion resistance.
Forming: Excellent cold formability; follow manufacturer guidelines for bend radius to prevent cracking.
Machining: Use sharp tools and controlled cutting speeds to avoid work hardening.
Surface Treatment: Anodizing, chromate conversion coatings, or marine-grade paint systems enhance corrosion protection. Ensure proper degreasing before coating.
Quality Control & Testing (for DNV Certification)
Chemical composition analysis
Mechanical tests (tensile, yield, elongation) in both longitudinal and transverse directions
Hardness tests
Ultrasonic or radiographic inspection (for thick plates)
Eddy current and surface crack detection as needed
Dimensional and visual inspections
Advantages Compared to Other Alloys
Vs. 5086: Slightly higher strength with similar corrosion resistance
Vs. 6061: Superior weldability and seawater corrosion resistance
Vs. Steel: Lightweight, non-rusting, and easier corrosion control, though lower stiffness
Handling, Storage & Safety
Store plates flat and well-supported to prevent deformation
Avoid direct contact with steel or other dissimilar metals
Keep dry and covered to prevent oxidation
Use appropriate PPE during machining and welding
Ordering & Traceability
When ordering from GNEE, please specify:
Alloy: 5083
Temper: H116
Dimensions: thickness, width, and length
Required certifications: DNV and EN 10204 3.1/3.2
Surface finish and welding compatibility requirements
GNEE, a leading Chinese supplier of marine-grade aluminum, provides DNV-certified 5083 H116 aluminium alloy plates manufactured to international standards - ensuring reliable performance, full traceability, and long-lasting durability in the most demanding marine environments.
