Aluminium
Aluminium 5083-H321
Cryogenic & marine-grade aluminium. LNG-qualified, retains toughness to −196 °C.
5083 is a high-Mg (4.0–4.9%) Al-Mg alloy with the best weldability and corrosion resistance of any non-heat-treatable Al alloy. The standard for cryogenic LNG containment, military hulls, and welded marine structures.
Equivalent Designations
| Standard | Designation |
|---|---|
| UNS | A95083 |
| Werkstoff Nr. | 3.3547 |
| EN | EN AW-5083 |
Standards
ASTM B209ASME II / VIII Div 1 (pressure vessel)DNV-GL, LRS, ABS marine class society approvals
Chemical Composition (% by mass)
| Si | 0.40 max |
| Fe | 0.40 max |
| Cu | 0.10 max |
| Mn | 0.4–1.0 |
| Mg | 4.0–4.9 |
| Cr | 0.05–0.25 |
| Zn | 0.25 max |
| Al | Remainder |
Mechanical Properties
| Ultimate Tensile Strength | 305 MPa |
| Yield Strength | 215 MPa |
| Elongation | 12 % |
Physical Properties
| Density | 2.66 g/cm³ |
| Melting Point | 570–640 °C |
Available Forms & Sizes
| Form | Size Range | Notes |
|---|---|---|
| Plate/Sheet | 3 mm to 200 mm thick × 1500×3000 mm or 1250×2500 mm | — |
| Round Bar | Ø8 mm to Ø150 mm | — |
Tempers Available
OH111H112H116H321
Use Cases
Cryogenic tanks (LNG, LN₂)
Retains toughness down to −196 °C; one of few alloys qualified for cryogenic marine LNG service.
Shipbuilding hulls
Preferred for armoured / military hull plate (LRS, DNV-GL approved grades).
Pressure vessels for chemical service
Welded structures with 5183 or 5356 filler; minimal HAZ strength loss.
Welded structures
Outstanding weldability among Al alloys. Use H116 or H321 tempers for marine service.
Design Notes
- Avoid prolonged exposure above 65 °C — sensitises grain boundaries to chloride SCC. Specify H116 / H321 tempers (NOT H32) for marine service.
- Do not use in concentrated nitric acid (depassivates).