O
Annealed for maximum ductility. Used for formed shell plating and parts with tight bends.
Marine · high-strength Al-Mg plate
5A01 Marine Aluminium Plate
5A01 is a Chinese-standard aluminium-magnesium plate with 6 – 7 % magnesium plus chromium and zirconium, designed to give ship structures more strength than 5083 while keeping good seawater resistance and weldability. It is used mainly on vessels designed to GB and CCS practice. Metline supplies 5A01 plate in O, H112 and H321 tempers, cut to size and certified, worldwide.
- Alloy
- 5A01 (Al-6.5Mg-Mn-Cr-Zr)
- Tempers
- O, H112, H321
- Thickness
- About 3 – 50 mm
- Standards
- GB/T 3190 · GB/T 22641
What is 5A01 marine plate?
5A01 belongs to the Chinese national 5A-series of aluminium-magnesium alloys. Its 6.0 – 7.0 % magnesium is the highest of the common 5A grades, and it adds 0.10 – 0.20 % each of chromium and zirconium, which refine the grain structure and raise the recrystallisation temperature.
The design goal is a hull plate that is substantially stronger than 5083 without the weldability problems of heat-treatable alloys. In annealed form 5A01 has a minimum tensile strength around 325 MPa, compared with 275 MPa for 5083-O, and its weld zones keep much of that strength because it relies on solid-solution strengthening rather than precipitation hardening.
Very high magnesium normally increases the risk of sensitisation and exfoliation corrosion. Published Chinese research on 5A01 plate reports good stress-corrosion and exfoliation resistance, attributed to the absence of a continuous β-phase network at grain boundaries in correctly processed material. That depends on controlled rolling and annealing, so buyers should specify corrosion testing for hull plate and keep service temperatures low.
5A01 chemical composition (wt %, GB/T 3190)
| Element | Limit | Role |
|---|---|---|
| Silicon + Iron (Si + Fe) | ≤ 0.40 | Impurities, held low for toughness and corrosion resistance |
| Copper (Cu) | ≤ 0.10 | Held low for seawater resistance |
| Manganese (Mn) | 0.30 – 0.7 | Strength and grain control |
| Magnesium (Mg) | 6.0 – 7.0 | Main strengthening element |
| Chromium (Cr) | 0.10 – 0.20 | Grain control, stress-corrosion resistance |
| Zirconium (Zr) | 0.10 – 0.20 | Fine grain, higher recrystallisation temperature, better weld-zone strength |
| Zinc (Zn) | ≤ 0.25 | Impurity |
| Titanium (Ti) | ≤ 0.15 | Grain refiner |
| Aluminium (Al) | Remainder |
Confirm the limits against the edition of GB/T 3190 on your order; "others" limits differ slightly between editions. Treat any certificate showing 6 – 7 % manganese as a transcription error.
Mechanical properties of 5A01 plate
Indicative minimums for 3 – 50 mm plate as quoted for Chinese marine-plate standards. Values for 5A01 are less widely published than for international alloys; confirm the guaranteed figures for your thickness and temper on the order and certificate.
| Temper | Thickness | Tensile strength Rm | Proof Rp0.2 (min) | Elongation (min) |
|---|---|---|---|---|
| O | 3 – 50 mm | 325 – 385 MPa | 165 MPa | 16 % |
| H112 | 6 – 50 mm | ≥ 325 MPa | 165 MPa | 10 % |
| H321 | 3 – 50 mm | ≥ 365 MPa | 245 MPa | 8 % |
| For comparison (IACS UR W25 rolled) | Tensile Rm | Proof Rp0.2 |
|---|---|---|
| 5083-O / H111 | 275 – 350 MPa | 125 MPa |
| 5083-H321 | 305 – 385 MPa | 215 – 295 MPa |
| 5059-O / H111 | ≥ 330 MPa | 160 MPa |
| 5059-H321 (≤ 20 mm) | ≥ 370 MPa | 270 MPa |
Approximate physical properties
- Density
- About 2.64 g/cm³
- Modulus of elasticity
- About 70 GPa
- Thermal expansion
- About 24 µm/m·°C
- Magnetic
- Non-magnetic
5A01 tempers
H112
As hot-rolled with guaranteed minimums, for thicker plate in flat structure.
H321
Strain-hardened and thermally stabilised for higher proof strength, in the style of 5083-H321. The usual choice where strength drives scantlings.
Other tempers
Some supplier lists show H32 or H111; confirm which tempers and certificates are actually available for your thickness before design.
Standards and class acceptance
5A01 composition is defined in GB/T 3190, and plate is supplied to Chinese plate standards such as GB/T 3880 or the marine-plate standard GB/T 22641. It is not one of the alloys named in IACS UR W25 or ASTM B928, so on vessels classed with other societies its use needs prior agreement, normally backed by corrosion and weld-procedure test data. On projects built to Chinese rules, the classification society's approval of the producing works applies.
| Item | Detail |
|---|---|
| Composition | GB/T 3190 |
| Plate standard | GB/T 22641 (marine), GB/T 3880 (general) |
| Comparable alloys | 5059 (Mg 5.0 – 6.0 %, Zr), 5A06 (Mg 5.8 – 6.8 %), Russian 1561 |
| Corrosion tests to request | Exfoliation (ASTM G66 or equivalent) and intergranular (ASTM G67 mass loss) |
5A01 plate sizes and weights
Supply range
- Thickness
- About 3 – 50 mm plate; sheet below 6 mm by enquiry
- Common sizes
- 1250 × 2500, 1500 × 3000 mm; long plates such as 2000 × 8000 mm by arrangement
- Width and length
- 1000 – 2400 mm wide up to 20 mm thick, up to about 3500 mm wide above, depending on the mill
- Processing
- Cut to size and CNC profiling
At about 2.64 g/cm³, 5A01 plate weighs roughly 2.64 kg per m² per mm.
| Thickness (mm) | kg per m² | 1250 × 2500 (kg) | 1500 × 3000 (kg) | 2000 × 6000 (kg) |
|---|---|---|---|---|
| 3 | 7.92 | 24.8 | 35.6 | 95.0 |
| 4 | 10.56 | 33.0 | 47.5 | 126.7 |
| 5 | 13.20 | 41.2 | 59.4 | 158.4 |
| 6 | 15.84 | 49.5 | 71.3 | 190.1 |
| 8 | 21.12 | 66.0 | 95.0 | 253.4 |
| 10 | 26.40 | 82.5 | 118.8 | 316.8 |
| 12 | 31.68 | 99.0 | 142.6 | 380.2 |
| 15 | 39.60 | 123.8 | 178.2 | 475.2 |
| 20 | 52.80 | 165.0 | 237.6 | 633.6 |
| 25 | 66.00 | 206.2 | 297.0 | 792.0 |
| 30 | 79.20 | 247.5 | 356.4 | 950.4 |
| 40 | 105.60 | 330.0 | 475.2 | 1267.2 |
| 50 | 132.00 | 412.5 | 594.0 | 1584.0 |
Welding and working 5A01
Welding
MIG or TIG with a high-magnesium filler such as 5B06-type wire, ER5183 or ER5556. Qualify the procedure on 5A01, since class bodies will ask for weld test results.
Heat input
Keep heat input and interpass temperature low; repeated repairs increase sensitisation risk.
Forming
O temper forms well cold; H321 needs larger radii. Avoid warm forming between about 100 and 250 °C.
Corrosion protection
Bare plate resists seawater well; isolate from copper alloys and steel and use compatible antifouling.
Temperature
Keep long-term service below about 65 °C.
Cutting
Plasma or waterjet; mechanically dress cut edges before welding.
Where 5A01 plate is used
- Hull shell and bottom plating on patrol boats, fast craft and passenger vessels built to GB practice
- Decks and bulkheads where higher strength allows thinner plate
- Superstructures where weight above the waterline must be minimised
- Fishing and service vessels requiring robust, weldable hull plate
In practice, 5A01 is chosen when a design already specifies it or when a builder working to Chinese rules wants 5059-class strength from a domestic grade. For vessels classed to IACS rules elsewhere, 5083, 5383 or 5059 is usually the simpler route.
5A01 compared with 5083, 5059 and 5A06
| Property | 5A01 | 5083 | 5059 | 5A06 |
|---|---|---|---|---|
| Magnesium | 6.0 – 7.0 % | 4.0 – 4.9 % | 5.0 – 6.0 % | 5.8 – 6.8 % |
| Zr / Cr additions | Yes / yes | No / yes | Yes / yes | No / no |
| Min tensile, O | About 325 MPa | 275 MPa | 330 MPa | About 315 MPa |
| Listed in UR W25 | No | Yes | Yes | No |
| Main market | China | Global | Europe, global | China, CIS |
How to order 5A01 plate
- SpecifyAlloy and temper, thickness, width and length or a nesting list, quantity and the governing standard with its edition (GB/T 22641 or GB/T 3880, with GB/T 3190 composition). If the vessel is classed, name the society and whether a class certificate is required.
- ConfirmWe confirm the standard and tolerance class can be met, which tests are included (tensile, chemistry, corrosion tests where the standard calls for them) and the delivery terms: EXW, FOB, CIF or DAP.
- InspectPlates are checked for thickness, flatness and surface; corrosion tests and class surveyor attendance are arranged when the order calls for them.
- DocumentEach lot ships with a mill test certificate to EN 10204 3.1 showing the cast analysis and mechanical results, traceable by cast or lot number.
- Pack and shipBars or plates are bundled or cased with moisture protection, marked with alloy, temper, size and lot, and shipped by sea or air to your port or yard.
References and standards
- GB/T 3190 – Chemical composition of wrought aluminium and aluminium alloys
- GB/T 22641 – Aluminium alloy plates and sheets for marine use
- IACS UR W25 – Aluminium alloys for hull construction and marine structure
- ASTM B928 – High Magnesium Aluminum-Alloy Sheet and Plate for Marine Service and Similar Environments
- ASTM G66 / G67 – Exfoliation (ASSET) and nitric-acid mass-loss intergranular corrosion tests for 5xxx aluminium alloys
5A01 marine aluminium (aluminum) plate: FAQs
What is 5A01 aluminium?
A Chinese national aluminium-magnesium alloy (GB/T 3190) with 6.0 – 7.0 % magnesium, 0.3 – 0.7 % manganese and small chromium and zirconium additions, used mainly for high-strength marine plate.
Is 5A01 stronger than 5083?
Yes. Indicative minimums for 5A01-O are about 325 MPa tensile and 165 MPa proof, against 275 MPa and 125 MPa for 5083-O.
Is 5A01 approved by classification societies?
It is not listed in IACS UR W25, so societies outside China treat it as a special alloy requiring prior agreement and test data. On vessels built to Chinese rules, approval of the producing works by the relevant society applies.
What is the international equivalent of 5A01?
There is no exact equivalent. 5059 is the closest internationally registered alloy in concept (high magnesium with zirconium), and 5A06 / AMg6 is close in magnesium content.
What corrosion tests should I request for 5A01 plate?
An exfoliation test (ASTM G66 or an equivalent) and an intergranular corrosion mass-loss test (ASTM G67), the same tests applied to 5083 and 5456 marine plate.
Can Metline supply 5A01 plate?
Tell us the thickness, temper, quantity and certification needed. We confirm availability and test options before you order, and supply with an EN 10204 3.1 certificate.
Need 5A01 plate for a GB-standard vessel?
Send temper, thicknesses, sizes, quantity and the tests required. We will reply with availability, certification and a delivered price.
