What 3003 H112 Plate Is
3003 H112 is a strain-hardened, non-heat-treatable aluminum-manganese plate supplied in the as-fabricated condition. The H112 designation applies to products that pick up a limited amount of strain hardening during hot rolling or forming without a final thermal treatment, and that still carry specified mechanical property limits. In practice this gives a plate with moderate strength, low residual stress and enough ductility for sawing, bending, rolling, machining and welding.
3003 belongs to the Al-Mn family: manganese at 1.0-1.5% is added to a commercial-purity aluminum base, which raises strength through solid solution and dispersed second phases without the corrosion penalty that copper brings. Typical limits are Mn 1.0-1.5, Cu 0.05-0.20, Fe 0.7 max, Si 0.6 max, Zn 0.10 max, with other elements 0.05 max each and 0.15 max in total. The same alloy is published as 3A21 in GB/T 3190 and as EN AW-3003 in EN 573-3, so a specification written for 3003, 3A21 or EN AW-3003 describes one material system.
Because the alloy cannot be strengthened by precipitation, temper is controlled by cold work plus stabilization or partial annealing. H112 is the lowest-strength of the commonly available tempers; H14, H24 and H32 are progressively harder and are chosen when stiffness or yield strength matters more than formability.
Mechanical Properties of H112 Plate
| 3003 H112 | |
|---|---|
| 110-145 MPa | |
| 0.2% proof stress | 40-70 MPa |
| 10-20% | |
| 28-55 HB | |
| 2.73 g/cm3 | |
| approximately 70 GPa |
The minimum values differ by thickness band and by the governing standard. For H112 plate the specified minimum tensile strength sits in the 95-110 MPa range and the minimum 0.2% proof stress in the 35-40 MPa range, with elongation minima of roughly 12-18% for ordinary thicknesses, as defined in ASTM B209 / B209M, EN 485-2 and GB/T 3880.2. Designers should take the minima from the standard edition named on the purchase order rather than from a single published table.
Commercial 3003 plate starts as a direct-chill (DC) cast slab that is scalped, homogenized and hot rolled to thickness, so the finished product is a wrought plate with a uniform, fine grain structure rather than a shaped casting. The described thickness range covers thin cold-rolled sheet through plate tens of millimetres thick, and edges are supplied sheared, sawed or machined. Thickness, width, flatness and edge tolerances follow the relevant part of GB/T 3880, EN 485-3 and EN 485-4, or ASTM B209 when the order is placed to the US system.
The natural oxide film on 3003 is stable in the pH range of most fresh water, foods, organic acids and neutral salt solutions, which is why the alloy dominates cookware, food-handling equipment, storage tanks and heat-exchanger components. Two limits matter during procurement. First, 3003 is not a substitute for a 5xxx alloy in strong chloride or sulphur-bearing marine service, where pitting resistance and higher strength are needed. Second, strong alkalis attack aluminum at any temper, so caustic cleaning agents have to be neutralized and rinsed in tank and chemical service.
Chemical process equipment and storage vessels, fuel and lube tanks, heat exchanger cores and fins, pressure-less ducting, architectural panels and roofing, sign blanks, cooking utensils and truck-body liners all use 3003 in the soft-to-medium tempers. The alloy is also a common choice for parts that will be brazed or welded, because the low Mg content keeps it compatible with common filler alloys and braze sheet.
Q: Can 3003 be hardened by heat treatment?
A: No. 3003 is a non-heat-treatable Al-Mn alloy, so strength is raised only by cold work, which is why tempers such as H14, H24 and H32 exist.
Q: Is 3003 H112 the same as 3A21 H112?
A: The two designations cover the same Al-Mn system published in different standards, so composition and mechanical properties are essentially the same, but the buyer should confirm the standard edition and the property minima that apply.
Q: What thickness range is normally available in H112 plate?
A: H112 is usually supplied from about 3 mm up to 100 mm and beyond, with thin gauges more often ordered in H14 or H24 because the extra cold work gives better stiffness and surface finish.
Q: How does 3003 compare with 5052 for tanks and chemical equipment?
A: 5052 gives roughly 50-70% higher yield strength and better chloride resistance, while 3003 offers better formability, higher thermal conductivity and lower cost, so 3003 suits moderate-duty and thermally loaded parts.
Q: Does H112 plate weld without cracking?
A: Yes. 3003 welds readily with 1100 or 4043 filler by TIG and MIG, and the H112 temper is the least crack-sensitive starting condition because the plate is already soft and low in residual stress.
Q:
A: Name the material standard for properties and the corresponding dimensional part, for example ASTM B209 / B209M, GB/T 3880.1 with GB/T 3880.2 and GB/T 3880.3, or EN 573-3 with EN 485-2 and EN 485-3 or EN 485-4.