1.4462 Stainless Steel Bar: Equivalent Grades, Composition and Properties
EN 1.4462, also written X2CrNiMoN22-5-3, is a duplex stainless steel bar grade whose microstructure is a balanced mixture of austenite and ferrite. That two-phase structure gives roughly twice the yield strength of 304 or 316 austenitic bar while keeping good ductility, weldability and strong resistance to pitting, crevice corrosion and chloride stress corrosion cracking.
Duplex 1.4462 bar is normally chosen when a 316L bar is no longer strong enough or cannot survive the chloride level of the service environment, but where a super duplex grade such as 1.4410 (2507) would exceed the cost and fabrication budget of the project. Typical service sectors are offshore and marine structures, chemical and petrochemical plants, desalination equipment, pulp and paper machinery, and pressure-bearing components.
Equivalent Grades of 1.4462 Bar Across Standards
| Standard System | Equivalent Designation |
|---|---|
| EN | 1.4462 / X2CrNiMoN22-5-3 (EN 10088-3) |
| UNS | S31803 and S32205 |
| ASTM | A276 and A479, Grade 2205 bar |
| AISI | 2205 |
| ISO | X2CrNiMoN22-5-3 |
| JIS | SUS 329J3L |
| GB | 022Cr22Ni5Mo3N (GB/T 20878) |
One practical caution: UNS S31803 and UNS S32205 are frequently quoted as if they were the same material. They are closely related and often supplied interchangeably, but S32205 is the tighter version of the grade, with a controlled minimum nitrogen content and a narrower nickel range. The tighter chemistry of S32205 raises its pitting resistance, so a purchase specification should state which of the two UNS numbers is actually required instead of leaving the point open.
Chemical Composition and Pitting Resistance
| Element | Content (%) |
|---|---|
| Chromium (Cr) | 21.0 - 23.0 |
| Nickel (Ni) | 4.5 - 6.5 |
| Molybdenum (Mo) | 2.5 - 3.5 |
| Nitrogen (N) | 0.14 - 0.20 |
| Manganese (Mn) | <= 2.00 |
| Silicon (Si) | <= 1.00 |
| Carbon (C) | <= 0.030 |
| Phosphorus (P) | <= 0.030 |
| Sulfur (S) | <= 0.020 |
The pitting resistance equivalent number is calculated as PREN = Cr + 3.3 x Mo + 16 x N. With the typical composition above, 1.4462 bar reaches PREN 34 - 35, which is the reason the grade performs well in chloride-bearing water, brine and many process acids where 316L (PREN about 24) would pit. Nitrogen also stabilises the austenite phase, which keeps the ferrite to austenite ratio close to 50:50 after solution annealing.
Mechanical Properties of 1.4462 Stainless Steel Bar
| Property | Typical Value | Reference |
|---|---|---|
| Tensile strength (Rm) | 620 - 880 MPa | EN 10088-3 / ASTM A276 |
| Yield strength (Rp0.2) | 450 MPa minimum | EN 10088-3 / ASTM A479 |
| Elongation (A5) | 25% minimum | EN 10088-3 |
| Hardness | 290 HBW maximum | EN 10088-3 |
| Charpy V-notch impact, 20 C | 100 J typical | ISO 148-1 |
| Modulus of elasticity | About 200 GPa | Typical design value |
| Density | 7.8 g/cm3 | Typical design value |
Because the yield strength is more than double that of annealed 316L, a thinner 1.4462 section can often carry the same load, which offsets part of the higher price per kilogram. The grade remains tough at low temperature, and it should always be supplied in the solution-annealed condition: a wrong annealing temperature can form sigma phase and drop both toughness and corrosion resistance sharply.
How 1.4462 Compares with 316L and 1.4410
| Property | 316L bar | 1.4462 / 2205 bar | 1.4410 / 2507 bar |
|---|---|---|---|
| Typical yield strength | About 220 MPa | 450 - 550 MPa | 550 - 750 MPa |
| PREN | About 24 | 34 - 35 | 41 and above |
| Chloride stress corrosion | Limited | Good | Excellent |
| Relative cost | Lowest | Medium | Highest |
Magnetic behaviour: 1.4462 is mildly magnetic because of its ferrite content, which is useful in some electromagnetic and sensor-related parts but must be considered when a fully non-magnetic part is required.
Thermal stability: mechanical properties and corrosion resistance are retained from cryogenic service up to roughly 300 C, above which long exposure is normally avoided to limit embrittlement.
Fabrication: the grade is welded with TIG, MIG and SMAW using matching duplex filler, and it can be bent, rolled and machined with slightly higher cutting forces than 304 or 316L.
Product Forms, Finishes and Documentation
Hot-rolled or cold-drawn round bar from 6 mm to 200 mm diameter
Hexagonal and square bar available on request
Random length 1 - 6 m, or cut to a fixed length
Manufacturing standards: ASTM A276, ASTM A479, EN 10088-3
Surface finish: black, pickled, centreless ground or polished
Inspection documents: EN 10204 3.1 or 3.2 certificate, PED documentation and NACE MR0175 compliance for sour service
Sour-service orders should state the NACE MR0175 hardness limit, and any order for pressure equipment should define the impact-test temperature and the acceptance level so that the mill test certificate can be reviewed against the correct requirement.
FAQ
Q: Is 1.4462 the same as 2205?
Yes. 1.4462 is the EN number and 2205 is the common AISI-style trade designation for the same duplex family, defined in UNS as S31803 or S32205.
Q: Can 1.4462 bar replace 316L bar directly?
In most chloride and high-load duties it can, because the yield strength is much higher and the PREN is about ten points higher, but the higher strength and mild magnetism must be accepted by the design.
Q: What filler metal should be used when welding 1.4462?
A matching duplex or super duplex filler with higher nickel than the base metal is normally specified to keep the ferrite balance in the weld metal.
Q: What is the maximum service temperature of 1.4462?
Roughly 300 C for continuous service. Longer exposure above that temperature risks embrittlement and a loss of toughness.
Q: Which surface finish is best for seawater duty?
A pickled or polished finish is preferred, because a clean, oxide-free surface removes the initiation sites that lead to pitting and crevice attack.
Q: What certificate is issued with the bar?
A mill test certificate to EN 10204 3.1 is standard, and 3.2 third-party witness documentation and PED documentation are available when the order requires them.
