What is the difference between 1.4462 and 1.4547?
EN 1.4462 (Duplex stainless steel 2205) and EN 1.4547 (254 SMO®) are both high-quality corrosion-resistant stainless steels commonly used in the following areas: offshore and marine systems, chemical plants, seawater and desalination equipment, heat exchangers, and pressure piping.
However, they have fundamental differences in metallurgical structure, corrosion resistance, strength, and cost. Choosing the wrong grade can lead to over-engineering or premature corrosion failure.
What is en 1.4547 material?
EN 1.4547 is a super austenitic stainless steel, also known as UNS S31254 or 254 SMO, containing high levels of chromium, nickel, and molybdenum. It exhibits excellent resistance to pitting corrosion, crevice corrosion, and stress corrosion cracking, especially in highly corrosive, chloride-rich environments such as seawater. Compared to standard stainless steels like 316L, it offers higher strength and superior corrosion resistance. It is suitable for use in marine, chemical, and pulp and paper industries.
What is EN 1.4462 stainless steel equivalent to?
EN 1.4462 is a duplex stainless steel equivalent to UNS S31803 (ASTM A182 F51) and UNS S32205 (ASTM A182 F60), also known as 2205 grade, offering excellent strength and corrosion resistance with a 22% Chromium content, ideal for challenging environments like chemical processing and desalination.
What is the difference between 1.4462 and 1.4547?
1.4462 (super duplex stainless steel, X2CrNiMoN22-5-3) is a high-strength, well-balanced duplex stainless steel, while 1.4547 (super austenitic stainless steel, 254 SMO, X1CrNiMoCuN20-18-7) is an austenitic stainless steel with a higher alloy content, possessing superior resistance to pitting and crevice corrosion (higher PREN value), but with lower strength and higher cost. Therefore, 1.4547 is suitable for extremely corrosive environments, while 1.4462 is suitable for general applications requiring high-strength duplex stainless steel.
Duplex 2205 vs. 254 SMO: Key Differences
Duplex 2205 vs. 254 SMO: Material Overview
| Grade | Common Name | UNS | Microstructure |
|---|---|---|---|
| 1.4462 | Duplex 2205 | S32205 / S31803 | Duplex (≈50% ferrite / 50% austenite) |
| 1.4547 | 254 SMO | S31254 | Super austenitic |
1.4462 vs 1.4547 – Chemical Composition
| Element | 1.4462 (Duplex 2205) | 1.4547 (254 SMO) |
|---|---|---|
| Carbon (C) | ≤ 0.030 | ≤ 0.020 |
| Chromium (Cr) | 21.0 – 23.0 | 19.5 – 20.5 |
| Nickel (Ni) | 4.5 – 6.5 | 17.5 – 18.5 |
| Molybdenum (Mo) | 2.5 – 3.5 | 6.0 – 6.5 |
| Nitrogen (N) | 0.14 – 0.20 | 0.18 – 0.22 |
| Copper (Cu) | ≤ 0.50 | 0.50 – 1.00 |
| Iron (Fe) | Balance | Balance |
Duplex 2205 vs. 254 SMO: Corrosion Resistance
| Grade | Typical PREN | Corrosion Performance |
|---|---|---|
| 1.4462 | ~34–36 | Very good |
| 1.4547 | ~42–45 | Excellent / Seawater-grade |
Duplex 2205 vs. 254 SMO: Mechanical Properties (Typical Values)
| Property | 1.4462 | 1.4547 |
|---|---|---|
| Yield Strength (0.2%) | ~450 MPa | ~300 MPa |
| Tensile Strength | 620–880 MPa | 650–750 MPa |
| Elongation | ≥ 25% | ≥ 35% |
| Hardness | ~250 HB | ~200 HB |
Duplex 2205 vs. 254 SMO: Weldability & Fabrication Considerations
| Aspect | 1.4462 | 1.4547 |
|---|---|---|
| Welding complexity | Medium (phase balance critical) | Easy (austenitic) |
| Heat input sensitivity | High | Low |
| Post-weld corrosion risk | Medium | Very low |
| Fabrication cost | Moderate | Higher material, easier welding |
What is the difference between smo 254 and ss316?
SMO 254 is a high-alloy super austenitic stainless steel with significantly higher molybdenum (approximately 6%) and nitrogen content than standard 316 stainless steel. 316 stainless steel is a more common grade with good general corrosion resistance, but it performs poorly under harsh conditions, although it is generally easier to process and less expensive. In short, 254 SMO is suitable for demanding applications, while 316 stainless steel is suitable for general industrial use where chloride content is not high.
1.4547 Stainless Steel Suppliers
If you have project requirements for 1.4547 stainless steel, we welcome your order. GNEE has a large inventory of popular products for you to choose from. It can be processed into various practical product forms, including plates, coils, tubes, bars, wires, etc. For detailed chemical composition information and free samples, please contact our factory immediately. We offer competitive prices and excellent service.Email: info@gneestainless.com
Testing and Documentation: Factory test certificate, EN 10204 3.1, chemical report, mechanical report, destructive testing report, non-destructive testing report, PMI test report, visual inspection report, third-party inspection report, NABL certified laboratory report.
Packaging: Wooden crate packaging, bubble wrap packaging, steel strapping, or packaging according to customer requirements.
