Ferralium 255 vs. 2205: key differences
What is the ASME equivalent of duplex 2205?
The ASME equivalents for Duplex 2205 (UNS S31803/S32205) are primarily found in standards like ASME SA-240 for plate, SA-182 (Grade F51/F60) for forgings, and SA-789/SA-790 for pipes, with specific designations depending on the product form, all referring to this common duplex stainless steel composition for corrosion resistance and strength.
What is Ferralium 255 material?
Ferralium 255 is a super duplex stainless steel in the Ferralium series. GNEE maintains a large inventory of this popular product for your selection. It can be processed into various practical product forms, including plates, coils, tubes, bars, and wires, designed to meet the needs of the oil, gas, and chemical industries. Ferralium 255 offers higher strength than most other stainless steels and corrosion-resistant alloys. For detailed chemical composition and free samples, please contact us!
Ferralium 255 vs 2205: What are the differences?
Ferralium 255 is a super duplex stainless steel with higher alloy content (more Cr, Mo, N, and Cu) than standard duplex 2205, giving it superior strength (higher yield strength), better resistance to pitting/crevice corrosion, and enhanced performance in harsher, chloride-rich marine or acidic environments, while 2205 offers excellent general-purpose duplex performance at a lower cost.
Chemical Composition Comparison (wt.%)
| Element | Ferralium 255 (UNS S32550) | Duplex 2205 (UNS S31803/S32205) |
|---|---|---|
| Chromium (Cr) | 24.0–27.0% | 21.0–23.0% |
| Nickel (Ni) | 4.5–6.5% | 4.5–6.5% |
| Molybdenum (Mo) | 2.9–3.9% | 2.5–3.5% |
| Copper (Cu) | 1.5–2.5% | (Not significant) |
| Nitrogen (N) | 0.10–0.25% | 0.08–0.20% |
| Carbon (C) | ≤ 0.04% | ≤ 0.03% |
| Manganese (Mn) | ≤ 1.5% | ≤ 2.0% |
| Silicon (Si) | ≤ 1.0% | ≤ 1.0% |
| Iron (Fe) | Balance | Balance |
Mechanical Properties Comparison
| Property | Ferralium 255 (Typical) | Duplex 2205 (Typical) |
|---|---|---|
| Yield Strength (0.2% proof) | ~550–586 MPa (~80–85 ksi) | ≥ 450–550 MPa (≥ 65–80 ksi) |
| Tensile Strength (UTS) | ~760–790 MPa (~110–115 ksi) | ~620–800 MPa (~90–116 ksi) |
| Elongation (%) | ~25% | ≥ 25% |
| Hardness (HB) | ~220–270 HB | ≤ 290 HB |
| Impact Resistance | Good at ambient & low temperatures | Typical for duplex (~tough) |
1. Ferralium 255 vs. Duplex 2205: Hardness
Ferralium 255 (UNS S32550) typically has a Brinell hardness of 290–320 HB (or 28–32 HRC), slightly higher than Duplex 2205 (UNS S31803/S32205), which has a maximum Brinell hardness of 290 HB (22–28 HRC) due to its lower alloy content.
2. Ferralium 255 vs. Duplex 2205: Corrosion Resistance
Ferralium 255 exhibits superior corrosion resistance, with a PREN value of 38–41 (compared to 32–36 for 2205) and a critical pitting temperature (CPT) of 50–60°C in 3% NaCl solution (compared to 30–45°C for 2205), attributed to its higher Mo (3.0–4.0% vs. 2.5–3.5%) and N (0.10–0.25% vs. 0.14–0.20%) content.
3. Ferralium 255 vs. Duplex 2205: Strength and Machinability
Ferralium 255 has higher strength (yield strength ≥550 MPa, tensile strength ≥760 MPa, compared to ≥450 MPa and ≥620 MPa respectively for 2205), but lower machinability due to its higher work hardening rate (cutting speed is approximately 10–15% slower than 2205).
4. Ferralium 255 vs. Duplex 2205: Applications
Ferralium 255 is used in extreme environments requiring ultra-high strength and corrosion resistance (e.g., deep-sea components, high-chloride chemical reactors), while 2205 is more suitable for standard duplex stainless steel applications such as heat exchangers, pressure vessels, and marine structures.
5. What are the differences between duplex stainless steels 2205 and 2507?
Duplex stainless steel 2507 (UNS S32750) differs from 2205 in its higher alloy content, resulting in a higher PREN value of ≥40 (vs. 32–36), a higher yield strength of ≥550 MPa (vs. ≥450 MPa), and superior pitting corrosion resistance (critical pitting temperature in 3% NaCl solution is approximately 60–70°C vs. 30–45°C), making it suitable for more demanding corrosive/high-pressure applications.