254SMO (UNS S31254) and S32205 are both high-performance stainless steels widely used in demanding corrosive environments such as chemical processing, marine engineering, and energy industries. HT PIPE is a leading stockist and global exporter with over 16 years of expertise in international trade. We supply pipes, plates, round bars, and a comprehensive range of pipe fittings, flanges, and valves. Contact us now for free quotes and personalized product information.
Chemical composition comparison
|
Element |
254SMO (UNS S31254) |
S32205 (Duplex Steel) |
|
Carbon (C) |
≤0.02 |
≤0.03 |
|
Chromium (Cr) |
19.5-20.5 |
21.0-24.0 |
|
Nickel (Ni) |
17.5-18.5 |
4.5-6.5 |
|
Molybdenum (Mo) |
6.0-6.5 |
2.5-3.5 |
|
Nitrogen (N) |
0.18-0.22 |
0.14-0.20 |
|
Copper (Cu) |
0.5-1.0 |
- |
Mechanical properties comparison
|
Performance Index |
254SMO |
S32205 |
|
Yield Strength (σ₀.₂, MPa) |
≥300 |
≥450 |
|
Tensile Strength (σᵦ, MPa) |
650-850 |
620-750 |
|
Elongation (δ, %) |
≥40 |
≥25 |
|
Hardness (HB) |
Approx. 220 |
Approx. 230 |
|
Low-Temperature Toughness (Akv, J) |
≥100 (-196℃) |
≥40 (-40℃) |
s31254 and s32205 corrosion Comparison
PREN value comparison: 254SMO ≥ 43, S32205 is 35-39, indicating that 254SMO has superior resistance to pitting and crevice corrosion.
Chloride ion environment adaptability: In acidic condensates containing 5%-15% Cl⁻, the charge transfer resistance (Rct) of 254SMO is significantly higher than that of S32205, and the passivation current density (0.022 mA/cm²) is much lower than that of S32205 (0.770 mA/cm²), demonstrating a clear advantage in corrosion resistance in extreme chloride ion environments.
Stress corrosion cracking (SCC) resistance: The duplex structure of S32205 provides better SCC resistance than ordinary austenitic stainless steel in low to medium concentration chloride ion environments, but 254SMO performs more stably in high concentration, strongly acidic chloride ion environments.
Adaptability to reducing media: Due to its copper content, 254SMO has better corrosion resistance to reducing acids such as sulfuric acid and phosphoric acid than S32205.
s31254 and s32205 Mechnical Performance
254SMO: The austenitic structure hardens quickly during machining, cold working requires low cutting speeds and the use of coolant, hot working temperature range is 1150-1200℃, and processing below 900℃ should be avoided to prevent embrittlement.
S32205: The duplex structure has moderate machinability, its high yield strength results in greater forming resistance than 254SMO, but the work hardening rate is lower than 254SMO, making it suitable for medium-strength cold forming.
ss2205 and 254smo Welding Performance
254SMO: TIG welding is recommended, using ER2594 welding wire. Interpass temperature should be controlled to ≤100℃ to avoid σ phase precipitation. No post-weld heat treatment is required, but the oxide layer must be removed.
S32205: TIG and MAG welding methods can be used, with ER2209 welding wire. The interpass temperature should be controlled below 150℃, and post-weld heat treatment is generally not required. The strength of the welded joint is close to that of the base material.
