Views: 0 Author: Site Editor Publish Time: 2025-04-18 Origin: Site
Stainless Steel S31254, commercially known as 254 SMO, is a super austenitic stainless steel designed for extreme environments. Renowned for its exceptional corrosion resistance, it bridges the gap between standard austenitic steels and high-cost nickel alloys, offering a cost-effective solution for aggressive applications.
Carbon (C): ≤0.02%
Chromium (Cr): 19.5–20.5%
Nickel (Ni): 17.5–18.5%
Molybdenum (Mo): 6.0–6.5%
Nitrogen (N): 0.18–0.22%
Copper (Cu): 0.5–1.0%
Manganese (Mn):≤1.0%
Silicon (Si): ≤0.8%
Iron (Fe): Balance
PREN (Pitting Resistance Equivalent Number) ≈ 45, calculated as Cr + 3.3Mo + 16N.
Excellent resistance to pitting, crevice corrosion, and stress corrosion cracking (SCC) in chloride-rich and acidic environments.
Performs well in both oxidizing (e.g., nitric acid) and reducing (e.g., sulfuric acid) conditions.
Tensile strength: 650–850 MPa
Yield strength: ~300 MPa
Elongation: ~35%
Maintains toughness at low temperatures.
Replaces expensive alloys like Hastelloy or titanium in applications such as seawater systems and chemical processing.
Marine & Offshore:Seawater desalination plants, pump shafts, heat exchangers.
Chemical Processing: Reactors, piping, and scrubbers handling sulfuric, phosphoric, or organic acids.
Environmental Engineering:Flue gas desulfurization (FGD) systems, pollution control equipment.
Oil & Gas:Components exposed to sour (H₂S) environments, certified under NACE MR0175.
Density: 8.0 g/cm³
Melting Range:1320–1390°C
Thermal Conductivity:15 W/m·K (at 100°C)
Magnetic Properties:Non-magnetic in annealed condition.
Welding: Compatible with TIG, MIG, and SAW methods. Use matching filler materials (e.g., AWS A5.14 ERNiCrMo-3). Low heat input recommended to preserve corrosion resistance.
Machining: Requires rigid tools due to work hardening; use slow speeds and coolants.
Forming: Good ductility allows cold working; annealing may be needed after severe deformation.
ASTM: A240 (plates/sheets), A479 (bars/wires), B688 (tubes).
EN: 1.4547
UNS: S31254
Certifications: NACE MR0175/ISO 15156 for sour service.
Ideal for demanding environments where standard stainless steels fail, S31254 combines longevity with reduced lifecycle costs. Its blend of high molybdenum, nitrogen, and chromium ensures reliability in the harshest conditions, making it a strategic choice for industries prioritizing safety and durability.
This introduction balances technical accuracy with accessibility, guiding engineers and procurement professionals to understand the alloy's value proposition in critical applications.
If you need to know more, please contact us at Julie@gaoshengpipe.com
