The 254SMO Seamless Pipe (UNS S31254 / 1.4547) is a high-performance super austenitic stainless steel tube, commonly referred to as Alloy 6Mo. Engineered for demanding environments, it delivers exceptional resistance to pitting, crevice corrosion, and chloride stress corrosion cracking, making it a reliable choice for aggressive industrial applications.

• High molybdenum content for superior pitting and crevice corrosion resistance in chloride-rich environments.
• Excellent resistance to chloride stress corrosion cracking, even at elevated temperatures.
• Outstanding mechanical strength and toughness compared to conventional austenitic grades.
• Reliable performance in seawater, chemical processing, and pollution control systems.
• Seamless construction ensures uniform wall thickness and structural integrity under pressure.

• Seawater handling and desalination equipment
• Chemical and petrochemical processing systems
• Flue gas desulfurization (FGD) scrubbers
• Pulp and paper industry equipment
• Oil and gas offshore platforms and piping
• Heat exchangers and condensers

254SMO Seamless Pipe

UNS S31254 | W.Nr. 1.4547 | EN: X1CrNiMoCuN20‑18‑7 | Alloy 6Mo, Super Austenitic Stainless Steel Seamless pipe standards: ASTM A312 / A213 / A269, EN 10216‑5, ASME SA312; solution annealed, with EN 10204 3.1 / 3.1B certificate, Norsok MDS available for offshore projectsAlleima

Chemical Composition (wt.%)

PREN ≥ 42.5; outstanding pitting & crevice corrosion resistance in high‑chloride media, far superior to 904L and duplex grades in many aggressive brine environmentsAlleima

Mechanical Properties (solution annealed, room temperature)

Key features: excellent resistance to chloride stress corrosion cracking, good weldability, higher strength than standard austenitic stainless steel; low carbon minimises intergranular corrosion risk after weldingAlleima

Size & Supply

• OD: 6 mm ~ 630 mm (1/8" up to 24")
• Wall: SCH 5S / 10S / 40S / 80S / 160 / XXS, custom wall available
• Surface: bright annealed, pickled & passivated; cold finished seamless
• Tests: hydraulic test, eddy current / ultrasonic inspection, PMI
• HS Code: 7304419000 (common for stainless seamless pipe)wzguohao.e...

Applications

• Seawater desalination, seawater cooling systems, seawater RO
• Offshore oil & gas, flue gas desulfurization (FGD)
• Chemical process: phosphoric acid, brine, bleach, chloride rich media
• Pulp & paper bleaching lines, acid reclamation
• Heat exchangers, condensers, pressure piping for corrosive service