What are the specifications of 254 SMO (6Mo) Seamless Pipe?

Available in UNS S31254 (ASTM A312 TP254SMO), OD 1/2"-20" NB, Sch 5S-80S, hot finished or cold drawn seamless construction.

Why is 254 SMO called "6Mo"?

The name refers to its approximately 6% molybdenum content, which is central to its exceptional resistance to pitting and crevice corrosion in chloride-rich environments.

How does 6Mo's corrosion resistance compare to duplex 2205?

6Mo's PREN is generally higher than 2205's, giving it an edge in the most chloride-aggressive conditions, though 2205 offers higher mechanical strength; the choice often comes down to specific process chemistry versus strength/cost requirements.

What welding precautions apply to 6Mo pipe?

Heat input must be tightly controlled to avoid intermetallic phase precipitation in the heat-affected zone, and matched filler metal (e.g. ERNiCrMo-3 or similar over-alloyed filler) is typically used to compensate for weld-metal dilution.

Does Sakshi Forge provide Material Test Certificates (MTC) for 254 SMO Seamless Pipe?

Yes, MTC as per EN 10204 3.1 is provided with every dispatch along with inspection reports.

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254 SMO (6Mo) Seamless Pipe - Super Austenitic High Alloy Pipe | Sakshi Forge

6% Molybdenum Super-Austenitic Pipe with PREN ≥ 42 for Extreme Chloride & Seawater Duty

~6% Molybdenum + Nitrogen alloying delivers PREN ≥ 42 for extreme pitting resistance

Unrivaled resistance to seawater, brackish water, and high-chloride process media

Full austenitic microstructure provides exceptional toughness and weldability without phase imbalance

EN 10204 3.1 MTC100% PMI TestedISO 9001:2015 CertifiedHydrostatic Tested

Hygienic Steel Grade

Request Price Quote

MTC EN 10204 3.1 Included

Global Sea & Air Freight

Electro-Chemical Finish Certificate

Response turnaround: Under 2 hours

Product Profile

254 SMO (UNS S31254 / ASTM A312 TP254SMO), universally known as 6Mo stainless steel, is an ultra-high alloy super-austenitic seamless pipe engineered specifically for extreme chloride environments where standard 316L and even 904L suffer pitting and crevice corrosion. Its chemistry combines high chromium (~20%), high nickel (~18%), heavy molybdenum (6.0%-6.5%), and a vital nitrogen addition (0.18%-0.22%). This combination yields a Pitting Resistance Equivalent Number (PREN) of ≥ 42-one of the highest among austenitic stainless steels. Unlike duplex stainless steels which can suffer embrittlement at low temperatures or in heavy sections, 254 SMO retains the full ductility, toughness, and ease of fabrication characteristic of austenitic microstructures. Sakshi Forge manufactures 254 SMO (6Mo) seamless pipes via hot extrusion and precision cold drawing followed by high-temperature solution annealing and rapid water quenching. It is the gold standard material for seawater desalination plants, subsea oil & gas piping, bleach plant pulp washing, and flue-gas desulfurization absorbers.

Terminology & Abbreviations

UNS S31254|S31254

Werkstoff 1.4547|1.4547

6Mo Super Austenitic|6Mo

254 SMO|254SMO

Key Technical Facts

Formulated with ~20% Cr, 18% Ni, 6.0-6.5% Mo, and 0.18-0.22% Nitrogen

High PREN (≥ 42) provides crevice corrosion resistance in chlorinated seawater up to 45°C

Nitrogen addition increases yield strength (300 MPa min) while preserving austenitic phase stability

Immune to chloride stress corrosion cracking (SCC) under most industrial operating conditions

Retains high impact toughness at cryogenic temperatures down to -196°C

Solution annealed at 1150°C - 1200°C followed by rapid water quench to eliminate sigma phase

Manufactured via seamless hot piercing/extrusion and cold drawing per ASTM A312 TP254SMO

Supplied 100% PMI verified with EN 10204 3.1 test certification and ASTM G48 pitting test data

Why Choose Sakshi Forge

Our commitment to sterile, high-purity processing makes us a trusted manufacturing partner globally.

100% Heat Lot Traceability

Every pipe stamped with heat number matching EN 10204 3.1 MTC

Positive Material Identification (PMI)

Handheld XRF testing on every length prior to dispatch

Advanced NDT Inspection

Hydrostatic test and Eddy Current / Ultrasonic flaw detection on all orders

Precision Cold Drawing

Tighter wall thickness tolerances and superior internal bore smoothness

Custom Cut Lengths

Fixed lengths up to 12 meters or custom cut-to-length options to eliminate jobsite scrap

Ferrite & Phase Balance Testing

Ferritescope testing for duplex and super duplex grades to ensure 40-60% phase balance

High-Temperature Stabilization

Controlled heat treatment to fully precipitate carbides and optimize creep life

Pan-India & Export Freight

Fast dispatch across India and seaworthy export packing for global projects

Extensive Mill Stocking

Immediate inventory availability in standard schedules from Sch 10S to Sch 160

Third-Party Inspection Approved

Full support for TUV, SGS, DNV, Bureau Veritas, and Lloyds audits

Frequently Asked Questions

Common technical and pricing queries regarding specifications and ordering.

254 SMO seamless pipe is manufactured to UNS S31254 / ASTM A312 TP254SMO. It features ~6% Molybdenum, 18% Nickel, and 0.20% Nitrogen, delivering a PREN ≥ 42.

Partner with Sakshi Forge for Reliable Industrial Steel Solutions

Delivering precision-engineered flanges, pipes, and forged steel components designed for strength, durability, and performance in critical high-pressure industrial applications.