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Eternal
Jiangyin Eternal Heavy Industry Co.,Ltd specializes in high-quality ASTM A182 F44 open-die forgings, manufactured from super-austenitic stainless steel (commonly known as 254 SMO or UNS S31254). This 6% molybdenum alloy delivers exceptional resistance to pitting, crevice corrosion, and chloride-induced stress corrosion cracking—making it the material of choice for the most demanding marine, chemical, and offshore environments .
With a Pitting Resistance Equivalent Number (PREN) of approximately 43, F44 significantly outperforms standard 316L stainless steel (PREN ~25) and even 904L and 2205 duplex grades in chloride-rich media . Our open-die forging service produces custom components weighing up to 30 tons, with diameters up to 3,000 mm .
Standard | Designation |
ASTM A182 | Grade F44 (Forged Fittings) |
UNS | S31254 |
EN / W.Nr. | 1.4547 / X1CrNiMoCuN20-18-7 |
Common Trade Name | 254 SMO® (Outokumpu trademark) |
ISO | 4547-312-541 |
Element | Cr | Ni | Mo | N | Cu | C | Mn | Si | P | S | Fe |
Min % | 19.5 | 17.5 | 6.0 | 0.18 | 0.50 | — | — | — | — | — | Balance |
Max % | 20.5 | 18.5 | 6.5 | 0.25 | 1.00 | 0.020 | 1.00 | 0.80 | 0.030 | 0.010 | Balance |
This high molybdenum + nitrogen + copper combination stabilizes the austenitic structure and enhances resistance to both oxidizing and reducing acids .
Property | Value |
Tensile Strength, Rm | ≥ 650 MPa (94 ksi) |
Yield Strength, Rp0.2 | ≥ 300 MPa (44 ksi) |
Elongation, A5 | ≥ 35% |
Reduction of Area, Z | ≥ 50% |
Hardness | ≤ 230 HBW |
Density | 8.0 g/cm³ |
Melting Range | 1320 – 1390°C |
We source premium 254 SMO / F44 billet from approved mills, with full PMI (Positive Material Identification) and chemical composition verification before production .
Heating: Billets are heated under controlled conditions to 1150–1200°C, using rapid heating protocols to avoid intermetallic phase precipitation within the critical temperature range (600–1000°C) .
Open-Die Forging Service: Our hydraulic forging presses shape the material using flat or simple contour dies. This free forging process improves grain structure, eliminates internal voids, and enhances mechanical properties through optimal grain flow orientation .
Forging Ratio: Minimum 3:1 reduction ensures uniform microstructure and superior fatigue resistance.
Following the forging process, all F44 components undergo mandatory solution annealing at 1120–1180°C (typically 1150–1170°C), followed by rapid water quenching .
Why this matters: F44 is a single-phase austenitic alloy that cannot be hardened by heat treatment. However, solution annealing is essential to:
Dissolve harmful sigma (σ) and chi (χ) intermetallic phases that may precipitate during forging
Restore full corrosion resistance and ductility
Achieve a homogeneous austenitic microstructure
Critical Warning: Never use as-forged or air-cooled F44 forgings. Slow cooling through the 600–900°C range will precipitate brittle intermetallic phases, drastically reducing corrosion resistance and impact toughness .
We offer comprehensive forging service packages including:
Rough machining (turning, milling, boring)
Precision CNC machining to customer drawings
Surface grinding and finishing
NDT: Ultrasonic Testing (UT) per EN 10228-3, Liquid Penetrant Testing (PT) per ASTM E709
Mechanical Testing: Tensile, yield, elongation, hardness
Intergranular Corrosion: ASTM A262 Practice E
Certification: EN 10204 3.1 / 3.2, with TÜV, DNV, ABS, Lloyd's Register, BV, RINA upon request
Our open-die forging service covers a wide range of geometries:
Product Type | Size Range |
Forged Bars (Round, Square, Flat) | Up to1,500 mm diameter |
Seamless Rolled Rings | Up to 3,000 mm OD (6,000 mm for special orders) |
Forged Shafts & Stepped Shafts | Up to 12,000 mm length |
Flanges (WN, SO, BL, SW) | Custom dimensions |
Discs, Blanks, Blocks | Custom sizes |
Valve Bodies & Stems | OEM specifications |
Custom Complex Geometries | According to drawings |
Maximum Single-Piece Weight: 20,000 kg
Industry | Applications |
Seawater Desalination | High-pressure pumps, reverse osmosis equipment, heat exchanger components, seawater intake systems |
Offshore Oil & Gas | Subsea manifolds, riser flanges, offshore platform components, sour gas (NACE MR0175) equipment |
Chemical Processing | Reactors, heat exchangers, piping systems, acid handling equipment |
Flue Gas Desulfurization (FGD) | Scrubber systems, ductwork, waste treatment |
Marine Engineering | Propeller shafts, rudder stocks, structural components |
Power Generation | Nuclear reactor shells, condenser tubes |
A: These are the same alloy grade referenced under different standards. 254 SMO is the common trade name (Outokumpu trademark), UNS S31254 is the Unified Numbering System designation, and ASTM A182 F44 is the standard for forged fittings and components .
A: F44 offers significantly higher molybdenum (6.0–6.5% vs. 2–3% for 316L) and nitrogen content, providing superior resistance to pitting and crevice corrosion in chloride environments. F44 outperforms 316L across all corrosive media and has a critical pitting temperature of ≥60°C (6% FeCl₃) compared to ~15°C for 316L .
A: Yes. All F44 open-die forgings must receive solution annealing at 1120–1180°C followed by water quenching. This is non-negotiable to dissolve intermetallic precipitates and restore full corrosion resistance. We never supply as-forged F44 components .
A: We provide EN 10204 3.1 (factory inspection) and 3.2 (third-party witness) certificates. Additional third-party inspection and certification can be arranged with TÜV, DNV, ABS, Lloyd's Register, Bureau Veritas, and RINA .
A: Our open-die forging service produces components from 30 kg to 30 tons, with ring diameters up to 3,000 mm (special orders up to 6,000 mm) and bar diameters up to 2,000 mm. Lengths up to 12,000 mm are achievable .
A: F44 is suitable for long-term service up to 400°C. At elevated temperatures, the alloy maintains good strength (approximately 550 MPa at 200°C). However, avoid exposure to the 600–900°C range during processing or service, as this promotes intermetallic phase precipitation .
A: F44 has a PREN value of approximately 43 (calculated as %Cr + 3.3×%Mo + 16×%N). This high PREN indicates superior resistance to pitting corrosion in chloride-containing environments, critical for seawater and chemical applications .
A: Yes. Our open-die forging service includes custom manufacturing according to customer drawings, with OEM specifications and full material traceability .
In-house production: Melting, forging, heat treatment, machining, and NDT all under one roof
Large-scale capability: Forgings up to 30 tons, rings up to 6,000 mm OD
Full traceability: Complete material documentation from ingot to finished product
Global compliance: ASTM A182, ASME, NACE MR0175, EN 10222-5
International certifications: ISO 9001:2015, EN 10204 3.1/3.2, with third-party witness options
