ASTM A182 F44 / UNS S31254 / 254SMO Forging Parts — Jiangsu Liangyi China
ASTM A182 F44, also designated UNS S31254 and commercially known as 254SMO, is a 6% molybdenum super austenitic stainless steel with a Pitting Resistance Equivalent Number (PREn) of 42–44. These three designations — ASTM A182 F44, UNS S31254, and 254SMO — refer to exactly the same alloy: a premium corrosion-resistant stainless steel offering outstanding resistance to pitting, crevice corrosion, and stress corrosion cracking in seawater, sour gas, and aggressive chemical environments. Jiangsu Liangyi Co., Limited, an ISO 9001:2015 certified open die forging manufacturer in Jiangyin, Jiangsu Province, China, produces ASTM A182 F44 / UNS S31254 / 254SMO forging parts including seamless rolled rings (up to 6,000 mm OD), round bars (up to 2,000 mm diameter), forged discs, hollow bars, and custom CNC-machined components. All products are supplied with EN 10204 3.1 material certificates.
ASTM A182 F44 / UNS S31254 / 254SMO — Key Facts at a Glance
EN Number: 1.4547 — X1CrNiMoCuN20-18-7
Material: ASTM A182 F44 / UNS S31254 / 254SMO — three designations for the same 6% Mo super austenitic stainless steel (EN 1.4547, X1CrNiMoCuN20-18-7)
Certifications: ISO 9001:2015 | EN 10204 3.1 material certificate supplied per batch
Three names, one alloy — ASTM A182 F44 = UNS S31254 = 254SMO
ASTM A182 Grade F44 Seamless Rolled Forged Rings (Up to 6,000 mm Diameter)
A182-F44 Forged Steel Round Bars (Up to 2,000 mm Diameter, 15,000 mm Length)
About ASTM A182 F44 / UNS S31254 / 254SMO Forged Steel & Our Manufacturing Capabilities
Jiangsu Liangyi is a professional A182-F44 forging parts manufacturer based in Jiangyin, Jiangsu Province, China. We have more than 25 years experience in open die forging. We mainly produce high-quality ASTM A182 Grade F44 open die forging parts and seamless rolled steel forged rings that meet the strictest international standards and customer specifications.
Our factory covers an area of 80,000 square meters and we have an annual capacity of 120,000 tons. We can produce A182-F44 forged parts ranging from 30 kg to 30,000 kg in weight, with sizes up to 6 meters for seamless rolled rings. We do all the production in house from steel melting, forging, heat treatment, CNC machining to final inspection, thus we can control the quality from raw material to finished products.
ASTM A182 F44 is a high-quality 6% molybdenum super austenitic stainless steel that is sold under the trade name 254SMO (Outokumpu) and is classified as UNS S31254 in the Unified Numbering System. It has moderate mechanical strength (minimum 300 MPa yield strength) and good resistance to corrosion. Its Pitting Resistance Equivalent Number (PREn) is 42–44, which means it has good resistance to pitting and crevice corrosion in harsh environments such as seawater, sour gas (H₂S) and a wide range of industrial chemicals. It also has great notch ductility at room temperature and below which makes it the best choice for cryogenic uses. A182-F44 is much more resistant to corrosion than standard 316L stainless steel (PREn ≈ 24) and duplex grades like F51 (PREn ≈ 34). This makes it suitable for use in the most demanding service conditions.
Why Choose Jiangsu Liangyi for Your A182-F44 Forging Needs?
- 25+ years of experience in forging austenitic stainless steel
- In-house manufacturing from steel melting to finished CNC machining
- Advanced 6,300-ton hydraulic press and 5-meter seamless ring rolling machine
- In-house quality control laboratory for comprehensive material testing
- 100% non-destructive testing (UT/MT/PT) on all critical parts
- Fast delivery (4–8 weeks) and competitive prices from our Jiangyin, China factory
- Exported to over 50 countries worldwide such as USA, Canada, UK, Germany, France, Australia, UAE and Saudi Arabia
- EN 10204 3.1 material certificate standard; 3.2 with TPI (BV, SGS, TÜV) acceptable
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Request A Free Quote NowASTM A182 F44 / UNS S31254 / 254SMO — Forged Product Shapes & Size Capabilities
We make a wide range of forged steel products in different shapes and sizes that meet the ASTM A182 F44 / UNS S31254 / 254SMO standards to meet your needs:
Forged Bars & Rods
- A182-F44 forged steel round bars (up to 2,000 mm diameter)
- A182-F44 square bars and flat bars
- A182-F44 rectangular bars and rods
- Custom step bars and profiled bars
Seamless Rolled Rings
- ASTM A182 F44 seamless rolled rings (up to 6,000 mm outer diameter)
- Custom contoured forged rings and gear rings
- Pressure vessel rings and flange blanks
Hollow Forgings
- A182-F44 hubs, housings and shells
- A182-F44 sleeves, bushes and bushings
- A182-F44 cases and heavy-wall hollow bars (up to 3,000 mm OD)
Discs & Plates
- A182-F44 forged discs and disks (up to 3,000 mm diameter)
- A182-F44 blocks and plates (up to 20 tons)
- Flanged blanks and pressure vessel heads
Pipes & Tubes
- A182-F44 forged steel pipes and tubes
- A182-F44 tubings, piping shells and casings
- A182-F44 barrels and pressure housings
Custom Forged Components
We also produce custom A182-F44 forged parts according to your drawings and specifications. Our experienced engineering team can work with you to optimize your design for forging manufacturability and cost efficiency.
Industrial Applications of ASTM A182 F44 / UNS S31254 / 254SMO Forging Parts
ASTM A182 F44 / UNS S31254 / 254SMO forging components are widely used in demanding industries where corrosion resistance, high strength, and reliability are critical. The following are our main application areas, as well as specific product examples and successful project references:
The Oil & Gas Industry (Upstream, Midstream & Downstream)
Due to its good resistance to sulfide stress cracking (SSC) and stress corrosion cracking (SCC), A182-F44 is the best material for acidic environments (containing H₂S and chlorides). Our F44 forgings have been successfully used in major oil and gas projects in the Middle East, the North Sea and the Gulf of Mexico:
- Blowout Preventer (BOP) bodies, rams and annular components
- Drilling pipes, tubes, drill rods and drilling collars
- Christmas trees, wellhead spool bodies and cylinders
- Casing heads, tubing heads, casing hangers and tubing hangers
- Casing spools, tubing spools and spacer spools
- Drilling tools, risers, connectors and flexible joints
- Double studded adapter flanges and integral mud flanges
- Downhole mud motor splined drive shafts
- Electrical submersible pumps (ESP) motor splined shafts
- Flanges, gaskets and various sealing components
- Subsea pipeline components and manifolds
Valve Manufacturing
Our A182-F44 forged valve components are trusted by leading valve manufacturers worldwide for their superior performance in corrosive and high-pressure applications:
- Valve balls, bonnets and bodies for ball valves, gate valves and check valves
- Valve stems, closures and seat rings
- Valve cores and discs for H-type two-way and one-way back pressure valves
- Butterfly valve main shafts and spindles
- High-performance butterfly valve (HPBV) shafts
- Cryogenic service valve components for LNG applications
- Control valve components and trim parts
Nuclear Power Industry
A182-F44 meets the stringent requirements of nuclear power applications, where safety and reliability are paramount:
- Nuclear reactor coolant pump casings, shells and blocks
- Nuclear reactor coolant pump containment seal chambers
- Nuclear-grade piping systems and components
- Heat exchanger components for nuclear power plants
Power Generation
- Turbine and compressor labyrinth shaft seals
- Turbo centrifugal compressor impellers and shrouded impellers
- Pressure vessel and reactor nozzles
- Flue gas desulfurization (FGD) system components
Pump & Process Equipment
- Pump casings, covers and barrels for chemical processing
- Pump impellers, shafts and housings
- Pump wear rings and pump cases
- Seawater pump components for desalination plants
Heat Exchanger & Pressure Vessel Industry
- Tube sheets, baffle plates and nozzles
- Channel flanges for boilers and heat exchangers
- Pressure vessel and reactor components
- Heater shells and piping systems for chemical plants
Flow Measurement Equipment
- Venturi cone meter bodies and blocks
- Ultrasonic flow meter bodies
- Oil measurement valve spools
- Coriolis flow meter components
Piping & Fittings
- Swept branches, outlets and swept saddles
- Studded crosses and flanged outlets
- Single and double bossed blanks and flanged bosses
- Transition cones and reducers
Chemical Composition of ASTM A182 F44 / UNS S31254 / 254SMO
The precise chemical composition of ASTM A182 F44 / UNS S31254 / 254SMO per ASTM A182 / EN 1.4547 ensures its exceptional corrosion resistance and mechanical properties. All three designations share an identical composition:
| Element | Symbol | Weight % (ASTM A182) |
|---|---|---|
| Carbon | C | 0.020 max |
| Manganese | Mn | 1.00 max |
| Phosphorus | P | 0.030 max |
| Sulfur | S | 0.015 max |
| Silicon | Si | 0.80 max |
| Nickel | Ni | 17.5 – 18.5 |
| Chromium | Cr | 19.5 – 20.5 |
| Molybdenum | Mo | 6.0 – 6.5 |
| Nitrogen | N | 0.18 – 0.22 |
| Copper | Cu | 0.50 – 1.00 |
Data reproduced from ASTM A182/A182M for reference only. For engineering design, always consult the current official standard. © ASTM International, www.astm.org
Mechanical Properties of ASTM A182 F44 / UNS S31254 / 254SMO Forgings
All our A182-F44 forging parts are supplied in the solution-annealed and water-quenched condition with the following guaranteed mechanical properties at room temperature (per ASTM A182):
| Property | Value | Unit |
|---|---|---|
| Ultimate Tensile Strength | 650 – 850 | MPa (94 – 123 ksi) |
| 0.2% Proof Strength (Yield) | 300 min | MPa (44 ksi) |
| Elongation | 35 min | % |
| Hardness (Maximum) | 260 | HB |
| Impact Energy (V-notch at 20°C) | 100 min | J (74 ft·lb) |
Data reproduced from ASTM A182/A182M for reference only. For engineering design, always consult the current official standard. © ASTM International, www.astm.org
A182-F44 vs. Other Stainless Steel Grades: Corrosion Resistance Comparison
The table below compares A182-F44 (UNS S31254) with commonly used stainless steel grades to illustrate why super austenitic 6Mo alloys are selected for extreme corrosion environments:
| Grade / Designation | UNS Number | Mo Content (%) | PREn (approx.) | NACE MR0175 | Typical Applications |
|---|---|---|---|---|---|
| A182-F44 (254SMO) | S31254 | 6.0 – 6.5 | 42 – 44 | ✓ Compliant | Sour gas, seawater, chemical processing |
| A182-F316L | S31603 | 2.0 – 3.0 | ~24 | Limited | General corrosion environments |
| A182-F51 (Duplex) | S31803 | 2.5 – 3.5 | ~34 | ✓ Compliant | Oil & gas, marine, desalination |
| A182-F53 (Super Duplex) | S32750 | 3.0 – 5.0 | ~41 | ✓ Compliant | High-pressure offshore, seawater |
| A182-F904L | N08904 | 4.0 – 5.0 | ~33 | ✓ Compliant | Sulphuric acid, phosphoric acid |
Manufacturing Qualification & Quality Control Process
At Jiangsu Liangyi, we follow strict manufacturing procedures to ensure the highest quality of our ASTM A182 F44 / UNS S31254 / 254SMO forging parts. Our comprehensive Manufacturing Process Plan (MPP) is submitted for client approval before production begins and includes detailed information on:
- Type of ingot (supplier, manufacturing process, dimensions and tests)
- Forging process parameters including temperature, deformation ratio and number of blows
- Heat treatment process details including solution annealing temperature (1,150–1,200°C) and water quenching parameters
- Comprehensive testing procedures on finished components
We maintain a fully equipped in-house quality control laboratory with advanced inspection equipment:
- Chemical analysis laboratory for precise steel heat analysis using optical emission spectrometry (OES)
- Mechanical testing laboratory for tensile, resilience, impact and creep tests per ASTM A370
- Metallurgical laboratory for macro-micro structural and inclusion examinations
- Non-destructive testing (UT/MT/PT) performed by qualified SNT-TC-1A Level II operators
- Fixed and portable Brinell hardness testing equipment
- Certified dimensional control equipment including CMM machines
Dissection of the first piece is required within the terms detailed in the part specification. This activity may be omitted, upon decision of clients, if we have already proven our ability to successfully produce components of similar shape, dimensions and manufacturing process.
Material Certification & Compliance
All our ASTM A182 F44 / UNS S31254 / 254SMO forged materials are supplied with EN 10204 Type 3.1 material certification per batch, which includes:
- Order number and customer reference
- Material grade and specification: ASTM A182 F44 / UNS S31254 / 254SMO / EN 1.4547
- Cast number and heat treatment number
- Melting and refining process details
- Certified chemical analysis
- Certified mechanical properties including impact test results
- Ultrasonic test certificate and other NDT reports
- Heat treatment curve and furnace calibration records
Our A182-F44 forgings are manufactured to meet the requirements of NACE MR0175 / ISO 15156 for sour service applications (solution-annealed condition, hardness ≤ 260 HB). Heat treatment furnace calibration and qualification test coupon procedures strictly adhere to industry specifications. EN 10204 Type 3.2 certification with third-party inspection (such as Bureau Veritas, SGS, or TÜV) is available upon request.
Frequently Asked Questions (FAQ) — ASTM A182 F44 / UNS S31254 / 254SMO Forgings
A182-F44 and 254SMO are essentially the same material. A182-F44 is the name used for forging products in ASTM A182 standard, while 254SMO is the registered trade name (Outokumpu) of this super austenitic stainless steel alloy. Both share the UNS S31254 designation and have the same chemical composition and mechanical properties. Other equivalent names include EN 1.4547, X1CrNiMoCuN20-18-7 and DIN 17440.
We can produce A182-F44 forgings weighing up to 30 tons. For seamless rolled rings, our maximum outer diameter is 6000 millimeters (6 meters). For round rods, our maximum diameter is up to 2,000 millimeters and the maximum length is 15,000 millimeters. The hollow rods (sleeves and shells) can reach an outer diameter of 3000 millimeters.
Yes, we offer complete internal CNC machining services. We can perform rough machining, semi-finished machining, or finish machining on A182-F44 forgings according to your drawings and specifications. We have multi-axis CNC lathes, boring machines, milling machine centers and three-coordinate measuring machines for size check.
The lead time of standard A182-F44 forgings is 4–6 weeks from order confirmation. For custom parts which require complex machining, extensive NDT testing or third-party inspection (TPI), the lead time may be 6–8 weeks. We can also deal with urgent orders. Please contact sales@jnmtforgedparts.com with your timeline requirements.
Yes. A182-F44 (UNS S31254) supplied in the solution-annealed and water-quenched condition inherently meets the material requirements of NACE MR0175 / ISO 15156 for austenitic stainless steels used in sour service — specifically hardness ≤ 260 HB, confirmed by 100% Brinell hardness testing. The EN 10204 3.1 material certificate documents compliance with these requirements. EN 10204 3.2 certificates with independent third-party inspection by Bureau Veritas (BV), SGS, or TÜV are available upon request.
The Pitting Equivalent Number (PREn) of A182-F44 is 42–44. You can find it by through the formula PREn = %Cr + 3.3×%Mo + 16×%N. A higher PREn means that the material is less likely to pit and corrode in places like seawater and process brines that contain chloride. A182-F44's PREn of 42–44 far exceeds standard austenitic grades like 316L (PREn ≈ 24) and even super duplex grades like F53 (PREn ≈ 41), making it suitable for highly aggressive corrosive applications where lesser materials would fail prematurely.
We conduct non-destructive testing (NDT) on all critical A182-F44 forged parts, such as Ultrasonic Testing (UT) per ASTM A388 or EN 10228-3, Magnetic Particle Testing (MT) per ASTM E709 or EN 10228-1, and Liquid Penetrant Testing (PT) per ASTM E165 or EN 10228-2. All NDT is conducted by operators who are SNT-TC-1A Level II qualified. Additional tests such as positive material identification (PMI), ferrite measurement, and intergranular corrosion testing per ASTM A262 are available upon request.
A182-F44 forgings are supplied in the solution-annealed and water-quenched condition. Solution annealing is performed at 1,150–1,200°C (2,100–2,190°F) in a calibrated furnace, followed by immediate water quenching to dissolve sigma and chi phases and restore maximum corrosion resistance and toughness. Heat treatment furnace calibration records and heat treatment curves are included with each batch's material certificate.
There is no strict minimum order quantity. Jiangsu Liangyi accepts both small orders which may be only one piece and mass production. Pricing is naturally more favorable for higher quantities. Send your drawing, material specification, and quantity to sales@jnmtforgedparts.com for a quotation.
Corrosion Performance of ASTM A182 F44 / UNS S31254 / 254SMO
Knowing the corrosion behavior of ASTM A182 F44 / UNS S31254/254SMO is important for engineers to choose suitable materials for harsh operating conditions. The following data cover the resistance to pitting, crevice corrosion and stress corrosion cracking behaviors in typical oil and gas, offshore and chemical processing application environments.
Critical Pitting Temperature (CPT) & Critical Crevice Temperature (CCT)
The critical pitting temperature (CPT) is the lowest temperature at which stable pitting occurs on the surface of a metal. A higher CPT means that the material can withstand chloride-containing environments at higher temperatures without pitting corrosion. The Critical Crevice Corrosion Temperature (CCT) is always lower than the CPT, indicating a more severe geometric constraint attack scenario.
| Grade | UNS | CPT (°C) — ASTM G48 Method C | CCT (°C) — ASTM G48 Method D | PREn |
|---|---|---|---|---|
| A182-F44 (254SMO) | S31254 | > 85 | 35 – 45 | 42 – 44 |
| A182-F53 (Super Duplex) | S32750 | 75 – 85 | 30 – 40 | ~41 |
| A182-F51 (Duplex 2205) | S31803 | 35 – 40 | 17 – 22 | ~34 |
| A182-F316L | S31603 | 15 – 20 | < 0 | ~24 |
| A182-F317L | S31703 | 25 – 30 | 5 – 10 | ~28 |
Key Takeaway: In 6% FeCl₃ solution per ASTM G48, A182-F44 demonstrates a CPT exceeding 85°C — approximately 4× higher than 316L stainless steel and superior to even super duplex F53. This means A182-F44 can handle hot, concentrated chloride environments (e.g., heated seawater above 50°C, process brines, offshore topside equipment) where duplex and standard austenitic grades would suffer rapid pitting failure.
CPT and CCT values are typical data based on Outokumpu 254SMO Product Data Sheet and published ASTM G48 test results. Actual values may vary depending on surface finish, test solution, and specimen geometry.
Seawater Corrosion Resistance
A182-F44 is one of the few forging alloys rated for use in natural seawater at temperatures up to approximately 35°C without pitting. In heated seawater (above 20–25°C), which is common in desalination plants, offshore heat exchangers, and FPSO topside piping, conventional duplex grades such as F51 (2205) and standard austenitic grades (316L, 317L) will pit and crevice corrode within months. A182-F44 offers the following advantages in seawater environments:
- Resistant to seawater pitting at temperatures up to ~85°C (CPT in test conditions)
- Excellent resistance to microbiologically influenced corrosion (MIC), a major failure mode in seawater piping
- No pitting in quiescent or stagnant seawater at ambient temperature — a condition that readily attacks 316L
- Suitable for splash zone and tidal zone service where periodic wetting and chloride concentration occur
Sour Service (H₂S) — NACE MR0175 / ISO 15156
In sour gas production environments containing hydrogen sulphide (H₂S), metals are susceptible to Sulphide Stress Cracking (SSC) and Stress Corrosion Cracking (SCC). A182-F44 meets the requirements of NACE MR0175 / ISO 15156 when supplied in the solution-annealed condition with the following verified properties:
- Hardness ≤ 260 HB (as required by NACE MR0175 for austenitic stainless steels)
- Excellent SCC resistance in H₂S + chloride environments at temperatures up to 120°C
- No Sulphide Stress Cracking (SSC) susceptibility in the solution-annealed condition
- Copper addition (0.5–1.0%) provides additional resistance to reducing acids and H₂S-containing brines
Resistance to Intergranular Corrosion (IGC)
A182-F44 has a very low carbon content (0.020% max) which, combined with the high nitrogen content (0.18–0.22%), ensures that the alloy is highly resistant to intergranular corrosion (IGC) in the sensitized condition. The material passes the ASTM A262 Practice E (Strauss Test) and Practice C tests. Welded joints — when made with appropriate 6Mo filler metal such as AWS ER385 or equivalent — also maintain IGC resistance without post-weld heat treatment (PWHT).
Corrosion Rate in Common Process Media
| Chemical Environment | Concentration | Temperature | Corrosion Rate (mm/year) |
|---|---|---|---|
| Sulphuric Acid (H₂SO₄) | 10% | 20°C | < 0.1 |
| Sulphuric Acid (H₂SO₄) | 10% | 80°C | < 0.5 |
| Phosphoric Acid (H₃PO₄) | 85% | 20°C | < 0.1 |
| Hydrochloric Acid (HCl) | 0.5% | 20°C | < 0.1 |
| Sodium Chloride (NaCl) — Seawater | 3.5% | 40°C | < 0.01 (no pitting) |
| Sodium Hydroxide (NaOH) | 40% | 100°C | < 0.1 |
| Acetic Acid (CH₃COOH) | 99% | Boiling | < 0.1 |
Note: Corrosion rate data are indicative values based on published laboratory test results. Source: Outokumpu 254SMO Product Data Sheet and published corrosion literature. The actual service performance depends on specific process conditions, flow rate, temperature cycling and the presence of contaminants. Contact our engineering team to discuss your specific application.
Physical & Thermal Properties of ASTM A182 F44 / UNS S31254 / 254SMO
The following physical and thermal properties of ASTM A182 F44 / UNS S31254 / 254SMO are required for engineering design calculations including pressure vessel design, thermal stress analysis, and heat transfer calculations:
| Property | Value | Unit | Temperature |
|---|---|---|---|
| Density | 8.00 | g/cm³ (0.289 lb/in³) | 20°C |
| Elastic Modulus (Young's Modulus) | 195 | GPa (28.3 × 10⁶ psi) | 20°C |
| Elastic Modulus | 175 | GPa | 200°C |
| Elastic Modulus | 160 | GPa | 400°C |
| Thermal Conductivity | 13.5 | W/(m·K) | 20°C |
| Thermal Conductivity | 16.0 | W/(m·K) | 200°C |
| Specific Heat Capacity (Cp) | 500 | J/(kg·K) | 20°C |
| Mean Coefficient of Thermal Expansion | 16.5 | ×10⁻⁶ /°C | 20–100°C |
| Mean Coefficient of Thermal Expansion | 17.5 | ×10⁻⁶ /°C | 20–300°C |
| Electrical Resistivity | 0.85 | μΩ·m | 20°C |
| Magnetic Permeability | ~1.003 | — | 20°C (non-magnetic) |
| Melting Range | 1,300 – 1,360 | °C (2,370 – 2,480°F) | — |
Physical property values are typical published values for UNS S31254 in the solution-annealed condition. They may vary slightly depending on actual heat chemistry and product form. Source: Outokumpu 254SMO Product Data Sheet and published literature.
ASTM A182 F44 / UNS S31254 / 254SMO — Material Selection Guide
One of the most common engineering questions is: "Do I actually need A182-F44, or can I use a less expensive grade?" The answer depends on your service environment, regulatory requirements, and lifecycle cost objectives. The following decision-making framework is based on practical application experience in oil and gas, offshore and chemical processing projects.
✅ Choose A182-F44 When Your Application Involves:
- Seawater or brackish water above 25°C — At high temperatures, duplex grades (F51, F53) and standard austenite (316L) suffer from rapid pitting corrosion. A182-F44 is the minimum recommended grade for applications of heating seawater.
- Sour gas (H₂S) + chloride environments — A182-F44 meets NACE MR0175 for sour service and outperforms duplex grades in combined H₂S + high-chloride service at elevated temperatures.
- Offshore and subsea equipment — Where maintenance access is restricted or impossible, the lifecycle cost of corrosion failure far exceeds the material premium. A182-F44 is widely specified for subsea Christmas trees, manifolds, and BOP components.
- Chloride concentration > 1,000 ppm at temperatures above 60°C — Standard austenitic grades will undergo crevice corrosion or SCC in such conditions. F44 remains stable.
- Cryogenic service (LNG, gas processing below −50°C) — A182-F44 exhibits excellent notch ductility and impact toughness at cryogenic temperatures (Charpy V-notch energy > 100 J at 20°C; performance maintained down to −196°C).
- API Spec 6A or NACE MR0175 mandatory compliance required by the customer — These standards are specified for wellhead equipment, Christmas trees, and associated oilfield equipment in H₂S-containing service. Our forgings can be manufactured to meet these material requirements; customers requiring API Spec 6A licensed product should advise at time of enquiry.
- Flue gas desulfurization (FGD) systems — The combination of sulphuric acid, chlorides, and elevated temperature in FGD service makes A182-F44 one of the few economical alloy choices.
⚠️ Consider Alternatives at Below Conditions:
- If the service temperature is below 25°C and chloride levels are moderate (< 500 ppm) — A182-F51 duplex or A182-F60 lean duplex may be more suitable at a lower cost.
- Main corrosion risk is sulphuric acid at high concentrations (> 50%) — Alloy 20 (UNS N08020) or Hastelloy C-276 may be less costly in concentrated H₂SO₄.
- High-temperature oxidising service above 400°C — A182-F44 is not optimised for high-temperature oxidation or creep resistance. Consider high-alloy grades or nickel alloys.
- Budget-constrained non-corrosive service — For dry, non-corrosive environments, carbon steel or low-alloy steel forgings (e.g., A182-F11, F22) are entirely adequate at a fraction of the cost.
A182-F44 vs. A182-F53 (Super Duplex): Choose Between Two Advanced Levels
Both A182-F44 and A182-F53 (UNS S32750) are high-performance and high-corrosion-resistant grades, with similar PREn values. Selection between them often comes down to the following factors:
| Selection Criterion | A182-F44 (Super Austenitic) | A182-F53 (Super Duplex) |
|---|---|---|
| PREn | 42 – 44 | ~41 – 43 |
| Yield Strength (0.2%) | 300 MPa (min) | 550 MPa (min) |
| CPT in 6% FeCl₃ | > 85°C | 75 – 85°C |
| SCC resistance (high chloride + H₂S) | Excellent | Good — but may be limited above 150°C |
| Cryogenic toughness (−196°C) | Excellent (fully austenitic) | Limited (duplex microstructure embrittles) |
| Weldability | Good (no PWHT required) | Moderate (heat input control critical) |
| Thermal stability > 300°C | Good | Risk of sigma phase embrittlement above 280°C |
| Relative Material Cost | Slightly higher (more Ni) | Moderate |
| Preferred Application | Cryogenic, high-temp seawater, NACE sour service | High-pressure structural, non-cryogenic offshore |
ASTM A182 F44 / UNS S31254 / 254SMO — Delivery Condition, Packaging & Shipping
Standard Delivery Condition
All ASTM A182 F44 / UNS S31254 / 254SMO forging parts are delivered in the solution-annealed and water-quenched condition as standard, consistent with ASTM A182 requirements. The following delivery options are available:
| Delivery Condition | Description | Typical Application |
|---|---|---|
| As-Forged + Annealed | Solution annealed and water quenched; black oxide scale surface; rough tolerances per ASTM A788 | Further machining at customer site; raw stock supply |
| Rough Machined | Machined to near-net shape with 3–5 mm stock allowance on all surfaces | Semi-finished stock for final machining by customer |
| Semi-Finished | Machined to drawing with 0.5–1 mm allowance remaining; key features completed | Final grinding or lapping by customer |
| Fully Finished / Ready-to-Install | Machined, surface-finished, and inspected to final drawing dimensions; Ra and tolerance fully met | Drop-in replacement components; assembly-ready parts |
| Pickled & Passivated | Chemical pickling (HNO₃/HF) + passivation per ASTM A967 or ASTM A380 to restore the passive chromium oxide film | Seawater service, food-grade, pharmaceutical, high-purity process |
Surface Finish Options
- Mill finish (as-forged, scale-on): Suitable for customers performing further machining
- Machined finish: Standard lathe/mill finish, Ra 3.2–6.3 μm unless otherwise specified
- Ground finish: Ra 0.8–1.6 μm for sealing faces, journal surfaces, and bearing areas
- Electropolished: Available for high-purity, pharmaceutical, or food-contact applications
- Pickled & passivated: Removes heat tint and restores passive layer after welding or machining
Marking & Identification
Each A182-F44 forging is individually marked with the following identification per ASTM A182 and customer requirements:
- Manufacturer name or trademark: Jiangsu Liangyi / JNMT
- Material grade: A182-F44 or UNS S31254
- Heat number / Cast number (traceability to mill certificate)
- Part number / Customer order reference
- NACE MR0175 compliance marking (where applicable)
- Piece weight and dimensions (for items > 100 kg)
Marking method is electro-etching or low-stress vibro-engraving (never high-stress stamping, which can initiate stress corrosion cracking in austenitic grades).
Packaging
A182-F44 forgings are packaged to prevent corrosion and mechanical damage during international ocean freight and air freight transit:
- VCI (Volatile Corrosion Inhibitor) film wrapping: Applied to all machined surfaces to prevent atmospheric corrosion during transit (effective for up to 24 months)
- Wooden crates or pallets: ISPM 15 heat-treated timber, suitable for international export and phytosanitary compliance
- Foam cushioning / rubber protection: Applied to precision-machined sealing faces and threads to prevent handling damage
- Thread protection caps: Plastic or steel thread protectors on all threaded connections
- Flanged face protection: Cardboard or plywood face covers on all raised face (RF) and ring-type joint (RTJ) flanges
- Individual tagging: Each piece tagged with stainless steel or aluminium tag showing heat number, grade, and dimensions
Shipping & Documentation
Jiangsu Liangyi ships from Shanghai Port or Taicang Port (approximately 60–80 km from our Jiangyin factory), giving access to weekly container services to all major global destinations. Standard export documentation includes:
- Commercial Invoice and Packing List
- Bill of Lading (B/L) or Airway Bill (AWB)
- EN 10204 3.1 Material Test Certificate (MTC) per ASTM A182
- Certificate of Origin (CO) — China, issued by Jiangyin Chamber of Commerce
- NDT Test Reports (UT, MT, PT as applicable)
- Dimensional Inspection Report
- Heat Treatment Record and Furnace Calibration Certificate
- NACE MR0175 compliance statement (if required)
- Third-party inspection certificate (BV, SGS, TÜV) — upon request
Payment terms accepted: T/T (Telegraphic Transfer), L/C (Letter of Credit at sight or usance), Western Union. Trade terms (Incoterms 2020): FOB Shanghai, CIF destination port, DAP destination or as negotiated.
A182-F44 Delivery Case Studies: Real Orders, Real Solutions
The following case illustrates how did Jiangsu Liangyi solve procurement and engineering challenges for international clients. Each case includes full order specifications, the customer's main pain point and how we delivered a compliant solution on schedule.
Case #JL-F44-2024-087 | North Sea Subsea BOP Ram Bodies — Emergency Replacement
Oil & Gas · Norway- Part: Blowout Preventer (BOP) blind shear ram body blocks
- Forging Shape: Open die forged rectangular blocks, rough machined to 5 mm allowance
- As-Forged Dimensions: 820 mm × 640 mm × 380 mm (per piece)
- Final Machined Envelope: 800 mm × 620 mm × 360 mm (customer final machine)
- Surface Finish Delivered: Rough machined, Ra ≤ 6.3 μm on all faces
- Standards: ASTM A182, NACE MR0175 / ISO 15156, EN 10204 3.2
- Third-Party Inspector: Bureau Veritas (BV) — Jiangyin witnessed inspection
The customer found that a blowout preventer on an active production platform in a Norwegian oilfield had failed during its regular maintenance window. Their existing supplier in Europe quoted 14–16 weeks for replacement forged blocks due to raw material availability. A platform shutdown of that duration was commercially catastrophic — estimated lost production revenue of approximately USD 2.8 million per week.
- Confirmed in-stock UNS S31254 ingot inventory within 8 hours of RFQ receipt
- Submitted full Manufacturing Process Plan (MPP) and NACE MR0175 compliance statement within 24 hours for customer approval
- Dedicated press scheduling (6,300-ton hydraulic press): forging completed within 12 days
- Solution annealing at 1,175°C, water quench — heat treatment furnace record included in MTC
- 100% UT per EN 10228-3 Level 3 acceptance criteria + PT per EN 10228-2
- BV inspection on-site, EN 10204 3.2 certificates issued
- Air freight (Shanghai Pudong → Oslo Gardermoen): 3 wooden cases, with a total weight of 11,250 kilograms, conforming to ISPM 15 standards
Case #JL-F44-2023-214 | High-Speed Seawater Lift Pump Casings — Desalination Plant
Desalination · UAE- Part: Multi-stage vertical seawater lift pump casings (split casing design)
- Forging Shape: Open die forged hollow blocks → CNC machined to final shape in-house
- Key Dimensions (largest piece): OD 1,150 mm × length 480 mm, wall thickness 85–120 mm
- Bore Tolerance: H7 (+0.045 / 0 mm) on main bore Ø 860 mm
- Surface Finish: Ra ≤ 1.6 μm on internal bore and seal faces; Ra ≤ 3.2 μm on external flange faces
- Delivery Condition: Fully machined + pickled & passivated (ASTM A967 Method C — citric acid passivation)
- Standards: ASTM A182, EN 10204 3.1, ASTM A262 Practice E (IGC test passed)
The EPC contractor first said that these pump casings should be made of duplex stainless steel (UNS S31803 / F51). During the review before commissioning, the corrosion engineer of the end customer pointed out that in summer, the inlet temperature of the raw seawater at this site often exceeded 36°C, surpassing the safe operating limit of the two-phase system in static seawater. In the final stage, the material upgrade of A182-F44 was enforced, forcing the EPC to repurchase the forgings with only 10 weeks left before the mechanical completion. Their original European pump housing supplier was unable to re-forge within the time frame of A182-F44.
- Received re-design drawings from EPC's pump OEM (German manufacturer) and confirmed manufacturability within 48 hours
- Proposed minor wall-thickness optimisation (+8 mm) to allow safer machining allowance without affecting weight budget — accepted by customer
- Forging on 6,300-ton press: all 12 hollow blocks completed in 18 days
- In-house CNC machining on 5-axis vertical turning centre: all bores, flanges, and seal grooves machined to H7 tolerance
- CMM dimensional report (ZEISS Contura) issued for all 12 pieces
- 100% PT per ASTM E165 on all finished surfaces + ASTM A262 Practice E IGC coupon test
- Citric acid passivation (ASTM A967 Method C) + VCI film + custom foam-lined wooden crates
- Ocean freight: Shanghai Port → Khalifa Port, Abu Dhabi (21-day transit); all 12 pieces in 2 x 40' open-top containers
Case #JL-F44-2024-031 | Seamless Rolled Rings for Subsea Gate Valve Bodies (Customer Spec: API 6A)
Valve Manufacturing · USA| Part No. | OD (mm) | ID (mm) | Height (mm) | Unit Weight | Qty |
|---|---|---|---|---|---|
| RNG-F44-A | 680 | 500 | 210 | ~145 kg | 16 pcs |
| RNG-F44-B | 920 | 690 | 280 | ~265 kg | 16 pcs |
| RNG-F44-C | 1,180 | 880 | 340 | ~390 kg | 16 pcs |
- Forging Method: Seamless ring rolling on 5-meter ring rolling mill
- OD Tolerance: +3 / −0 mm; ID Tolerance: +0 / −3 mm; Height: ±2 mm
- Delivery Condition: Solution annealed + water quenched + rough faced (top and bottom faces turned)
- Hardness: 100% Brinell hardness survey — all pieces ≤ 210 HB (NACE limit 260 HB; customer requested tighter 210 HB max)
- Standards: ASTM A182, NACE MR0175 / ISO 15156, EN 10204 3.2 (customer-specified)
- Third-Party Inspector: SGS — Houston office coordinated; physical inspection at our Jiangyin facility
This Houston-based subsea valve OEM had a long-term agreement with a domestic US forging supplier for A182-F44 rolled rings. In Q4 2023, their US supplier announced a 22-week backlog due to press scheduling constraints caused by a surge in LNG project orders. The valve OEM had firm delivery commitments to a major Gulf of Mexico deepwater operator for 48 gate valves to be used in API 6A service, with a liquidated damages (LD) clause of USD 15,000 per day of delay. Their procurement team contacted Jiangsu Liangyi via the website's RFQ form at 2:00 AM Houston time.
- Response within 3 hours of RFQ submission (team in China time zone) — preliminary lead time and price confirmed same day
- Customer's tighter hardness requirement (≤ 210 HB vs NACE standard ≤ 260 HB) reviewed — confirmed achievable with our standard solution annealing cycle; no additional processing cost
- SGS inspection scope agreed within 48 hours: full chemical (OES), mechanical (per ASTM A370), 100% UT (ASTM A388), 100% Brinell hardness survey, dimensional report
- All 48 rings rolled on 5-meter rolling mill, solution annealed at 1,180°C, water quenched: completed in 22 days
- SGS inspector (Jiangyin) witnessed all testing; EN 10204 3.2 certificates issued within 3 days of test completion
- Export packaging: each ring individually wrapped in VCI film, stood upright in timber-slatted crates on rubber pads to prevent face damage
- Air freight for Size A (16 rings, 2,480 kg): Shanghai PVG → Houston IAH — 2 days transit
- Ocean freight for Sizes B & C (32 rings, 20,960 kg): Shanghai Port → Houston in 20' flat rack container — 18-day transit
Related Forgings
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Applicable Standards & Official References
The following international standards and specifications govern the manufacture, testing, and application of ASTM A182 F44 / UNS S31254 / 254SMO forging parts. Links point to the official issuing body for each standard:
| Standard / Specification | Issuing Body | Scope | Official Source |
|---|---|---|---|
| ASTM A182 / A182M | ASTM International | Forged or rolled alloy and stainless steel pipe flanges, forged fittings, and valves for high-temperature service — covers Grade F44 (UNS S31254) | astm.org |
| NACE MR0175 / ISO 15156 | AMPP (formerly NACE) / ISO | Materials for use in H₂S-containing environments in oil and gas production (sour service) — Part 3 covers CRAs including UNS S31254 | ampp.org |
| API Specification 6A | American Petroleum Institute | Wellhead and Christmas tree equipment — specifies material, dimensional, and test requirements for oilfield pressure-containing equipment. Frequently specified by customers for oilfield forgings; Jiangsu Liangyi produces A182-F44 forgings to meet the material requirements of this standard | api.org |
| EN 10204 | CEN (European Committee for Standardization) | Metallic products — types of inspection documents. Type 3.1 and 3.2 material test certificates are issued with all Jiangsu Liangyi A182-F44 forgings | en-standard.eu |
| ASTM A370 | ASTM International | Standard test methods and definitions for mechanical testing of steel products — governs tensile, yield, elongation, impact, and hardness testing | astm.org |
| ASTM A262 | ASTM International | Detecting susceptibility to intergranular attack in austenitic stainless steels — Practice C (Huey test) and Practice E (Strauss test) applied to A182-F44 | astm.org |
| ASTM G48 | ASTM International | Pitting and crevice corrosion resistance of stainless steels using ferric chloride solution — Method C (CPT) and Method D (CCT) referenced in this page's corrosion data | astm.org |
| ASTM A388 / EN 10228-3 | ASTM International / CEN | Ultrasonic examination of steel forgings — governs UT acceptance criteria applied during Jiangsu Liangyi quality control | astm.org |
| ISO 9001:2015 | ISO (International Organization for Standardization) | Quality management systems — Jiangsu Liangyi is certified to ISO 9001:2015 for the design, manufacture, and inspection of open die forgings and seamless rolled rings | iso.org |
| ASTM A967 / ASTM A380 | ASTM International | Passivation and cleaning of stainless steel parts — governs citric acid and nitric acid passivation treatments applied per customer specification | astm.org |
Contact Us for ASTM A182 F44 / UNS S31254 / 254SMO Forging Quotations
Jiangsu Liangyi is your trusted China ASTM A182 F44 / UNS S31254 / 254SMO forging manufacturer for high-quality super austenitic stainless steel forging parts. We welcome your inquiries for custom A182-F44 forged components according to your drawings and specifications. Our experienced engineering team will work with you to provide the best solution at competitive prices.
To get a detailed quotation, please send us your drawing, material requirement, quantity, and any special specifications. We typically respond to all inquiries within 24 hours.