Stainless Steel S39277
UNS S39277
S39277 (Forta SDX 2707, AF918) is a copper- and tungsten-modified super duplex stainless steel from Outokumpu with corrosion resistance approaching hyper-duplex levels for demanding oil and gas service.
Reference datasheet — S39277 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the SA condition
S39277 tempers and conditions
S39277 is supplied in 4 conditions, soft to hard. SA is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As-welded deposit | Property reference for welded joints made without post-weld solution anneal; ferrite balance and toughness are the controlling checks. | 620 | 860 | 22 | 27 HRC | 2 % IACS |
SADefault Solution Annealed | Standard supply condition for plate, bar, forgings and pipe — balanced ~50/50 ferrite/austenite with maximum corrosion resistance. | 640 | 880 | 30 | 28 HRC | 2 % IACS |
Forged and solution annealed (ASTM A182 forging condition) | Wellhead bodies, valve blocks, flanges and hangers where NACE MR0175 hardness limits (≤34 HRC) must be met. | 660 | 890 | 28 | 29 HRC | 2 % IACS |
Cold drawn | Pick when yield strengths above 750 MPa are needed (umbilical tubing, downhole components) and NACE hardness caps allow it. | 830 | 1,000 | 18 | 33 HRC | 2 % IACS |
Supply forms, finishes and certifications
Ways S39277 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
HFA-Bar | Hot finished, solution annealed bar | Supply form |
SA-Plate | Solution Annealed, hot-rolled plate | Supply form |
SA-TUBE | Seamless tube/pipe, solution annealed | Supply form |
What is S39277?
S39277 (Forta SDX 2707, AF918) is a copper- and tungsten-modified super duplex stainless steel from Outokumpu with corrosion resistance approaching hyper-duplex levels for demanding oil and gas service. Solution-annealed plate, tube, bar and forgings, plus hot-finished and cold-drawn bar, give 640 MPa yield, 880 MPa tensile, 30% elongation and 280 HB (28 HRC), with service to 280 °C. Machinability rates 25, so cycle times and tooling costs are high, and welding requires strict heat-input and ferrite control. S32750 is the lower-cost, more widely available alternative. S39277 has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,350°C (2,462 °F). S39277 has a yield strength of 640 MPa (92.8 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 90% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
What is S39277 used for?
- subsea components
- high-pressure fittings
- oilfield equipment
Advantages
- Good corrosion resistance — 88/100, better than 97% of stainless steel grades
- High strength — 640 MPa (92.8 ksi), better than 90% of stainless steel grades
Limitations
- Limited service temperature — 280°C (536 °F), worse than 96% of stainless steel grades
- Difficult to machine — 25/100, worse than 88% of stainless steel grades
- Low electrical conductivity — 2 % IACS, worse than 77% of stainless steel grades
S39277 properties
Typical room-temperature values for S39277-SA; bars are the position among stainless steel grades.
Physical3
S39277 has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,350°C (2,462 °F).
Mechanical16
S39277 has a yield strength of 640 MPa (92.8 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 90% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
S39277 is rated for continuous service to 280°C (536 °F). It conducts heat at 15 W/m·K (8.67 BTU/hr·ft·°F), worse than 59% of stainless steel grades. Thermal expansion is 13 µm/m·K (7.22 µin/in·°F).
Electrical3
S39277 conducts electricity at 2 % IACS, worse than 77% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), better than 97% of stainless steel grades.
Sustainability4
Producing a kilogram of S39277 takes about 62 MJ of energy and emits 5.2 kg of CO₂ — more than 75% of stainless steel grades. Typical recycled content is 55%.
Manufacturability7
S39277's machinability is poor (25/100, worse than 88% of stainless steel grades); weldability good (55/100); formability fair (40/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. S39277 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with S39277
Is S39277 easy to machine?
Machine like super duplex: rigid setups, sharp coated carbide, 40–70 % of 316L speeds, heavy positive feed to cut under the work-hardened layer, and copious high-pressure coolant.
Can S39277 be welded?
GTAW/GMAW/SMAW with over-alloyed 25Cr-10Ni-4Mo or Ni-base (ERNiCrMo-x for root/overlay); keep heat input ~0.5–1.5 kJ/mm, interpass ≤150 °C, N₂-bearing backing gas, no PWHT unless a full 1080–1120 °C solution anneal + quench is possible.
Can S39277 be formed, bent or molded?
Hot form at 1000–1200 °C followed by full solution anneal and water quench; cold forming needs ~2× the force of austenitic grades with large springback allowance and a stress-relief anneal for heavily worked parts.
S39277 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Clow carbon to avoid carbide precipitation | ≤ 0.03 | 0.02 |
| Si | ≤ 0.8 | 0.4 |
| Mn | ≤ 0.8 | 0.5 |
| P | ≤ 0.03 | 0.02 |
| Svery low S for sour service and hot workability | ≤ 0 | 0 |
| Cr | 24 – 26 | 25 |
| Ni | 6.5 – 8 | 7.2 |
| Mo | 3 – 4 | 3.5 |
| Cuimproves resistance in reducing acids | 1.2 – 2 | 1.6 |
| Wraises PREN with Mo | 0.8 – 1.2 | 1 |
| Naustenite stabiliser, pitting resistance | 0.23 – 0.33 | 0.28 |
| Fe | balance |
What surface finishes work on S39277?
Pickle (HNO₃/HF) and passivate after welding or grinding to restore the Cr-rich film; electropolishing gives the best CPT — never anodize, and avoid carbon-steel tooling contamination.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel S39277 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- Forta SDX 2707AF918
How much does S39277 cost?
S39277 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
S39277 — frequently asked
What is S39277 used for?
S39277 is typically used for subsea components, high-pressure fittings and oilfield equipment. In short: cu/W-modified super duplex; near hyper-duplex corrosion resistance; low machinability, high tooling cost.
What is the yield strength of S39277?
S39277 has a typical yield strength of 640 MPa (92.8 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 90% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is S39277 easy to machine?
Not especially — machinability is rated poor (25/100, worse than 88% of stainless steel grades). Machine like super duplex: rigid setups, sharp coated carbide, 40–70 % of 316L speeds, heavy positive feed to cut under the work-hardened layer, and copious high-pressure coolant.
Can S39277 be welded?
Yes — weldability is rated good (55/100). GTAW/GMAW/SMAW with over-alloyed 25Cr-10Ni-4Mo or Ni-base (ERNiCrMo-x for root/overlay); keep heat input ~0.5–1.5 kJ/mm, interpass ≤150 °C, N₂-bearing backing gas, no PWHT unless a full 1080–1120 °C solution anneal + quench is possible.
What surface finishes work on S39277?
Pickle (HNO₃/HF) and passivate after welding or grinding to restore the Cr-rich film; electropolishing gives the best CPT — never anodize, and avoid carbon-steel tooling contamination.
Can S39277 be formed, bent or molded?
Hot form at 1000–1200 °C followed by full solution anneal and water quench; cold forming needs ~2× the force of austenitic grades with large springback allowance and a stress-relief anneal for heavily worked parts.
What is the maximum service temperature of S39277?
S39277 is rated for continuous use to about 280°C (536 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between S39277-SA and S39277-CD?
SA is the default condition — standard supply condition for plate, bar, forgings and pipe — balanced ~50/50 ferrite/austenite with maximum corrosion resistance. CD: pick when yield strengths above 750 MPa are needed (umbilical tubing, downhole components) and NACE hardness caps allow it. Yield strength is 640 MPa in SA versus 830 MPa in CD.
How much does S39277 cost?
S39277 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM A182/A182M — Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Fittings, Valves and Parts — ASTM International (2023)
- ASTM A789/A790 — Seamless and Welded Ferritic/Austenitic Stainless Steel Tubing and Pipe — ASTM International (2021)
- ANSI/NACE MR0175 / ISO 15156-3 — Cracking-Resistant CRAs for H₂S Service — NACE/ISO (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys (duplex stainless steels) — ASM International (1990)
- Super duplex 25Cr Cu/W-modified grade datasheets (Industeel AF918, Sumitomo DP3W class) — Producer datasheets (2021)
- IMOA Practical Guidelines for the Fabrication of Duplex Stainless Steels — International Molybdenum Association (2014)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.