Project Description
SAF 2507 (UNS S32750, EN 1.4410, DIN X2CrNiMoN25-7-4, JIS SUS329J4L) is a super duplex stainless steel with a balanced 50/50 austenite-ferrite microstructure. Its high chromium (25%), molybdenum (4%), and nitrogen (0.27%) content delivers a PREN exceeding 40—placing it well above standard duplex 2205 (PREN ≈ 34) and on par with high-nickel austenitic alloys. Yield strength is roughly double that of 304L/316L, enabling thinner-wall designs, lighter structures, and significant weight savings in topside and subsea installations. The alloy is immune to chloride SCC, a failure mode that plagues 300-series austenitics in hot chloride service, and its ferromagnetic nature allows convenient non-destructive field inspection. SHUNFU METAL supplies SAF 2507 bar under ISO 9001:2015 and API Q1 certified systems, with full melt-to-shipment traceability and NACE MR0175/ISO 15156-3 sour-service compliance where specified. Every heat is solution-annealed at 1040–1120°C and water-quenched, with ferrite content verified at 35–55% per NORSOK M-630. SHUNFU METAL holds ex-stock inventory of common diameters and offers both rolled and forged bar with short mill lead times for project-driven requirements.
Global Equivalent Standards of SAF 2507
SAF 2507 is registered under multiple international designations spanning ASTM, EN, DIN, JIS, and GB systems. SHUNFU METAL certifies every bar to the buyer’s specified standard from the table below, with EN 10204 3.1 mill test reports as standard. The alloy is also covered under NORSOK M-630 MDS D55 and D57 for North Sea applications, and ASME BPVC Section II Part D permits design stresses for UNS S32750 up to 315°C. ASTM A923 test methods verify the absence of detrimental intermetallic phases in the finished product.
| Standard | Designation |
| UNS | S32750 |
| ASTM | A276, A479 (Bar); A182 F53 (Forgings) |
| EN | 1.4410 / X2CrNiMoN25-7-4 |
| DIN | X2CrNiMoN25-7-4 |
| JIS | SUS329J4L |
| GB | 022Cr25Ni7Mo4N (S25073) |
| Trade Name | SAF 2507® (Sandvik), UR 52N+ (Industeel) |
SAF 2507 Bar in Oil & Gas Applications
Subsea Manifolds & Piping
2507 bar machined into hubs, connectors, and spool pieces for subsea production systems. PREN ≥ 40 delivers decades of service in deepwater chloride and H2S-bearing environments without SCC failure.
Wellhead & Xmas Tree Components
Valve bodies, gate seats, stems, and choke trim forged from F53-grade 2507 bar. Compliant with NACE MR0175 Level VII for severe sour gas service up to 28 HRC maximum.
Downhole Control Lines
Cold-drawn 2507 bar converted into hydraulic and chemical injection control lines. High yield strength (550 MPa min) supports deeper deployment without collapse under external annulus pressure.
Seawater Lift & Firewater Pumps
Pump shafts, impeller wear rings, and sleeve bearings machined from 2507 bar. Immunity to crevice corrosion in stagnant seawater at CCT ≥ 35°C per ASTM G48 Method F.
Topside Heat Exchangers
Tube sheets, baffle plates, and tie rods for shell-and-tube exchangers in produced-water cooling and crude preheat trains. Thermal conductivity (15 W/m·K) exceeds austenitic grades, improving heat transfer efficiency.
High-Pressure Bolting
Stud bolts and nuts per ASME B18.2.1, ASTM A1082. 2507 bar delivers 800 MPa tensile strength with 28 HRC max for NACE sour bolting. Charpy ≥ 45 J at −46°C per NORSOK M-630.
Umbilical Tubing
Super duplex 2507 bar drawn into seamless umbilical tubes for hydraulic, methanol, and scale-inhibitor injection in subsea tie-backs. CPT ≥ 50°C per ASTM G48 Method E assures reliability in oxygenated seawater.
Produced Water Treatment
Valve internals, nozzle bodies, and instrument fittings for hydrocyclones and degassing vessels. 2507 bar resists both chlorides and CO2-acidified brine at temperatures up to 80°C.
Chemical Injection Systems
Metering valve spindles, check-valve internals, and atomizing nozzles machined from 2507 bar. Resistant to methanol, glycol, amine-based corrosion inhibitors, and oxygen scavengers at injection-point conditions.
Supply Range of SAF 2507 Bar
SHUNFU METAL stocks and produces SAF 2507 bar in a broad dimensional envelope under ISO 9001 and API Q1 certified systems. Incoming billets are verified by OES before rolling or forging, and every finished bar ships with full EN 10204 3.1 certification. Solution annealing at 1040–1120°C with rapid water quenching is mandatory for all products; SHUNFU METAL verifies quench effectiveness through ferrite content measurement per ASTM E562 and Charpy impact testing at −46°C per NORSOK M-630. Forged bars are typically produced from ESR or VAR remelted ingots to ensure maximum microstructural cleanliness, particularly for large-section components where centerline segregation must be controlled.
| Form | Diameter / Thickness | Width | Length |
| Rolled Round | 6–300 mm | — | Up to 6,000 mm |
| Forged Round | 50–600 mm | — | Up to 5,000 mm |
| Rolled Flat | 5–100 mm | 10–300 mm | Up to 6,000 mm |
| Forged Flat | 20–200 mm | 50–500 mm | Up to 4,000 mm |
SHUNFU METAL maintains ex-stock inventory of the most frequently called diameters and can expedite mill-run production for non-stock sizes. All bars are protected with end caps and corrosion-inhibiting wrapping for ocean freight to project sites.
Chemical Composition of SAF 2507
Composition below per ASTM A276/A479 and EN 10088-3 (1.4410). SHUNFU METAL sources only fully certified heats with full-spectrum OES and IGF nitrogen verification at incoming inspection. The tightly controlled Cr-Mo-N balance is essential to achieving the required PREN and maintaining the 50/50 austenite-ferrite phase balance after solution annealing. The high chromium content (24–26%) provides the fundamental passivity layer, while molybdenum (3–4.5%) enhances resistance to pitting and crevice corrosion in chloride media. Nitrogen (0.24–0.32%) acts as a potent austenite stabilizer and interstitial strengthener, simultaneously raising the PREN and delaying the precipitation of sigma phase during fabrication.
| Element | C | Mn | Si | P | S | Cr | Ni | Mo | N |
| wt % | ≤0.030 | ≤1.20 | ≤0.80 | ≤0.035 | ≤0.015 | 24.0–26.0 | 6.0–8.0 | 3.0–4.5 | 0.24–0.32 |
Cu ≤ 0.50%; Fe balance. EN 10088-3 specifies Mo 3.0–5.0% and N 0.24–0.35%. PREN = Cr + 3.3 × Mo + 16 × N ≈ 24.5 + 3.3 × 3.75 + 16 × 0.28 ≈ 41.4, classifying 2507 well above the NORSOK super duplex threshold of PREN ≥ 40.
Mechanical Properties of SAF 2507 Bar
Properties below represent ASTM A479 minimum requirements for solution-annealed SAF 2507 bar. Annealing is conducted at 1040–1120°C followed by rapid water quenching; slow cooling through the 350–950°C range must be strictly avoided as it precipitates sigma phase, which severely embrittles the material and degrades corrosion resistance. The alloy is not hardenable by heat treatment; its exceptional strength is derived from the dual-phase microstructure and interstitial nitrogen strengthening in the austenite phase. At SHUNFU METAL, every batch is hardness-tested and tensile-certified; ferrite content is measured by image analysis per ASTM E562 for NORSOK-compliant material. For heavy sections above 50 mm, the specified tensile and yield minima are slightly reduced to account for the inherently slower quench rate achievable in larger cross-sections.
| Property | ≤50 mm Section | >50 mm Section |
| Tensile Strength, Rm | ≥ 800 MPa (116 ksi) | ≥ 760 MPa (110 ksi) |
| Yield Strength, Rp0.2 | ≥ 550 MPa (80 ksi) | ≥ 515 MPa (75 ksi) |
| Elongation, A5 | ≥ 25% | ≥ 15% |
| Hardness (General) | ≤ 32 HRC / ≤ 310 HBW | |
| Hardness (NACE Sour) | ≤ 28 HRC / ≤ 277 HBW | |
| Charpy V-Notch at −46°C | ≥ 45 J avg / ≥ 35 J individual | |
| Modulus of Elasticity | 200 GPa | |
NORSOK M-630 MDS D55/D57 and NACE MR0175/ISO 15156-3 impose additional qualification requirements for North Sea and sour-service applications. SHUNFU METAL supplies dual-certified material to ASTM A479 + NORSOK where required. CPT per ASTM G48 Method E: ≥ 50°C (typical 55–70°C). CCT per ASTM G48 Method F: ≥ 35°C. Density: 7.81 g/cm³.