# SAF 2507 Forgings: Rolled Rings, Flanges, Bars, Discs and Shafts UNS S32750 / 1.4410 / X2CrNiMoN 25-7-4 / SS 2328 / ASTM A182 Grade F53 / ASME SA-182 F53 Source page: https://www.steelforgepieces.com/Stainless-Steel/SAF-2507.html Manufacturer: Jiangyin Jiangnan Metal Co., Ltd., No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China Contact: sales@steelforgepieces.com / +86 189 2135 9659 Published 3 October 2026. Last reviewed 3 October 2026. --- ## Summary SAF 2507 is a 25 Cr, 7 Ni, 4 Mo, 0.3 N super duplex stainless steel holding austenite and ferrite in roughly equal proportion. The chromium, molybdenum and nitrogen put the pitting resistance equivalent above 40, giving chloride pitting and crevice resistance comparable to the 6 percent molybdenum superaustenitic alloys, while the two-phase structure carries mechanical strength 50 to 100 percent above most austenitic stainless steels. Jiangyin Jiangnan Metal Co., Ltd. melts and forges this grade in one works in Jiangyin, Jiangsu Province, China: seamless rolled rings to 6,000 mm outside diameter, flanges, bars, shafts, discs, tube sheets, sleeves and hollows up to 30 tonnes per piece, solution annealed and certified to EN 10204 3.1 or 3.2. Minimum order 10 kg, lead time 20 to 60 days. | Field | Value | | --- | --- | | UNS number | S32750 | | Werkstoff | 1.4410 | | EN name | X2CrNiMoN 25-7-4 | | Swedish SS | 2328 | | Alloy type | Super duplex, austenitic-ferritic | | Cr / Ni / Mo / N | 25 / 7 / 4 / 0.3 % | | PREN | Above 40, about 42 at aim composition | | Forging standard | ASTM A182 Grade F53 | | Delivery condition | Solution annealed and quenched | --- ## What SAF 2507 is SAF 2507 is a wrought super duplex stainless steel. The accepted band for wrought duplex structures is 35 to 65 percent ferrite by volume, with austenite making up the balance. Three elements carry the performance. Chromium at 24 to 26 percent builds the passive film. Molybdenum at 3 to 5 percent carries pitting and crevice resistance in chlorides. Nitrogen at 0.24 to 0.32 percent stabilises austenite, raises strength and adds more to the pitting number, weight for weight, than either of the other two. The ferritic half of the structure supplies resistance to chloride stress corrosion cracking, the failure mode that limits 300-series austenitics in warm chloride service. Two consequences follow for anyone buying forgings. Yield strength at 550 MPa minimum is roughly double that of 316L, so wall thicknesses and section sizes come down. Against that, the grade is sensitive to temperature in a way austenitics are not: held in the intermediate range, it precipitates intermetallic phases that take toughness and corrosion resistance with them. That sensitivity governs how the material is forged, annealed, welded and used, and it is why a super duplex forging either comes out right or comes out brittle. --- ## Designations and standards | System or product form | Designation | | --- | --- | | UNS number | S32750 | | Werkstoff, DIN and EN | 1.4410 | | EN name | X2CrNiMoN 25-7-4 | | Swedish SS | 2328 | | Forgings, flanges and fittings | ASTM A182 Grade F53, ASME SA-182 F53 | | Bar and shapes | ASTM A276, ASTM A479 | | Plate, sheet and strip | ASTM A240 | | EN flat products for pressure purposes | EN 10028-7 | | Bar to EN | EN 10088-3 | | ASME welding classification | P-number 10H, Group number 1 | | Sour service | NACE MR0175 / ISO 15156 | | Welding consumables | AWS ER2594 for GTAW, E2594 for SMAW | SAF and SAF 2507 are trademarks of their proprietor. This works manufactures to the UNS S32750 composition and to the ASTM, ASME and EN specifications listed. Trade names appear only to identify the grade. --- ## Chemical composition, weight percent Limits follow UNS S32750 as written into ASTM A182 Grade F53 and ASTM A479. The aim column gives the target each heat is melted to. | Element | Min | Max | Aim | Function | | --- | --- | --- | --- | --- | | Cr, chromium | 24.0 | 26.0 | 25.0 | Passive film, general corrosion resistance | | Ni, nickel | 6.0 | 8.0 | 7.0 | Austenite balance, toughness | | Mo, molybdenum | 3.0 | 5.0 | 4.0 | Pitting and crevice resistance in chlorides | | N, nitrogen | 0.24 | 0.32 | 0.30 | Austenite stabiliser, strength, pitting resistance | | C, carbon | - | 0.030 | 0.020 max | Held low against carbide precipitation | | Mn, manganese | - | 1.20 | 0.80 max | Deoxidiser, nitrogen solubility | | Si, silicon | - | 0.80 | 0.40 max | Deoxidiser | | Cu, copper | - | 0.50 | 0.30 max | Residual, capped | | P, phosphorus | - | 0.035 | 0.025 max | Impurity | | S, sulphur | - | 0.020 | 0.010 max | Impurity, affects hot workability | | Fe, iron | Balance | - | - | Matrix | EN 1.4410 caps sulphur at 0.015 percent, tighter than the 0.020 percent allowed by the ASTM range, and orders written to the EN number are melted to the tighter limit. Nitrogen is controlled under vacuum oxygen decarburisation, because the grade only reaches its strength and pitting numbers if nitrogen lands inside the band. --- ## Mechanical properties, solution annealed, room temperature Minimum values required by ASTM A182 Grade F53. | Property | Metric | Imperial | | --- | --- | --- | | Tensile strength, Rm, minimum | 800 MPa | 116 ksi | | Yield strength, Rp0.2, minimum | 550 MPa | 80 ksi | | Elongation, minimum | 15 % | 15 % in 2 in | | Hardness, maximum | 310 HB | about 32 HRC | | Ferrite content | 35 to 65 % | 35 to 65 % | Strength comes from the duplex structure and from nitrogen in solution, not from any transformation, so it cannot be raised by heat treatment. A specification calling for a solution plus age cycle on S32750 should be queried before the order is released. A182 does not call for impact testing on F53 as standard. Offshore, subsea and sour-service specifications routinely add Charpy V-notch testing at low temperature together with a hardness cap tighter than 310 HB. State the test temperature, energy values and sampling location on the enquiry, since those requirements drive forging reduction and annealing practice. --- ## Physical data and service limits | Property | Value | Note | | --- | --- | --- | | Density | 7.8 g/cm3 | 0.281 lb/in3 | | Magnetic response | Ferromagnetic | The ferrite phase makes the grade magnetic | | Hot working range | 1000 to 1200 C | Reheat if the piece falls below 1000 C | | Solution anneal | 1040 to 1120 C | 1900 to 2050 F, rapid quench | | Stress relief | Not by subcritical hold | Full solution anneal and quench instead | | Maximum service temperature | about 315 C | 600 F, set by secondary phase formation | | Hardening by heat treatment | Not possible | Solid solution and duplex structure only | Duplex grades carry a lower thermal expansion coefficient and higher thermal conductivity than austenitic stainless steels, which helps in heat exchangers and where a duplex part is bolted to carbon steel. Take exact values for expansion, conductivity, modulus and specific heat from the mill datasheet applying to your order, because published figures differ between product forms. --- ## Corrosion performance The pitting resistance equivalent number is chromium plus 3.3 times molybdenum plus 16 times nitrogen. At the aim composition the result is about 42. Across the full specification range the arithmetic gives roughly 38 at the minima and 48 at the maxima, so the 40 to 42 quoted in trade literature describes normal production material. Pitting resistance is balanced between the two phases, so neither austenite nor ferrite becomes the weak link. | Mechanism or medium | Behaviour | Comment | | --- | --- | --- | | Chloride stress corrosion cracking | Excellent | The reason the grade replaces 316L in warm chlorides | | Chloride pitting and crevice | Excellent | Comparable to 6 % Mo superaustenitic alloys. Passes ASTM G48 method A at 50 C minimum | | Organic acids | Very good | Formic and acetic acid where austenitics corrode quickly | | Inorganic acids | Good | Broadly comparable to high-alloy austenitic grades | | Seawater and brine | Very good | Watch crevices and deposits at the upper temperature end | | Erosion and corrosion fatigue | Very good | High strength works with corrosion resistance | | Sour service | Qualified | Listed under NACE MR0175 / ISO 15156 within its limits | | High temperature oxidation | Not applicable | Corrosion resistant, not heat resistant. Above 315 C use Inconel 625 or Incoloy 825 | Corrosion figures are selection guidance from published mill literature for UNS S32750, not a warranty for a specific service. Welded and as-forged surfaces behave differently from pickled coupons, and crevice geometry usually sets the service limit rather than the alloy. --- ## SAF 2507 forged products Every item is forged against a drawing or a dimensional data sheet, solution annealed, machined to the agreed allowance and tested before shipment. Single pieces and prototype quantities are quoted. - **Seamless rolled rings.** Radial-axial rolled from an upset and pierced blank, grain flow following the circumference. Rectangular, contoured and stepped sections to 6,000 mm outside diameter. - **Forged flanges.** Weld neck, blind, slip-on, socket weld, lap joint, orifice and long weld neck to A182 F53, with ASME B16.5, B16.47 or API 6A dimensions, or to drawing. RF, RTJ and FF faces. - **Round bars and shafts.** Forged, peeled or rough turned for pump and mixer shafts, stems, downhole tooling and fasteners. Turned lengths to 14,000 mm. - **Discs, blanks and tube sheets.** Upset forged discs, covers, blind flanges and heat exchanger tube sheets, drilled or undrilled, proof machined for volumetric inspection. To 5,000 mm machined diameter. - **Sleeves, bushings and hollows.** Bored and trepanned hollows for cylinders, liners, nozzles and pump casings, to 1,600 mm diameter by 10,000 mm. - **Valve and wellhead parts.** Bodies, bonnets, stems, seat rings, blocks, spools and manifolds for ball, gate, globe, check and plug valves. API 6A and NACE MR0175 / ISO 15156 on request. ### Dimensions to state on the enquiry | Form | Dimensions to give | | --- | --- | | Seamless rolled ring | Outside diameter, inside diameter, height, section profile if not rectangular | | Flange | Type, nominal size, class, facing, bore, or the drawing | | Round bar or shaft | Diameter, length, straightness class, surface condition | | Disc or tube sheet | Diameter, thickness, bore if any, drilling pattern | | Sleeve or hollow | Outside diameter, inside diameter, length, bored or trepanned | | All forms | Quantity, delivery condition, NDT class, certification level, impact and ferrite requirements, project specification | --- ## Forging route and heat treatment **Melting.** Carbon, alloy, stainless and duplex grades run through the electric arc furnace, are refined in a ladle furnace and are decarburised under vacuum where low carbon and controlled nitrogen are needed. For S32750 the vacuum oxygen decarburisation step is the one that matters, because nitrogen has to finish inside a band 0.08 percent wide. Electroslag remelting is available where a project calls for a tighter inclusion rating or better transverse properties. Each heat is analysed before release and the heat number follows the steel through every later operation. **Open-die forging and ring rolling.** Billets are heated slowly to 1000 C, then worked in the hot window to a controlled reduction schedule. Deformation resistance climbs steeply as temperature falls, and below 1000 C the steel is at risk of sigma phase precipitation, so a piece that cools past that point returns to the furnace rather than taking another blow. This discipline, not press tonnage, separates a sound super duplex forging from a brittle one. **Solution annealing.** Finished forgings are solution annealed at 1040 to 1120 C and quenched rapidly in water, immediately after hot or cold forming. Rapid cooling restores the austenite and ferrite balance and takes intermetallic phases back into solution. Section thickness governs how fast the quench has to be, which is why heavy rings and thick tube sheets are planned around the furnace and quench tank from the start. Where maximum corrosion resistance is specified, annealed parts are pickled and rinsed. --- ## Machining and welding **Machining.** Compared with machinability-improved 2205, cutting speed in turning with coated cemented carbide tooling comes down by about 40 to 50 percent, while feeds are reduced only slightly, in the order of 10 to 15 percent, and with care. Rigid setups, sharp tools, positive rake geometry and generous coolant pay for themselves, because the material work hardens under a rubbing or dwelling tool. **Welding.** Weldability is good. GTAW is the first choice, SMAW also used. Filler is over-alloyed in nickel to rebuild austenite in the weld metal: ER2594 for GTAW, E2594 for SMAW. Preheat and post-weld heat treatment are not normally required. Keep heat input and interpass temperature controlled, since time in the intermediate temperature range precipitates secondary phases in the heat affected zone. Where a welded assembly must carry the full corrosion performance of the parent metal, a post-weld solution anneal and quench is the only way to restore it. --- ## Testing and certification | Scope | Detail | | --- | --- | | Chemical analysis | Ladle analysis on every heat, product analysis on request, PMI before shipment | | Mechanical testing | Tensile and hardness to A182 F53, Charpy V-notch at low temperature where specified | | Ferrite content | Point count to ASTM E562 or magnetic measurement, reported against 35 to 65 % | | Intermetallic phases | ASTM A923 screening by the nominated method | | Corrosion testing | ASTM G48 method A at the agreed temperature, coupon location stated on the order | | Ultrasonic examination | EN 10228-3, SEP 1921 or ASTM A388 | | Surface examination | Dye penetrant to ASTM E165, visual and dimensional inspection | | Certification | EN 10204 3.1, or 3.2 with third party release by TUV, SGS, BV, DNV, LR or NK | --- ## Plant capability | Item | Detail | | --- | --- | | Legal name | Jiangyin Jiangnan Metal Co., Ltd. | | Established | 1997 | | Employees | 460, including 9 senior engineers, 32 intermediate engineers and 140 technicians | | Melting | EF, LF, VOD, IF, VIM, IGESR, VAR. Maximum heat 60 t | | Forging | Open-die presses 6,300 t, 4,000 t, 2,000 t. Hammers 5 t to 750 kg | | Ring rolling | Radial-axial mills 6 m, 3 m, 1 m. Maximum outside diameter 6,000 mm | | Heat treatment | 14 furnaces, car-bottom and well type, deepest well 15,000 mm | | Machining | Vertical lathes to 5,000 mm swing, horizontal lathes to 14,000 mm, CNC lathes and machining centres, deep-hole drilling to 1,600 mm by 10,000 mm | | Maximum single piece | 30,000 kg | | Minimum order | 10 kg, no minimum piece count | | Lead time | 20 to 60 days | | Approvals | CCS, BV, DNV, LR, NK | | Export markets | North America, Europe, Middle East, Asia-Pacific | --- ## Applications - **Oil and gas.** Subsea and deepwater production hardware, downhole tooling, wellhead and manifold parts, platform process and service water piping, firewater systems. - **Desalination and seawater.** High pressure reverse osmosis plant, seawater piping and pumps, ballast and injection water systems, salt evaporation equipment. - **Chemical and petrochemical.** Heat exchangers, separators, pressure vessels, tube sheets, piping and fittings in chloride-bearing or organic acid streams. - **Pulp and paper.** Digesters, liquor tanks, bleach plant equipment, paper machine components. - **Power generation.** Flue gas desulphurisation plant, condenser and cooling water components, turbine and compressor shafts and rings. - **Mechanical engineering.** Gearbox and compressor parts, pump shafts and sleeves, high strength corrosion resistant structural components. --- ## Questions buyers ask **What is SAF 2507 equivalent to?** UNS S32750, Werkstoff 1.4410, EN name X2CrNiMoN 25-7-4 and Swedish SS 2328 describe the same grade. Forgings are ordered to ASTM A182 or ASME SA-182 Grade F53. Bar, plate and shapes fall under ASTM A479, A240 and A276. **What are the minimum mechanical properties?** 800 MPa, or 116 ksi, minimum tensile strength, 550 MPa, or 80 ksi, minimum 0.2 percent yield strength, 15 percent minimum elongation in two inches and hardness no higher than 310 HB, about 32 HRC. **What is the PREN?** About 42 at the aim composition. Across the full specification range the arithmetic gives roughly 38 at the minima and 48 at the maxima, which is why published figures sit between 40 and 42 for production material. Where a project sets a minimum PREN, state it on the enquiry so the melt can be aimed at it. **At what temperature is it forged?** Between about 1000 and 1200 C, with slow heating to 1000 C. A piece that falls below 1000 C returns to the furnace, because deforming or holding the steel under that temperature risks sigma phase. **How is it heat treated after forging?** Solution annealed at 1040 to 1120 C and quenched rapidly in water, immediately after forming. There is no hardening treatment for this grade, so an ageing cycle in a specification should be queried. **What is the maximum service temperature?** Normally 315 C, or 600 F. Super duplex grades precipitate secondary phases above that on long exposure, and toughness falls before corrosion resistance. Hotter duty usually moves to Inconel 625 or Incoloy 825. **How does it compare with 2205?** 2205 runs roughly 22 Cr and 3 Mo and is ordered as A182 Grade F51, requiring 620 MPa tensile and 450 MPa yield as minima. SAF 2507 carries 25 Cr, 4 Mo and more nitrogen, lifting those minima to 800 and 550 MPa. The cost is harder machining, a narrower forging window and tighter heat treatment control. Where 2205 already passes the corrosion duty it remains the cheaper choice. **Is it the same as A182 F55?** No. F53 covers UNS S32750, this grade. F55 covers UNS S32760, a different super duplex containing tungsten and copper. Both exceed PREN 40 but neither substitutes for the other without the buyer approving the change in writing. **What size forgings can you supply?** Rings to 6,000 mm outside diameter, single pieces to 30,000 kg, turned lengths to 14,000 mm, bored hollows to 1,600 mm by 10,000 mm. Minimum order 10 kg. Heavy super duplex sections are governed by quench capability as much as press size, so send the drawing and the test scope together. **Who manufactures these forgings?** Jiangyin Jiangnan Metal Co., Ltd., No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. Melting and forging on one site since 1997, holding CCS, BV, DNV, LR and NK approvals. Enquiries to sales@steelforgepieces.com or +86 189 2135 9659. --- ## Related grades A182 F53, A182 F55 (S32760), A182 F44 (S31254), A182 F61, 904L, Sanicro 28, 17-4 PH, 15-5 PH, PH13-8Mo, Nitronic 50, Incoloy 825, Inconel 625. --- ## References - Alleima, SAF 2507 billets material datasheet: UNS S32750 and EN 1.4410 composition, hot working and machining data. - Rolled Alloys, Alloy 2507 datasheet: specification list, service temperature limit, welding consumables. - ASTM A182 / A182M, Grade F51 and F53 mechanical requirements. - NACE MR0175 / ISO 15156, ferrite content limits for wrought duplex structures. Technical data is indicative and given for material selection. Confirm every requirement against the governing project specification and the mill certificate issued with the order.