Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175 / ISO 15156-2
- NORSOK M-650 Qualified
- API 6A Certified
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Super Duplex 2507 Round Bar, UNS S32750 ASTM A479
Super Duplex 2507 round bar in UNS S32750 (Werkstoff 1.4410, X2CrNiMoN25-7-4) is the workhorse machining stock for shafts, valve stems, pump impellers, fastener blanks and forging billets where chloride pitting and crevice corrosion would defeat duplex 2205 and the 6 percent molybdenum austenitics. TorqBolt holds round bar from 6 mm through 600 mm at the Mumbai warehouse, hot-rolled and peeled or cold-finished, supplied with full mill test certificates per EN 10204 Type 3.1 (Type 3.2 third-party-witnessed available on request).
The bar is supplied to ASTM A479 for stainless steel bar in pressure-vessel and general service, with chemistry per UNS S32750 and EN 10088-3 Werkstoff 1.4410. Heavier sections and forging stock follow ASTM A182 grade F53. Sour-service certification per NACE MR0175 / ISO 15156-3 is available with controlled hardness and ferrite balance.
Super Duplex 2507 Round Bar Size Range
| Form | Diameter | Length |
|---|---|---|
| Hot-rolled and peeled (ASTM A479) | 20 mm to 300 mm | 3.0 to 6.0 m random, cut-to-length |
| Forged and rough-machined (A182 F53) | 200 mm to 600 mm | Cut-to-length per drawing |
| Cold-finished (drawn or ground) | 6 mm to 80 mm | 3.0 to 6.0 m random |
| Tolerance | ASTM A484 for hot-rolled, ASTM A484 / DIN 671 h9 / h11 for cold-finished | |
Super Duplex 2507 Round Bar Chemistry per ASTM A479
Chemistry mirrors UNS S32750: 25Cr-7Ni-3.5Mo-0.3N. Copper is restricted to 0.50 max as residual, not intentional. PREN of 41 or higher.
| Element | A479 Min % | A479 Max % |
|---|---|---|
| Carbon (C) | (no min) | 0.030 |
| Chromium (Cr) | 24.0 | 26.0 |
| Nickel (Ni) | 6.0 | 8.0 |
| Molybdenum (Mo) | 3.0 | 5.0 |
| Nitrogen (N) | 0.24 | 0.32 |
| Copper (Cu) | (no min) | 0.50 max, residual, not intentional |
| Manganese (Mn) | (no min) | 1.20 |
| Silicon (Si) | (no min) | 0.80 |
| Phosphorus (P) | (no min) | 0.035 |
| Sulfur (S) | (no min) | 0.020 |
Super Duplex 2507 Round Bar Mechanical Properties
| Property | Minimum | Test Standard |
|---|---|---|
| Tensile strength | 800 MPa (116 ksi) | ASTM A370 |
| Yield strength (0.2 percent offset) | 550 MPa (80 ksi) | ASTM A370 |
| Elongation in 50 mm | 15 percent | ASTM A370 |
| Hardness (sour-service) | 32 HRC max bar, 28 HRC max NACE service | NACE MR0175 |
| Charpy V-notch at minus 46 degrees Celsius | 45 J min (full set) | NORSOK M-630, ASTM E23 |
| Ferrite content | 35 to 55 percent base metal | ASTM E562 |
Solution Anneal and Water Quench
All ASTM A479 super duplex 2507 bar is solution annealed at 1040 to 1100 degrees Celsius and water quenched. The water quench must drive the bar rapidly through the 600 to 1000 degrees Celsius window so that sigma phase, chi phase and secondary austenite cannot precipitate. Quench delay or air cooling on heavy section bar is the single most common cause of low Charpy values and failed pitting tests on as-supplied stock.
Machining Super Duplex 2507 Bar
- Cutting speeds about 50 percent of austenitic 316L. Use rigid setups, sharp tooling and positive rake.
- Carbide grades suited to stainless: ISO M20 to M30 or coated K-grades. Avoid built-up edge by keeping feed positive.
- Flood coolant with 8 to 10 percent emulsion. Heat in the cut accelerates work-hardening and damages tool flanks.
- Threading: single-point with full profile inserts; rolled threads on cold-finished stock for fasteners reduce notch effects.
Super Duplex 2507 Round Bar Applications
- Pump shafts, impellers and seal sleeves for seawater lift and firewater duty
- Valve stems and trim for chloride process and oil and gas service
- Forging stock for flanges, fittings and subsea hardware to ASTM A182 F53
- Fastener blanks for stud bolts, nuts and screws to ASTM A276 and A479
- Heat-exchanger tube-sheet inserts and weld-overlay billets
Related Products and Standards
- Super Duplex 2507 hex bar for nut and fitting blanks
- Super Duplex 2507 flat bar
- Super Duplex 2507 square bar
- Super Duplex 2507 forged bar per A182 F53
- Super Duplex 2507 cold finished bar
- Super Duplex 2507 fasteners
- ASTM A479 standard reference
- NORSOK M-630 datasheet
Super Duplex 2507 Round Bar FAQ
Which standards cover Super Duplex 2507 round bar?
ASTM A479 (stainless bar for pressure vessels), ASTM A276 (stainless bar and shapes), ASTM A182 grade F53 (forged bar and billets), EN 10088-3 (Werkstoff 1.4410 / X2CrNiMoN25-7-4), NORSOK M-630 (material data sheet) and NACE MR0175 / ISO 15156-3 for sour service.
What is the size range and tolerance for 2507 round bar?
Hot-rolled and peeled bar runs 20 mm to 300 mm; forged stock from 200 mm to 600 mm; cold-finished from 6 mm to 80 mm. Tolerances follow ASTM A484 for hot-rolled. Cold-finished bar is supplied to A484 or DIN 671 h9 / h11 depending on the customer drawing.
Can I forge directly from 2507 round bar?
Yes. Forging window is 1100 to 1230 degrees Celsius. Finish above 950 degrees Celsius and water quench from solution-anneal temperature 1040 to 1100 degrees Celsius. Air cooling heavy sections risks sigma-phase precipitation and a Charpy collapse.
What ferrite content does TorqBolt certify on 2507 bar?
35 to 55 percent ferrite by ASTM E562 point counting on the base metal. NORSOK M-630 acceptance is the same band. Heat-treatment records and ferrite count are reported on the EN 10204 Type 3.1 certificate.
Does 2507 contain copper?
No, copper is not an intentional alloying element in UNS S32750. ASTM A479 permits 0.50 max as residual, not intentional. If a project specifies a copper-bearing super duplex, the correct grade is Zeron 100 (UNS S32760) or Ferralium 255 (UNS S32550), supplied separately.
Is 2507 round bar suitable for sour service?
Yes, qualified per NACE MR0175 / ISO 15156-3 with hardness restricted to 28 HRC maximum and ferrite content within the 35 to 65 percent band for the application zone. H2S partial pressure and chloride limits depend on the sour-service classification and are stated on the certificate when ordered with NACE compliance.
Satisfaction Survey
