Related Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
ASTM A1082/A1082M Grade S32750 | Super Duplex 2507 Stainless Steel
Exceptional corrosion resistance and mechanical strength for severe offshore service
Grade S32750 (UNS S32750) is a high-performance super duplex stainless steel, commonly known as Super Duplex 2507, featuring 25% chromium, 4% molybdenum, and 7% nickel to deliver exceptional resistance to pitting, crevice corrosion, and stress corrosion cracking (SCC). Designated as ASTM A1082/A1082M F53, this grade provides a PREN value exceeding 40, outperforming standard duplex and austenitic stainless steels in aggressive chloride environments such as offshore oil and gas production, marine engineering, and chemical processing. S32750 offers nearly double the yield strength of austenitic alloys, allowing for significant weight reduction in complex structural designs and pressure-containing equipment. Its unique dual-phase microstructure ensures high toughness and excellent weldability, making it a critical material for subsea pipelines, desalination plants, and high-pressure desalination systems.
ASTM A1082/A1082M Grade S32750 Chemical RequirementsA
| Grades | UNS Designation | Type | C | Mn | P | S | Si | Cr | Ni | Mo | N | Other ElementsB |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ASTM A1082/A1082M Duplex (Ferritic-Austenitic) Grades | S32750 | 2507 | 0.030 | 1.20 | 0.035 | 0.020 | 0.80 | 24.0-26.0 | 6.0-8.0 | 3.0-5.0 | 0.24-0.32 | Cu 0.50 |
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ASTM A1082/A1082M Grade S32750 Mechanical Properties
| UNS Designation | Solution Temperature, °F [°C] (B, C) | Size Range, in. | Tensile Strength, min, ksi [MPa] | Yield Strength, 0.2% offset, min, ksi [MPa] | Elongation in 2" [50 mm] or 4D, min, % | Rockwell HRC, max | Brinell max (D) |
|---|---|---|---|---|---|---|---|
| S32750 | 1880 - 2060 [1025 - 1125] | 2 in. and under | 116 [800] | 80 [550] | 15 | 33 | 310 |
| >2 in. | 110 [760] | 75 [515] | 15 | 33 | 310 | ||
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ASTM A1082/A1082M Markings
| UNS Designation | Type | Grade Symbol |
|---|---|---|
| S32750 | 2507 | TB 32750 |
Frequently Asked Questions
What is Super-Duplex 2507 (S32750)?
Super-Duplex 2507 (S32750) is a stainless steel grade covered under ASTM A1082/A1082M for high-strength bolting in special-purpose applications such as pressure vessels. UNS designation S32750. Available as bolts, studs, screws and nuts manufactured by TorqBolt for global oil/gas/nuclear/power/marine sectors.
What are the mechanical properties of Super-Duplex 2507 (S32750) per ASTM A1082?
Mechanical property requirements for S32750 are defined in ASTM A1082 Table 2 (PH grade solution treatment) or Table 4 (duplex annealed condition). Properties vary by treatment condition - refer to the bolting specification for the H-condition (PH) or annealed yield/tensile/elongation/hardness requirements applicable to your order.
Is Super-Duplex 2507 (S32750) suitable for sour service (NACE MR0175)?
Refer to NACE MR0175 / ISO 15156 Tables A.16-A.19. Most A1082 duplex grades are permitted at ≤28 HRC; PH grades require condition-specific qualification (typically H1150 for 17-4 PH at 28 HRC). TorqBolt supplies sour-service certified product on request with full PMI + hardness traceability.
What ASME / ISO dimensional standards can Super-Duplex 2507 (S32750) be supplied to?
This grade is available across the full ASME and ISO bolting dimensional standards covered on this site - ASME B18.2.1 (hex bolts, hex cap screws, lag screws), B18.2.2 (hex nuts, square nuts, lock nuts), B18.3 (socket head cap screws), B18.31.2 (clamping studs), B16.5 (flange stud bolts), ISO 4032 / 4033 / 4035 (metric nuts), and metric B18.2.3.xM / B18.2.4.xM series.
References & Standards
- ASTM A1082 / A1082M - Standard Specification for High-Strength Precipitation-Hardening and Duplex Stainless Steel Bolting for Special-Purpose Applications (current edition 2016, active)
- ASTM A962 / A962M - General Requirements for Special-Purpose Bolting Materials
- ASTM A370 - Mechanical Testing of Steel Products
- NACE MR0175 / ISO 15156 - Sour-service hardness limits for petroleum & natural gas industries
- ASME B18 series - Dimensional standards for bolts, screws, nuts, studs
- ISO 4032 / 4033 / 4035 - Metric hexagon nut dimensional standards
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