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 S32950 | Super Duplex Stainless Steel
Premium super duplex steel providing exceptional strength and corrosion resistance
Grade S32950 (UNS S32950) is a high-performance super duplex stainless steel featuring 26% chromium, 4.5% nickel, and 1.5% molybdenum, designed to deliver exceptional mechanical strength and outstanding resistance to corrosion in aggressive industrial environments. With its balanced ferritic-austenitic microstructure, this grade provides superior resistance to chloride-induced stress corrosion cracking (SCC), pitting, and crevice corrosion compared to standard duplex and austenitic alloys. S32950 is widely utilized in chemical processing, offshore oil and gas production, marine engineering, and heat exchanger systems where long-term durability and structural integrity are critical. Its high yield strength—nearly double that of standard austenitic grades—combined with excellent toughness and weldability, makes it an ideal material for complex industrial assemblies and high-pressure components operating in severe conditions.
ASTM A1082/A1082M Grade S32950 Chemical Composition
| Grades | UNS Designation | Type | C | Mn | P | S | Si | Cr | Ni | Mo | N | Other ElementsB |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ASTM A1082/A1082M Duplex (Ferritic-Austenitic) Grades | S32950 | . . . | 0.030 | 2.00 | 0.035 | 0.010 | 0.60 | 26.0-29.0 | 3.5-5.2 | 1.00-2.50 | 0.15-0.35 | . . . |
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Frequently Asked Questions
What is Super-Duplex 2950 (S32950)?
Super-Duplex 2950 (S32950) is a stainless steel grade covered under ASTM A1082/A1082M for high-strength bolting in special-purpose applications such as pressure vessels. UNS designation S32950. 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 2950 (S32950) per ASTM A1082?
Mechanical property requirements for S32950 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 2950 (S32950) 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 2950 (S32950) 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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