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 S32906 | Super Duplex Stainless Steel
Highly-alloyed super duplex steel for exceptional performance in aggressive environments
Grade S32906 (UNS S32906) is a high-performance super duplex stainless steel containing 29% chromium, 6% nickel, and 2% molybdenum, specifically engineered for exceptional resistance to corrosion in the most aggressive industrial environments. Featuring a balanced ferritic-austenitic dual-phase microstructure, this grade provides superior resistance to chloride-induced pitting, crevice corrosion, and stress corrosion cracking (SCC) compared to standard duplex alloys. S32906 is widely utilized in severe chemical processing, urea production, fertilizer plants, and offshore oil and gas equipment where extreme mechanical durability and long-term structural integrity are required. Its unique high-chromium composition ensures outstanding resistance to oxidizing acids and localized attack, allowing for extended service life in critical applications involving high temperatures and concentrated corrosive media.
ASTM A1082/A1082M Grade S32906 Chemical Composition
| Grades | UNS Designation | Type | C | Mn | P | S | Si | Cr | Ni | Mo | N | Other ElementsB |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ASTM A1082/A1082M Duplex (Ferritic-Austenitic) Grades | S32906 | . . . | 0.030 | 0.80-1.50 | 0.030 | 0.030 | 0.50 | 28.0-30.0 | 5.8-7.5 | 1.50-2.60 | 0.30-0.40 | Cu 0.80 |
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ASTM A1082/A1082M Grade S32906 Mechanical Properties
| UNS Designation | Solution Temperature, °F [°C] (B, C) | 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) |
|---|---|---|---|---|---|---|
| S32906 | 1830 to 2100 [1000 to 1150] | 109 [750] | 80 [550] | 25 | 33 | 310 |
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ASTM A1082/A1082M Markings
| UNS Designation | Grade Symbol |
|---|---|
| S32906 | TB 32906 |
Frequently Asked Questions
What is Super-Duplex 2906 (S32906)?
Super-Duplex 2906 (S32906) is a stainless steel grade covered under ASTM A1082/A1082M for high-strength bolting in special-purpose applications such as pressure vessels. UNS designation S32906. 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 2906 (S32906) per ASTM A1082?
Mechanical property requirements for S32906 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 2906 (S32906) 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 2906 (S32906) 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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