Why Specify UNS S32760 Seamless Pipe?
- Localized corrosion resistance: strong resistance to pitting and crevice corrosion in chloride-bearing media, subject to temperature, pH and service chemistry.
- High strength: minimum room-temperature yield strength is typically 550 MPa under applicable product specifications. Final wall thickness must be established by the governing design code and corrosion allowance.
- Stress-corrosion cracking resistance: the duplex microstructure provides strong resistance to chloride SCC; it should not be described as immune under all service conditions.
- Cu and W additions: these additions distinguish S32760 from S32750 and can support performance in selected acidic and erosion-corrosion environments.
- Temperature note: prolonged elevated-temperature service requires review against the design code and metallurgical limits.
Technical Specifications of UNS S32760 / F55
Equivalent Grade
| UNS | Common grade name | EN material number | EN steel name | JIS grade | GB/T grade |
|---|---|---|---|---|---|
| S32760 | Zeron 100 | 1.4501 | X2CrNiMoCuWN25-7-4 | – | 022Cr25Ni7Mo4WCuN (S27603, approx.) |
Grade correspondence does not make ASTM, ASME, EN, JIS and GB delivery requirements interchangeable. Confirm chemistry, heat treatment, mechanical properties, dimensions, testing and certification against the purchase specification. See the grade designation index.
Chemical Composition
The composition of UNS S32760 is precisely controlled to maximize its duplex properties and corrosion resistance.
The following UNS S32760 composition limits should be confirmed against the applicable product specification and the actual heat analysis.
| Grade | C | Mn | Si | P | S | Cr | Ni | Mo | N | Cu | W |
|---|---|---|---|---|---|---|---|---|---|---|---|
| UNS S32760 | ≤ 0.030 | ≤ 1.00 | ≤ 1.00 | ≤ 0.030 | ≤ 0.010 | 24.0–26.0 | 6.0–8.0 | 3.0–4.0 | 0.20–0.30 | 0.50–1.00 | 0.50–1.00 |
All values in wt.%.
Typical Mechanical Properties
UNS S32760 is specifically designed to maintain its strength and shape in high-stress, corrosive environments.
| Tensile Strength | Yield Strength | Elongation | Hardness |
|---|---|---|---|
| ≥750 MPa | ≥ 550 MPa | ≥25% | ≤ 300 HBW (ASTM A790 Table 3; the standard sets no Rockwell limit for Grade S32760) |
Typical Physical Properties
These physical properties highlight the material’s ability to perform reliably under a wide range of conditions.
| Density | Melting Point | Thermal Expansion | Thermal Conductivity | Modulus of Elasticity | Electrical Resistivity |
|---|---|---|---|---|---|
| 7.8 g/cm³ | 1450 °C (approx.) | 13.5 μm/m·°C (20–100°C) | 15.0 W/m·K (20°C) | 200 GPa | 0.80 × 10−6 Ω·m (20°C) |
Size Tolerance Chart (mm)
| NPS Designator (Inches) | Permissible Variations in Outside Diameter (Inches) |
| 1⁄8 to 1 1⁄2, inclusive | Over: 1⁄64 in. (0.015 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 1 1⁄2 to 4, inclusive | Over: 1⁄32 in. (0.031 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 4 to 8, inclusive | Over: 1⁄16 in. (0.062 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 8 to 18, inclusive | Over: 3⁄32 in. (0.093 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 18 to 26, inclusive | Over: 1⁄8 in. (0.125 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 26 to 34, inclusive | Over: 5⁄32 in. (0.156 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 34 to 48, inclusive | Over: 3⁄16 in. (0.187 in.) |
| Under: 1⁄32 in. (0.031 in.) |
Wall Thickness (WT) Tolerance
The wall thickness tolerances are defined by the nominal wall thickness (t) and the outside diameter (D).
1. Minimum Wall Thickness
The minimum wall thickness at any point on the pipe shall not be more than {12.5%} under the nominal (specified) wall thickness.
2. Maximum Wall Thickness (Percentage Over Nominal)
The maximum allowable wall thickness variation depends on the size and the t/D ratio (ratio of nominal wall thickness to ordered outside diameter):
| NPS Designator (Inches) | t/D Ratio | Permissible Variation (Over Nominal WT) |
| 1/8 to 2, inclusive | All ratios | +20.0% |
| 3 to 18, inclusive | t/D ≤ 5% | +22.5% |
| 3 to 18, inclusive | t/D >5% | +15.0% |
| 20 and larger (Seamless) | t/D ≤ 5% | +22.5% |
| 20 and larger (Seamless) | t/D >5% | +15.0% |
| 20 and larger (Welded) | All ratios | +17.5% |
For pipe ordered to a Specific Cut Length, the standard tolerance is +1⁄8 in. [3.2 mm], -0 in. [0 mm].
Pipe is typically supplied in Single Random Lengths (17 to 24 ft) or Double Random Lengths (38 to 40 ft), unless otherwise specified.
Disclaimer: These tolerances are based on the common requirements found in ASTM A790, primarily through its reference to ASTM A999. The full and most current specification document must always be consulted for official design and procurement purposes.
Applications, Inspection and Grade Selection
UNS S32760 seamless pipe is considered for seawater and desalination systems, offshore and subsea piping, chemical processing, flue-gas desulfurization, marine cooling systems and selected sour-service duties. Suitability must be confirmed from the actual fluid chemistry, temperature, pressure, governing design code and project specification.
Deepwater Oil & Gas
Subsea manifolds, risers, and flowlines handling sour (H₂S-rich) fluids
Desalination Plants
High-pressure Reverse Osmosis (RO) piping and brine concentrators
Chemical Processing
Production of organic/fatty acids, flue gas desulfurization (FGD) scrubbers
Marine & Naval
Fire-main systems, propeller shafts, and seawater cooling systems
Inspection and Documentation
Testing and documentation are supplied according to the purchase specification. Available options include EN 10204 3.1 or 3.2 certification, PMI, ASTM G48 corrosion testing, impact testing, UT or ET, hydrostatic testing and third-party inspection. These services are not automatic unless stated in the quotation and purchase order.
UNS S32760 vs. S32750 and Duplex 2205
Compared with Duplex 2205, S32760 provides higher alloy content, strength and resistance to localized chloride corrosion. Compared with S32750, S32760 includes deliberate copper and tungsten additions. Grade selection should be based on the environment, governing design code and required certification rather than grade name alone.
Frequently Asked Questions
Is UNS S32760 the same as ZERON® 100?
ZERON® 100 is a registered proprietary alloy that complies with UNS S32760 and uses tighter internal controls. Do not describe generic S32760 as ZERON® 100 unless the material certificate supports it.
Is F55 the pipe grade for S32760?
F55 is commonly used for UNS S32760 forged components under ASTM A182. Seamless pipe is normally ordered by UNS S32760 under ASTM A790 or ASME SA790.
What dimensions and MOQ are available?
Available outside diameter is 6–710 mm, wall thickness is 0.5–40 mm and MOQ is 200 kg. Final availability depends on dimensions, condition and inspection requirements.
Which documents and tests can be supplied?
EN 10204 inspection certification and project-specific testing such as PMI, corrosion, impact, NDT and third-party inspection can be supplied when agreed in the quotation and purchase order.
Request UNS S32760 pipe specifications, MTC requirements and a mill quote.
Ready to Request a Quotation?
Send the NPS and schedule (or actual OD and wall), quantity, length, end finish and the inspection items you need as acceptance criteria — you will get a written quotation stating the specification and edition, delivery condition, documents included and lead time.
