Super Stainless Steel

S31260 Supply Detail

Category

  • Bar and Rod

  • Plate and Sheet

  • Strip

  • Pipe and Tube

  • Wire

  • Welding

  • Powder Material

  • Cast Products

  • Forged Products

  • Fittings

  • Fastening

    Forms & Sizes

    Round Bar:
    φ2–500 mm, 1–6 m length

    Flat/Square Bar:
    4–100 mm thickness/width

    Hex Bar:
    A/F 3–100 mm

    Hollow Bar:
    OD 20–300 mm

    Forms & Sizes

    Sheet:
    0.3–6 mm thickness

    Medium Plate:
    6–25 mm thickness

    Heavy Plate:
    25–100 mm thickness

    Forms & Sizes

    Standard Strip:
    0.05–3 mm thick,
    10–600 mm wide

    Precision strip:
    0.01–0.5 mm thick,
    tight tolerance ±0.005 mm

    Foil:
    0.005–0.1 mm thick

    Forms & Sizes

    Seamless Tube:
    OD 6–450 mm,
    WT 1–50 mm,
    1–12 m length

    Welded Tube:
    OD 10–600 mm,
    WT 1–20 mm

    Capillary Tube:
    OD 1–10 mm,
    WT 0.1–2 mm

    Forms & Sizes

    Wire Form:
    Cold Drawn Wire,
    Bright Wire,
    Spring Wire,
    Fine Wire,
    Ultra-fine Wire

    General Diameter:
    φ0.1–10 mm

    Coil Weight:
    50–500 kg,
    customizable tolerance

    Forms & Sizes

    Solid Wire:
    φ0.8–4.0 mm

    Flux-cored Wire:
    φ1.2–4.0 mm

    Welding Rod:
    φ2.0–5.0 mm

    Forms & Sizes

    Powder Form:
    AM 3D Printing Powder,
    Spherical Powder,
    Gas-atomized Powder,
    Water-atomized Powder

    Particle Size:
    10–150 μm

    Sphericity:
    ≥90% for AM grade

    Forms & Sizes

    Cast Ingot:
    φ200–800 mm

    Precision Casting:
    min wall 0.5 mm

    Cast Pipe:
    OD 100–600 mm,
    WT 10–50 mm

    Forms & Sizes

    Forged Bar:
    Φ35–500 mm

    Forged Ring:
    OD 200–2000 mm

    Forging Weight:
    1–5000 kg

    Forms & Sizes

    Fittings Form:
    Elbow, Tee, Reducer, Flange, Cap, Outlet, Lap Joint

    Size range:
    1/2''–24'' (DN15–DN600)

    Wall thickness:
    Sch10–Sch160, STD, XS, XXS

    Pressure Class:
    150–2500 LB

    Forms & Sizes

    Fastening Form:
    Bolt, Nut, Screw, Stud, Washer, Pin, Rivet

    Metric: M3–M64

    Imperial: #4–2.5''

    Length: 6–500 mm

S31260 Product Description

Overview

S31260 is a tungsten- and copper-bearing 25Cr ferritic-austenitic (duplex) stainless steel, with a microstructure of roughly equal ferrite and austenite. This datasheet presents the material within the American standard system.

With about 25% chromium, 6.5% nickel, 3% molybdenum, small tungsten and copper additions and nitrogen, S31260 offers roughly twice the yield strength of standard austenitic grades, together with strong resistance to chloride pitting, crevice corrosion and stress-corrosion cracking. The tungsten and copper additions enhance localized-corrosion and acid resistance, placing its performance between standard 2205 duplex and the higher-PREN super duplex grades.

Typical applications include oil-and-gas equipment, subsea components, seawater systems, heat exchangers and chemical-process equipment requiring high strength with chloride resistance.

1. Physical Properties

Property Value Unit
Density 7.8 g/cm³
Melting range 1350-1400 °C
Young's modulus (20 °C) 200 GPa
Thermal conductivity (20 °C) 16 W/m·K
Coefficient of thermal expansion (20-100 °C) 13 µm/m·°C
Specific heat (20 °C) 480 J/kg·K
Magnetic response Ferromagnetic (duplex)

2. Chemical Composition (wt %)

Element Symbol Min % Max % Role in Alloy
Iron Fe Balance Base element
Chromium Cr 24.0 26.0 Ferrite former; corrosion resistance
Nickel Ni 5.5 7.5 Austenite former; phase balance
Molybdenum Mo 2.5 3.5 Pitting + crevice resistance
Copper Cu 0.20 0.80 Acid resistance
Tungsten W 0.10 0.50 Pitting resistance
Nitrogen N 0.10 0.30 Austenite former; strength; pitting
Manganese Mn 1.00 Deoxidiser
Silicon Si 0.75 Deoxidiser
Carbon C 0.030 Low (intergranular resistance)
Phosphorus P 0.030 Residual impurity
Sulphur S 0.030 Residual impurity

3. Mechanical Properties

Solution-annealed condition, per ASTM A240 for UNS S31260.

Property Value Unit
Tensile strength >=690 MPa
0.2% yield strength >=485 MPa
Elongation at break >=25 %
Brinell hardness <=290 HB
Rockwell hardness <=31 HRC

Confirm against the mill test report.

4. Corrosion Resistance

Environment Performance Notes
Chloride SCC Excellent Key duplex advantage over austenitics
Chloride pitting Very good Cr + Mo + W + N
Crevice corrosion Very good Better than 316L
Acids Very good Copper addition
General (oxidizing) Very good High chromium
Sulphide / sour Good Listed in NACE MR0175

Localized-corrosion resistance sits between standard 2205 duplex and the high-PREN super duplex grades.

5. Heat Treatment

Not hardenable by heat treatment; properties are set by solution annealing and phase balance.

Solution Anneal approximately 1040-1120 °C, followed by rapid water quench to retain the balanced ferrite-austenite structure and avoid embrittling intermetallic phases. Rapid cooling is critical owing to the high alloy content. Avoid prolonged exposure in the 300-1000 °C range (sigma-phase / 475 °C embrittlement).

6. Weldability and Joining

Weldable by common fusion methods; use a matching or over-alloyed duplex/super-duplex filler and control heat input to maintain phase balance.

Process Applicability Filler / Consumable
GTAW / TIG Good Duplex / super-duplex filler
GMAW / MIG Good Duplex filler
SMAW / stick Good Matching duplex electrode

No preheat; control interpass temperature and heat input to maintain phase balance and avoid intermetallic phases.

7. Machinability and Fabrication

Machining Guidelines

Parameter Recommendation
Machinability Duplex; carbide tools, low-to-moderate speeds, rigid setup
Work hardening Significant; positive feeds, avoid dwelling
Coolant Ample flood coolant

Forming Processes

Process Notes
Hot forming ~1200-1000 °C; solution anneal + quench afterward
Cold forming Higher forces than austenitics (high duplex strength)

8. Applications

Industry Typical Components Key Requirements
Oil & gas Subsea components, tubing Pitting + sour-service resistance
Marine / seawater Seawater systems, heat exchangers Chloride resistance
Chemical processing Vessels, piping Localized-corrosion resistance
Desalination Heat exchangers Chloride resistance

9. Available Product Forms and Standards

Product Form Standard Notes
Plate, sheet and strip ASTM A240 / ASME SA-240 · UNS S31260
Bar and shapes ASTM A276 / A479 · UNS S31260
Seamless / welded tube ASTM A789 · UNS S31260
Seamless / welded pipe ASTM A790 / A928 · UNS S31260
Forgings / fittings ASTM A182 · UNS S31260
Sour service NACE MR0175 / ISO 15156 Acid-gas applications

Tungsten- and copper-bearing 25Cr ferritic-austenitic (duplex) stainless steel. UNS S31260.

10. Comparison with Related Alloys (UNS System)

UNS Cr % Ni % Mo % W % Cu % Best Used For
S31260 24-26 5.5-7.5 2.5-3.5 0.1-0.5 0.2-0.8 W+Cu 25Cr duplex; chloride service
S32205 22-23 4.5-6.5 3.0-3.5 Standard duplex
S32750 24-26 6.0-8.0 3.0-5.0 Super duplex
S32760 24-26 6.0-8.0 3.0-4.0 0.5-1.0 0.5-1.0 W+Cu super duplex
S31803 21-23 4.5-6.5 2.5-3.5 Standard duplex (original)

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