Super Stainless Steel

X2CrNiMoN25-7-3 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

X2CrNiMoN25-7-3 Product Description

Overview

X2CrNiMoN25-7-3 is a 25Cr ferritic-austenitic (duplex) stainless steel with small tungsten and copper additions, with a microstructure of roughly equal ferrite and austenite. This datasheet presents the material within the European standard system.

With about 25% chromium, 6.5% nickel, 3% molybdenum, small tungsten and copper additions and nitrogen, X2CrNiMoN25-7-3 offers roughly twice the proof strength of standard austenitic grades, together with strong resistance to chloride pitting, crevice corrosion and stress-corrosion cracking. The chemistry places its localized-corrosion resistance between standard 1.4462 duplex and the higher-PREN super duplex grades. The EN symbol X2CrNiMoN25-7-3 reflects the base Cr-Ni-Mo-N chemistry.

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 0.035 Residual impurity
Sulphur S 0.015 Residual impurity

3. Mechanical Properties

Solution-annealed (+AT) condition, per EN 10088-3 for W.Nr. 1.4481.

Property Value Unit
Tensile strength (Rm) 690-900 MPa
0.2% proof strength (Rp0.2) >=485 MPa
Elongation at fracture >=25 %
Impact energy (KV, +20 °C) >=100 J
Brinell hardness <=290 HB

Values per EN 10088-3 (resistant to intergranular corrosion in delivery and welded condition). Confirm against the inspection certificate (EN 10204).

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 1.4404
Acids Very good Copper addition
General (oxidizing) Very good High chromium
Intergranular (welded) Resistant Low carbon

Localized-corrosion resistance sits between standard 1.4462 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. 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

Good weldability 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; resistant to intergranular corrosion in the as-welded condition owing to the low carbon.

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 EN 10088-2 · W.Nr. 1.4481 X2CrNiMoN25-7-3
Bar, rod, wire and sections EN 10088-3 · W.Nr. 1.4481
Seamless / welded tube EN 10216-5 / EN 10217-7 · W.Nr. 1.4481
Sour service ISO 15156-3 Acid-gas applications

Tungsten- and copper-bearing 25Cr ferritic-austenitic (duplex) stainless steel. W.Nr. 1.4481 (X2CrNiMoN25-7-3); EN 10088-3.

10. Comparison with Related Alloys (EN Symbol System)

EN Symbol Cr % Ni % Mo % W % Cu % Best Used For
X2CrNiMoN25-7-3 24-26 5.5-7.5 2.5-3.5 0.1-0.5 0.2-0.8 W+Cu 25Cr duplex; chloride service
X2CrNiMoN22-5-3 21-23 4.5-6.5 2.5-3.5 Standard duplex
X2CrNiMoN25-7-4 24-26 6.0-8.0 3.0-4.5 Super duplex
X2CrNiMoCuWN25-7-4 24-26 6.0-8.0 3.0-4.0 0.5-1.0 0.5-1.0 W+Cu super duplex
X2CrNiMo17-12-2 16.5-18.5 10-13 2.0-2.5 Austenitic general service

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