Nickel & Cobalt Alloys

X8NiCrSi38-18 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

X8NiCrSi38-18 Product Description

Overview

X8NiCrSi38-18 is the EN symbol designation for a heat-resistant austenitic nickel-iron-chromium steel with a silicon addition. This datasheet presents the material within the EN symbol designation system.

A general-purpose heat-resisting material, X8NiCrSi38-18 combines high nickel and chromium contents with about 2% silicon to give good oxidation and scaling resistance up to about 1100 °C, particularly under cyclic conditions of heating and cooling. The high silicon and chromium contents give it excellent resistance to carburisation and good resistance to nitrogen-containing atmospheres with low oxygen content. It has a solid-solution composition with small amounts of precipitated titanium nitride and carbide, is not hardenable by heat treatment, and offers good high-temperature strength with excellent workability and weldability. It is supplied in the annealed and solution-treated condition.

Typical applications include industrial heating-furnace components, muffles, retorts, conveyor systems, carburising boxes and baskets, alloy grids, flare tips, and boiler and furnace fixtures.

1. Physical Properties

Property Value Unit
Density 7.94 g/cm³
Melting range 1350–1400 °C
Elastic modulus 196 GPa
Coefficient of thermal expansion (20–100 °C) 15.5 µm/m·°C
Thermal conductivity (20 °C) 12.0 W/m·K
Specific heat (20 °C) 460 J/kg·K
Structure Austenitic (FCC)

2. Chemical Composition (wt %)

Element Symbol Min % Max % Role in Alloy
Iron Fe Balance Base element
Nickel Ni 37.0 39.0 Austenite stabiliser; carburisation resistance
Chromium Cr 17.0 19.0 Oxidation / scaling resistance
Silicon Si 1.00 2.00 Enhances oxidation / carburisation resistance
Manganese Mn 1.50 Deoxidiser
Titanium Ti 0.60 Forms nitride / carbide
Carbon C 0.10 Carbide formation

3. Mechanical Properties

Annealed condition, per EN reference data for W.Nr. 1.4862.

Condition Property Value
Annealed Tensile strength (Rm) ≥550 MPa
Annealed 0.2% proof strength (Rp0.2) ≥230 MPa
Annealed Elongation (A5) ≥30 %
Elevated temperature High-temperature strength Good; creep-resistant
Elastic modulus 196 GPa

Values per EN reference data; properties depend on product form and condition. Confirm against the inspection certificate (EN 10204).

4. Corrosion Resistance

Environment Performance Notes
High-temperature oxidation Excellent To about 1100 °C, incl. cyclic
Carburisation Excellent High Si + Cr
Nitriding (low-oxygen N₂ atmospheres) Very Good Good resistance
Chloride stress-corrosion cracking Very Good High nickel content
Sulfidation Moderate Better under oxidizing than reducing conditions

The high nickel, chromium and silicon contents give excellent resistance to oxidation and carburisation at high temperature; resistance to sulfidation is better under oxidizing than reducing conditions, as sulfide scale tends to spall.

5. Heat Treatment

A solid-solution austenitic steel; not hardenable by precipitation. Properties are set by annealing.

Anneal Anneal (solution treat) at approximately 1020–1150 °C and cool by water quenching or as fast as possible. Annealing is recommended after hot working. The steel is not strengthened by heat treatment; cold work raises strength.

6. Weldability and Joining

Good weldability by the conventional processes for austenitic heat-resistant steels; neither pre- nor post-weld heat treatment is required. Matching or compatible filler is used.

Welding Process Applicability Filler / Consumable
GTAW / TIG Good Matching / compatible filler
GMAW / MIG Good Compatible filler
SMAW / stick Good For heavier sections

Weld with conventional austenitic practice and clean surfaces; no pre- or post-weld heat treatment is required.

7. Machinability and Fabrication

Machining Guidelines

Parameter Recommendation
Machinability Requires higher power than mild steel; work-hardens
Tooling Sharp carbide; rigid setups, positive feeds
Coolant Ample coolant

Forming Processes

Process Notes
Cold forming Good; work-hardens, anneal between heavy operations
Hot forming 1150–950 °C; water quench / fast cool, anneal afterward

8. Applications

Industry Typical Components Key Requirements
Industrial furnaces Muffles, retorts, fixtures Oxidation + carburisation resistance
Heat treatment Carburising boxes, baskets, grids Carburisation resistance
Process / petrochemical Conveyor systems, flare tips High-temperature strength
Power / boiler Furnace and boiler fixtures Oxidation resistance

9. Available Product Forms and Standards (DIN / EN System)

Product Form DIN / EN Standard Notes
Bar, rod and section EN 10095 · W.Nr. 1.4862 X8NiCrSi38-18
Plate, sheet and strip EN 10095 · W.Nr. 1.4862
Seamless pipe and tube DIN 17470 · W.Nr. 1.4862
Inspection documents EN 10204

Nickel-iron-chromium heat-resistant steel with silicon. W.Nr. 1.4862 (X8NiCrSi38-18).

10. Comparison with Related Alloys (EN Symbol System)

EN Symbol Ni % Cr % Si % Best Used For
X8NiCrSi38-18 37–39 17–19 1.0–2.0 High-Cr/Si heat-resistant steel; carburisation resistance, furnace parts
X12NiCrSi35-16 34–37 15–17 1.0–2.0 Heat-resistant Ni-Cr-Fe-Si alloy (1.4864)
X10NiCrAlTi32-21 30–35 19–23 ≤1.0 Higher-temperature creep service (800H)
X15CrNiSi25-21 19–22 24–26 ≤1.5 High-temperature oxidation resistance (310S)
X25CrMnNiN25-9-7 4–6 24–26 ≤1.0 Heat-resistant austenitic furnace steel

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