Nickel & Cobalt Alloys

N08825 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

N08825 Product Description

Overview

N08825 is a titanium-stabilised nickel–iron–chromium alloy with additions of molybdenum and copper, designed to provide exceptional resistance to a wide range of corrosive environments. This datasheet presents the material within the American (ASTM / ASME / SAE-AMS / UNS) standard system.

The nickel content is sufficient for resistance to chloride-ion stress-corrosion cracking; together with molybdenum and copper it gives outstanding resistance to reducing environments such as sulphuric and phosphoric acids. Molybdenum also aids resistance to pitting and crevice corrosion, while the chromium content confers resistance to oxidising substances such as nitric acid, nitrates and oxidising salts. The titanium addition, with appropriate heat treatment, stabilises the alloy against sensitisation to intergranular corrosion.

These properties make it especially useful in sulphuric and phosphoric acid service, sulphur-bearing flue gases, sour-gas and oil-field equipment, pickling operations, nuclear fuel reprocessing, propeller shafts, tank trucks and seawater handling. It has good mechanical properties from cryogenic to moderately high temperatures; exposure above about 540 °C can cause phase formation that lowers ductility, so it is not normally used where creep-rupture strength governs. It is listed in NACE MR0175 / ISO 15156 (type 4c) for sour service.

1. Physical Properties

Values per Special Metals official datasheet, annealed condition.

Property Value Unit
Density 8.14 g/cm³
Specific heat capacity (26 °C) 440 J/kg·K
Thermal conductivity (26 °C) 11.3 W/m·K
Electrical resistivity (26 °C) 1.13 µΩ·m
Young's modulus (20 °C) 196 GPa
Poisson's ratio 0.32
Magnetic permeability (annealed) <1.005 Essentially non-magnetic
Maximum service temperature ~540 °C

2. Chemical Composition (Limiting, wt %)

Limiting composition per ASTM B425 (UNS N08825).

Element Symbol Min % Max % Role in Alloy
Nickel Ni 38.0 46.0 Chloride-SCC resistance; reducing-acid resistance
Iron Fe 22.0 balance Base element
Chromium Cr 19.5 23.5 Oxidising-media resistance; passive film
Molybdenum Mo 2.5 3.5 Pitting/crevice + reducing-acid resistance
Copper Cu 1.5 3.0 Sulphuric/phosphoric-acid resistance
Titanium Ti 0.6 1.2 Stabiliser against sensitisation
Carbon C 0.05 Low; minimises sensitisation
Manganese Mn 1.0 Deoxidiser
Aluminium Al 0.2 Residual
Silicon Si 0.5 Deoxidiser
Sulphur S 0.03 Residual impurity

3. Mechanical Properties

Typical room-temperature properties, annealed condition.

Property Value Source
Ultimate tensile strength 662 MPa (96 ksi) Special Metals / mill-annealed plate
0.2% proof strength (yield) 338 MPa (49 ksi) Special Metals / mill-annealed plate
Elongation at break ≥45 % Special Metals
Hardness 135–165 HRB Special Metals

The alloy retains strength and toughness at cryogenic temperatures and can be substantially strengthened by cold work. It is not age-hardenable. Values are typical; confirm against the mill test certificate for each delivery.

4. Corrosion Resistance

Environment Performance Notes
Sulphuric acid Outstanding Ni + Mo + Cu give resistance across a wide concentration range
Phosphoric acid Outstanding Suitable for evaporators and process duty
Chloride stress-corrosion cracking Outstanding High Ni content
Pitting and crevice corrosion Very Good Molybdenum addition
Nitric acid / oxidising media Very Good Chromium content
Intergranular corrosion Excellent Ti-stabilised; resists sensitisation after welding
Sour service (H₂S) Good NACE MR0175 / ISO 15156 type 4c
Seawater Very Good Used for propeller shafts and marine hardware

5. Heat Treatment

A solid-solution, titanium-stabilised alloy; not age-hardenable. Heat treatment is for annealing / stabilisation only.

Anneal / Stabilise Anneal Temperature: ~940 °C (1725 °F) Purpose: softening, recrystallisation, and (with the titanium addition) stabilisation against intergranular sensitisation.

Service caution: exposure above ~540 °C can cause phase formation that lowers ductility and impact strength; the alloy is normally limited to ~540 °C in service.

6. Weldability and Joining

Good weldability by all conventional processes. Welds should be made in the annealed condition; the titanium stabilisation helps resist weld-zone sensitisation.

Welding Process Applicability Filler / Consumable
GTAW / GMAW Excellent AWS A5.14 ERNiFeCr-1 (Filler Metal 65)
SMAW / stick Good Welding Electrode 135
Higher-alloy / dissimilar joints INCO-WELD 686CPT (AWS ERNiCrMo-14) for higher-alloy joints

Clean, oxide-free joint preparation is essential for sound welds.

7. Machinability and Fabrication

Machining Guidelines

Parameter Recommendation
Work hardening Moderate (austenitic behaviour)
Tooling Rigid setup, sharp tools
Coolant Flood coolant recommended
Preferred condition Annealed

Forming Processes

Process Notes
Hot forming Standard hot-working practice for Ni-Fe-Cr alloys
Cold forming Readily formed (austenitic-stainless practice); strengthens by cold work
Annealing ~940 °C after heavy cold work

8. Applications

Industry Typical Components Key Requirements
Chemical processing Phosphoric-acid evaporators, vessels, piping Sulphuric/phosphoric-acid resistance
Oil and gas Sour-well downhole tubulars, packers, subsurface equipment H₂S resistance (NACE MR0175 type 4c)
Pickling / metal finishing Pickling tanks and equipment Acid resistance
Nuclear Spent-fuel reprocessing equipment Broad corrosion resistance
Marine Propeller shafts, seawater piping, exhaust systems Chloride-SCC + seawater resistance
Pollution control Flue-gas (sulphur-bearing) handling, waste processing Mixed acid + oxidising resistance

9. Available Product Forms and Standards (ASTM / ASME System)

Product Form ASTM Standard ASME Code
Rod, bar and wire ASTM B425 ASME SB-425
Forgings ASTM B564 ASME SB-564
Plate, sheet and strip ASTM B424 / B906 ASME SB-424 / SB-906
Seamless pipe and tube ASTM B163 / B423 / B829 ASME SB-163 / SB-423
Welded pipe / tube ASTM B704 / B705 / B751 / B775 ASME SB-704 / SB-705
Fittings ASTM B366 ASME SB-366
Welding consumables AWS A5.14 ERNiFeCr-1 (Filler 65) · Electrode 135

Listed in NACE MR0175 / ISO 15156 (type 4c) for sour service; ASME Code Cases 1936 / N-572.

10. Comparison with Related Alloys (UNS System)

UNS Ni % Cr % Other Best Used For
N08825 38–46 19.5–23.5 Mo 2.5–3.5, Cu 1.5–3 Sulphuric/phosphoric acid; sour service; seawater
N08800 30–35 19–23 Al+Ti Heat resistance; less aqueous-acid resistance
N08020 32–38 19–21 Cu 3–4, Nb Sulphuric acid; lower-cost Fe-base
N08028 30–32 26–28 Mo 3.5 Phosphoric/sulphuric acid; higher Cr
N06625 ≥58 20–23 Mo 8–10, Nb Seawater + higher strength; broader corrosion

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