Hangbo Alloy Group
Shanghai · Est. 2012
N10004 technical guide: nominal chemical composition, mechanical and physical properties, corrosion resistance, welding, product forms and ASTM standards...
Hastelloy W (UNS N10004) is a nickel-molybdenum-chromium alloy. Ni-Mo-Cr for HF / mixed-acid service. More oxidising tolerance than Hastelloy B. This guide covers its nominal chemical composition, typical mechanical and physical properties, corrosion behaviour, welding, common applications, available product forms and the ASTM standards that apply — everything a specifier needs to evaluate Hastelloy W for a project.
Hastelloy W belongs to the nickel-molybdenum-chromium alloy class of materials. It is ni-mo-cr for hf / mixed-acid service. It is more oxidising tolerance than hastelloy b. It is predecessor grade (b-2/b-3 preferred for new).
Nominal (wt%) composition of Hastelloy W (UNS N10004):
| Element | Composition (wt%) |
|---|---|
| Nickel (Ni) | Balance |
| Molybdenum (Mo) | 23.0 – 27.0 |
| Chromium (Cr) | 4.0 – 6.0 |
| Iron (Fe) | 4.0 – 7.0 |
| Cobalt (Co) | ≤ 2.5 |
| Carbon (C) | ≤ 0.12 |
| Manganese (Mn) | ≤ 1.0 |
| Silicon (Si) | ≤ 1.0 |
| Phosphorus (P) | ≤ 0.040 |
| Sulphur (S) | ≤ 0.030 |
Typical physical properties:
| Property | Value |
|---|---|
| Density | 9.30 g/cm³ |
| Melting Range | 1320 – 1380 °C |
| Thermal Expansion (20–1000 °C) | 11.5 µm/m·K |
| Thermal Conductivity (100 °C) | 12.0 W/m·K |
| Electrical Resistivity | 1.30 µΩ·m |
| Modulus of Elasticity | 211 GPa |
Typical room-temperature mechanical properties (annealed / specified condition unless noted):
| Property | Typical Value |
|---|---|
| Tensile Strength (Rm) | 760 MPa (110 ksi) |
| Yield Strength, 0.2% (Rp0.2) | 345 MPa (50 ksi) |
| Elongation in 50 mm | 40% |
| Hardness (Rockwell B) | 85 – 100 HRB |
| Property | Value |
|---|---|
| Service temperature | Up to ≈ 650 °C (non-oxidising) |
| Service note | Resists HF and HCl mixtures |
Hastelloy W is a nickel-molybdenum-chromium alloy developed for hydrofluoric acid and mixed acid services. The 4–6 % chromium gives it a little more tolerance to mild oxidising conditions than Hastelloy B while keeping strong resistance to non-oxidising acids including HF and HCl.
Welded with matching fillers under a qualified procedure; the chromium is low so avoid strongly oxidising service. Modern equivalents (B-2/B-3) are generally preferred for new builds.
The grade is supplied to the following common specifications:
| Standard | Product Form / Scope |
|---|---|
| ASTM B333 | Plate, sheet & strip |
| ASTM B335 | Bar |
| ASTM B619/B622 | Pipe/tube |
| ASTM B366 | Fittings |
Hastelloy W (UNS N10004) is a nickel-molybdenum-chromium alloy developed for hydrofluoric acid and mixed-acid services. The 4–6 % chromium gives a little more tolerance to mild oxidising conditions than Hastelloy B, while keeping strong resistance to non-oxidising acids like HF and HCl.
Annealed: ≈ 760 MPa tensile, ≈ 345 MPa yield, 40 % elongation, 85–100 HRB.
W adds 4–6 % chromium, giving more tolerance to mildly oxidising conditions, whereas plain B is purer Ni-Mo for strictly non-oxidising HCl. Both are largely superseded by B-2/B-3.
Yes, with matching fillers under a qualified procedure; keep it out of strongly oxidising service. New builds usually specify B-2 or B-3.
HF alkylation units, mixed HCl/HF and non-oxidising acid equipment, acid-plant heat exchangers and reactors.
Plate/sheet/strip ASTM B333, bar ASTM B335, pipe/tube ASTM B619/B622, fittings ASTM B366.
As a dedicated nickel alloy manufacturer serving chemical processing, oil & gas sectors, Hangbo Alloy Group supplies the grades discussed here across all standard product forms with full ASTM/ASME documentation and EN 10204 3.1 certification. Our material is specified for applications where corrosion resistance, high-temperature strength, and traceable quality are non-negotiable. See our production & testing facilities for more on how every heat is verified.