Hastelloy B-3 · UNS N10675 · W. Nr. 2.4600 · NiMo29Cr · Alloy B-3
Hastelloy B-3 (N10675): composition, properties, fittings and flanges
Hastelloy B-3 (UNS N10675, W. Nr. 2.4600) is the improved successor to B-2, with 27.0-32.0 % molybdenum and nickel balance. It delivers the ultimate resistance to hydrochloric acid at any concentration and temperature up to the atmospheric boiling point, plus good resistance to sulphuric, acetic and phosphoric acids and to…
- UNS
- N10675
- W. Nr.
- 2.4600
- Density
- 9.22 g/cm³ (0.333 lb/in³)
- Key strength
- 760 MPa / 110 ksi
Identification and standards
| Short form | Hastelloy B-3 · UNS N10675 · W. Nr. 2.4600 · NiMo29Cr · Alloy B-3 |
|---|---|
| Classification | Nickel-molybdenum alloy for non-oxidising acid service |
| UNS | N10675 |
| Werkstoff number | 2.4600 |
| Material family | Hastelloy Alloys |
Chemical composition
| Element | Composition (wt %) | Why it is there |
|---|---|---|
| Nickel (Ni) | 65.0 min | Matrix |
| Molybdenum (Mo) | 27.0 - 32.0 | Resistance to non-oxidising acids |
| Chromium (Cr) | 1.0 - 3.0 | Controlled to suppress harmful phase formation |
| Iron (Fe) | 1.0 - 3.0 | - |
| Manganese (Mn) | 3.00 max | - |
| Tungsten (W) | 3.0 max | - |
| Cobalt (Co) | 3.00 max | - |
| Aluminium (Al) | 0.50 max | - |
| Copper (Cu) | 0.20 max | - |
| Niobium (Nb) | 0.20 max | - |
| Tantalum (Ta) | 0.20 max | - |
| Titanium (Ti) | 0.20 max | - |
| Vanadium (V) | 0.20 max | - |
| Zirconium (Zr) | 0.10 max | - |
| Silicon (Si) | 0.10 max | - |
| Carbon (C) | 0.01 max | - |
| Phosphorus (P) | 0.030 max | - |
| Sulphur (S) | 0.010 max | - |
Note Single figures are maximum limits unless shown as a range. Always confirm against the heat-specific EN 10204 3.1 certificate supplied with your order.
Mechanical properties
| Tensile strength, min (annealed, ASTM B333) | 760 MPa / 110 ksi |
|---|---|
| 0.2 % yield strength, min | 350 MPa / 51 ksi |
| Elongation in 2 in, min | 40 % |
| Typical hardness, annealed | 190 - 230 HB |
| Typical Charpy V impact energy at room temperature | Above 120 J |
| Recommended maximum service temperature | About 400 °C in reducing environments |
Warning Values depend on product form, section thickness and heat treatment. Larger sections generally achieve lower strength than thin product; always design against the applicable code allowable stress rather than these figures.
Physical properties
| Density | 9.22 g/cm³ (0.333 lb/in³) |
|---|---|
| Melting range | 1370 - 1418 °C (2500 - 2585 °F) |
| Modulus of elasticity | 216 GPa (31.4 x 10⁶ psi) |
| Thermal conductivity at 20 °C | 11.2 W/m·K |
| Mean coefficient of thermal expansion, 20-100 °C | 10.6 µm/m·°C |
| Electrical resistivity at 20 °C | 1.35 µΩ·m |
Specifications by product form
| Plate / sheet / strip | ASTM B333 / ASME SB-333 |
|---|---|
| Bar / rod / wire | ASTM B335 / ASME SB-335 |
| Seamless pipe & tube | ASTM B622 / ASME SB-622 |
| Welded pipe & tube | ASTM B619 / B626 |
| Forgings & flanges | ASTM B564 / ASME SB-564 (UNS N10675) |
| Butt weld fittings | ASTM B366 / ASME SB-366 (WPB3 / WPHB3) |
| Welding consumables | ERNiMo-10 wire, ENiMo-10 electrode |
| UNS / EN / China | UNS N10675 · EN NiMo29Cr · W. Nr. 2.4600 |
Product forms available
Hangbo supplies this grade in the following forms. Sizes outside the listed range can often be produced to order.
- Seamless pipe and tube for acid transfer lines
- Forged flanges to ASME B16.5
- Butt weld elbows and tees to ASME B16.9
- Machined agitators, baffles and heat exchanger parts
Typical applications
- Hydrochloric acid production, storage and recovery systems
- Acetic acid and acetic anhydride plants using the methanol carbonylation route
- Linear alkyl benzene and alkylate processes catalysed by HF
- Sulphuric acid alkylation and organic chloride reactions
- Pharmaceutical intermediate reactors requiring non-oxidising acid containment
- Pickling facilities where free HCl concentration is high
Welding, forming and machining
- Welding
- Weld with ERNiMo-10 filler using low heat input and interpass temperature below 100 °C. Avoid preheating; rapid cooling after solution annealing is essential to prevent ordered Ni2Mo4C formation.
- Hot forming
- Solution anneal at 1065-1100 °C and quench rapidly in water. Hot work should be completed above 980 °C because the alloy loses ductility below about 900 °C.
- Machining
- Higher strength than austenitic stainless steel. Use carbide tooling, positive rake, low cutting speeds and flood coolant.
- Service warning
- Never use B-3 where oxidising contaminants such as ferric chloride, cupric chloride, dissolved oxygen or nitric acid are present - corrosion rates rise dramatically. Specify C-22 or C-276 instead.
Buy Hastelloy B-3 from Hangbo
Material is supplied with full heat-number traceability, solution annealing or ageing performed under calibrated furnace control, and an EN 10204 3.1 certificate covering chemical analysis, mechanical properties, heat treatment records and the agreed NDT scope. Positive material identification and third party inspection and test reports from SGS are available for critical service.