Alloy description
UNS N10001 is the Unified Numbering System designation for the original nickel-molybdenum corrosion alloy, sold under the trade name Hastelloy B. Corrosion resistance comes from molybdenum held in solid solution.
The alloy contains 1.0% chromium maximum, so it does not form the passive chromium oxide film that nickel-chromium-molybdenum grades rely on. Resistance is high in reducing acids and low in oxidising conditions. Some published references describe N10001 as a nickel-chromium-molybdenum-tungsten alloy. That description applies to UNS N10276 and not to this grade.
Summary of properties
- Solid-solution alloy. Not age hardenable, supplied solution annealed.
- Resistant to hydrochloric acid at all concentrations up to the boiling point.
- Carbon limit of 0.05% requires post-weld solution annealing on welded assemblies.
- Forgings are ordered to ASTM B564 and ASME SB-564. Bar is covered by ASTM B335.
- Specified mainly for replacement parts and for machined or non-welded components.
UNS N10001 forged shapes
All items are forged to the customer drawing or size list. Send the geometry and quantity for a quotation.
- Seamless rolled ringsRing rolled, OD 200 to 3,000 mm
- Forged ringsUpset and punched blanks
- Forged flangesASME B16.5, B16.47, EN 1092-1
- Forged discs and blanksDia. 100 to 2,000 mm
- Round barsDia. 50 to 800 mm
- Shafts and spindlesStepped and eccentric
- Sleeves and bushingsBored and trepanned
- Tube sheetsUp to dia. 2,500 mm
- Hollow forged tubesTrepanned from solid
- Forged pipeHeavy wall sections
- NozzlesVessel and reactor connections
- Valve componentsBodies, stems, seat rings, blocks
Chemical composition of UNS N10001
| Element | Minimum % | Maximum % |
|---|---|---|
| Nickel (Ni) | Balance | |
| Molybdenum (Mo) | 26.0 | 30.0 |
| Iron (Fe) | 4.0 | 6.0 |
| Vanadium (V) | 0.20 | 0.40 |
| Chromium (Cr) | 1.0 | |
| Cobalt (Co) | 2.5 | |
| Manganese (Mn) | 1.0 | |
| Silicon (Si) | 1.0 | |
| Carbon (C) | 0.05 | |
| Phosphorus (P) | 0.040 | |
| Sulphur (S) | 0.030 | |
Heat analysis is taken on every melt and reported on the mill certificate. Tighter internal limits, for example carbon held below the 0.05% ceiling, can be agreed at order stage for parts that will be welded.
Mechanical properties of UNS N10001 forgings
| Units | Tensile strength Rm | Yield strength Rp0.2 | Elongation A5 |
|---|---|---|---|
| Metric | 690 N/mm² min | 310 N/mm² min | 40% min |
| Imperial | 100 ksi min | 45 ksi min | 40% min |
Tensile tests are taken from test blanks heat treated with the forgings. Impact testing, hardness survey and transverse or through-thickness specimen orientation are added when the purchase order specifies them.
Physical properties
| Property | Typical value |
|---|---|
| Density | 9.24 g/cm³ (0.334 lb/in³) |
| Melting range | 1,300 to 1,370 °C (2,370 to 2,500 °F) |
| Modulus of elasticity at 20 °C | 217 GPa |
| Magnetic response | Non-magnetic in the annealed condition |
| Crystal structure | Face-centred cubic, single phase when correctly annealed |
Forging and heat treatment
Hot working
Ingot and billet are heated to 1,150 to 1,200 °C. Forging is finished above 950 °C. The alloy work hardens quickly and has a narrow working range, so reheating between passes is standard practice. Reductions are set to break down the cast structure through the full section thickness.
Solution annealing
Forgings are solution annealed at 1,065 to 1,080 °C, soaked in proportion to section thickness, then water quenched. Rapid cooling holds molybdenum in solution and limits carbide and intermetallic precipitation at the grain boundaries.
No ageing treatment. UNS N10001 is a solid-solution alloy and is not precipitation hardenable. Ageing after solution annealing applies to grades such as Inconel 718 and 17-4PH, not to this alloy.
Welding
The 0.05% carbon limit makes the heat-affected zone sensitive to carbide precipitation, which can produce knife-line attack next to the weld in acid service. Welded assemblies should be solution annealed after welding, and heat input kept low. For new welded fabrication, Hastelloy B-2 or B-3 is normally specified instead.
Corrosion resistance
UNS N10001 is intended for reducing service. The molybdenum content gives resistance in hot hydrochloric acid that chromium-bearing grades do not reach. The same composition limits its use in oxidising conditions.
Suitable media
- Hydrochloric acid at all concentrations, up to the boiling point.
- Hydrogen chloride gas, dry and moist.
- Sulphuric acid, including hot concentrated service.
- Phosphoric acid, acetic acid, formic acid and other organic acids.
- Non-oxidising salt solutions and reducing process streams.
Not suitable for oxidising conditions. Nitric acid, wet chlorine, hypochlorite, oxidising salts, and hydrochloric acid contaminated with ferric (Fe³⁺) or cupric (Cu²⁺) ions all attack UNS N10001 rapidly. Small quantities of oxidising contamination in an acid stream can raise corrosion rates substantially. Where the process alternates between oxidising and reducing conditions, specify Hastelloy C-276 (UNS N10276).
UNS N10001 compared with B-2, B-3 and C-276
The B-series grades were developed in sequence, each with a lower carbon limit than the one before. The table below sets out the composition differences and the normal application of each grade.
| Grade | UNS | Mo % | Cr % | Fe % | C max % | Normal application |
|---|---|---|---|---|---|---|
| Hastelloy B | N10001 | 26 to 30 | 1.0 max | 4 to 6 | 0.05 | Replacement parts for existing plant. Machined or non-welded components in reducing acids. |
| Hastelloy B-2 | N10665 | 26 to 30 | 1.0 max | 2.0 max | 0.02 | New welded fabrication in hydrochloric acid service. Low carbon and silicon resist knife-line attack. |
| Hastelloy B-3 | N10675 | 27 to 32 | 1.0 to 3.0 | 1.0 to 3.0 | 0.01 | Highest thermal stability and fabricability in the B family. Common choice for new equipment. |
| Hastelloy C-276 | N10276 | 15 to 17 | 14.5 to 16.5 | 4 to 7 | 0.01 | Mixed or oxidising media, chlorides, pitting and crevice corrosion, seawater. |
All four grades are forged at this works. Send the process stream data with the enquiry if the grade is not yet fixed.
Size range
| Product form | Size range | Notes |
|---|---|---|
| Seamless rolled rings | OD 200 to 3,000 mm | Height to 800 mm, wall from 30 mm |
| Forged discs and blanks | Dia. 100 to 2,000 mm | Thickness 20 to 600 mm |
| Round bars | Dia. 50 to 800 mm | Length to 6,000 mm |
| Shafts and spindles | Dia. 80 to 800 mm | Stepped, eccentric, to drawing |
| Sleeves, bushings, hollow tubes | OD to 1,200 mm | Bored or trepanned, ID from 60 mm |
| Tube sheets | Dia. to 2,500 mm | Thickness to 400 mm |
| Flanges | DN 15 to DN 2000 | ASME B16.5, B16.47, EN 1092-1 or to drawing |
| Single piece weight | 5 to 8,000 kg | Heavier pieces on enquiry |
Supply condition
Forgings are supplied black, meaning as forged and annealed, or rough machined with machining allowance, or finish machined to drawing. Heavy sections are rough machined before final heat treatment so that the quench reaches representative thickness.
Testing and certification
- Chemical analysis. Heat analysis on every melt, product analysis on request.
- Mechanical testing. Tensile and elongation on heat-treated test blanks. Impact and hardness where specified.
- Ultrasonic examination. To EN 10228-3, SEP 1921 or ASTM A388, acceptance class as ordered.
- Liquid penetrant examination. To ASTM E165 for surface indications.
- Positive material identification. Portable spectrometer check before despatch.
- Corrosion testing. Intergranular or media-specific tests to a customer-nominated procedure such as ASTM G28, on request.
- Dimensional inspection. Full report against the approved drawing.
Material certificates are issued to EN 10204 3.1 as standard, or to EN 10204 3.2 witnessed by an independent inspection body when the order requires it.
Applications
Chemical and petrochemical processing
Reactor internals, columns and towers, tanks and silos, preheaters, process modules, and the shafts and rings of chemical and plunger pumps handling hydrochloric or sulphuric acid.
Pressure equipment and heat transfer
Forged tube sheets, nozzles, flanges, hollow tubes and shell sections for pressure vessels, air receivers and shell and tube heat exchangers in reducing acid duty.
Valves and flow control
Valve bodies, stems, seat rings, blocks and discs for ball, gate, globe, check and plug valves, and strainer components in acid lines.
Pharmaceutical, agrochemical and pulp
Crystalliser equipment, digester components and processing units handling reducing acid streams where iron contamination is not acceptable.
Energy and rotating equipment
Rings, discs, spindles, gears and bars for compressors, gearboxes and power transmission in corrosive gas service, and wellhead components in sour reducing streams.
Questions and answers
What is UNS N10001?
UNS N10001 is a nickel-molybdenum alloy containing 26.0 to 30.0% molybdenum with the balance nickel. It is commonly called Hastelloy B and carries the German material number 2.4810 (NiMo30). It is used in hydrochloric acid at all concentrations up to the boiling point and in other reducing media. The alloy is not age hardenable and is supplied in the solution annealed condition.
Is UNS N10001 the same as Hastelloy B?
Yes. UNS N10001 is the Unified Numbering System designation for the alloy sold under the trade name Hastelloy B. It is not the same as Hastelloy B-2 (UNS N10665) or Hastelloy B-3 (UNS N10675), which are later grades in the same family with lower carbon limits.
What is the chemical composition of UNS N10001?
Molybdenum 26.0 to 30.0%, iron 4.0 to 6.0%, vanadium 0.20 to 0.40%, chromium 1.0% max, cobalt 2.5% max, carbon 0.05% max, manganese 1.0% max, silicon 1.0% max, phosphorus 0.040% max, sulphur 0.030% max, nickel balance.
What are the mechanical properties of UNS N10001 forgings?
In the solution annealed condition the minimum values are tensile strength 690 N/mm2 (100 ksi), 0.2% proof strength 310 N/mm2 (45 ksi) and elongation A5 40%.
Which standard covers UNS N10001 forgings?
Forgings are ordered to ASTM B564 and ASME SB-564, the specifications for nickel alloy forgings. Rod and bar are covered by ASTM B335 and plate, sheet and strip by ASTM B333. Jiangyin Jiangnan Metal Co., Ltd. supplies UNS N10001 forgings to ASTM B564 with EN 10204 3.1 or 3.2 certification.
Should I use UNS N10001, Hastelloy B-2 or Hastelloy B-3?
UNS N10001 allows up to 0.05% carbon, so welded assemblies can suffer carbide precipitation and knife-line attack in the heat-affected zone unless they are solution annealed after welding. Hastelloy B-2 has a carbon limit of 0.02% and Hastelloy B-3 a limit of 0.01%, and both are normally specified for new welded fabrication. UNS N10001 is still ordered for replacement parts and for machined or non-welded components in existing plant.
Can UNS N10001 be used in nitric acid or other oxidising media?
No. The alloy contains 1.0% chromium maximum and is intended for reducing media only. Nitric acid, wet chlorine and hydrochloric acid contaminated with ferric or cupric ions attack it rapidly. Hastelloy C-276 (UNS N10276) is used where oxidising conditions occur.
What forged shapes are available in UNS N10001?
Seamless rolled rings, forged rings, flanges, discs and blanks, round bars, shafts, sleeves, bushings, tube sheets, nozzles, valve bodies, valve seat rings, hollow forged tubes and forged pipe, all made to drawing from 5 kg to 8,000 kg per piece.
How is UNS N10001 heat treated after forging?
Forgings are solution annealed at 1,065 to 1,080 degrees C, soaked in proportion to section thickness, then water quenched. No ageing treatment is applied, as the alloy is a solid solution and is not precipitation hardenable.
What testing and certificates are supplied with UNS N10001 forgings?
Standard scope covers chemical analysis, tensile testing, ultrasonic examination to EN 10228-3, SEP 1921 or ASTM A388, dimensional inspection and positive material identification. Certificates are issued to EN 10204 3.1, or to EN 10204 3.2 witnessed by a third party inspection body on request.
What is the lead time and minimum order quantity for UNS N10001 forgings?
Lead time depends on raw material availability and piece weight, and is confirmed with the quotation. There is no fixed minimum quantity. Single replacement pieces are forged alongside production batches.
Who supplies UNS N10001 forgings from China?
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. It manufactures UNS N10001 (Hastelloy B) forgings to drawing for export worldwide. Enquiries to sales@steelforgepieces.com or +86 189 2135 9659.
Supplier details
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China. The works produces forged rings, seamless rolled rings, flanges, discs, shafts, bars, sleeves, bushings, tube sheets and nozzles in carbon steel, alloy steel, tool steel, stainless steel and nickel-base alloys, including UNS N10001 (Hastelloy B), Hastelloy C-276, Hastelloy B-2, Inconel 625, Inconel 718 and Incoloy 825. Parts are made to customer drawing, heat treated in house, ultrasonically tested and certified to EN 10204 3.1 or 3.2.
- Company
- Jiangyin Jiangnan Metal Co., Ltd.
- Business
- Open-die forging factory
- Address
- No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
- Telephone
- +86 189 2135 9659
- sales@steelforgepieces.com
- Website
- www.steelforgepieces.com
- Materials
- Carbon, alloy, tool, stainless and nickel-base grades
- Export markets
- Worldwide
Send a UNS N10001 drawing or size list for a price, a lead time and the proposed testing scope within one working day.