Nickel alloy · W.Nr. 2.4600 · UNS N10675 · DIN 17744
NiMo29Cr Forgings
Seamless rolled rings, flanges, round bars, discs, shafts, sleeves, bushings and tube sheets, open-die forged in nickel-molybdenum alloy NiMo29Cr to DIN 17744 and ASTM B564 / ASME SB-564.
NiMo29Cr (W.Nr. 2.4600, UNS N10675) is a wrought nickel-molybdenum alloy containing 27–32% molybdenum with nickel as the balance, plus deliberate small additions of chromium and iron. Like the rest of the B family it does not rely on a passive oxide film, so it holds up in hot concentrated hydrochloric acid where stainless steels and even nickel-chromium-molybdenum grades will not. What separates it from the older Alloy B-2 is metallurgical stability. The chromium, the controlled iron and the very low carbon and silicon together suppress the ordering reaction that embrittles B-2 around 600–800 °C. In practice that means NiMo29Cr can be welded and thermally cycled where B-2 cannot.
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. It forges NiMo29Cr to customer drawings: rings, flanges, bars, discs, shafts, sleeves, bushings and tube sheets. Parts are supplied solution annealed and rapidly quenched, ultrasonically tested and certified to EN 10204 3.1 or 3.2. For a quotation, contact sales@steelforgepieces.com or +86 189 2135 9659.
NiMo29Cr at a glance
- Grade
- NiMo29Cr (also written NiMo 29 Cr, NiMo30Cr)
- UNS number
N10675- Werkstoff / DIN
2.4600· DIN 17744- Generic name
- Alloy B-3
- VdTÜV
- Werkstoffblatt 517
- Alloy family
- Nickel-molybdenum, solid solution, non age-hardenable
- Nominal composition
- Ni 65 min · Mo 27–32% · Cr 1–3% · Fe 1–3%
- Forging standard
- ASTM B564 / ASME SB-564
- Flanges & valve parts
- ASTM B462 / ASME SB-462
- Bar standard
- ASTM B335
- Delivery condition
- Solution annealed ≈1,065 °C, rapid water quenched
- Density
- 9.22 g/cm³ (0.333 lb/in³)
- Melting range
- ≈1,370–1,418 °C (2,498–2,584 °F)
- Designed for
- HCl at all concentrations to boiling; reducing acids
- Never use in
- Nitric acid, Fe³⁺/Cu²⁺ salts, wet chlorine, hypochlorite
- Welding filler
ERNiMo-10/ENiMo-10- Certification
- EN 10204 3.1 or 3.2 (third-party witnessed)
- Forged by
- Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China
What NiMo29Cr is, and when to specify it
Most corrosion-resistant alloys work by growing a thin chromium-oxide film and then keeping it intact. The nickel-molybdenum B family works on a different principle. Its corrosion resistance comes from the intrinsic nobility of the nickel-molybdenum system, not from a passive layer, so there is no film to break down in the first place. That accounts for both halves of its reputation: it survives hot, concentrated, air-free hydrochloric acid, and it fails quickly in anything oxidising.
NiMo29Cr carries 1–3% chromium. That is enough to shift its behaviour, not enough to change the rule: it remains a reducing-service material. So the question to settle before specifying it is rarely the acid named on the datasheet. It is what else the stream is carrying. Dissolved oxygen, ferric ions picked up from upstream carbon-steel pipework, or a leaking cooler will each do more damage than the acid itself.
Where NiMo29Cr differs from its predecessor is in what happens to the metal, not the medium. Alloy B-2 forms an ordered Ni4Mo (β) phase when it sits around 600–800 °C, which costs ductility and leaves weld heat-affected zones open to preferential attack. NiMo29Cr was developed to suppress that reaction, using the chromium and iron additions together with carbon held to 0.010% and silicon to 0.10%. Acid resistance came out essentially unchanged. What changed is that the alloy can now be welded, cycled and forged in heavy section without the same anxiety.
Write UNS N10675 plus the product standard on the purchase order (for forgings: ASTM B564; for flanges and valve parts: ASTM B462). The DIN name NiMo29Cr and the Werkstoff number 2.4600 identify the same material, but the UNS number plus a product standard is the least ambiguous form. As the next section explains, 2.4600 on its own is not unambiguous at all.
Why 2.4600 alone is not enough on a purchase order
This trips up more enquiries than any other point on the grade. The Werkstoff number 2.4600 is used commercially for two different UNS grades:
- Alloy B-3, UNS N10675. The grade this page describes, and the mapping given in the Haynes and VdTÜV documentation for NiMo29Cr.
- Alloy B-4, UNS N10629. A separate stabilised nickel-molybdenum grade that several suppliers also list and certify under 2.4600.
Neither is wrong. The DIN 17744 composition band for NiMo29Cr is wide enough that both UNS grades can fall inside it, so a certificate reading “2.4600” does not by itself tell you which alloy arrived. The two are close in service but not identical, and if a design registration, a code case or a corrosion history is involved, the difference matters.
State the UNS number: UNS N10675 for Alloy B-3, or UNS N10629 for Alloy B-4, alongside the product standard. Jiangyin Jiangnan Metal Co., Ltd. forges both and certifies to whichever designation the purchase order names. If the drawing only says 2.4600, tell us which UNS grade the original equipment used and it will be matched.
Chemical composition of NiMo29Cr (UNS N10675)
The table below is the specification range Jiangyin Jiangnan Metal forges to. Every heat is supplied with a ladle analysis on the mill certificate; product analysis on the finished forging can be added on request. The four highlighted rows are the deliberate choices that separate this grade from Alloy B-2.
| Element | Minimum % | Maximum % | Role in the alloy |
|---|---|---|---|
| Molybdenum (Mo) | 27.0 | 32.0 | The active element. Delivers resistance to hydrochloric and other reducing acids |
| Nickel (Ni) | 65.0 min (balance) | Base element. Provides the nobility the alloy relies on instead of a passive film | |
| Chromium (Cr) | 1.0 | 3.0 | Deliberate addition. Contributes to the thermal stability that Alloy B-2 lacks |
| Iron (Fe) | 1.0 | 3.0 | Controlled to a band rather than capped as a residual |
| Cobalt (Co) | — | 3.0 | Residual limit; also controlled for nuclear service |
| Manganese (Mn) | — | 3.0 | Deoxidiser; combines with sulfur |
| Tungsten (W) | — | 3.0 | Residual limit |
| Aluminium (Al) | — | 0.50 | Deoxidiser |
| Copper (Cu) | — | 0.20 | Residual limit |
| Niobium (Nb) | — | 0.20 | Residual limit |
| Tantalum (Ta) | — | 0.20 | Residual limit |
| Titanium (Ti) | — | 0.20 | Residual limit |
| Vanadium (V) | — | 0.20 | Residual limit |
| Zirconium (Zr) | — | 0.10 | Residual limit |
| Silicon (Si) | — | 0.10 | Kept very low. High silicon promotes the embrittling phases this grade exists to avoid |
| Carbon (C) | — | 0.010 | Half the Alloy B-2 limit. Prevents grain-boundary carbide precipitation during welding |
| Phosphorus (P) | — | 0.030 | Residual limit |
| Sulfur (S) | — | 0.010 | Kept low for hot workability |
Source: Jiangyin Jiangnan Metal Co., Ltd., NiMo29Cr forging specification, compiled from DIN 17744 and published UNS N10675 limits. On an incoming certificate, check the carbon ceiling of 0.010% first. It is the clearest single indicator that the material is genuinely N10675 and not a B-2 heat sold against a 2.4600 marking.
Mechanical properties of NiMo29Cr forgings
Specification minima and typical values, solution annealed
Two sets of numbers matter on a forging order, and buyers confuse them regularly. Specification minima are what the material must achieve to be certified. Typical values are what a well-processed forging actually tests at. But heavy sections cool more slowly at the core, so they normally land nearer the minimum than the typical figure suggests.
| Property | ASTM B564 min. | DIN 17750 min. | Typical |
|---|---|---|---|
| Tensile strength, Rm | 760 MPa (110,000 psi) | 750 MPa | 860–880 MPa |
| Yield strength, Rp0.2 | 350 MPa (51,000 psi) | 340 MPa | 420–440 MPa |
| Elongation at break, in 50.8 mm (2 in) | 40 % | 40 % | 50–55 % |
| Hardness, Brinell | — | 240 HBW max | ≈200 HBW |
Typical values are for design screening only. The mill test certificate issued with each forging governs acceptance. Where your specification is stricter than the product standard, state the acceptance minima and the test-piece location on the purchase order and they will be certified. For heavy sections, agree the test-piece position before production rather than after.
Physical properties
| Property | Metric | Imperial |
|---|---|---|
| Density | 9.22 g/cm³ | 0.333 lb/in³ |
| Melting range | ≈1,370–1,418 °C | ≈2,498–2,584 °F |
| Modulus of elasticity | ≈216 GPa | ≈31.3 × 10⁶ psi |
| Mean expansion, 20–100 °C | ≈10.6 µm/m·K | ≈5.9 × 10⁻⁶ in/in·°F |
| Electrical resistivity | ≈1.37 µΩ·m | ≈824 Ω·circ mil/ft |
| Thermal diffusivity | ≈3.0 × 10⁻⁶ m²/s | — |
| Magnetic response | Essentially non-magnetic in the annealed condition | |
Two of these figures affect commercial decisions rather than design. At 9.22 g/cm³ NiMo29Cr is roughly 17% denser than carbon steel, so a weight estimated from a steel drawing understates the alloy weight, and the price, by about the same margin. The melting range also sits some 40 °C above Alloy B-2. That is one reason the two grades cannot simply swap places in a forge shop schedule.
Corrosion behaviour: what NiMo29Cr resists, and what destroys it
NiMo29Cr is superb in one half of the chemical world and poor in the other. The dividing line is oxidising potential, not acid strength, which is where most wrong specifications start. And the chromium addition does not move that line: it improves thermal stability, and buys no meaningful oxidising resistance.
| Resists well | Do not use in |
|---|---|
| Hydrochloric acid, all concentrations, ambient to boiling | Nitric acid and other oxidising acids, at any strength |
| Hydrobromic acid | Ferric chloride (Fe³⁺) and cupric chloride (Cu²⁺) solutions |
| Sulfuric acid over a wide concentration range, including concentrated | Wet chlorine, hypochlorite and other oxidising bleaches |
| Phosphoric, acetic and formic acids; acetic anhydride | Aerated or oxygenated acid streams |
| Hydrogen chloride gas, dry and moist | Mixed acids where the redox potential can swing oxidising |
| Fluoride-bearing media that attack zirconium alloys | Oxidising salts and nitrate-bearing streams |
| Non-oxidising chloride salts; chlorinated hydrocarbons | Sea water and aerated chloride service |
Contamination, not concentration. A few parts per million of ferric or cupric ions in hydrochloric acid will raise the corrosion rate of NiMo29Cr by orders of magnitude. They usually arrive from upstream carbon-steel pipework, a leaking cooler, or air ingress rather than from the acid supply. The chromium in this grade does not change that. If the stream cannot be kept reducing and clean, specify a nickel-chromium-molybdenum grade such as Alloy C-276, Alloy C-22 or Alloy 59, which tolerate both reducing and oxidising conditions.
Thermal stability. Alloy B-2 must be kept out of the 600–800 °C band, which constrains welding, post-weld treatment and any thermal cycling in service. NiMo29Cr is stabilised against the same ordering reaction, so a welded fabrication does not normally need a post-weld solution anneal, and a heavy forged section is not at risk from a slower core cooling rate. On a welded vessel or an exchanger that cycles, that difference usually outweighs the higher material cost.
NiMo29Cr is not indefinitely stable at temperature. It is markedly more resistant to precipitation than Alloy B-2, but it remains a nickel-molybdenum alloy, and prolonged exposure in the intermediate range will eventually produce secondary phases. For corrosion service the practical ceiling is around 400–500 °C. Above that, and where oxidation resistance is also needed, move to a nickel-chromium grade.
NiMo29Cr vs NiMo28 vs Alloy B-4: how to choose
All three are nickel-molybdenum alloys with roughly 28% Mo and comparable resistance to hydrochloric acid. They differ in thermal stability, which is another way of saying they differ in how much fabrication and thermal cycling they will tolerate before the metallurgy turns against you.
| Criterion | NiMo29Cr / Alloy B-3 | NiMo28 / Alloy B-2 | Alloy B-4 |
|---|---|---|---|
| UNS number | N10675 | N10665 | N10629 |
| DIN / Werkstoff | 2.4600 · NiMo29Cr | 2.4617 · NiMo28 | Also listed as 2.4600 by some suppliers |
| Nominal Mo | 27–32% | 27–29% | ≈28% |
| Chromium | 1–3% deliberate | 1.0% max residual | Small deliberate addition |
| Carbon limit | 0.010% max | 0.02% max | 0.010% max |
| Thermal stability | Stabilised; markedly better | β-phase ordering at 600–800 °C | Stabilised; better than B-2 |
| Weld HAZ behaviour | Tolerant of welding; post-weld anneal not normally needed | Vulnerable; post-weld anneal advised for severe duty | Tolerant of welding |
| HCl resistance | Excellent | Excellent | Excellent |
| Oxidising media | Unsuitable — the whole B family shares this limit | ||
| Relative cost | Highest of the three | Lowest | Between the two |
| Choose it when | Welded fabrications, thermal cycling, heavy sections, or HAZ attack has been seen before | Fully annealed static equipment, no thermal cycling, budget matters, or the spec names 2.4617 | European projects specifying the stabilised grade under 2.4600 |
If the part will be welded into an assembly, or the equipment cycles thermally, or the section is heavy enough that core cooling is slow, specify NiMo29Cr / N10675. If it is a solution-annealed forging going into static, fully annealed equipment and the budget is tight, NiMo28 does the same corrosion job for less money. Jiangyin Jiangnan Metal forges all three, so put both grades on the enquiry and compare the delivered price before deciding.
NiMo29Cr equivalent designations
| System | Designation |
|---|---|
| DIN / EN name (Germany) | NiMo29Cr — DIN 17744 |
| Werkstoff Nr. (Germany) | 2.4600 |
| UNS (USA) | N10675 · weld metal W80675 |
| Generic industry name | Alloy B-3 |
| VdTÜV (Germany) | Werkstoffblatt 517 |
| China (nearest) | NS3203 — confirm against the GB standard in force |
| Trade name | Hastelloy® B-3® (Haynes International) |
| Also written as | NiMo 29 Cr, NiMo30Cr, Alloy B3, B-3 alloy |
Trademark notice. Hastelloy® and B-3® are registered trademarks of Haynes International, Inc. Jiangyin Jiangnan Metal Co., Ltd. is not affiliated with, sponsored by or endorsed by the trademark holder. Those names appear here only to identify the equivalent material specification. Material we forge is correctly described as NiMo29Cr / W.Nr. 2.4600 / UNS N10675, the same generic chemistry, manufactured independently. Designations marked “nearest” are close but not identical; where a design registration or code case is involved, order to the UNS number and verify equivalence on the mill certificate.
Applicable standards by product form
| Product form | ASTM | ASME |
|---|---|---|
| Forgings (our core product) | B564 | SB-564 |
| Forged flanges, fittings and valve parts | B462 | SB-462 |
| Rod and bar | B335 | SB-335 |
| Billet | B472 | — |
| Plate, sheet and strip | B333 | SB-333 |
| Seamless pipe and tube | B622 | SB-622 |
| Welded pipe | B619 | SB-619 |
| Welded tube | B626 | SB-626 |
| Fittings | B366 | SB-366 |
| German standards | DIN 17744 (NiMo29Cr, W.Nr. 2.4600) · DIN 17750 sheet · 17751 tube · 17752 bar · 17753 wire | |
| Welding consumables | AWS A5.14 ERNiMo-10 (bare, DIN 2.4695) · AWS A5.11 ENiMo-10 (covered, DIN 2.4696) | |
| Ultrasonic testing | EN 10228-3 · SEP 1921 · ASTM A388, or customer class | |
| Intergranular corrosion | ASTM G28 or an agreed procedure | |
| Certification | EN 10204 3.1 · EN 10204 3.2 (third-party witnessed) | |
| Sour service | NACE MR0175 / ISO 15156-3 compliance certified where the application permits | |
NiMo29Cr forgings we produce
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory. Every item below is forged to the customer's drawing or dimensional sketch. There is no fixed catalogue, no tooling charge and no minimum order quantity by piece.
Size and weight capability
| Product form | Dimensional range | Unit weight |
|---|---|---|
| Seamless rolled rings | OD 200–3,000 mm, height to 800 mm | 20–8,000 kg |
| Round bars | Ø80–800 mm, length to 6,000 mm | 20–6,000 kg |
| Discs, tube sheets | Ø200–2,500 mm, thickness to 600 mm | 30–8,000 kg |
| Shafts, sleeves, blocks | To 6,000 mm long | To 8,000 kg |
Machining allowance is normally 6–20 mm per surface depending on section size, unless your drawing states otherwise. Finish-machined parts to print are also supplied. For nickel-molybdenum alloys the practical maximum is set by available ingot size rather than by press capacity, so confirm large sizes with the enquiry. Plant: 1 t, 3 t, 5 t and 9 t open-die hammers, a 5,000-tonne hydraulic press, and 3 m and 6 m seamless ring-rolling mills.
How we make NiMo29Cr forgings
- Melting. NiMo29Cr stock is melted by EAF + VOD, with ESR remelting to improve cleanliness and reduce segregation. The 0.010% carbon and 0.10% silicon ceilings are held at this stage, not corrected later. They are the reason the grade exists.
- Heat verification. Heat chemistry is checked by optical emission spectrometer against the NiMo29Cr limits, with particular attention to carbon, silicon, chromium and iron, before any material is heated.
- Open-die forging. Hot worked from approximately 1,175 °C down to 900 °C with a controlled reduction ratio, to close porosity and develop a wrought grain flow that follows the part contour. Rings are ring-rolled seamless. The workpiece is reheated rather than finished below the minimum forging temperature.
- Solution annealing. Held at approximately 1,065 °C (1,950 °F), then rapid water quenched. NiMo29Cr is not age hardened. It tolerates cooling far better than Alloy B-2, but the quench is still run fast so that heavy sections reach full corrosion performance at the core rather than only at the surface.
- Descaling and machining. Descaled and pickled, then rough or finish machined to your drawing with the agreed allowance. NiMo29Cr work-hardens quickly: rigid setups, positive rake, modest speeds and heavy positive feeds, with flood coolant.
- Non-destructive testing. Ultrasonic examination to EN 10228-3, SEP 1921, ASTM A388 or your nominated class. Liquid penetrant and dimensional inspection as required.
- Certification and despatch. EN 10204 3.1 mill certificate as standard; 3.2 with third-party witness (TÜV, BV, LR, SGS, DNV) on request. Hard stamped, preserved and packed for sea or air freight.
Where NiMo29Cr forgings are used
NiMo29Cr is a specialist material and the duties that justify its cost sit in chemical processing, wherever hydrochloric or other non-oxidising acids are handled and the equipment is welded or cycled.
| Industry | Components forged in NiMo29Cr |
|---|---|
| Chemical processing | Hydrochloric acid reactor and vessel forgings, acid regeneration and recovery hardware, hydrogenation and alkylation catalyst equipment, aluminium chloride service, pickling line components, forged nozzles and manways |
| Acetic acid & acetyls | Reactor internals, agitator and pump shafts, valve bodies and flanges for acetic acid and acetic anhydride plant |
| Pumps | Chemical pump shafts and sleeves, plunger pump components, wear rings, impeller and casing blanks |
| Valves | Bodies, bonnets, seat rings, stems, gate, plug and ball blanks for ball, check, globe, gate and plug valves and strainers |
| Pressure vessels & heat exchangers | Forged tube sheets, shell flanges, girth rings, blind covers, channel covers and nozzle forgings for shell-and-tube exchangers on acid duty |
| Columns, towers & process modules | Flanges, rings, forged pipe and nozzle sections for columns, towers, tanks and skid-mounted process modules |
| Pharmaceutical & fine chemicals | Reactor components, crystalliser hardware, sleeves and seat rings for halogenated and acidic reaction steps |
| Agrochemicals | Discs, bushings and valve internals for pesticide and herbicide synthesis |
| Chlorinated organics | Pipe flanges, hollow bars and nozzles for VCM and chlorinated hydrocarbon production |
| Hydrometallurgy | Pump shafts, impeller hubs and rolled rings for chloride leach and metal recovery circuits |
One reason accounts for all of these duties. Nothing else at the price holds up in hot, air-free hydrochloric acid while also surviving welding and thermal cycling. Where a plant handles reducing acid consistently and can keep oxidising contaminants out, NiMo29Cr outlasts stainless steel by a wide margin. Where the stream is variable, it is the wrong choice. See the corrosion section before committing.
For general machinery work such as gearboxes, crankshafts, mill rolls and structural shafting, NiMo29Cr is uneconomic, and its strength offers no advantage over alloy steel. Jiangyin Jiangnan Metal also forges carbon steel, alloy steel, tool steel and stainless steel, and will say so if a cheaper grade will do the job.
Testing, inspection and certification
- Chemical analysis. Spectrometric heat analysis and, on request, product analysis on the finished forging.
- Mechanical testing. Room-temperature tensile, yield, elongation and hardness; elevated-temperature tensile and impact testing to your specification.
- Ultrasonic testing. EN 10228-3, SEP 1921 Class C/D/E, ASTM A388 or a nominated customer class.
- Surface NDT. Liquid penetrant examination per ASTM E165 / ASME V Article 6.
- Corrosion testing. Intergranular corrosion to ASTM G28 and immersion testing to an agreed procedure where the specification calls for it.
- Positive material identification. PMI on the finished forging on request. Specify it on nickel-molybdenum work, where mix-ups with Ni-Cr-Mo grades and with Alloy B-2 are expensive to discover late.
- Heat treatment record. Furnace chart and quench record for the solution anneal, issued with the certificate.
- Certification. EN 10204 3.1 as standard; EN 10204 3.2 witnessed by TÜV, BV, LR, SGS or DNV on request. Full heat traceability and hard stamping.
Inspection plant includes a universal testing machine, impact testing machine, hardness testers, magnetic particle and ultrasonic flaw detection, spectrometer and metallographic microscope. Jiangyin Jiangnan Metal operates an ISO 9001:2015 quality system.
Frequently asked questions about NiMo29Cr
What is NiMo29Cr?
NiMo29Cr is the German (DIN 17744) name for a wrought nickel-molybdenum alloy carrying Werkstoff number 2.4600 and UNS number N10675. It contains 27–32% molybdenum, 65% minimum nickel, and deliberate small additions of chromium (1–3%) and iron (1–3%). It is a solid-solution alloy that is not age-hardenable. It resists hydrochloric acid at all concentrations up to the boiling point, and unlike the older Alloy B-2 it is stabilised against the ordering reaction that embrittles nickel-molybdenum alloys around 600–800 °C. Jiangyin Jiangnan Metal Co., Ltd. forges NiMo29Cr into rings, flanges, bars, discs, shafts, sleeves and tube sheets.
Is NiMo29Cr the same as Hastelloy B-3?
Yes, the same material specification under different names. NiMo29Cr is the DIN 17744 designation, W.Nr. 2.4600; Hastelloy® B-3® is the trade name used by Haynes International; and the generic designation is Alloy B-3 or UNS N10675. Material forged by Jiangyin Jiangnan Metal Co., Ltd. is correctly described as NiMo29Cr / 2.4600 / UNS N10675, not by any trademarked name. When ordering, quote UNS N10675 plus the product standard, which for forgings is ASTM B564, so the requirement is unambiguous. See also our Hastelloy B-3 forgings page.
Does Werkstoff 2.4600 mean Alloy B-3 or Alloy B-4?
Both are offered under 2.4600 commercially, which is a common source of confusion on enquiries. The DIN 17744 composition band for NiMo29Cr is wider than either UNS grade, so Alloy B-3 (UNS N10675) and Alloy B-4 (UNS N10629) can both be certified against 2.4600 depending on the supplier. If your design depends on one or the other, order to the UNS number rather than the Werkstoff number and have the mill certificate state it. Jiangyin Jiangnan Metal Co., Ltd. forges both and will certify to whichever designation the purchase order names.
What is the chemical composition of NiMo29Cr?
Molybdenum 27.0–32.0%, nickel 65% minimum (balance), chromium 1.0–3.0%, iron 1.0–3.0%, cobalt 3.0% max, manganese 3.0% max, tungsten 3.0% max, aluminium 0.50% max, copper, niobium, tantalum, titanium and vanadium 0.20% max each, zirconium 0.10% max, silicon 0.10% max, phosphorus 0.030% max, sulfur 0.010% max and carbon 0.010% max, by weight. The very low carbon and silicon are what stabilise the alloy against embrittling phases. Carbon at 0.010% is half the Alloy B-2 limit, and it is the fastest way to tell the two grades apart on an incoming certificate. Every heat is supplied with a ladle analysis on the EN 10204 mill certificate.
Which acids does NiMo29Cr resist, and where must it not be used?
NiMo29Cr resists hydrochloric acid at all concentrations from room temperature to the boiling point, plus hydrobromic, sulfuric, phosphoric, acetic and formic acids, hydrogen chloride gas and non-oxidising chloride salts. It also handles concentrated sulfuric acid and fluoride-bearing media that attack zirconium. It must not be used in oxidising media: nitric acid, ferric chloride, cupric chloride, wet chlorine, hypochlorite or aerated acids. The limit is strict. Even a few parts per million of ferric or cupric ions in hydrochloric acid, or dissolved oxygen carried in with the feed, will raise the corrosion rate sharply. The 1–3% chromium in this grade buys thermal stability, not oxidising resistance. Where the process can swing between reducing and oxidising conditions, a nickel-chromium-molybdenum grade such as Alloy C-276 or Alloy 59 is the safer specification.
What heat treatment is correct for NiMo29Cr forgings?
Solution annealing at approximately 1,065 °C (1,950 °F), held to temperature through section, followed by a rapid water quench. NiMo29Cr is a solid-solution alloy and is not age-hardened. Applying an ageing treatment precipitates secondary phases and reduces both ductility and corrosion resistance. Although NiMo29Cr tolerates slower cooling far better than Alloy B-2, the quench is still specified fast so that heavy sections reach full corrosion performance at the core. Jiangyin Jiangnan Metal Co., Ltd. supplies all NiMo29Cr forgings solution annealed and rapidly quenched, with the furnace chart and quench record on the certificate.
What is the difference between NiMo29Cr (Alloy B-3) and NiMo28 (Alloy B-2)?
Thermal stability. NiMo28 / Alloy B-2 (2.4617 / N10665) forms an ordered Ni4Mo (β) phase when held around 600–800 °C, which reduces ductility and can leave a weld heat-affected zone open to preferential attack. NiMo29Cr / Alloy B-3 (2.4600 / N10675) carries deliberate chromium and iron additions with carbon at 0.010% and silicon at 0.10%, which suppress that reaction. Hydrochloric acid resistance is essentially the same. For welded fabrications, thermally cycled equipment and heavy forged sections, NiMo29Cr is the safer selection; for fully annealed static parts where budget matters, NiMo28 remains sound and is cheaper. Jiangyin Jiangnan Metal Co., Ltd. forges both.
Can NiMo29Cr be welded, and which filler metal is used?
Yes, and it welds considerably better than Alloy B-2. NiMo29Cr is welded by GTAW, GMAW and SMAW with a matching nickel-molybdenum filler: AWS A5.14 ERNiMo-10 bare wire, or AWS A5.11 ENiMo-10 covered electrode. In the German system these are DIN 2.4695 (SG-NiMo30Cr) and DIN 2.4696 (EL-NiMo28Cr). Keep heat input moderate and interpass temperature down as normal practice for nickel alloys. A post-weld solution anneal is not usually required for NiMo29Cr, which is the main practical reason plants change over from Alloy B-2.
What are the mechanical properties of NiMo29Cr forgings?
ASTM B564 requires a minimum of 760 MPa (110,000 psi) tensile strength, 350 MPa (51,000 psi) yield strength at 0.2% offset and 40% elongation in the solution-annealed condition. DIN 17750 sets comparable minima of 750 MPa tensile, 340 MPa yield, 40% elongation and 240 HBW maximum hardness. Typical measured values run higher, at around 860 MPa tensile, 420 MPa yield and 53% elongation. Density is 9.22 g/cm³ and the melting range is approximately 1,370–1,418 °C. Typical values are for design screening; the mill test certificate issued with each forging governs acceptance.
What sizes of NiMo29Cr forgings can you supply?
Seamless rolled rings from 200 to 3,000 mm outside diameter and up to 800 mm height; round bars 80–800 mm diameter up to 6,000 mm long; discs and tube sheets to 2,500 mm diameter and 600 mm thickness; shafts, sleeves and blocks to 6,000 mm long. Single-piece weights run from about 20 to 8,000 kg. Open-die forging needs no dies, so there is no tooling charge and no minimum order quantity by piece, and one-off or prototype parts are economic. For nickel-molybdenum alloys the practical maximum is set by available ingot size, so confirm large sizes with the enquiry.
What testing and certification do you supply with NiMo29Cr forgings?
Every NiMo29Cr forging ships with an EN 10204 3.1 mill test certificate as standard, showing heat number, chemical analysis, mechanical results, heat treatment record and NDT results. EN 10204 3.2 certification witnessed by TÜV, BV, LR, SGS or DNV is available on request at the time of order. Ultrasonic testing is carried out to EN 10228-3, SEP 1921, ASTM A388 or a nominated customer class, with liquid penetrant examination to ASTM E165 / ASME V Article 6, positive material identification, and intergranular corrosion testing to ASTM G28 or an agreed procedure where required.
How long does a NiMo29Cr forging take to produce?
Lead time depends on whether NiMo29Cr raw stock is on hand and on the size of the forging. Simple rings and discs from stock material typically run 25–40 days. Parts needing a fresh melt, ESR remelting, heavy machining or third-party witnessed inspection take longer. Send a drawing or the dimensions to sales@steelforgepieces.com and we will confirm a firm date with the quotation.
Who supplies open-die forged NiMo29Cr (2.4600 / N10675) parts in 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 forges NiMo29Cr (W.Nr. 2.4600, UNS N10675) and other nickel alloys, stainless steels, tool steels, alloy steels and carbon steels into seamless rolled rings, flanges, round bars, discs, shafts, sleeves, bushings and tube sheets, and exports worldwide. Enquiries: sales@steelforgepieces.com or +86 189 2135 9659.
Request a quotation for NiMo29Cr forgings
Send a drawing, a sketch, or just the dimensions
We quote open-die forgings in NiMo29Cr with no tooling charge and no piece minimum. Useful details if you have them: grade and standard (NiMo29Cr / W.Nr. 2.4600 / UNS N10675 / ASTM B564 or B462), product form, dimensions with machining allowance, quantity, delivery condition, NDT class, certificate type (EN 10204 3.1 or 3.2) and required delivery date.
- Company
- Jiangyin Jiangnan Metal Co., Ltd.
- Business
- Open-die forging factory, since 2008
- Address
- No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
- Telephone / WhatsApp
- +86 189 2135 9659
- Website
- www.steelforgepieces.com