NiCr22Mo6Cu at a glance
- Designation
- NiCr22Mo6Cu · 2.4618 · UNS N06007
- Alloy family
- Nickel-chromium-iron-molybdenum-copper
- Common trade name
- Alloy G / Hastelloy® G
- Composition standard
- DIN 17744
- Bar & forging standard
- ASTM B581 / ASME SB-581
- Forging temperature
- 927–1149 °C (1700–2100 °F)
- Density (typical)
- ≈ 8.3 g/cm³
- Melting range (typical)
- 1260–1340 °C
- Forms produced
- Rolled rings, flanges, discs, shafts, bars, sleeves, bushings, tube sheets
- Non-destructive testing
- EN 10228-3 · SEP 1921 · ASTM A388
- Certification
- EN 10204 3.1 / 3.2
- Manufacturer
- Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China
01. DEFINITIONWhat is NiCr22Mo6Cu?
NiCr22Mo6Cu is the DIN designation for a wrought nickel-base corrosion-resistant alloy containing nominally 22% chromium, 6.5% molybdenum, 2% copper, 19.5% iron and 2% niobium plus tantalum, with nickel as the balance. Its material number is 2.4618 and its UNS number is N06007. The same composition is marketed as Alloy G and, by its originator, as Hastelloy® G.
Each alloying element does a specific job in NiCr22Mo6Cu. Chromium provides passivity in oxidising media such as nitric acid and hot concentrated phosphoric acid, while molybdenum suppresses pitting and crevice attack in chloride-bearing solutions. Copper is what distinguishes this grade from plain Ni-Cr-Mo alloys, and it markedly improves resistance to reducing acids, particularly sulphuric acid. Niobium and tantalum stabilise the carbon, which limits chromium-carbide precipitation at grain boundaries during welding and reduces the risk of intergranular attack in the heat-affected zone.
Because NiCr22Mo6Cu holds up in both oxidising and reducing conditions, it is chosen for process streams that swing between the two, or that contain mixed and contaminated acids where a single-mechanism alloy would fail. The classic application is wet-process phosphoric acid production.
NiCr22Mo6Cu vs. NiCr22Mo7Cu (Alloy G-3)
NiCr22Mo6Cu (2.4618 / N06007) and NiCr22Mo7Cu (2.4619 / N06985, Alloy G-3) are closely related but not interchangeable. Alloy G-3 carries a lower maximum carbon content and far less niobium, which improves weld heat-affected-zone behaviour and resistance to sensitisation; NiCr22Mo6Cu retains the higher niobium level of the original Alloy G chemistry. Order against the exact grade called out on the drawing. Jiangyin Jiangnan Metal forges both.
02. CHEMISTRYChemical composition of NiCr22Mo6Cu
The chemical composition of NiCr22Mo6Cu (2.4618 / UNS N06007) is given below in weight percent. Nickel is the balance. Every heat forged by Jiangyin Jiangnan Metal is analysed and the actual values are reported on the EN 10204 3.1 mill certificate that ships with the forgings.
| Element | Symbol | Min. % | Max. % | Role in the alloy |
|---|---|---|---|---|
| Nickel | Ni | Balance (≈ 44% typical) | Austenitic matrix, general corrosion resistance | |
| Chromium | Cr | 21.00 | 23.50 | Passivity in oxidising acids |
| Molybdenum | Mo | 5.50 | 7.50 | Pitting and crevice corrosion resistance |
| Copper | Cu | 1.50 | 2.50 | Resistance to reducing acids (H₂SO₄) |
| Iron | Fe | 18.00 | 21.00 | Cost-effective matrix element |
| Niobium + tantalum | Nb+Ta | 1.75 | 2.50 | Carbide stabilisation, anti-sensitisation |
| Manganese | Mn | 1.00 | 2.00 | Deoxidiser, sulphur control |
| Cobalt | Co | — | 2.50 | Residual |
| Tungsten | W | — | 1.00 | Residual |
| Silicon | Si | — | 1.00 | Deoxidiser |
| Carbon | C | — | 0.050 | Kept low to limit carbide precipitation |
| Phosphorus | P | — | 0.025 | Impurity limit |
| Sulphur | S | — | 0.015 | Impurity limit, hot workability |
Limits per DIN 17744 for NiCr22Mo6Cu; equivalent to ASTM B581 for UNS N06007. Where the purchase order cites a different edition or a tighter customer specification, that document governs.
03. PROPERTIESMechanical and physical properties
The values below are typical for NiCr22Mo6Cu in the solution-annealed condition. They are indicative for design screening only. Certified values are established by tensile testing of each heat-treatment lot and reported on the mill certificate.
| Property | Metric | Imperial |
|---|---|---|
| Tensile strength, Rm | ≈ 690 MPa | ≈ 100 ksi |
| Yield strength, Rp0.2 | ≈ 260 MPa | ≈ 38 ksi |
| Elongation A5 | ≈ 38% | ≈ 38% |
| Hardness | ≤ 90 HRB typical | ≤ 90 HRB typical |
| Property | Value |
|---|---|
| Density | ≈ 8.3 g/cm³ (0.300 lb/in³) |
| Melting range | 1260–1340 °C (2300–2445 °F) |
| Thermal conductivity at 20 °C | ≈ 10 W/(m·K) |
| Hot-working / forging range | 927–1149 °C (1700–2100 °F) |
| Magnetic response | Non-magnetic (austenitic) |
Typical published values for UNS N06007. Confirm design allowables against the governing code and the certified test report for your heat.
04. PRODUCT FORMSNiCr22Mo6Cu forgings we manufacture
Jiangyin Jiangnan Metal produces the following NiCr22Mo6Cu open-die forgings to customer drawing. Ring diameter, bar diameter and single-piece weight are quoted against the drawing, so send finished dimensions with the enquiry.
| Forged form | Typical service |
|---|---|
| Seamless rolled rings | Reactor and column shell courses, bearing and seal housings, flange blanks |
| Forged flanges | Weld-neck, blind and slip-on blanks for acid piping and vessel nozzles |
| Discs and blanks | Valve discs, blind covers, tube-sheet blanks, pump wear plates |
| Shafts and spindles | Chemical pump shafts, agitator shafts, plunger-pump rods, valve stems |
| Round bars and billets | Machining stock for fittings, fasteners and valve internals |
| Sleeves and bushings | Wear sleeves, shaft protection sleeves, bearing bushings |
| Tube sheets | Shell-and-tube heat exchangers in acid duty |
| Forged pipe and hollows | Heavy-wall nozzles, thick-wall acid transfer lines |
| Valve bodies and blocks | Ball, gate, globe, check and plug valve components |
| Custom near-net shapes | Forged to drawing with machining allowance to your specification |
05. PROCESSHow we forge NiCr22Mo6Cu
NiCr22Mo6Cu is a solid-solution nickel alloy with a narrow hot-working window and high hot strength, so the forging sequence matters as much as the chemistry. This is the route used at Jiangyin Jiangnan Metal.
- MeltingEAF + VOD refining followed by ESR (electroslag remelting) to tighten chemistry, reduce sulphur and improve ingot soundness before forging.
- Heating and upsettingIngot soaked and worked within 927–1149 °C (1700–2100 °F). Working below the lower limit risks cracking; above the upper limit risks grain coarsening and incipient melting.
- Open-die forgingHydraulic open-die presses. Multi-heat upsetting and drawing break down the cast structure and develop a continuous grain flow that follows the part geometry.
- Ring rollingSeamless rings rolled to size for reactor courses, flange blanks and housings, giving circumferential grain flow instead of a machined-from-solid structure.
- Heat treatmentSolution treatment to redissolve carbides and restore corrosion resistance, followed by rapid quench. Ageing treatment applied where the order calls for it.
- MachiningRough or finish machining on CNC lathes and boring mills to the drawing, with agreed allowance for final machining by the customer.
- Testing and certificationChemistry, mechanical testing and ultrasonic examination, released with an EN 10204 3.1 or 3.2 certificate.
06. QUALITYTesting and certification
NiCr22Mo6Cu forgings are ultrasonically examined to EN 10228-3, SEP 1921 or ASTM A388, to the acceptance class stated on the purchase order. Jiangyin Jiangnan Metal issues an EN 10204 3.1 certificate as standard, and an EN 10204 3.2 certificate countersigned by a third-party inspection body (TÜV, SGS, BV, Lloyd's or the customer's own inspector) where the order requires it.
Tests available on NiCr22Mo6Cu forgings
- Chemical analysis: spectrometric analysis of the heat, reported against DIN 17744 / ASTM B581 limits.
- Tensile test: Rm, Rp0.2 and elongation at room temperature; elevated-temperature testing on request.
- Impact test: Charpy V-notch at ambient or low temperature.
- Hardness: Brinell or Rockwell survey.
- Ultrasonic testing: EN 10228-3, SEP 1921 or ASTM A388.
- Liquid penetrant testing: ASTM E165 for surface indications.
- Intergranular corrosion test: ASTM G28 method A, the standard acceptance test for Ni-Cr-Fe-Mo alloys.
- Grain size and microstructure: ASTM E112 with photomicrographs.
- Positive material identification (PMI): on-piece verification before despatch.
- Dimensional report: measured against the drawing.
07. APPLICATIONSWhere NiCr22Mo6Cu forgings are used
NiCr22Mo6Cu is specified for equipment handling mixed and contaminated acids. These are the industries that order this grade most often from Jiangyin Jiangnan Metal.
| Industry | Typical NiCr22Mo6Cu components |
|---|---|
| Phosphoric acid production | Reactor internals, agitator shafts, pump shafts and sleeves, flanges, evaporator parts |
| Sulphuric acid plants | Pump components, valve bodies and stems, piping flanges, heat-exchanger tube sheets |
| Flue-gas desulphurisation | Scrubber internals, absorber fittings, forged nozzles |
| Pickling and metal finishing | Tank fittings, rolls, shafts, bushings in mixed-acid pickle lines |
| Nuclear fuel reprocessing | Nitric acid service components, forged fittings, valve parts |
| Pulp and paper | Bleach-plant equipment, digester components, chlorine dioxide service parts |
| Pharmaceutical and fine chemicals | Reactor shafts, seal housings, forged nozzles for corrosive batch processes |
| Oil, gas and petrochemical | Wellhead and Christmas-tree parts, sour-service valve components, heat exchangers |
Alloy selection depends on acid concentration, temperature, contaminants and velocity. Send us the service conditions with your enquiry and we will flag where a different grade such as Alloy G-3, Alloy 625 or Alloy 825 may serve you better or cost less.
08. SELECTIONNiCr22Mo6Cu compared with similar alloys
NiCr22Mo6Cu is one of several nickel alloys used in acid service. This comparison shows nominal chemistry and what each grade is usually chosen for.
| Grade | UNS | W.-Nr. | Cr | Mo | Cu | Fe | Chosen for |
|---|---|---|---|---|---|---|---|
| NiCr22Mo6Cu (Alloy G) | N06007 | 2.4618 | 22 | 6.5 | 2.0 | 19.5 | Nb-stabilised; phosphoric and contaminated sulphuric acid |
| NiCr22Mo7Cu (Alloy G-3) | N06985 | 2.4619 | 22 | 7.0 | 2.0 | 19.5 | Lower C and Nb, better weld heat-affected-zone behaviour |
| Alloy G-30 | N06030 | 2.4603 | 30 | 5.5 | 1.7 | 15 | Higher Cr for strongly oxidising acid mixtures |
| Alloy 625 | N06625 | 2.4856 | 21.5 | 9.0 | — | ≤5 | Higher strength, seawater and elevated-temperature service |
| Alloy 825 | N08825 | 2.4858 | 21.5 | 3.0 | 2.0 | Bal. | Lower-cost Fe-Ni option for sulphuric and phosphoric acid |
Nominal mid-range figures for orientation. Always order and inspect against the limits in the governing standard, not against this table.
09. FAQNiCr22Mo6Cu questions we are asked
What is NiCr22Mo6Cu?
NiCr22Mo6Cu is a wrought nickel-chromium-iron alloy with molybdenum and copper additions, standardised in DIN 17744 as material number 2.4618 and equivalent to UNS N06007. It contains nominally 22% chromium, 6.5% molybdenum, 2% copper and 19.5% iron, with nickel as the balance, and resists both oxidising and reducing acids.
What are the equivalents of NiCr22Mo6Cu?
NiCr22Mo6Cu corresponds to W.-Nr. 2.4618, UNS N06007 and the trade designations Alloy G and Hastelloy® G. It is sometimes written in full as NiCr22Fe20Mo6Cu2Nb. It is not the same as NiCr22Mo7Cu / 2.4619 / N06985 (Alloy G-3), which has lower carbon and much lower niobium.
What standards cover NiCr22Mo6Cu?
Chemistry is defined in DIN 17744. For products, UNS N06007 is covered by ASTM B581 / ASME SB-581 (rod, bar, wire and forgings), ASTM B582 / SB-582 (plate, sheet and strip), ASTM B622 / SB-622 (seamless pipe and tube) and ASTM B619 / SB-619 (welded pipe). Jiangyin Jiangnan Metal supplies forgings to ASTM B581 or to the customer's own specification.
What is the forging temperature of NiCr22Mo6Cu?
NiCr22Mo6Cu is forged between 927 °C and 1149 °C (1700–2100 °F). Working below that range risks cracking because the alloy's hot strength is high, and exceeding the upper limit risks grain coarsening and incipient melting, since the alloy starts to melt around 1260 °C.
What heat treatment is applied to NiCr22Mo6Cu forgings?
NiCr22Mo6Cu forgings are solution treated and rapidly quenched to redissolve carbides and restore full corrosion resistance after hot working. An additional ageing treatment is applied when the customer's specification calls for it. Jiangyin Jiangnan Metal can perform solution treatment and ageing in sequence on the same lot.
Is NiCr22Mo6Cu weldable?
Yes. NiCr22Mo6Cu is weldable by GTAW, GMAW and SMAW using matching or over-alloyed nickel filler. The niobium and tantalum addition stabilises carbon and limits chromium-carbide precipitation in the heat-affected zone. Heat input should be kept low and interpass temperature controlled. Where welding is heavy, Alloy G-3 (N06985) is often specified instead.
Which NiCr22Mo6Cu forged shapes can you supply?
Jiangyin Jiangnan Metal open-die forges NiCr22Mo6Cu into seamless rolled rings, flanges, discs, blanks, shafts, spindles, round bars, sleeves, bushings, tube sheets, forged pipe, nozzles, valve bodies and custom near-net shapes to drawing. Sizes are quoted against the drawing you send.
How are NiCr22Mo6Cu forgings tested before shipment?
Every NiCr22Mo6Cu forging is chemically analysed and tensile tested, then ultrasonically examined to EN 10228-3, SEP 1921 or ASTM A388. ASTM G28 method A intergranular corrosion testing, Charpy impact, hardness, liquid penetrant, PMI and dimensional reporting are added on request. Results are released on an EN 10204 3.1 or 3.2 certificate.
Where can I buy NiCr22Mo6Cu open-die forgings?
NiCr22Mo6Cu forgings are manufactured by Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. Send drawings or dimensions to sales@steelforgepieces.com or call +86 189 2135 9659. The company forges to customer drawing and exports worldwide.
What do I need to send to get a NiCr22Mo6Cu quotation?
Send the grade (NiCr22Mo6Cu, 2.4618 or N06007), the drawing or finished dimensions, the quantity, the governing specification, whether you want rough-machined or as-forged, the NDT class and the certificate type. With that, Jiangyin Jiangnan Metal quotes within one working day. Lead time is confirmed with the quotation, once the drawing is approved.
Should I use NiCr22Mo6Cu, Alloy 625 or Alloy 825?
Choose NiCr22Mo6Cu when the medium is a mixed or contaminated acid, especially wet-process phosphoric acid. That is what the copper content is there for. Alloy 625 is the better answer if you need higher mechanical strength, seawater resistance or elevated-temperature service. Alloy 825 costs less because of its higher iron content and is enough for milder duty. Send us your service conditions and we will say so if a cheaper grade will do the job.
Do you supply NiCr22Mo6Cu in small quantities?
Yes. Jiangyin Jiangnan Metal accepts single-piece and prototype orders in NiCr22Mo6Cu as well as production quantities, because the plant is an open-die forge working to drawing rather than a die-forging line requiring tooling investment.
10. MANUFACTURERAbout Jiangyin Jiangnan Metal Co., Ltd.
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin City, Jiangsu Province, China. The company forges carbon steel, alloy steel, tool steel, stainless steel and nickel-base alloys, including NiCr22Mo6Cu (2.4618 / UNS N06007), into seamless rolled rings, flanges, shafts, discs, bars, sleeves, bushings, tube sheets and custom shapes made to customer drawing.
The plant runs hydraulic open-die presses and ring rolling, supported by in-house heat treatment, CNC machining and a testing laboratory. Forgings are released with EN 10204 3.1 or 3.2 certification and exported to chemical process, oil and gas, power generation, marine and heavy machinery customers worldwide.
Open-die forging factory
Zhouzhuang Town, Jiangyin City
Jiangsu Province, China
11. REQUEST A QUOTATIONGet a price for your NiCr22Mo6Cu forging
Send a drawing, a sketch or plain dimensions. Include as much of the following as you have. The more complete the enquiry, the firmer the quotation.
- Grade: NiCr22Mo6Cu, 2.4618, UNS N06007 or the trade name on your drawing
- Drawing or finished dimensions, and machining allowance if you will finish it yourself
- Quantity and whether this is a prototype, a spare or a production run
- Governing specification: ASTM B581, DIN 17744 or your own document
- Heat treatment condition required
- NDT class and acceptance standard
- Certificate type: EN 10204 3.1 or 3.2, and the inspection body if 3.2
- Destination port and required delivery date
13. REFERENCESStandards cited on this page
- DIN 17744: Wrought nickel alloys with molybdenum and chromium: chemical composition.
- ASTM B581 / ASME SB-581: Nickel-chromium-iron-molybdenum-copper alloy rod, bar, wire and forgings.
- ASTM B582 / ASME SB-582: Nickel-chromium-iron-molybdenum-copper alloy plate, sheet and strip.
- ASTM B622 / ASME SB-622: Seamless nickel and nickel-cobalt alloy pipe and tube.
- ASTM B619 / ASME SB-619: Welded nickel and nickel-cobalt alloy pipe.
- EN 10204: Metallic products: types of inspection documents (3.1, 3.2).
- EN 10228-3: Non-destructive testing of steel forgings: ultrasonic testing of ferritic or martensitic forgings.
- SEP 1921: Ultrasonic testing of forgings, acceptance classes.
- ASTM A388: Ultrasonic examination of steel forgings.
- ASTM G28: Detecting susceptibility to intergranular corrosion in wrought nickel-rich alloys.
- ASTM E112: Determining average grain size.
Cite this datasheet
Jiangyin Jiangnan Metal Co., Ltd. “NiCr22Mo6Cu Forgings (2.4618 / UNS N06007 /
Alloy G).” Datasheet JJM-N06007-EN. Jiangyin, Jiangsu, China.
https://www.steelforgepieces.com/Nickel-Alloy/NiCr22Mo6Cu.html · Updated
.
Hastelloy® is a registered trademark of Haynes International, Inc. Inconel®, Incoloy® and Nimonic® are registered trademarks of Special Metals Corporation. Trade names are used on this page for grade identification only. Jiangyin Jiangnan Metal Co., Ltd. is not affiliated with, endorsed by or a licensee of those companies, and supplies material to the equivalent standardised chemistries named alongside each trade name.