Home › Nickel Alloy › UNS N06985
Nickel alloy / open-die forging
UNS N06985 Forgings, Hastelloy® G-3 / W.-Nr. 2.4619
UNS N06985 is a solid-solution nickel-chromium-iron alloy with molybdenum and copper additions, known by the trade name Hastelloy® G-3 and by the material number 2.4619. Nominal composition is approximately 44 % nickel, 21.0–23.5 % chromium, 18.0–21.0 % iron, 6.0–8.0 % molybdenum and 1.5–2.5 % copper, with carbon limited to 0.015 % maximum to reduce sensitisation in weld heat-affected zones. Jiangyin Jiangnan Metal Co., Ltd. is an integrated steel melting and open-die forging works in Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, operating since 1997. We forge UNS N06985 into rings, seamless rolled rings, shafts, discs, sleeves, hollow bars and blocks to customer drawings, and solution anneal each part after the final hot working operation in the plant's own high-temperature furnaces.
- UNS
- N06985
- Werkstoff
- 2.4619
- Trade names
- Hastelloy® G-3
Alloy G-3, Inconel® G-3 - Family
- Ni-Cr-Fe-Mo-Cu
solid solution - Forging range
- 927–1149 °C
1700–2100 °F - Anneal
- 1177 °C / 2150 °F
rapid cool - Density
- 8.3 g/cm³
0.30 lb/in³ - Chemistry spec
- ASTM B581
ASTM B582
Key data
UNS N06985 at a glance
- 44 %Nominal nickel content
- 6–8 %Molybdenum, pitting and crevice resistance
- 0.015 %Maximum carbon
- 927–1149 °CHot forging range
- 1177 °CSolution annealing temperature
- 621 MPaMinimum tensile strength, annealed
Solution annealing after forging. Hot working leaves UNS N06985 in a strained condition with precipitated carbides that reduce corrosion resistance. A solution anneal at approximately 1177 °C, followed by water quenching or rapid air cooling, is required to restore the annealed properties. When comparing suppliers, ask for the annealing furnace chart and the quench delay record in addition to the chemical analysis.
Product forms
UNS N06985 forged product forms and sizes
The forms below are forged on open-die presses and radial-axial ring mills, then solution annealed, descaled, machined and tested on site. The size figures are the plant envelope across all grades.
| Form | Plant envelope | Typical application |
|---|---|---|
| Seamless rolled rings | OD 50 to 6,000 mm on the 6 m, 3 m and 1 m ring mills | Scrubber and vessel flange rings, tube sheet rings, valve seat rings |
| Forged rings and flanges | Upset and punched for sections outside the ring mill envelope | Weld neck and blind flanges, nozzle reinforcement, retaining rings |
| Shafts and round bars | Turned length to 14,000 mm, Ø to 1,800 mm on horizontal lathes | Agitator and pump shafts in acid service, downhole components |
| Discs, tube sheets, blanks | Machined to Ø 5,000 mm on the vertical turning lathe | Blind covers, valve discs, heat exchanger tube sheets |
| Sleeves, bushes, hollow bars | Bored to Ø 1,600 mm by 10,000 mm on the CNC deep-hole drilling machine | Pump wear parts, liners, hanger and coupling bodies |
| Blocks and near-net shapes | Single-piece weight to 30,000 kg; minimum order 10 kg, no minimum piece count | Machining blanks, valve bodies, custom shapes |
For UNS N06985 the governing constraint is usually the solution anneal rather than the press, because the part has to be re-annealed after forging. Three high-temperature car-bottom furnaces cover that treatment, with a working chamber of 3,500 by 1,300 by 1,100 mm. Send the part envelope with the enquiry and the route will be confirmed before quotation. Delivery condition: as-forged, solution annealed, rough machined or finish machined to drawing.
Process
Forging and heat treatment of UNS N06985
UNS N06985 has a narrower hot working range than carbon and low-alloy steel, and the solution annealing temperature lies above the upper forging limit. Parts are reheated whenever the forging temperature falls below approximately 927 °C.
1. Melting and traceability
Nickel alloys are melted on site rather than bought in as billet. The superalloy route is a 3 t vacuum induction furnace with 6 t vacuum arc remelting and 3 t and 6 t protective-atmosphere electroslag remelting. Maximum heat size in the plant is 60 t. The melt number follows the part to shipment.
2. Open-die forging
Upsetting and drawing between 927 and 1149 °C with reheats as required, on 6,300 t, 4,000 t and 2,000 t hydraulic presses, with 6 m, 3 m and 1 m radial-axial ring mills for ring work.
3. Solution annealing
Three high-temperature car-bottom furnaces, working chamber 3,500 by 1,300 by 1,100 mm, take the part to approximately 1177 °C. It is then water quenched or rapidly air cooled. Furnace charts are retained with the order file.
4. Machining
Vertical turning to Ø 5,000 mm swing, horizontal turning to 14,000 mm between centres and CNC deep-hole boring to Ø 1,600 by 10,000 mm. The alloy work hardens, so positive rake tooling, adequate feed rates and rigid setups are used.
5. Testing
In-house optical emission spectrometry, infrared carbon and sulphur analysis, PMI, tensile testing on 600 kN and 300 kN machines, Charpy impact to −60 °C, ultrasonic and magnetic particle inspection and ASTM E112 grain size. ASTM G28 intergranular corrosion testing is placed with an accredited third-party laboratory and reported alongside the mill certificate.
6. Documentation
EN 10204 3.1 mill test certificate as standard, EN 10204 3.2 witnessed by BV, DNV, LR, SGS, TÜV or your own inspector on request. The works holds CCS, BV, DNV, LR and NK approvals. Marking and packing according to purchaser instructions.
Data
UNS N06985 chemical composition
Composition limits in weight percent, according to the chemistry requirements of ASTM B581 and ASTM B582. Nickel is the balance and is normally close to 44 %.
| Element | Min % | Max % | Function |
|---|---|---|---|
| Nickel, Ni | Balance (approx. 44) | Chloride stress corrosion cracking and reducing acid resistance | |
| Chromium, Cr | 21.0 | 23.5 | Resistance to oxidising media |
| Iron, Fe | 18.0 | 21.0 | Balance of cost and structure |
| Molybdenum, Mo | 6.0 | 8.0 | Pitting and crevice corrosion resistance |
| Copper, Cu | 1.5 | 2.5 | Sulphuric and phosphoric acid resistance |
| Cobalt, Co | — | 5.0 | Residual |
| Tungsten, W | — | 1.5 | Solid solution strengthening |
| Manganese, Mn | — | 1.0 | Deoxidation |
| Silicon, Si | — | 1.0 | Deoxidation |
| Niobium + Tantalum, Nb+Ta | — | 0.5 | Carbide stabilisation |
| Phosphorus, P | — | 0.04 | Controlled impurity |
| Sulphur, S | — | 0.03 | Controlled impurity |
| Carbon, C | — | 0.015 | Limited to reduce weld HAZ sensitisation |
The values above are the standard composition limits, published for reference. The certified heat analysis supplied with the order is the governing document.
Mechanical and physical properties
UNS N06985 is solid-solution strengthened and cannot be age hardened. Strength above the annealed minimum is obtained by cold work, which is why cold-drawn OCTG product shows much higher yield strength with reduced elongation.
| Condition | Tensile, MPa | Tensile, ksi | Yield 0.2 %, MPa | Yield 0.2 %, ksi | Elongation, % |
|---|---|---|---|---|---|
| Solution annealed, typical minimum | 621 | 90 | 241 | 35 | 45 |
| Cold worked, OCTG type product | 896 | 130 | 862 | 125 | 13 |
Typical published figures for reference and material selection. Acceptance values for a given order are those stated in the purchase specification and reported on the test certificate.
Physical properties
| Property | Metric | Imperial |
|---|---|---|
| Density | 8.3 g/cm³ | 0.30 lb/in³ |
| Melting range, approximate | 1260–1343 °C | 2300–2450 °F |
| Hot forging range | 927–1149 °C | 1700–2100 °F |
| Solution annealing | approx. 1177 °C | approx. 2150 °F |
| Response to heat treatment | Not hardenable by heat treatment; cold work only | |
Standards, equivalents and designations
| Standard | Scope |
|---|---|
| ASTM B581 / ASME SB-581 | Rod and bar |
| ASTM B582 / ASME SB-582 | Plate, sheet and strip |
| ASTM B622 / ASME SB-622 | Seamless pipe and tube |
| ASTM B619 | Welded pipe |
| ASTM B626 | Welded tube |
| ASTM B366 | Wrought fittings |
| AWS A5.14 ERNiCrMo-9 | Bare filler metal |
| AWS A5.11 ENiCrMo-9 | Covered electrode |
No ASTM specification is dedicated to UNS N06985 forgings. Forgings are normally ordered to the chemistry of ASTM B581 or B582 together with the purchaser drawing, mechanical test and NDT requirements. For sour service, the applicable table of NACE MR0175 / ISO 15156-3 should be confirmed against the H₂S partial pressure, chloride level and temperature of the application.
| System | Designation |
|---|---|
| UNS | N06985 |
| Werkstoff / DIN | 2.4619 |
| EN name | NiCr22Mo7Cu |
| Trade names | Hastelloy® G-3, Alloy G-3, Inconel® G-3, Nicrofer® 5423 hMo |
| Also written as | N06985, G3 alloy, Hastelloy G3, UNS N06985 G-3 |
UNS N06985 is the designation to state on drawings and purchase orders. Trade names are the property of their owners and are shown here to identify the alloy.
Applications for UNS N06985 forgings
The alloy is specified for service conditions that alternate between oxidising and reducing, and for welded fabrications where the heat-affected zone would otherwise be the point of attack. The combination of chromium, molybdenum, copper and low carbon accounts for this behaviour.
Chemical processing
- Phosphoric acid plant evaporators, heat exchangers and tank linings
- Sulphuric acid service and mixed acid duty
- Agitator and pump shafts, valve and pump bodies
- Pulp and paper bleaching equipment
Flue gas desulphurisation
- Scrubber quencher and damper components
- Outlet ducting flanges and stiffener rings
- Air pollution control equipment
Oil and gas
- Hot sour well components and OCTG related hardware
- Hangers, couplings, landing nipples and packer parts
- Wellhead and completion components in chloride bearing brine
Reasons for selection
- Nickel content resists chloride stress corrosion cracking that affects austenitic stainless steel
- Molybdenum resists pitting and crevice attack under deposits
- Carbon at 0.015 % maximum limits chromium carbide sensitisation in welds
- Copper content improves resistance to reducing acids
UNS N06985 compared with C-276, Alloy 825 and 316L
The table below sets UNS N06985 against three alloys it is commonly evaluated against during material selection.
| Alloy | Ni % | Cr % | Mo % | Principal service | Relative cost |
|---|---|---|---|---|---|
| UNS N06985 (G-3) | ~44 | 21.0–23.5 | 6–8 | Reducing acids, phosphoric acid plant, FGD scrubbers, hot sour wells | Medium |
| UNS N10276 (C-276) | ~57 | 14.5–16.5 | 15–17 | Severe mixed acids, hot hydrochloric acid, wet chlorine | High |
| UNS N08825 (Alloy 825) | 38–46 | 19.5–23.5 | 2.5–3.5 | Sulphuric acid, pickling lines, moderate sour service | Lower |
| 316L stainless steel | 10–14 | 16–18 | 2–3 | General service; limited by chloride SCC and strong acids | Lowest |
Composition figures are nominal ranges given for orientation. Material selection for a specific service must be made by the design authority against the actual temperature, concentration, chloride level and H₂S partial pressure. Alternatives can be quoted side by side on request.
Related grades: Hastelloy G-3, Incoloy 825, Inconel 625, Alloy 20, Alloy 59.
Ordering
Request a quotation for UNS N06985 forgings
Information required for quotation
- Drawing, or rough dimensions with the required machining allowance
- Quantity and required delivery date
- Delivery condition: as-forged, annealed, rough machined or finish machined
- Governing specification and acceptance criteria
- Supplementary requirements: UT, PT, ASTM G28, PMI, grain size, impact testing
- Certificate type: EN 10204 3.1 or 3.2 with third-party inspection
- Marking, preservation and packing instructions
Minimum order is 10 kg with no minimum piece count, so a single part is quotable. Normal lead time is 20 to 60 days from order confirmation. Nickel alloys sit at the upper end of that range because the remelting cycle, the slower forging schedule and the longer solution treatment all add days.
Jiangyin Jiangnan Metal Co., Ltd.
Melting works and open-die forge, Jiangyin, Jiangsu, China
- Address
- No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
- Phone
- 0086-189-2135-9659
- sales@steelforgepieces.com
- Website
- www.steelforgepieces.com
- Established
- 1997
- Response
- Quotation within two working days
- Approvals
- CCS, BV, DNV, LR, NK
- Hours
- Monday to Saturday, 08:00 to 17:30 China Standard Time (UTC+8)
- Export markets
- North America, Europe, the Middle East and Asia-Pacific
FAQ
Frequently asked questions about UNS N06985
What is UNS N06985?
UNS N06985 is a solid-solution nickel-chromium-iron alloy with molybdenum and copper additions, known by the trade name Hastelloy® G-3 and by the material number 2.4619. Nominal composition is approximately 44 % nickel, 21.0–23.5 % chromium, 18.0–21.0 % iron, 6.0–8.0 % molybdenum and 1.5–2.5 % copper, with carbon limited to 0.015 % maximum. The low carbon limit reduces sensitisation in weld heat-affected zones, molybdenum provides pitting and crevice corrosion resistance, and the nickel and copper content gives resistance to reducing acids such as sulphuric and phosphoric acid.
What is the forging temperature range for UNS N06985?
The alloy is hot worked between approximately 927 °C and 1149 °C (1700 °F to 2100 °F). Forging below approximately 927 °C increases the risk of cracking and leaves residual strain. Soaking above approximately 1149 °C increases the risk of grain coarsening and incipient melting. After the final hot working operation the part is solution annealed at approximately 1177 °C (2150 °F) and cooled rapidly by water quench or fast air cool. Jiangyin Jiangnan Metal Co., Ltd. solution anneals every UNS N06985 forging and retains the furnace chart.
Is UNS N06985 the same as Hastelloy G-3?
Yes. UNS N06985 is the UNS designation for the alloy sold under the Haynes International trade name Hastelloy® G-3, also written Alloy G-3 or Inconel® G-3, and designated 2.4619 or NiCr22Mo7Cu in the European system. UNS N06985 is the designation to use on drawings and purchase orders because it defines the chemistry without reference to a trade name.
Can UNS N06985 be hardened by heat treatment?
No. The alloy is solid-solution strengthened and cannot be age hardened. Strength above the annealed minimum is obtained by cold work. Solution annealed material typically meets 621 MPa (90 ksi) tensile strength, 241 MPa (35 ksi) yield strength and 45 % elongation. Cold-worked OCTG product reaches approximately 896 MPa (130 ksi) tensile and 862 MPa (125 ksi) yield, with elongation of approximately 13 %.
Which standards cover UNS N06985?
ASTM B581 covers rod and bar, ASTM B582 plate, sheet and strip, ASTM B622 seamless pipe and tube, ASTM B619 welded pipe, ASTM B626 welded tube and ASTM B366 wrought fittings, with the corresponding ASME SB numbers for pressure equipment. Filler metals are AWS A5.14 ERNiCrMo-9 and AWS A5.11 ENiCrMo-9. No ASTM specification is dedicated to UNS N06985 forgings, so forgings are ordered to the chemistry of ASTM B581 or B582 together with the purchaser drawing, mechanical test and NDT requirements.
How does UNS N06985 compare with Hastelloy C-276?
UNS N06985 is normally lower in cost per kilogram than C-276, because it contains approximately 44 % nickel and 6–8 % molybdenum against approximately 57 % nickel and 15–17 % molybdenum in C-276. For reducing acid duty, phosphoric acid plant equipment and flue gas desulphurisation, N06985 often provides adequate corrosion life at lower alloy cost. For hot concentrated hydrochloric acid or severe oxidising and chloride bearing service, C-276 or C-22 is normally specified. Both grades can be quoted on request.
Who forges UNS N06985 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. The company produces UNS N06985 forged rings, seamless rolled rings, shafts, discs, sleeves, hollow bars and blocks to customer drawings, solution annealed and certified. The works has operated since 1997, melts its own steel and superalloy, and holds CCS, BV, DNV, LR and NK approvals. Telephone 0086-189-2135-9659, email sales@steelforgepieces.com.
What information is needed to quote a forging?
The drawing or rough dimensions with machining allowance, the quantity, the delivery condition, the governing specification, and any supplementary requirements such as ultrasonic testing, positive material identification, ASTM G28 intergranular corrosion testing, NACE MR0175 compliance or third-party inspection. Minimum order is 10 kg with no minimum piece count, normal lead time is 20 to 60 days, and a quotation is returned within two working days.
Manufacturer
Jiangyin Jiangnan Metal Co., Ltd. is an integrated steel melting and open-die forging works in Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, operating since 1997 with 460 staff including 9 senior engineers, 32 intermediate engineers and 140 technicians. Melting, forging, ring rolling, heat treatment, machining and testing are carried out on one site.
For nickel alloys the melting route is in-house: a 3 t vacuum induction furnace, a 6 t vacuum arc remelting furnace and 3 t and 6 t protective-atmosphere electroslag furnaces. Most forging shops in China have to import billet for these grades. Because the steel is melted here, the certificate traces a UNS N06985 part back to its melt number rather than stopping at a purchased billet certificate.
The works holds CCS, BV, DNV, LR and NK approvals and exports to North America, Europe, the Middle East and Asia-Pacific. Customer audits and third-party witness inspection are welcome; arrange visits by email in advance so an English-speaking engineer is available.
The technical data on this page is compiled from published alloy references and from production practice. It is provided for engineering reference and does not replace the material certificate, the governing standard, or the judgement of the design authority responsible for material selection.