Overview
2.4602 is the Werkstoff number for a low-carbon nickel-chromium-molybdenum-tungsten corrosion-resistant alloy, also designated UNS N06022, EN NiCr21Mo14W and ISO NiCr21Mo14W3, and sold commercially as Alloy 22 or Hastelloy C-22. It contains nominally 21% chromium, 13.5% molybdenum and 3% tungsten with nickel as the balance, giving it resistance to both oxidising and reducing acids, to pitting and crevice attack in acid-halide media, and to intergranular attack in the as-welded condition.
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. It produces 2.4602 forged rings, seamless rolled rings, flanges, round bars, discs, shafts, sleeves, bushings and tube sheets from 20 kg to 10,000 kg per piece, to DIN 17744, ASTM B564 and ASME SB-564, supplied solution annealed at 1105–1135 °C with a rapid water quench. Enquiries: sales@steelforgepieces.com, telephone +86 189 2135 9659.
Equivalent designations for 2.4602
The same chemistry appears on drawings and mill certificates under several designations. All of the designations below specify one material, and an enquiry for 2.4602, N06022 or Alloy 22 is quoted identically.
| System | Designation | Note |
|---|---|---|
| Werkstoff (EN / DIN) | 2.4602 | Material number used across Europe |
| EN chemical name | NiCr21Mo14W | DIN 17744 |
| ISO | NiCr21Mo14W3 | ISO 9723 / 9724 |
| UNS | N06022 | ASTM / ASME designation |
| JIS | NW6022 | Japanese equivalent |
| Common trade names | Hastelloy C-22, Alloy 22, INCONEL alloy 22, VDM Alloy 22, Nicrofer 5621 hMoW, ATI 22 | Producer brands for the same chemistry |
| Matching filler metal | ERNiCrMo-10 / ENiCrMo-10 (W86022) | AWS A5.14 / A5.11 |
Hastelloy is a registered trademark of Haynes International. Jiangyin Jiangnan Metal Co., Ltd. supplies this grade under the generic designations 2.4602 and UNS N06022 and is not affiliated with any trademark holder.
2.4602 forged product forms we supply
All forms listed below are open-die forged or ring rolled from VOD-refined or ESR-remelted 2.4602 billet. Forging refines the as-cast structure and produces grain flow that follows the part contour, which is the reason pressure vessel and valve codes specify forgings rather than components cut from plate.
- Seamless rolled ringsOD 200–3,000 mm
- Forged ringsRectangular and contoured
- Forged flangesWN, SO, BL, LJ, orifice
- Round barsØ80–1,200 mm
- Discs and disksUp to Ø2,500 mm
- Shafts and spindlesUp to 8,000 mm long
- Sleeves and bushingsBored and turned
- Tube sheetsHeat-exchanger service
- Hollow bars and tubesForged and trepanned
- Valve bodies and stemsBall, gate, globe, check
- Blocks and slabsRectangular forgings
- Nozzles and manifoldsTo drawing
Chemical composition of 2.4602
Composition limits per DIN 17744 and ASTM B574 / B564. Single figures are maxima; ranges are minimum–maximum. Nickel is the balance and typically runs near 56%.
| Element | Ni | Cr | Mo | W | Fe | Co | Mn | V | Si | C | P | S |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | bal. | 20.0 | 12.5 | 2.5 | 2.0 | — | — | — | — | — | — | — |
| Max | bal. | 22.5 | 14.5 | 3.5 | 6.0 | 2.5 | 0.50 | 0.35 | 0.08 | 0.015 | 0.025 | 0.02 |
DIN 17744 restricts carbon further, to 0.010% maximum. Where a purchase order calls out DIN 17744 rather than ASTM, Jiangyin Jiangnan Metal Co., Ltd. procures billet melted to the lower carbon limit.
Function of the main elements
Chromium at 20.0 to 22.5% gives resistance to oxidising media such as nitric acid and ferric and cupric chlorides. This is the principal difference between 2.4602 and the earlier C-276, which carries about 16% chromium. Molybdenum and tungsten give resistance to reducing media such as sulphuric and hydrochloric acid, and together with chromium determine the pitting resistance.
Carbon is held to a low maximum and the material is supplied solution annealed, so chromium carbides do not precipitate at the grain boundaries. 2.4602 therefore retains its corrosion resistance in the as-welded condition, and post-weld heat treatment is not required.
Pitting resistance equivalent number: PREN = Cr + 3.3(Mo + 0.5W) = 21 + 3.3(13.5 + 1.5) = 70 at nominal composition.
Mechanical properties of 2.4602 forgings
Room-temperature values in the solution-annealed condition, to ASTM B564 and B574.
| Property | Metric | Imperial | Requirement |
|---|---|---|---|
| 0.2% proof stress (Rp0.2) | 310 MPa | 45 ksi | Minimum |
| Tensile strength (Rm) | 690 MPa | 100 ksi | Minimum |
| Elongation (A, 4D / 50 mm) | 45% | 45% | Minimum |
| Hardness | 100 HRB | 100 HRB | Maximum |
Impact testing, elevated-temperature tensile testing and through-thickness (short transverse) sampling are available on request. State these requirements on the enquiry so that test material can be allowed for in the forging.
Physical properties of 2.4602
| Property | Value | Condition |
|---|---|---|
| Density | 8.69 g/cm³ (0.314 lb/in³) | 20 °C |
| Melting range | ≈1335–1400 °C | Solidus to liquidus |
| Modulus of elasticity | 206 GPa (29.9 × 10³ ksi) | Tension, 20 °C |
| Thermal conductivity | 10.1 W/(m·K) | 20 °C |
| Mean coefficient of expansion | 11.1–12.4 × 10⁻⁶ K⁻¹ | 20–100 °C |
| Electrical resistivity | 1.14 µΩ·m | 20 °C |
| Magnetic permeability | ≈1.0 | Fully austenitic, non-magnetic |
How we make a 2.4602 forging
Production sequence for a 2.4602 forging. Each stage is completed and released before the next begins.
- Melting and remeltingBillet is EAF melted and AOD or VOD refined. ESR remelt is used where the drawing, NACE service or a heavy cross-section requires closer control of cleanliness and segregation.
- HeatingCharged and soaked at 1160 to 1180 °C. 2.4602 is hot short above this range and will crack during the first reduction if it is overheated.
- Open-die forging or ring rollingUpsetting, drawing and punching on hydraulic presses. Rings are punched, expanded and rolled to give circumferential grain flow. Finishing temperature is held above 954 °C, with reheating as required by the section size.
- Solution annealing1105 to 1135 °C, soaked according to section thickness, then quenched rapidly in water. This dissolves carbides and topologically close-packed phases and restores the corrosion resistance of the alloy.
- Descaling and machiningShot blasting or pickling, followed by boring, facing, turning and drilling. Parts are supplied black, rough machined or finish machined to drawing.
- Testing and certificationChemical analysis, tensile and hardness testing, ultrasonic examination and any optional corrosion testing. EN 10204 3.1 certification, or 3.2 with third-party witness, is issued against the heat number.
2.4602 is not age hardenable
2.4602 is a single-phase, solid-solution-strengthened alloy. An ageing cycle does not raise its strength. It precipitates carbides and topologically close-packed phases, which reduce ductility and lower the corrosion resistance for which the alloy was specified. Any hold in the range 600 to 900 °C has the same effect, including slow cooling from the solution anneal.
The correct final condition is solution annealed at 1105 to 1135 °C followed by a rapid water quench.
Testing, inspection and certification
| Test | Standard | Scope |
|---|---|---|
| Chemical analysis | Spectrometer / ICP-OES per heat | Standard |
| Tensile and hardness | ASTM A370 / ISO 6892-1 | Standard |
| Ultrasonic examination | EN 10228-3, SEP 1921, ASTM A388 | Standard |
| Intergranular corrosion | ASTM G28 Method A | Optional |
| Pitting and crevice corrosion | ASTM G48 Method C / D | Optional |
| Positive material identification | PMI, XRF or OES | Optional |
| Liquid penetrant examination | ASTM E165 / EN ISO 3452 | Optional |
| Impact testing | ASTM E23 / ISO 148-1 | Optional |
| Certification | EN 10204 3.1, or 3.2 witnessed by TÜV, SGS, BV, LR or DNV | Standard / on request |
Where 2.4602 forgings are used
2.4602 is specified for duties that combine oxidising and reducing conditions, or that alternate between them, and for chloride-bearing environments in which stainless steel is not suitable. Typical forged parts by sector:
| Industry | Typical 2.4602 forged parts | Why this grade |
|---|---|---|
| Chemical and petrochemical | Reactor flanges, rolled rings, tube sheets, nozzles, agitator shafts | Mixed acid service, as-welded corrosion resistance |
| Flue gas desulphurisation | Rings, discs, fan shafts, damper components | Wet chloride and low-pH condensate |
| Oil, gas and offshore | Valve bodies, stems, seat rings, wellhead and subsea blocks | Sour service under NACE MR0175 / ISO 15156 |
| Pharmaceutical and fine chemicals | Vessel flanges, sleeves, bushings, sanitary fittings | Product purity, cleanability, no iron pickup |
| Pulp and paper | Bleach-plant shafts, rolls, rings | Chlorine dioxide bleaching environments |
| Nuclear and waste treatment | Containment rings, discs, forged blocks | Long-term general and localised corrosion resistance |
| Marine and desalination | Pump shafts, sleeves, impeller hubs | Seawater pitting and crevice resistance |
| Power generation | Heat-exchanger tube sheets, flanges, fasteners stock | Condensate and scrubber duty |
2.4602 compared with C-276 and Alloy 625
These three grades are frequently quoted against one another. Alloy 625 has the highest strength and the lowest cost of the three. C-276 is preferred for strongly reducing acids. 2.4602 covers both oxidising and reducing conditions in one material.
| Property | 2.4602 / Alloy 22 N06022 |
2.4819 / C-276 N10276 |
2.4856 / Alloy 625 N06625 |
|---|---|---|---|
| Chromium, % | 20.0–22.5 | 14.5–16.5 | 20.0–23.0 |
| Molybdenum, % | 12.5–14.5 | 15.0–17.0 | 8.0–10.0 |
| Tungsten, % | 2.5–3.5 | 3.0–4.5 | — |
| PREN (approx.) | ≈70 | ≈75 | ≈51 |
| Min. tensile, MPa | 690 | 690 | 827 |
| Oxidising acids | Excellent | Moderate | Good |
| Reducing acids | Excellent | Excellent | Moderate |
| As-welded IGA resistance | Excellent | Good | Good |
| Relative cost | High | High | Moderate |
All three grades are forged at Jiangyin Jiangnan Metal Co., Ltd. Where the grade is not yet fixed, state the medium, concentration, temperature and chloride content on the enquiry and alternatives will be quoted. Related pages: Hastelloy C-276 forgings, Inconel 625 forgings, Alloy 59 forgings.
Size and weight capability
| Form | Range | Notes |
|---|---|---|
| Single-piece weight | 20 – 10,000 kg | Rough forged weight |
| Seamless rolled ring OD | 200 – 3,000 mm | Wall and height to drawing |
| Forged disc diameter | up to 2,500 mm | Solid or bored |
| Round bar diameter | 80 – 1,200 mm | Forged, peeled or turned |
| Shaft length | up to 8,000 mm | Stepped or straight |
| Delivery condition | Solution annealed | Black, rough machined or finish machined |
| Typical lead time | 25 – 45 days | Subject to billet availability |
Frequently asked questions about 2.4602
What is material 2.4602?
2.4602 is the Werkstoff (EN/DIN) number for a low-carbon nickel-chromium-molybdenum-tungsten corrosion-resistant alloy, designated UNS N06022, EN NiCr21Mo14W and ISO NiCr21Mo14W3. It contains nominally 21% chromium, 13.5% molybdenum and 3% tungsten with nickel as the balance, and is widely known by the trade name Hastelloy C-22 or Alloy 22.
Is 2.4602 the same as Hastelloy C-22?
Yes. 2.4602, UNS N06022, NiCr21Mo14W and Alloy 22 all describe the same chemistry. Hastelloy C-22 is the registered trade name used by Haynes International; other producers sell the identical grade as VDM Alloy 22, Nicrofer 5621 hMoW, INCONEL alloy 22 and ATI 22. Jiangyin Jiangnan Metal Co., Ltd. supplies forgings in this grade under the generic designations 2.4602 / UNS N06022.
What is the chemical composition of 2.4602?
2.4602 contains 20.0–22.5% chromium, 12.5–14.5% molybdenum, 2.5–3.5% tungsten, 2.0–6.0% iron, maximum 2.5% cobalt, maximum 0.50% manganese, maximum 0.35% vanadium, maximum 0.08% silicon, maximum 0.025% phosphorus, maximum 0.02% sulphur and maximum 0.015% carbon, with nickel as the balance, typically about 56%.
What are the minimum mechanical properties of 2.4602 forgings?
In the solution-annealed condition at room temperature, 2.4602 forgings meet a minimum 0.2% proof stress of 310 MPa (45 ksi), a minimum tensile strength of 690 MPa (100 ksi), a minimum elongation of 45% and a maximum hardness of 100 HRB.
Can 2.4602 be age hardened?
No. 2.4602 is a single-phase solid-solution-strengthened austenitic alloy and is not age hardenable. The correct final heat treatment is a solution anneal at 1105–1135 °C followed by a rapid water quench. Holding the alloy in the 600–900 °C range precipitates carbides and topologically close-packed phases that reduce ductility and corrosion resistance, so slow cooling and ageing treatments must be avoided.
What is the difference between Alloy 22 and Hastelloy C-276?
Alloy 22 (2.4602 / N06022) carries about 21% chromium against roughly 16% in C-276 (2.4819 / N10276), so it performs better in oxidising media such as nitric acid and ferric or cupric chloride, and resists intergranular attack in the as-welded condition. C-276 carries more molybdenum and tungsten and is generally preferred for strongly reducing conditions such as concentrated hydrochloric acid. Both have similar strength and are supplied solution annealed.
Which standards cover 2.4602 forgings?
Forgings are covered by ASTM B564 and ASME SB-564; rod and bar by ASTM B574, ASTM B462 and ASME SB-574; plate, sheet and strip by ASTM B575 and ASME SB-575. German and European standards include DIN 17744 for chemical composition, DIN 17752 and 17754, and VdTÜV Sheet 479. The grade is also listed in NACE MR0175 / ISO 15156 and NACE MR0103 / ISO 17945 for sour service.
What size range of 2.4602 forgings can be produced?
Jiangyin Jiangnan Metal Co., Ltd. open-die forges 2.4602 components from about 20 kg to 10,000 kg per piece, with seamless rolled rings up to 3,000 mm outside diameter, forged discs up to 2,500 mm diameter, forged bars from 80 mm to 1,200 mm diameter and shafts up to 8,000 mm long.
What testing and certification is supplied with 2.4602 forgings?
Standard scope includes chemical analysis, room-temperature tensile and hardness testing, and ultrasonic examination to EN 10228-3, SEP 1921 or ASTM A388. Optional testing includes ASTM G28 Method A intergranular corrosion, ASTM G48 pitting and crevice corrosion, PMI, liquid penetrant examination and impact testing. Material is certified to EN 10204 3.1, or EN 10204 3.2 with third-party witness by TÜV, SGS, BV, Lloyd's Register or DNV.
How do I request a quotation for 2.4602 forgings?
Send the drawing or the finished and rough dimensions, quantity, applicable standard and required certification to sales@steelforgepieces.com, or call +86 189 2135 9659. Jiangyin Jiangnan Metal Co., Ltd. is at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, and normally returns a quotation within 24 hours.
Request a quotation for 2.4602 forgings
Send a drawing for quotation. Where no drawing is available, the following details are sufficient to price the work:
- Grade: 2.4602 or the equivalent designation on your drawing
- Form and dimensions: rough or finished, with tolerances
- Quantity and required delivery date
- Applicable standard: ASTM B564, DIN 17744, NACE MR0175 and similar
- Certification: EN 10204 3.1, or 3.2 with a named third party
Telephone / WhatsApp / WeChat: +86 189 2135 9659
Email: sales@steelforgepieces.com
Web: www.steelforgepieces.com
Standards and references
Property data on this page is consistent with the following published specifications and producer data sheets. Jiangyin Jiangnan Metal Co., Ltd. is an independent forging supplier and is not affiliated with any of these organisations.
- ASTM B574: Standard Specification for Low-Carbon Ni-Cr-Mo Rod and Bar
- Special Metals: INCONEL alloy 22 technical bulletin
- VDM Metals: Alloy 22 / Nicrofer 5621 hMoW data sheet
- Hastelloy alloy family: overview
Published 18 March 2024. Last reviewed by the technical sales department of Jiangyin Jiangnan Metal Co., Ltd. Data is given for guidance. Confirm design values against the governing specification for the application.