Grade identity
What is 2.4603 material?
2.4603 is a fully austenitic nickel-base alloy developed as an improved version of Alloy G-3 (2.4619 / UNS N06985). Raising chromium to about 30 % and adding cobalt and tungsten made it much more resistant to commercial phosphoric acid and to complex mixtures of oxidising acids.
Because the alloy has a very low carbon ceiling (0.03 % max) and a controlled niobium addition, it resists the grain-boundary carbide precipitation that would otherwise sensitise the heat-affected zone. In practice this means 2.4603 fabrications can normally be put into chemical-process service in the as-welded condition, without post-weld solution annealing.
The same material appears in tender documents and on drawings under several names. All of the following refer to one grade.
| System | Designation | Notes |
|---|---|---|
| EN / DIN material number | 2.4603 | Werkstoffnummer, used across Europe |
| DIN name | NiCr30FeMo | Composition-based designation |
| UNS (USA) | N06030 | Used in all ASTM and ASME specifications |
| Trade name | Hastelloy® G-30® | Registered trademark of Haynes International |
| Common short form | Alloy G-30 / G30 | Generic, non-trademarked |
| Welding consumable | ERNiCrMo-11 / ENiCrMo-11 | AWS A5.14 wire, AWS A5.11 electrode |
| Casting and fitting grades | CRHG30 / WPHG30 | Per ASTM B366 |
| ASME Section IX | P-No. 45 | Brazing P-No. 111 |
Hastelloy® and G-30® are registered trademarks of Haynes International, Inc. Jiangyin Jiangnan Metal Co., Ltd. is not affiliated with Haynes International. These names are used only to identify the alloy grade.
Analysis
Chemical composition of 2.4603
The composition below is the specification range required by ASTM B581 and ASTM B582 for UNS N06030, which is identical to the DIN range for 2.4603 (NiCr30FeMo). Every heat we forge is supplied with a certified ladle analysis against these limits.
| Element | Specification range | Typical | Function |
|---|---|---|---|
| Nickel, Ni | Balance | approx. 43 | Austenitic matrix, general corrosion resistance |
| Chromium, Cr | 28.0 to 31.5 | 30.0 | Passive Cr2O3 film, oxidising-acid resistance |
| Iron, Fe | 13.0 to 17.0 | 15.0 | Matrix stability, cost balance |
| Molybdenum, Mo | 4.0 to 6.0 | 5.5 | Reducing-acid and pitting resistance |
| Tungsten, W | 1.5 to 4.0 | 2.5 | Localised corrosion resistance, solid-solution strength |
| Copper, Cu | 1.0 to 2.4 | 2.0 | Resistance to sulphuric and phosphoric acid |
| Niobium, Nb (Cb+Ta) | 0.30 to 1.50 | 0.8 | Carbide stabiliser, protects the weld HAZ |
| Cobalt, Co | 5.0 max | - | Residual or incidental |
| Manganese, Mn | 1.50 max | - | Deoxidiser, sulphur control |
| Silicon, Si | 0.80 max | - | Deoxidiser |
| Carbon, C | 0.030 max | - | Kept low to prevent HAZ sensitisation |
| Phosphorus, P | 0.040 max | - | Impurity limit |
| Sulphur, S | 0.020 max | - | Impurity limit, hot workability |
| Source: ASTM B581 and ASTM B582 for UNS N06030, DIN 2.4603 NiCr30FeMo. Tighter internal limits can be agreed at enquiry stage. | |||
Data
Mechanical and physical properties
Room-temperature mechanical properties
Specification minima apply in the solution-annealed condition. Forgings routinely test well above them. The typical column reflects measured values on solution-annealed plate and bar.
| Property | Specified minimum | Typical measured |
|---|---|---|
| Tensile strength, Rm | 586 MPa (85 ksi) | 678 to 710 MPa |
| Yield strength, Rp0.2 | 241 MPa (35 ksi) | 310 to 351 MPa |
| Elongation, A | 30 % | 53 to 65 % |
| Reduction of area, Z | by agreement | 67 to 77 % |
| Hardness | by agreement | approx. 90 HRB |
| Charpy impact, 20 °C | by agreement | approx. 442 J |
| Charpy impact, -196 °C | by agreement | approx. 527 J |
| Minima per ASTM B581 and ASME SB-581 for UNS N06030. | ||
Elevated-temperature tensile properties
| Temperature | Rp0.2 (MPa) | Rm (MPa) | Elongation (%) |
|---|---|---|---|
| 20 °C | 310 to 351 | 678 to 710 | 53 to 65 |
| 93 °C | 289 | 655 | 54 |
| 204 °C | 248 | 607 | 59 |
| 427 °C | 214 | 552 | 60 |
| 538 °C | 200 | 524 | 62 |
Physical properties
| Property | Value | Condition |
|---|---|---|
| Density | 8.22 g/cm³ (0.297 lb/in³) | 20 °C |
| Modulus of elasticity | 202 GPa | 20 °C |
| Modulus of elasticity | 187 GPa | 400 °C |
| Thermal conductivity | 10 W/m·K | 20 °C |
| Thermal conductivity | 19 W/m·K | 400 °C |
| Mean thermal expansion | 12.8 µm/m·K | 20 to 100 °C |
| Mean thermal expansion | 15.8 µm/m·K | 20 to 600 °C |
| Electrical resistivity | 1.16 µΩ·m | 20 °C |
| Magnetic response | Non-magnetic | Annealed |
Compliance
Which standard covers 2.4603 forgings?
For forged products the governing document is ASTM B462 / ASME SB-462. UNS N06030 is the first alloy named in the scope of that specification, which covers forged or rolled pipe flanges, forged fittings, valves and parts for corrosive and high-temperature service. Note that N06030 is not listed in ASTM B564. Quoting B564 on a 2.4603 purchase order is a common and avoidable error.
| Product form | ASTM | ASME |
|---|---|---|
| Forged flanges, fittings, valves and parts | B462 | SB-462 |
| Billets and bars for reforging | B472 | SB-472 |
| Rod, bar and wire | B581 | SB-581 |
| Plate, sheet and strip | B582 | SB-582 |
| Factory-made wrought fittings | B366 (WPHG30) | SB-366 |
| Seamless pipe and tube | B622 | SB-622 |
| Welded pipe | B619 | SB-619 |
| Welded tube | B626 | SB-626 |
| Electric fusion welded pipe | B474 | SB-474 |
State the product-form standard, not just the grade. "2.4603 forged ring, ASTM B462, solution annealed, EN 10204 3.1" is unambiguous and can be quoted immediately. "2.4603 ring" on its own will trigger a clarification round and cost you a day.
Scope of supply
2.4603 forged products we manufacture
Everything below is open-die forged or ring-rolled to your drawing. There are no stock catalogue sizes and no die costs.
- Seamless rolled rings: radial-axial rolled, for vessel shells, tube sheets and bearing housings
- Forged rings and sleeves: upset and punched, including thick-wall proportions that ring rolling cannot reach
- Forged flanges: WN, SO, BL, LJ, orifice and special-bore, to ASME B16.5, B16.47 or drawing
- Forged shafts and spindles: pump shafts, agitator shafts, eccentric shafts, stepped and hollow-bored
- Forged discs and blanks: blind discs, tube-sheet blanks, gear blanks, closure heads
- Forged bushings and hollow bars: trepanned or punched and drawn
- Forged round, square and flat bars: including reforging billet to ASTM B472
- Forged valve components: bodies, bonnets, seat rings, stems, gates and plug blanks
- Forged nozzles, tube sheets and pipe blanks: for pressure vessels and shell-and-tube exchangers
- Forged rolls and near-net shapes: to reduce machining loss on expensive alloy
Works capability
Size range for 2.4603 forgings
| Parameter | Range |
|---|---|
| Single-piece weight | 5 kg to 20 000 kg |
| Rolled ring outside diameter | 150 to 4 000 mm |
| Ring wall thickness | 20 to 600 mm |
| Ring height | 20 to 1 500 mm |
| Shaft and bar length | up to 8 000 mm |
| Round bar diameter | 60 to 1 200 mm |
| Disc and blank diameter | up to 2 500 mm |
| Minimum order | 1 piece |
| Delivery condition | Forged and solution annealed, rough or finish machined |
Sizes outside this envelope are often still possible through our partner works. Send the drawing and we will tell you whether we can make it.
Process
How a 2.4603 forging is made
2.4603 is an expensive, work-hardening alloy with a narrow hot-working window. The route below is what keeps the grain structure sound and the corrosion performance intact.
- MeltingEAF with AOD or VOD refining to hold the 0.03 % carbon ceiling and control sulphur and phosphorus.
- ESR remeltingElectroslag remelting where the specification or section size calls for improved cleanliness and segregation control.
- Billet inspectionReforging stock verified to ASTM B472. Ladle analysis and macro-etch reviewed before cutting.
- HeatingSoaked to about 1150 °C in a controlled, low-sulphur furnace atmosphere.
- Open-die forgingUpsetting and drawing between 1150 °C and 930 °C, with reheats. Forging below 930 °C risks cracking.
- Ring rollingRadial-axial rolling for seamless rings, giving circumferential grain flow.
- Solution annealingAbout 1180 °C, held 10 to 30 min per section, then water quenched. No ageing step.
- Rough machiningDescaling and machining to test-piece and NDT geometry.
- TestingTensile, hardness, ultrasonic and, on request, ASTM G28 Method A intergranular corrosion testing.
- Certification and despatchEN 10204 3.1 or 3.2 certificate, hard-stamped heat number, marine packing.
Thermal processing
Forging temperatures and heat treatment
| Operation | Parameter | Notes |
|---|---|---|
| Hot working range | 1150 down to 930 °C | Finish above 930 °C. Reheat rather than force the last blow |
| Solution anneal | approx. 1180 °C, 10 to 30 min | Time scaled to section thickness |
| Quench | Water | Rapid air cooling acceptable below about 10 mm section |
| Age hardening | Not applicable | Solid-solution alloy, ageing does not strengthen it |
| Cold work | Re-anneal required | Re-anneal after outer-fibre elongation of 7 % or more |
| Stress relief | Not recommended | Intermediate temperatures risk carbide precipitation |
Some supplier data sheets, including an earlier version of this page, describe 2.4603 as receiving "solution treatment and ageing treatment together". That is wrong. 2.4603 is a solid-solution-strengthened alloy and cannot be age hardened. It is being confused with precipitation-hardening nickel grades such as Inconel 718, Incoloy 925 or Incoloy 945.
An ageing cycle adds no strength to 2.4603, and holding it in the 500 to 800 °C range risks precipitating grain-boundary carbides that reduce the corrosion resistance the alloy was bought for. The correct treatment is solution anneal and quench, nothing after that.
Service performance
Corrosion resistance of 2.4603
2.4603 was designed for the wet-process route in which phosphate rock is digested with sulphuric acid to produce phosphoric acid, typically concentrated up to 54 %. Its high chromium gives strong performance in oxidising media, while molybdenum and copper give useful resistance in reducing acids. Rates below 0.1 mm/year are generally regarded as acceptable for continuous service.
| Medium | Condition | Rate (mm/year) |
|---|---|---|
| Sulphuric acid 77 % + 8 % P2O5 + 4 % HF | 54 °C | 0.01 |
| Nitric acid 10 % | Boiling | 0.01 |
| Acetic acid 99 % | Boiling | 0.03 |
| Nitric acid 18 % + hydrochloric acid 8 % | 80 °C | 0.05 |
| Formic acid 88 % | Boiling | 0.05 |
| Nitric acid 65 % | Boiling | 0.13 |
| Sulphuric acid 50 % + 42 g/l Fe₂(SO₄)₃ (ASTM G28 A) | Boiling | 0.18 |
| Sulphuric acid 2 % | Boiling | 0.20 |
| Sulphuric acid 80 % | 52 °C | 0.30 |
| Sulphuric acid 50 % + 10 % nitric acid | Boiling | 0.40 |
| Sulphuric acid 50 % | 107 °C | 0.93 |
| Nitric acid 20 % + 6 % HF | 80 °C | 4.43 |
| Published laboratory data for solution-annealed material, given for comparison only. Plant conditions differ. Always qualify the alloy against your own process stream before final material selection. | ||
2.4603 is also moderately resistant to chloride-induced pitting and crevice attack, which is a practical concern beneath deposits in P2O5 evaporators. It is much less susceptible to chloride stress-corrosion cracking than austenitic stainless steels.
Fabrication
Welding 2.4603 forgings
- Filler metals: ERNiCrMo-11 bare wire (AWS A5.14) for GTAW and GMAW, ENiCrMo-11 covered electrode (AWS A5.11) for SMAW.
- ASME Section IX: welding P-No. 45, brazing P-No. 111.
- Preheat: not required. Keep interpass temperature below about 150 °C.
- PWHT: normally unnecessary. The low carbon and niobium stabilisation resist HAZ carbide precipitation, so most chemical-process service is acceptable as-welded.
- Severe acid service: where the process stream is aggressive, a full re-solution anneal after welding restores optimum corrosion resistance.
- Cleanliness: nickel alloys are intolerant of sulphur and chloride contamination. Degrease and remove all marker, grease and shop-dirt residue before striking an arc.
End use
Where 2.4603 forgings are used
| Industry | Forged components |
|---|---|
| Phosphoric acid and fertiliser | Evaporator and reactor rings, agitator shafts, pump casings and shafts, flanges, nozzles, valve bodies |
| Chemical process | Pressure-vessel shell rings, tube sheets, heat-exchanger flanges, column and tower forgings, closure discs |
| Nitric and mixed-acid plant | Absorber internals, forged bends and blanks, valve seat rings and stems |
| Pickling and metal finishing | Tank flanges, sleeves and bushings, roll journals, heating-coil headers |
| Air-pollution control and FGD | Scrubber and duct flanges, damper shafts, fan hubs, stack-liner rings |
| Pulp and paper | Bleach-plant shafts and sleeves, digester nozzles, forged rolls |
| Gold extraction and hydrometallurgy | Autoclave forgings, agitator hubs, valve components |
| Nuclear waste processing | Reprocessing vessel flanges, forged discs and nozzles |
| Pesticide and agrichemical | Reactor flanges, forged bushings, pump and mixer shafts |
Quality
Testing, inspection and certification
Non-destructive testing
- Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388, to the quality class you nominate
- Liquid penetrant testing to ASTM E165 or EN ISO 3452
- Dimensional inspection against drawing, with a signed report
Destructive and corrosion testing
- Tensile and hardness testing to ASTM A370 or EN ISO 6892-1
- Charpy V-notch impact testing at ambient or cryogenic temperature
- Intergranular corrosion testing to ASTM G28 Method A
- Grain size and microstructure examination to ASTM E112
- PMI (positive material identification) by XRF or OES on every piece, on request
Documentation
- EN 10204 3.1 mill certificate as standard
- EN 10204 3.2 with third-party witness by TUV, BV, SGS, Lloyd's or your own inspector
- Full heat traceability with hard-stamped heat and item numbers
- Certificate of origin, packing list and mill test reports issued with every shipment
Next step
How to request a quotation
Send a drawing or the six lines below to sales@steelforgepieces.com. Complete enquiries are quoted within one working day.
- Grade and standard: for example 2.4603 / UNS N06030, ASTM B462
- Product form and dimensions: OD x ID x height, or the drawing number
- Quantity: pieces, and whether repeat orders are expected
- Delivery condition: as-forged, solution annealed, rough machined or finish machined
- Testing and certification: UT class, EN 10204 3.1 or 3.2, ASTM G28 A if required
- Destination port and required delivery date
Questions
Frequently asked questions about 2.4603
Is 2.4603 the same as Hastelloy G-30?
Yes. 2.4603 is the European material number for the alloy sold under the Haynes International trade name Hastelloy® G-30®, designated UNS N06030 in the American system and NiCr30FeMo in DIN. All four refer to the same nickel-chromium-iron-molybdenum-copper composition.
Does 2.4603 need age hardening after forging?
No. 2.4603 is a solid-solution-strengthened alloy and cannot be age hardened. The only heat treatment it requires after forging is a solution anneal at about 1180 °C followed by a water quench. Ageing adds no strength and, if held in the 500 to 800 °C range, can precipitate grain-boundary carbides that reduce corrosion resistance.
Which ASTM standard applies to 2.4603 forgings?
ASTM B462 and ASME SB-462 cover forged or rolled UNS N06030 pipe flanges, forged fittings, valves and parts for corrosive and high-temperature service. Reforging billets and bars fall under ASTM B472, and rod and bar under ASTM B581. UNS N06030 is not included in ASTM B564, so that specification should not be cited for this grade.
What is the chemical composition of 2.4603?
Nickel balance (about 43 %), chromium 28.0 to 31.5 %, iron 13.0 to 17.0 %, molybdenum 4.0 to 6.0 %, tungsten 1.5 to 4.0 %, copper 1.0 to 2.4 %, niobium 0.30 to 1.50 %, cobalt 5.0 % max, manganese 1.50 % max, silicon 0.80 % max, carbon 0.030 % max, phosphorus 0.040 % max and sulphur 0.020 % max.
What are the mechanical properties of 2.4603?
In the solution-annealed condition the specified minima are 586 MPa (85 ksi) tensile strength, 241 MPa (35 ksi) yield strength at 0.2 % offset, and 30 % elongation. Typical measured values are considerably higher: 678 to 710 MPa tensile, 310 to 351 MPa yield and 53 to 65 % elongation. Density is 8.22 g/cm³.
How does 2.4603 compare with Alloy G-3 (2.4619)?
2.4603 is the improved successor to Alloy G-3, UNS N06985, W.Nr. 2.4619. It carries higher chromium, about 30 % against roughly 22 %, plus cobalt and tungsten additions. That gives substantially better resistance in commercial phosphoric acid and in mixed oxidising acids, along with improved resistance to pitting and crevice attack.
Can 2.4603 be used in the as-welded condition?
In most chemical-process environments, yes. The 0.03 % maximum carbon and the niobium addition resist grain-boundary carbide precipitation in the heat-affected zone, so post-weld solution annealing is usually not required. For the most aggressive acid service, a full re-solution anneal after welding restores optimum corrosion performance.
What is the corrosion rate of 2.4603 in phosphoric acid?
Published laboratory data show 0.01 mm/year in 77 % sulphuric acid with 8 % P₂O₅ and 4 % hydrofluoric acid at 54 °C. Rates below 0.1 mm/year are generally regarded as acceptable for continuous service. Plant streams vary, so qualify the alloy against your own process conditions before final selection.
What is the maximum size of 2.4603 forging you can produce?
Single-piece forgings from 5 kg to 20 tonnes, seamless rolled rings up to 4 000 mm outside diameter, shafts up to 8 000 mm long and discs up to 2 500 mm diameter. Minimum order is one piece, and there are no die costs on open-die work.
Who manufactures 2.4603 open-die forgings in China?
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging works at No. 1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, producing 2.4603 / UNS N06030 forged rings, flanges, shafts, discs and bars to customer drawing. Contact sales@steelforgepieces.com or +86 189 2135 9659. Quotations are issued within one working day of a complete enquiry.
What certification is supplied with 2.4603 forgings?
EN 10204 3.1 mill certificates as standard, or EN 10204 3.2 with third-party witness by TUV, BV, SGS, Lloyd's or your own inspector. Certificates cover ladle analysis, mechanical test results, heat treatment record, ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388, and full heat traceability by hard-stamped heat number.
Jiangyin Jiangnan Metal Co., Ltd.
Open-die forging works · Manufacturer of 2.4603 forgings
- Address
- No. 1 Chengxiqiao Road,
Zhouzhuang Town, Jiangyin City,
Jiangsu Province 214423, China - Telephone
- +86 189 2135 9659
0086-189-2135-9659 - Website
- www.steelforgepieces.com
- Specialisation
- Open-die forgings and seamless rolled rings in nickel alloy, stainless, tool, alloy and carbon steel
- Response time
- Quotation within one working day of a complete enquiry
Cite this page
Jiangyin Jiangnan Metal Co., Ltd. (2026). 2.4603 (UNS N06030 / Hastelloy G-30) Forgings: Material Data Sheet and Forging Capability. Retrieved from https://www.steelforgepieces.com/Nickel-Alloy/2.4603.html