2.4851 Forgings Alloy 601, UNS N06601, NiCr23Fe, Inconel® 601, NS313. Open-die forged rings, flanges, shafts, discs and bars.

What is 2.4851 material?

2.4851 is the German Werkstoff number for a nickel-chromium-iron alloy with an aluminium addition. Europe standardises it as NiCr23Fe under EN 10095, North America as UNS N06601. It is the same material sold under the trade names Inconel® 601, Nicrofer® 6023 H and Pyromet® 601, and designated NS313 in Chinese practice.

The alloy is not precipitation hardenable. Strength comes from solid-solution strengthening of the face-centred-cubic nickel matrix, so 2.4851 forgings leave the works solution annealed rather than solution treated and aged. Where a higher strength level is needed, it has to come from cold work plus a controlled anneal, not from an ageing cycle.

Aluminium at 1.0 to 1.7 % is what separates this grade from the rest of the Ni-Cr family. Above roughly 1,040 °C the aluminium forms a dense Al₂O₃ layer beneath the chromia scale, and that layer is more stable than Cr₂O₃ on its own. It is why 2.4851 outlasts 2.4816 (Alloy 600) in cyclic oxidation, carburising and nitriding atmospheres, while both grades behave similarly in aqueous corrosion.

2.4851 chemical composition

Composition limits below follow EN 10095 for NiCr23Fe / 2.4851. All values are mass percent.

The two standard systems do not match exactly. ASTM B564 for UNS N06601 allows copper to 1.00 % and treats iron as the balance rather than capping it at 18 %. On orders calling for dual certification to EN 10095 and ASTM B564, Jiangyin Jiangnan Metal Co., Ltd. melts to the tighter of the two limit sets and reports both on the mill certificate.

2.4851 mechanical properties

Room-temperature minimum values for solution-annealed 2.4851 forgings. Results in practice depend on section size, forging reduction ratio and grain size. Each heat and test lot is reported on the EN 10204 certificate.

Elevated-temperature tensile data, stress-rupture data and impact values can be sent with the quotation when the enquiry states a design temperature.

2.4851 physical properties

How Jiangyin Jiangnan Metal forges 2.4851

Melting and starting stock

2.4851 forging stock comes from electric arc furnace melting followed by AOD or VOD refining. Electroslag remelting is added where the order calls for reduced segregation and tighter inclusion cleanliness, which usually means rotating components or thick-section pressure parts.

Open-die forging and ring rolling

2.4851 is forged between 1,040 °C and 1,230 °C. Working stops before the piece drops below roughly 950 °C and the part goes back to the furnace, because Alloy 601 has a hot-ductility trough between about 650 °C and 870 °C where forging cracks start. Furnace atmosphere is kept low in sulphur and stock is degreased before charging, since sulphur pick-up embrittles nickel alloys at forging heat.

Rings are produced by upsetting, punching and radial-axial ring rolling. That route gives continuous circumferential grain flow and removes the weld line a fabricated ring carries. Shafts, bars and stepped forgings are drawn out under the press at a controlled forging ratio, so the reduction achieved is verifiable back to the ingot dimensions.

Heat treatment

Finished 2.4851 forgings are solution annealed at 1,100 to 1,180 °C and cooled quickly through the 540 to 760 °C band. Fast cooling avoids sensitisation and thermal cracking. Soak time is kept short to hold grain growth down. No ageing step follows, since 2.4851 gains nothing from precipitation hardening.

Machining allowance

Forgings ship black, rough machined or finish machined. Jiangyin Jiangnan Metal Co., Ltd. machines to the customer drawing and can leave the allowance needed for ultrasonic inspection of the final contour.

2.4851 forging size range and capability

Send a drawing or a finished-size sketch to sales@steelforgepieces.com and Jiangyin Jiangnan Metal Co., Ltd. will confirm the forging ratio, ingot size and price for that specific part.

Where 2.4851 forgings are used

2.4851 keeps its protective scale under thermal cycling and in carburising gas, which puts it in hot-end components that would scale away in stainless steel.

2.4851 against other nickel alloys

Picking between the Ni-Cr grades usually comes down to two questions: how hot does it run, and is the attack gaseous or aqueous.

Testing and certification supplied with 2.4851 forgings

• Chemical analysis per heat by optical emission spectrometry, reported against EN 10095 and ASTM B564 limits.
• Mechanical testing: tensile, elongation and hardness at room temperature, with elevated-temperature tensile on request.
• Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388, at the acceptance class stated on the purchase order.
• Positive material identification on request, piece by piece.
• Grain size and microstructure to ASTM E112 where specified.
• Dimensional report against the customer drawing before shipment.
• EN 10204 3.1 certificate as standard. EN 10204 3.2 with TUV, BV, SGS, Lloyd's or DNV witness on request.
• Heat number, grade and order number hard-stamped or vibro-etched on each forging for traceability.

Quality system: ISO 9001:2015.

Frequently asked questions about 2.4851

Related grades and forged product pages

• 2.4816 forgings
• 2.4668 forgings
• Inconel 625 forgings
• 17-4PH forgings
• 15-5PH forgings
• PH13-8Mo forgings
• Forged rings
• Forged flanges
• Forged shafts
• Forged bushings
• Forged spindles
• All nickel alloy forgings