UNS N07263 Forgings: Nimonic 263 / Haynes 263 / W.Nr. 2.4650

What UNS N07263 is

UNS N07263 is an age-hardenable nickel-cobalt-chromium-molybdenum superalloy, sold under the trade names Nimonic 263, Haynes 263 and Alloy C-263 and designated W.Nr. 2.4650. It holds useful strength and oxidation resistance to about 850 °C while remaining far easier to form and weld than Waspaloy or René 41. Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory at No. 1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, forges UNS N07263 to customer drawings as seamless rolled rings, discs, shafts, flanges, sleeves, bushings, tube sheets and round bars, and supplies every heat with an EN 10204 3.1 or 3.2 mill test certificate.

The alloy was developed by Rolls-Royce (1971) Ltd. to solve a specific fabrication problem: Nimonic 80A had the high-temperature strength that turbine casings needed, but welded assemblies cracked. Alloy 263 keeps roughly 20 % chromium and 20 % cobalt, adds about 6 % molybdenum for solid-solution strengthening, and deliberately holds combined aluminium plus titanium down to 2.4–2.8 %. That modest gamma-prime volume fraction is the whole point. It buys weldability and intermediate-temperature ductility at the cost of a little peak strength.

On the shop floor this shows up in three ways. The alloy is supplied and worked in the solution-treated condition, so it upsets and draws down without the cracking risk of higher gamma-prime grades. It ages in a single 800 °C step rather than a two-stage cycle. And because it does not suffer strain-age cracking on post-weld heat treatment, fabricated ring and casing assemblies can be welded after forging and then aged as a unit.

Where UNS N07263 is the right choice

• Choose it for hot-section gas turbine hardware between 650 °C and 850 °C that must be welded, formed or fabricated: combustor casings, transition liners, exhaust cones, rings and turbine casings.
• Choose Waspaloy or René 41 instead when peak stress-rupture strength above 800 °C governs and the part is machined from solid rather than fabricated.
• Choose Inconel 718 instead below about 650 °C, where 718 is stronger, cheaper and more widely stocked.

Designations, equivalents and standards

UNS N07263 is the same alloy as Nimonic 263, Haynes 263, Alloy C-263, Nicrofer 5120 and W.Nr. 2.4650 (NiCr20Co18Ti); for bars, forgings and rings the governing specifications are AMS 5886, BS HR10 and AECMA prEN 2200.

Chemical composition of UNS N07263

UNS N07263 contains 19.0–21.0 % chromium, 19.0–21.0 % cobalt, 5.6–6.1 % molybdenum, 1.9–2.4 % titanium and 0.04–0.08 % carbon, with combined aluminium plus titanium held to 2.4–2.8 % and the balance nickel (typically 49–52 %).

The four tramp elements at the bottom of Table 3, Pb, Ag, Bi and S, are the ones that decide whether a heat can be forged at all. Lead, silver and bismuth segregate to grain boundaries and cause hot shortness during upsetting, which is why Alloy 263 specifications control them to parts per million. We reject incoming stock that does not certify against all four.

Mechanical properties of UNS N07263 forgings

Solution treated and aged UNS N07263 bar and forgings develop a typical room-temperature 0.2 % proof strength of 585 MPa, a tensile strength of 1004 MPa and 45 % elongation; at 780 °C the minimum values fall to 403 MPa proof, 541 MPa tensile and 12 % elongation. In the solution-treated condition, before ageing, hardness is 248 HB maximum.

Source: Jiangyin Jiangnan Metal Co., Ltd., UNS N07263 forging specification, consistent with AMS 5886 and BS HR10. Values are for the certified test-piece condition; section size, test-piece orientation and position within a large ring or disc all shift results. Tell us the acceptance criteria in your drawing and we will confirm achievability before we accept the order.

Test-piece orientation on rings and discs

For seamless rolled rings we take tangential test pieces from a prolongation on the ring, which is the orientation most ring specifications call for. For large disc forgings we can machine test pieces tangentially from near the centre, or radially, whichever your specification demands. State the orientation on the enquiry, because it changes both the quoted price and the forging reduction we plan.

Physical properties

UNS N07263 has a density of 8.36 g/cm³, a melting range of 1300–1355 °C and a room-temperature elastic modulus of approximately 221 GPa, and is non-magnetic in all supplied conditions.

Specific heat, thermal conductivity, electrical resistivity and mean coefficient of thermal expansion across the full temperature range are available on request. Email sales@steelforgepieces.com and we will send the data sheet we work from.

Heat treatment of UNS N07263 forgings

UNS N07263 bar and forgings are solution treated at 1150 °C for 1.5–2.5 hours followed by a water quench, then aged at 800 °C for 8 hours and air cooled. That is a single-stage ageing cycle, per AMS 5886 and BS HR10.

Which condition to order

Order solution treated if the forging will be welded into an assembly or heavily machined after delivery. The material is soft, ductile and forgiving, and you age the finished fabrication yourself. Order solution treated and aged if the forging is a finished part and you want certified aged properties on the test report. We can also supply solution treated with a documented ageing recipe on the certificate, so your own furnace can reproduce it.

Forging practice for Alloy 263

UNS N07263 is hot worked between about 1000 °C and 1150 °C, with the finishing temperature kept above 1000 °C and the piece reheated as often as the schedule requires; forging below the gamma-prime solvus wastes press energy and risks cracking.

Horizontal scale runs 700 °C to 1200 °C. Compiled by Jiangyin Jiangnan Metal Co., Ltd. from the AMS 5886 / BS HR10 heat-treatment schedule and our own shop practice on Alloy 263. In words: forge between 1000 °C and 1150 °C, solution treat at 1150 °C, age at 800 °C, and run the finished part continuously at no more than 850 °C.

How we forge it

1. Incoming stock. Billet is supplied to the Table 3 chemistry with a full ladle analysis including Pb, Bi, Ag and S. Standard melting route is EAF + VOD + ESR; VIM + ESR or VIM + VAR is available where an aerospace or OEM specification requires a double- or triple-melt route. Confirm the melt route you need at enquiry stage, because it is the single largest cost driver on this alloy.
2. Heating. Soak to 1150 °C, held long enough for the section to equalise. Alloy 263 is not tolerant of a cold core on the first blow.
3. Open-die working. Upsetting and drawing on 1 t, 3 t, 5 t and 9 t hammers, or on the 5000-tonne hydraulic press for heavy sections. Reduction is planned to break down the as-cast structure through the full section, not just the surface.
4. Ring rolling. Pierced and rolled seamless, 200–2500 mm OD. Contoured profiles are rolled where the drawing justifies the tooling.
5. Reheat discipline. Back to the furnace whenever the surface drops toward 1000 °C. Finishing cold on this alloy is how ring cracks start.
6. Solution treat, quench, age per Table 6, then ultrasonic test, machine to the drawing allowance and certify.

Machining allowance

Alloy 263 work-hardens and is not a free-cutting material, so we forge generous stock for finish machining. As a starting point we allow 6–10 mm on diameter for rings and discs up to 800 mm, and 10–20 mm above that; on shafts, 8–15 mm on diameter and 15–25 mm on length. Send the finished-part drawing and we will return the forged-blank drawing with allowances marked, so there is no argument later about who owns the stock.

UNS N07263 forged products and size range

Jiangyin Jiangnan Metal open-die forges UNS N07263 as seamless rolled rings from 200 to 2500 mm outside diameter, discs to 1800 mm, shafts and bars to 8 m in length, and single pieces from 10 kg to 8000 kg. Every item below is made to the customer's drawing. We do not hold Alloy 263 as a catalogue stock item.

• N07263 forged rings

  Seamless and contoured rolled rings, pierced from forged blanks.

  200–2500 mm OD

• N07263 forged discs

  Solid and bored discs, upset from billet for radial grain flow.

  to Ø 1800 mm

• N07263 forged shafts

  Plain, stepped and flanged shafts drawn on hammer or press.

  to 8 m long

• N07263 round bars

  Forged bar and forging stock, peeled or black as ordered.

  Ø 25–500 mm

• N07263 forged flanges

  Weld-neck, blind and special flanges to drawing.

  to 2500 mm OD

• N07263 sleeves & bushings

  Bored hollow forgings for hot-gas path service.

  to 2500 mm OD

• N07263 forged tubes

  Thick-wall hollow sections and forged tube blanks.

  to drawing

• N07263 forged rolls

  Rolls and roll shafts for hot process equipment.

  to drawing

Where UNS N07263 forgings are used

The dominant application for UNS N07263 forgings is the hot section of aero and industrial gas turbines: combustion chamber casings, transition liners, exhaust cones, turbine casings and rings, where the part must survive 650–850 °C and be welded or fabricated rather than machined from solid.

If your application sits below 650 °C, ask us about Inconel 718 or Inconel 706 forgings before you commit to Alloy 263, since both are cheaper and more readily available in large ring sizes. Above 850 °C under load, look at Waspaloy or René 41.

UNS N07263 compared with related superalloys

Against Waspaloy and René 41, UNS N07263 trades peak high-temperature strength for much better weldability and forming behaviour; against Nimonic 80A it offers markedly better ductility in welded assemblies; against Inconel 718 it is usable roughly 200 °C hotter.

Strength figures are representative aged room-temperature values for bar and forgings and are given for selection guidance only; order against the governing specification for your part. Service limits are practical load-bearing limits, not oxidation limits.

Testing, inspection and certification

Every UNS N07263 forging leaves Jiangyin with an EN 10204 3.1 mill test certificate as standard, or EN 10204 3.2 with third-party witness from SGS, BV, TÜV, Lloyd's or your own inspector, and is ultrasonically tested to EN 10228-3, SEP 1921 or ASTM A388 to the acceptance class your drawing specifies.

Standard test package

• Chemical analysis. Ladle analysis on every heat; product analysis on the finished forging on request.
• Tensile test. Room temperature as standard; elevated temperature to 780 °C on request.
• Hardness. Brinell, on the forging or on the test prolongation.
• Impact. Charpy V-notch where the specification calls for it.
• Ultrasonic examination. EN 10228-3, SEP 1921 or ASTM A388, acceptance class to drawing.
• Magnetic particle and dye penetrant. Alloy 263 is non-magnetic, so surface NDT is by liquid penetrant to ASTM E165.
• Grain size and microstructure. Metallographic examination on request.
• Dimensional report. Against the forged-blank drawing we agree before production.

The shop is certified to ISO 9001:2015 and equipped with a universal testing machine, impact testing machine, hardness testers, magnetic particle flaw detector, ultrasonic flaw detectors and a metallographic microscope. Raw material, forging, heat treatment, machining, testing and inspection are all under one roof in Jiangyin, which is why we can hold a 25–45 day lead time on a made-to-order superalloy forging.

Engineering tools for UNS N07263

Three calculators that run in your browser. Nothing is uploaded anywhere; the numbers use the Table 5 density of 8.36 g/cm³ and the Table 6 heat-treatment cycles.

Request a quotation for UNS N07263 forgings

To quote an Alloy 263 forging we need six things: the product form, the finished dimensions or a drawing, the quantity, the governing specification, the delivery condition and the certificate type. Fill the fields below and the tool writes the enquiry for you. Or email the drawing to sales@steelforgepieces.com and skip the form.

Cite this datasheet

Related nickel alloy forgings

Other superalloys we open-die forge in the same shop, ordered by how often they replace Alloy 263 on an enquiry:

• Waspaloy
• René 41
• Nimonic 80A
• Nimonic 75
• Inconel 718
• Inconel 706
• Inconel 617
• Inconel 625
• Inconel X-750
• Haynes 230
• Haynes 188
• Haynes 25
• Hastelloy X
• Udimet 500
• Udimet 520
• Udimet 720
• UNS N07252
• Incoloy 800H
• All nickel alloys