Cobalt superalloy, Werkstoff 2.4683
2.4683 Forgings, Haynes 188 / UNS R30188
Open-die forged rings, flanges, shafts, discs, sleeves, bushings and bars, made to drawing in Jiangyin, China.
2.4683 is the Werkstoff number for Haynes 188, also listed as UNS R30188. It is a cobalt-nickel-chromium-tungsten superalloy with oxidation resistance to 1095 °C (2000 °F). Jiangyin Jiangnan Metal forges 2.4683 into rings, flanges, shafts, discs and bars from 1 kg to 3,000 kg, to AMS 5772, with EN 10204 3.1 certificates and ultrasonic testing.
What 2.4683 is and what else it is called
2.4683 is a cobalt-base superalloy. Cobalt makes up about 39 % of the composition, with roughly 22 % nickel, 22 % chromium and 14 % tungsten. The small lanthanum addition stabilises the surface oxide, which is the main reason for the alloy's oxidation resistance at high temperature.
The same alloy is sold under several designations. We quote against any of them.
| System | Designation |
|---|---|
| Werkstoff (DIN / EN) | 2.4683 |
| UNS | R30188 |
| Trade names | Haynes 188, Alloy 188, UDIMET 188 |
| Bars, forgings, rings | AMS 5772 |
| Sheet, strip, plate | AMS 5608 |
| Welding wire | AMS 5801 |
For forged product the controlling specification is AMS 5772, covering bars, forgings and rings. AMS 5608 applies to flat-rolled product and is listed here for cross-reference only.
Forged shapes we produce in 2.4683
All parts are open-die forged to drawing. The shapes below are the ones most often ordered in this grade.
- Seamless rolled rings, including deep rings and stepped ring profiles for turbine and valve assemblies.
- Forged flanges: blind, weld-neck, slip-on and custom profiles for pressure vessels and heat exchangers.
- Shafts and spindles, including eccentric shafts and stepped shafts for pumps and power transmission.
- Discs, disks and blanks, solid or trepanned, for turbine rotors and nozzle diaphragms.
- Sleeves, bushings and hollow bars, bored and stress relieved for compressor and subsea service.
- Round bars, square bars and blocks, as forged, rough machined or finish machined.
- Tube sheets, forged tubes and nozzles for shell-and-tube heat exchangers and air receivers.
- Valve components: seat rings, stems, bodies and blocks for ball, gate, globe, check and plug valves.
- Single-piece weight
- 1 kg to 3,000 kg
- Ring outside diameter
- 100 to 3,000 mm
- Bar diameter
- 20 to 800 mm
- Maximum shaft length
- 6,000 mm
- Supply condition
- Solution annealed
- Surface
- As forged or machined
Chemical composition of 2.4683
Composition limits follow AMS 5772 for UNS R30188. Cobalt is the balance and typically runs near 39 %. Certified values for the supplied heat are stated on the EN 10204 3.1 mill certificate shipped with the order.
| Element | Symbol | Content (%) |
|---|---|---|
| Cobalt | Co | Balance, approx. 39 |
| Nickel | Ni | 20.00 to 24.00 |
| Chromium | Cr | 20.00 to 24.00 |
| Tungsten | W | 13.00 to 16.00 |
| Iron | Fe | 3.00 max |
| Manganese | Mn | 1.25 max |
| Silicon | Si | 0.20 to 0.50 |
| Carbon | C | 0.05 to 0.15 |
| Lanthanum | La | 0.02 to 0.12 |
| Phosphorus | P | 0.02 max |
| Boron | B | 0.015 max |
| Sulfur | S | 0.015 max |
Mechanical properties of 2.4683
Typical room-temperature values in the solution-annealed condition. The high elongation is characteristic of this alloy and is what keeps it formable at this strength level.
| Property | Metric | Imperial |
|---|---|---|
| Tensile strength | 965 MPa | 140,000 psi |
| Yield strength, 0.2 % offset | 446 MPa | 64,700 psi |
| Elongation at break | 55 % | 55 % |
| Density | 8.98 g/cm³ | 0.324 lb/in³ |
| Magnetic response | Non-magnetic | Non-magnetic |
Strength falls off progressively above about 650 °C. Where the design is governed by creep or stress rupture at a stated temperature and hold time, send the condition with your enquiry and we will confirm against the heat data instead of quoting a nominal figure.
Heat treatment
2.4683 is solution heat treated at about 1177 °C (2150 °F ± 25 °F) and then rapidly cooled, either air cooled or water quenched. Bright annealed product is cooled in hydrogen.
2.4683 is not age hardenable. It gains no strength from an ageing cycle, unlike precipitation-hardening grades such as Inconel 718 or Waspaloy. Extra strength comes from cold work only, and because the alloy work hardens quickly, complex forming sequences need intermediate anneals.
How we make 2.4683 forgings
- Melting. EAF plus VOD, followed by ESR refining, to control gas content and inclusion cleanliness.
- Open-die forging. Billet is upset and drawn on hydraulic presses to the drawing envelope, with the forging ratio recorded for the certificate.
- Ring rolling. Pierced blanks are rolled to final ring section where a seamless rolled ring is specified.
- Solution annealing. About 1177 °C followed by rapid cooling, in calibrated furnaces with recorded charts.
- Machining. Rough or finish machining to your tolerances, including bored and faced rings.
- Testing and release. Chemistry, mechanical testing, NDT and dimensional inspection before certification.
Testing and certification
Ultrasonic testing is carried out to EN 10228-3, SEP 1921 or ASTM A388, to the acceptance class stated on your order. 2.4683 is non-magnetic, so magnetic particle inspection does not apply. Surface examination is by liquid penetrant to ASTM E165.
Material certificates are issued to EN 10204 3.1 as standard. EN 10204 3.2 certification witnessed by a third party such as TUV, SGS, BV, Lloyd's or your own inspector is available on request. Positive material identification, hardness mapping, impact testing and intergranular corrosion testing can be added to the release package.
Where 2.4683 forgings are used
| Industry | Typical forged components |
|---|---|
| Aero engines | Combustor cans, transition ducts, flame holders, spray bars, afterburner liners |
| Land-based gas turbines | Rotor discs, nozzle diaphragm valves, combustion liners, turbine rings |
| Oil, gas and subsea | Wellhead and Christmas tree components, valve bodies, seat rings, stems |
| Chemical processing | Pump shafts, plunger pump parts, reactor internals, high-temperature furnace parts |
| Pressure equipment | Tube sheets, forged flanges, nozzles, shell-and-tube heat exchanger parts |
| Power and rotating equipment | Compressor components, gearbox parts, spindles, forged rolls |
2.4683 compared with related grades
Selection notes for the grades most often considered alongside 2.4683.
| Grade | Base | Specify it when |
|---|---|---|
| 2.4683 / Haynes 188 | Cobalt | Prolonged oxidation and sulfidation resistance above 900 °C matters more than room-temperature strength |
| Haynes 25 / L-605 | Cobalt | Same cobalt-tungsten family without the lanthanum addition, often named in an existing qualification |
| Inconel 625 | Nickel | Aqueous and chloride corrosion resistance dominates and peak service temperature is lower |
| Waspaloy | Nickel | High strength at temperature is required and the part can be age hardened |
| Hastelloy X | Nickel | Good high-temperature oxidation resistance is needed at lower alloy cost than a cobalt base |
Frequently asked questions about 2.4683
Is 2.4683 the same as Haynes 188?
Yes. 2.4683 is the German Werkstoff number, Haynes 188 is the trade name and UNS R30188 is the American designation. All three refer to the same cobalt-nickel-chromium-tungsten superalloy. It is also sold as Alloy 188 and UDIMET 188.
What is the maximum service temperature of 2.4683?
2.4683 resists oxidation in prolonged exposure up to about 1095 °C (2000 °F). Practical service temperature depends on stress, hold time and atmosphere, so the design limit for a loaded component is normally lower than the oxidation limit.
Can 2.4683 be strengthened by heat treatment?
No. 2.4683 is not age hardenable. It is supplied solution annealed, and additional strength can only be obtained by cold work. The alloy work hardens quickly, so complex forming requires intermediate annealing.
Which specification applies to 2.4683 forgings?
AMS 5772 covers bars, forgings and rings in UNS R30188. AMS 5608 covers sheet, strip and plate, and AMS 5801 covers welding wire. For forged product, order to AMS 5772.
What size 2.4683 forgings can you make?
We open-die forge single pieces from 1 kg to 3,000 kg, rolled rings from 100 mm to 3,000 mm outside diameter, and bars from 20 mm to 800 mm diameter. Parts outside this envelope are worth asking about. Send the drawing and we will confirm.
Do you supply mill certificates and third-party inspection?
Every order ships with an EN 10204 3.1 certificate covering chemistry, mechanical properties, heat treatment and NDT results. EN 10204 3.2 certification witnessed by TUV, SGS, BV, Lloyd's or your own inspector is available on request.
Is magnetic particle inspection used on 2.4683?
No. 2.4683 is non-magnetic, so magnetic particle inspection is not applicable. Surface defects are found by liquid penetrant testing to ASTM E165 and internal soundness by ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388.
How do I get a price for a 2.4683 forging?
Send a drawing or the finished dimensions, the quantity, the governing specification and any NDT or certification requirements to sales@steelforgepieces.com. 2.4683 is a cobalt-base alloy, so price moves with cobalt and tungsten and quotations are made against current raw material cost.
Get a quote on 2.4683 forgings
Send us the drawing or the dimensions of the 2.4683 forged part you need. Include quantity, specification and any inspection requirements, and we will come back with price and lead time.
- Company
- Jiangyin Jiangnan Metal Co., Ltd.
- Factory address
- No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
- Telephone / WhatsApp
- +86 189 2135 9659
Related grades we forge
Technical data on this page is compiled from AMS 5772 and published producer data for UNS R30188. Certified values for a supplied heat are stated on the mill certificate. Page updated .