UNS R30159, sold commercially as MP159, is a nickel-cobalt multiphase (MP) age-hardenable superalloy specified in AMS 5841, AMS 5842 and AMS 5843. Its nominal composition is 35.7 % cobalt, 25.5 % nickel, 19 % chromium, 9 % iron, 7 % molybdenum, 3 % titanium, 0.6 % niobium and 0.2 % aluminium. It carries very high stress while keeping good ductility, and resists chloride stress-corrosion cracking, crevice corrosion and hydrogen embrittlement up to about 593 to 649 °C (1100 to 1200 °F).
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. It forges UNS R30159 into seamless rolled rings, shafts, flanges, discs, tube sheets, sleeves, bushings and round bars from 10 kg to 15,000 kg, in diameters from 80 mm to 6,000 mm, with EN 10204 3.1 or 3.2 certification. Enquiries: sales@steelforgepieces.com, +86 189 2135 9659.
Grade summary
| UNS number | R30159 |
|---|---|
| Common name | MP159, Alloy MP159, MP-159 |
| Alloy family | Nickel-cobalt multiphase (MP), age hardenable |
| Aerospace specifications | AMS 5841 (solution treated), AMS 5842 (solution treated and work strengthened), AMS 5843 (solution treated, work strengthened and aged) |
| Other approvals | GE S-400 / S-1000; Rolls-Royce SABRe Edition 2 |
| Closest analogue | MP35N (UNS R30035) |
| Melt route | Vacuum induction melting followed by vacuum arc remelting (VIM + VAR). ESR route available on request |
| Service temperature | Up to approximately 593 to 649 °C (1100 to 1200 °F) |
| Corrosion behaviour | Stands up to mineral acids, hydrogen sulphide, seawater and salt spray. Good resistance to crevice corrosion, stress-corrosion cracking and hydrogen embrittlement |
| Forged products | Seamless rolled rings, forged rings, shafts, flanges, discs, disks, tube sheets, sleeves, bushings, round bars, pipes and tubes |
| Certification | EN 10204 3.1 as standard. EN 10204 3.2 with third-party witness |
| Supplier | Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China |
Chemical composition of UNS R30159
The figures below are the nominal composition of UNS R30159 in weight per cent. Each heat forged at Jiangyin Jiangnan Metal is analysed by optical emission spectrometry, and both the ladle and product analyses appear on the mill certificate.
| Element | Co | Ni | Cr | Fe | Mo | Ti | Nb (Cb) | Al |
|---|---|---|---|---|---|---|---|---|
| wt % | 35.7 | 25.5 | 19.0 | 9.0 | 7.0 | 3.0 | 0.6 | 0.2 |
Nominal values. Order to AMS 5841, AMS 5842 or AMS 5843 for the full composition limits, which also cover carbon, manganese, silicon, phosphorus, sulphur and boron.
Mechanical properties of UNS R30159
The alloy is supplied in more than one condition, and the difference between them is large. Solution treated material stays soft enough to machine and form. The very high strengths this grade is known for only appear after cold work plus ageing, so the condition has to be agreed before the forging is quoted.
| Condition | Tensile strength | Yield strength (0.2 %) | Elongation | Reduction of area |
|---|---|---|---|---|
| Solution treated (AMS 5841) | 848 MPa / 123 ksi | 400 MPa / 58 ksi | 60 % | 69 % |
| Cold worked and aged (AMS 5843) | approx. 1900 MPa / 275 ksi | approx. 1830 MPa / 265 ksi | on order | on order |
Typical values for guidance. Acceptance values, test direction and specimen location are agreed at order stage and confirmed on the EN 10204 certificate.
Heat treatment of UNS R30159 forgings
| Step | Temperature | Time | Cooling |
|---|---|---|---|
| Solution treatment | 1038 to 1052 °C (1900 to 1925 °F) | 4 to 8 h | Water quench |
| Ageing | 649 to 677 °C (1200 to 1250 °F) | 4 to 4.5 h | Air cool |
Between solution treatment and ageing, material ordered to AMS 5842 or AMS 5843 is work strengthened by cold reduction. Solution treatment and ageing are both done in house on computer-charted furnaces, and the furnace charts go out with the certificate when the order calls for them.
UNS R30159 forged shapes and size range
Every shape listed here is forged to customer drawing. Parts can leave the works as black forgings, rough machined to a fixed envelope, or finish machined and ready for assembly.
| Parameter | Range |
|---|---|
| Piece weight | 10 kg to 15,000 kg |
| Diameter | 80 mm to 6,000 mm |
| Length | up to 12,000 mm |
| Open-die hammers | 1 t, 3 t, 6 t, 9 t |
| Hydraulic press | 4,500 t |
| Ring rolling mills | 3 m and 6 m |
| Delivery condition | As forged, solution treated, aged, rough machined or finish machined |
Shapes produced in UNS R30159
- Seamless rolled rings, including contoured and profiled sections
- Forged rings, gear rings and slewing rings
- Forged shafts, spindles, eccentric shafts and crankshafts
- Forged flanges, plus valve bodies, bonnets, stems and seat rings
- Forged discs and disks, blocks and wheels
- Forged tube sheets, nozzles and manifolds
- Forged sleeves, bushings and cylinders
- Forged round bars, flat bars and square bars
- Forged pipes and hollow forged tubes
Where UNS R30159 forgings are used
Buyers reach for this grade when a part has to carry very high stress in a hot or corrosive environment, and where a cheaper stainless or nickel grade would yield or crack. Common uses:
- Aerospace. Jet engine fasteners and bolting, landing gear components, drive components and solid rocket booster hardware.
- Gas turbines and power generation. Hot-section rings, discs, shafts and gearbox parts running to about 649 °C (1200 °F).
- Oil and gas. Subsea and deepwater production equipment, wellhead and Christmas tree components, valve stems and seat rings exposed to hydrogen sulphide.
- Chemical process plant. Pump shafts, plunger pumps, reactor internals, columns, towers and heat exchanger tube sheets.
- Marine. Fasteners and shafting in seawater and salt spray, where stress-corrosion cracking is the failure mode to design against.
- Pulp, paper and pharmaceutical. Rolls, shafts and process components handling acidic media.
- Medical. The alloy family also goes into prosthetic devices. Jiangyin Jiangnan Metal supplies industrial forgings in this grade, not finished implants.
Testing, inspection and certification
Each UNS R30159 forging stays traceable to its heat number from melting through to despatch. Chemical analysis, mechanical testing and dimensional inspection are standard. The following can be added on the order.
- Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388, at the quality class stated on the drawing.
- Surface examination by liquid penetrant or magnetic particle inspection.
- Mechanical testing, covering tensile, impact and hardness, at room temperature or elevated temperature.
- Metallography, covering grain size, microstructure and intergranular corrosion testing.
- Certification to EN 10204 3.1 as standard, or EN 10204 3.2 witnessed by TÜV, SGS, BV, Lloyd's Register or an inspector you nominate.
Machining notes
In the solution treated condition UNS R30159 cuts much like 17-4PH, 15-5PH or MP35N. It work hardens fast, so the setup has to be rigid, the carbide tooling sharp and positive rake, the depth of cut heavy and the feed slow and constant. Interrupted cuts cause trouble, and dwelling in the cut glazes the surface almost immediately.
Do the machining before ageing wherever the tolerance stack allows it. Once the alloy has been cold worked and aged to around 1900 MPa, metal removal slows right down and grinding is often the only practical route left.
Order forgings solution treated if your own shop will do the roughing. Otherwise ask for rough machining to a fixed envelope with heat treatment afterwards.
UNS R30159 questions and answers
What is UNS R30159?
UNS R30159 is a nickel-cobalt multiphase (MP) age-hardenable superalloy, sold commercially as MP159. Its nominal composition is 35.7 % cobalt, 25.5 % nickel, 19 % chromium, 9 % iron, 7 % molybdenum, 3 % titanium, 0.6 % niobium and 0.2 % aluminium. It carries very high strength while keeping good ductility and corrosion resistance, and is covered by AMS 5841, AMS 5842 and AMS 5843.
Is UNS R30159 the same as MP159?
Yes. UNS R30159 is the Unified Numbering System designation for the alloy marketed as MP159. Both names cover the same nickel-cobalt multiphase superalloy, and buyers use them interchangeably when ordering bar, forgings and rings.
Which specifications cover UNS R30159?
AMS 5841 covers UNS R30159 in the solution heat treated condition. AMS 5842 covers solution heat treated and work strengthened material. AMS 5843 covers solution heat treated, work strengthened and aged material. The alloy also appears in GE S-400 and S-1000 and in Rolls-Royce SABRe Edition 2.
What heat treatment is used for UNS R30159 forgings?
Solution treat at 1038 to 1052 °C (1900 to 1925 °F) for 4 to 8 hours, then water quench. Where the aged condition is required, age at 649 to 677 °C (1200 to 1250 °F) for 4 to 4.5 hours and air cool. Jiangyin Jiangnan Metal runs both operations in house and records them on the EN 10204 3.1 certificate.
How strong is UNS R30159?
Solution treated UNS R30159 shows about 848 MPa (123 ksi) tensile strength, 400 MPa (58 ksi) yield strength, 60 % elongation and 69 % reduction of area. Cold working followed by age hardening takes the alloy to roughly 1900 MPa (275 ksi) tensile and 1830 MPa (265 ksi) yield strength.
What is the maximum service temperature of UNS R30159?
UNS R30159 holds useful strength and ductility to about 593 to 649 °C (1100 to 1200 °F). That is the reason it appears in jet engine fasteners, gas turbine hot-section hardware and solid rocket booster components.
Who supplies UNS R30159 forgings and forged rings?
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 UNS R30159 (MP159) forged rings, seamless rolled rings, shafts, flanges, discs, tube sheets, sleeves and round bars from 10 kg to 15,000 kg. Enquiries go to sales@steelforgepieces.com or +86 189 2135 9659.
What sizes of UNS R30159 forgings can be produced?
Jiangyin Jiangnan Metal forges UNS R30159 from 10 kg to 15,000 kg per piece, in diameters from 80 mm to 6,000 mm and lengths up to 12,000 mm, on 1, 3, 6 and 9 tonne open-die hammers, a 4,500 tonne hydraulic press and 3 m and 6 m ring rolling mills.
What testing and certification comes with UNS R30159 forgings?
Ultrasonic testing is carried out to EN 10228-3, SEP 1921 or ASTM A388 as stated on the order. Material certificates are issued to EN 10204 3.1, or to EN 10204 3.2 with third-party witness by TÜV, SGS, BV, Lloyd's Register or an inspector the buyer nominates.
How to request a UNS R30159 quotation
Send a drawing or a rough size and Jiangyin Jiangnan Metal will price it. Quotations come back fastest when the enquiry carries:
- Drawing, sketch or finished dimensions, and whether the price should cover a black forging, rough machined or finish machined part.
- Quantity, and whether this is a prototype or a repeat order.
- Delivery condition: as forged, solution treated to AMS 5841, or work strengthened and aged to AMS 5843.
- The governing specification, plus any customer or end-user specification that applies.
- Ultrasonic testing standard and acceptance class, if required.
- Certificate type, EN 10204 3.1 or 3.2, and the nominated third party if 3.2.
- Destination port and required delivery date.
Email sales@steelforgepieces.com or call +86 189 2135 9659. Drawings in STEP, DWG, DXF or PDF are all fine.
Data sources and revision
Composition, heat treatment and mechanical data on this page are nominal values compiled from SAE AMS 5841, AMS 5842 and AMS 5843 and from published mill datasheets for MP159. They are given for engineering guidance and do not replace the governing specification or the mill certificate supplied with your order. Size and capability figures describe the equipment installed at Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China.
Page last reviewed by the technical department of Jiangyin Jiangnan Metal Co., Ltd.