X6NiCrTi26-15 is a precipitation hardening austenitic steel carrying material number 1.2779. It contains roughly 26 % nickel, 15 % chromium and 2 % titanium in an iron matrix, with molybdenum, vanadium and boron additions. Unlike quenched and tempered tool steels, it gets its strength from intermetallic phases precipitated out of a tough austenitic matrix during ageing, so it stays non-magnetic and keeps its hardness in service. The alloy is close in chemistry to A-286 (UNS S66286, W.Nr. 1.4980, GH2132) and is widely used as a cheaper substitute for nickel base alloys in extrusion tooling and hot work parts running to 750 °C.
Jiangyin Jiangnan Metal Co., Ltd. is an open die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. We make X6NiCrTi26-15 forgings to customer drawings: forged and seamless rolled rings, round bars, shafts, discs, sleeves, flanges, extrusion stems, mandrels, liners, liner holders, dies and die holders. Forgings are ultrasonically tested to EN 10228-3, SEP 1921 or ASTM A388 and certified to EN 10204 3.1 or third party 3.2. Send a drawing to sales@steelforgepieces.com or call +86-189-2135-9659.
Equivalent and related designations
X6NiCrTi26-15 sits in the A-286 family. Buyers reach this grade under several names, so the table below lists the ones that turn up most often on drawings and enquiries. Chemistry windows differ between the standards. Tell us which specification governs your part and we will forge and certify to that one.
| Standard or region | Designation |
|---|---|
| Material number, primary | 1.2779 |
| DIN / EN name | X6NiCrTi26-15, also written X6NiCrTi26.15 |
| Closely related material number | 1.4980, X6NiCrTiMoVB25-15-2, X5NiCrTi26-15 |
| Common trade name | Alloy A-286, A286 |
| UNS | S66286 |
| ASTM | Grade 660, ASTM A453 Gr 660, ASTM A638 Gr 660 |
| AMS | AMS 5525, AMS 5731, AMS 5732, AMS 5734, AMS 5737, AMS 5804 |
| British | BS HR 51 |
| French | Z6NCTDV25-15 |
| Japanese | SUH 660 |
| Chinese | GH2132, formerly GH132 |
| Proprietary versions | Modified grades based on 1.2779 are sold under mill brand names for extrusion tooling |
Cross references are for guidance only. Check the governing specification before substituting one designation for another.
Chemical composition
Composition we work to, in weight percent. Every heat is supplied with its own ladle and product analysis on the certificate.
| Element | Symbol | Min | Max |
|---|---|---|---|
| Carbon | C | – | 0.08 |
| Manganese | Mn | – | 2.00 |
| Silicon | Si | – | 1.00 |
| Chromium | Cr | 13.50 | 16.00 |
| Nickel | Ni | 24.00 | 27.00 |
| Molybdenum | Mo | 1.00 | 1.50 |
| Titanium | Ti | 1.90 | 2.30 |
| Vanadium | V | 0.10 | 0.50 |
| Aluminium | Al | – | 0.35 |
| Boron | B | 0.003 | 0.010 |
| Iron | Fe | Balance | |
Mechanical properties
Minimum room temperature values in the solution treated and aged condition. Test pieces are cut from the forging itself, in the position and orientation your specification calls for.
| Property | Metric | Imperial | Basis |
|---|---|---|---|
| Tensile strength | 895 N/mm² | 130 ksi | Minimum |
| 0.2 % proof stress | 585 N/mm² | 85 ksi | Minimum |
| Elongation | 15 % | 15 % | Minimum |
| Reduction of area | 18 % | 18 % | Minimum |
| Charpy V-notch at −60 °C | 57 J | 42 ft·lbf | Minimum |
| Hardness for sour service | 35 HRC max | NACE MR0175 / ISO 15156 | |
| Typical hardness after ageing | 248 to 341 HB | Indicative | |
Section size matters. A heavy forging cools more slowly through the solution treatment than a bar and can read at the lower end of the range. Send the finished weight and the largest wall thickness with your enquiry so we can confirm what is achievable before quoting.
Heat treatment
Strength comes from ageing, not from quenching. Two routes are normally specified. We run both and keep the furnace charts on file against the job number.
| Route | Solution treatment | Ageing | Used for |
|---|---|---|---|
| Creep strength | 980 °C ± 10 (1800 °F), 1 to 2 h, rapid cool | 720 °C ± 10 (1325 °F), 16 h, air cool | Long term hot service, extrusion tooling, turbine parts |
| Ductility | 900 °C ± 10 (1650 °F), 1 to 2 h, rapid cool | 720 °C ± 10 (1325 °F), 16 h, air cool | Best room temperature strength and ductility, fasteners |
The 980 °C solution treatment coarsens the grain a little and gives the higher creep rupture strength. The 900 °C treatment gives better ductility and room temperature strength. Hot working runs between about 1010 °C and 1200 °C. We do not forge this grade below roughly 930 °C.
Behaviour in service
- Holds useful load bearing strength to about 700 °C. In tooling applications where stress is lower, working temperatures of 750 °C are normal.
- Good creep resistance and oxidation resistance, which is why it replaces nickel base alloys in extrusion liners and hot work tooling at a much lower material cost.
- Stays austenitic, ductile and non-magnetic down to about −196 °C, so it also turns up in cryogenic and non-magnetic hardware.
- Aqueous corrosion resistance is on a par with 316 and 316L, at far higher strength. That combination is what puts it into subsea and wellhead fasteners.
- Accepted for sour service inside the NACE MR0175 hardness limit of 35 HRC.
- Forgeable in heavy sections, so a large ring, disc or shaft can be made in one piece instead of being fabricated.
X6NiCrTi26-15 forgings we make
Everything here is forged to your drawing or to a rough machined envelope. We hold no standard stock in this grade. Each order is melted or sourced against the heat requirement, then forged, heat treated and tested for that job.
Extrusion press tooling
- Extrusion liners and liner holders
- Extrusion stems and dummy blocks
- Extrusion mandrels and pressure pads
- Extrusion dies, die inserts and die holders
Rings and discs
- Forged rings and seamless rolled rings
- Forged discs, blanks and blind discs
- Forged flanges, tube sheets and covers
- Valve seat rings and retaining rings
Bars, shafts and hollows
- Forged round bars and step shafts
- Eccentric shafts, spindles and gear blanks
- Forged pipes, tubes, hollow bars and bushings
- Forged sleeves and cylinders
Valve and pressure parts
- Valve bodies, blocks and bonnets
- Valve stems and internals for ball, gate, globe, check and plug valves
- Nozzles, manifolds and forged blocks for wellhead and Christmas tree assemblies
Size range
| Product | Range |
|---|---|
| Single piece forged weight | 20 kg to 20,000 kg |
| Rolled ring outside diameter | Up to 4,000 mm |
| Round bar diameter | 60 mm to 1,200 mm |
| Forged length | Up to 8,000 mm |
Anything outside this range is worth asking about. Send the drawing and we will say straight away whether it is workable.
Where these forgings are used
| Industry | Forged components |
|---|---|
| Aluminium extrusion | Liners, liner holders, stems, mandrels, dies, die holders, pressure pads and dummy blocks |
| Hot work tooling | Tooling for hot forming and hot pressing running up to 750 °C |
| Gas turbines and aero engines | Discs, wheels, casings, frames, afterburner parts, hot fasteners |
| Oil, gas and subsea | Wellhead and Christmas tree parts, subsea fasteners, valve bodies and stems |
| Power generation | Generator retaining rings, rotor parts, non-magnetic hardware, nuclear components |
| Pressure equipment | Flanges, tube sheets, shells for heat exchangers and air receivers |
| Furnaces and heat treatment | Retorts, jigs, rolls and fixtures for high temperature process plant |
| Automotive and industrial | Manifold and engine fasteners, turbocharger parts, compressor and gearbox components |
| Cryogenic | Non-magnetic ductile hardware for cryogenic and nitrogen generation plant |
How the forgings are made
Every X6NiCrTi26-15 order runs the same eight stages. Paperwork from each stage is filed against the job number, so a repeat order can be made the same way.
Testing and paperwork
- Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388, at the acceptance class named on your order.
- Magnetic particle or dye penetrant inspection where the drawing asks for it.
- Tensile, hardness and Charpy impact testing, including low temperature impact.
- Ladle and product chemical analysis reported on the certificate.
- Certification to EN 10204 3.1, or 3.2 witnessed by TUV, BV, SGS, DNV or Lloyd's Register.
- Intergranular corrosion testing, grain size, microstructure and PMI on request.
What to send with an enquiry
Open die forgings are priced from input weight and machining envelope, so there is no catalogue price. To quote the same day we need:
- Drawing or dimensions. Finished size plus your machining allowance, or the rough forging envelope if you will machine it yourself.
- Quantity, and whether this is a one off, a repeat, or an annual call off.
- Governing specification and revision, for example ASTM A453 Gr 660 Class A or AMS 5737.
- Delivery condition, and which solution temperature you want.
- Test and NDT requirements, including UT acceptance class and impact test temperature.
- Certificate type, 3.1 or 3.2, and the inspection body if 3.2.
- Destination port and required delivery date.
Request a quotation
Send the drawing or the size you need. You get back a price, a forging route and a delivery date. We answer in English or Chinese, normally within one working day.
- Company
- Jiangyin Jiangnan Metal Co., Ltd.
- Works
- Open die forging factory
- Address
- No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
- Telephone
- +86-189-2135-9659
- sales@steelforgepieces.com
- Website
- www.steelforgepieces.com
Questions we get asked
What is X6NiCrTi26-15?
X6NiCrTi26-15 is a precipitation hardening austenitic steel with material number 1.2779. It contains about 24 to 27 % nickel, 13.5 to 16 % chromium and 1.9 to 2.3 % titanium, plus molybdenum, vanadium and boron, balance iron. Strength comes from intermetallic phases precipitated out of the austenitic matrix during ageing rather than from carbide hardening, so the grade stays non-magnetic and holds its properties at temperature.
What is the material number for X6NiCrTi26-15?
1.2779. It is listed among the tool steels, although it behaves nothing like a conventional quenched and tempered hot work steel. The closely related heat resisting grade 1.4980, designated X6NiCrTiMoVB25-15-2, has almost the same chemistry and is better known as A-286 or UNS S66286. Buyers use the two numbers loosely, so confirm which specification applies before ordering.
Is X6NiCrTi26-15 the same as A-286?
They share the same alloy concept and nearly the same analysis, but they are registered under different standards. X6NiCrTi26-15 is 1.2779 in the tool steel list. A-286 is 1.4980 in the heat resisting steel list, also known as UNS S66286, Grade 660, SUH 660 in Japan and GH2132 in China. In practice they are cross referenced constantly. State the governing specification on the order rather than relying on the trade name.
What is the maximum service temperature?
Useful load bearing strength runs to about 700 °C. In extrusion and hot work tooling, where the stress is lower, this grade works at up to 750 °C, which is the reason it is used as a cheaper stand-in for nickel base alloys. Oxidation resistance extends further still, but only at low stress. At the cold end it stays ductile and non-magnetic down to around −196 °C.
What heat treatment do the forgings get?
Solution treatment followed by ageing. The usual route is 980 °C for one to two hours with rapid cooling, then 720 °C for 16 hours and air cool, which gives the higher creep rupture strength. A 900 °C solution treatment is used when room temperature strength and ductility matter more. Jiangyin Jiangnan Metal runs both and keeps the furnace charts on file.
Can it be used in sour service?
Yes, within limits. NACE MR0175 and ISO 15156 cap the supply hardness at 35 HRC. Forgings have to be supplied solution treated and aged, and hardness tested to prove the limit is met. Put the sour service requirement on the enquiry so the heat treatment and the hardness survey are planned in from the start.
What shapes can you forge in this grade?
Jiangyin Jiangnan Metal makes X6NiCrTi26-15 as forged rings and seamless rolled rings, discs and blanks, round bars, step shafts, spindles, sleeves, bushings, hollow bars, forged pipes, flanges, tube sheets, valve bodies and stems, and complete aluminium extrusion tooling including liners, liner holders, stems, mandrels, dies, die inserts, die holders and pressure pads. Every part is forged to drawing rather than cut from stock.
What testing and certification come with the forgings?
Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388 at the acceptance class named on the order, with magnetic particle or dye penetrant inspection where required. Tensile, hardness and Charpy impact testing is done on test pieces cut from the forging, and ladle plus product analysis is reported. Certificates are issued to EN 10204 3.1, or to EN 10204 3.2 witnessed by a third party such as TUV, BV, SGS, DNV or Lloyd's Register.
Who supplies X6NiCrTi26-15 open die forgings in China?
Jiangyin Jiangnan Metal Co., Ltd. is an open die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. We forge X6NiCrTi26-15 (1.2779) to customer drawings for the aluminium extrusion, gas turbine, oil and gas, power generation and pressure equipment industries. Enquiries go to sales@steelforgepieces.com or +86-189-2135-9659.
Is there a minimum order quantity?
No fixed piece count. Because the parts are made to order, the practical minimum comes from the heat size needed for the grade and from the billet weight. One large ring or shaft is often viable. A handful of very small parts may not be. Send the drawing and the quantity and we will tell you whether it works.
About Jiangyin Jiangnan Metal Co., Ltd.
We are an open die forging factory in Zhouzhuang Town, Jiangyin City, Jiangsu Province, in the forging cluster on the south bank of the Yangtze between Shanghai and Nanjing. The works is around two hours from Shanghai Pudong airport and close to the ports of Zhangjiagang and Shanghai.
We forge to drawing in carbon steel, alloy steel, tool steel, stainless steel and nickel base and iron nickel alloys. Product range covers rings and seamless rolled rings, round bars, shafts, discs, sleeves, flanges, pipes and complete aluminium extrusion press tooling. Work is quoted from the drawing, forged and heat treated in our own works, tested to the standard named on the order, and shipped with EN 10204 3.1 or third party 3.2 certification.