A-286 (UNS S66286, W.Nr. 1.4944, Grade 660) is an iron-nickel-chromium precipitation-hardening austenitic superalloy and one of the most widely used high-temperature engineering materials in existence. Its metallurgical signature is fine, coherent gamma-prime Ni3(Ti,Al) precipitates that form during the 718°C/16 h aging cycle, pinning dislocations and driving yield strength above 585 MPa in the standard ASTM A638 condition while preserving the ductility and fabrication friendliness of an austenitic matrix. This aging response, coupled with a chromium content of 14–16% for oxidation resistance up to 700°C, places A-286 at the center of the cost-performance spectrum: stronger than conventional stainless steels, more affordable than nickel-based superalloys, and non-magnetic in all conditions. The alloy retains its mechanical integrity across a uniquely wide temperature window—from cryogenic service at -196°C in LNG hardware to sustained 650°C operation in jet-engine turbine casings and fasteners. Titanium (1.9–2.35%), molybdenum (1.0–1.5%), and vanadium (0.10–0.50%) work in concert: Ti drives precipitation hardening, Mo contributes solid-solution strength and creep resistance, and V plus a tightly controlled boron addition of 0.001–0.010% refine grain-boundary stability against oxygen embrittlement. At FUSHUN METAL, A-286 is melted via VIM for tight chemistry control, refined through VAR for superior inclusion cleanliness, and optionally upgraded with PESR for the cleanest solidification structure in large-section forgings exceeding 300 mm. Every heat ships under our ISO 9001 and AS9120B accredited quality management system with full melt-route traceability, chemical certification, and mechanical test data. Two standard solution-treatment routes are offered and FUSHUN METAL applies whichever matches the customer’s service profile: 982°C/1 h rapid-cool solutions for maximum creep-rupture life in turbine hardware, and 899°C/2 h rapid-cool solutions for enhanced ductility in aerospace fastener stock.
Equivalent Grades of A-286 (S66286 / 1.4944)
| Standard | Designation |
|---|---|
| UNS | S66286 |
| ASTM | A453 Grade 660 / A638 Grade 660 / B637 / B670 / B564 |
| AMS | 5525 / 5731 / 5732 / 5734 / 5737 / 5853 / 5895 |
| EN / DIN | X6NiCrTiMoVB25-15-2 (1.4980) / X5NiCrTi26-15 (1.4944) |
| ISO | X6NiCrTiMoVB25-15-2 (4980-662-86-X) |
| GB | GH2132 / 06Cr15Ni25Ti2MoAlVB (S51525) |
| JIS | SUH 660 |
| BS | 286S31 / HR 52 / DTD 5026 |
| GOST | ЭП786 (3M786) |
| Trade Names | Incoloy A-286 / Pyromet A-286 / ATI A286 / TURBALOY 286VM |
Applications of A-286 (S66286 / 1.4944)
Aerospace Fasteners
Bolts, screws, nuts, and studs for jet engines, airframes, and landing gear—AMS 5731/5732 stock is the industry standard for 650°C-class threaded hardware.
Gas Turbine Components
Turbine wheels, compressor discs, blades, casings, afterburner liners, and sound-suppressor parts in both aircraft and industrial gas turbines.
Turbocharger Wheels & Shafts
Automotive and heavy-duty diesel turbocharger rotors operating at sustained temperatures up to 700°C and high rotational speeds.
Oil & Gas Downhole Tools
Valve stems, packer bodies, and drill-string components in high-pressure, high-temperature (HPHT) corrosive well environments—NACE MR0175 compliant.
Cryogenic Equipment
LNG valve bodies, pump shafts, and structural hardware retaining usable Charpy impact toughness (~35 J) down to -196°C.
Nuclear Service Components
Reactor internals, control-rod drive mechanisms, and bolting where non-magnetic, radiation-resistant, high-strength material is required.
High-Temperature Springs
Compression and extension springs in exhaust valves, fuel nozzles, and thermal control systems where relaxation resistance above 500°C is critical.
Missile & Defense Hardware
Structural frames, thrust chambers, and guidance-system components balancing weight, strength, and thermal stability.
Supply Range — A-286 (S66286 / 1.4944)
FUSHUN METAL supplies A-286 in all standard mill forms, manufactured from VIM–VAR (optionally PESR) ingots. Every product ships with an EN 10204 3.1 certificate; 3.2 witness-tested certification is available on request. All material is ultrasonic-tested and carries full heat-lot traceability under our ISO 9001 and AS9120B system.
| Product Form | Diameter / Thickness Range | Typical Standards |
|---|---|---|
| Hot-Rolled Round Bar | 6 – 300 mm | ASTM A638 / AMS 5731 |
| Forged Round Bar | 80 – 800 mm | AMS 5732 / ASTM B637 |
| Forged Flat / Block | Thickness 20–400 mm, Width to 1200 mm | AMS 5734 / ASTM B564 |
| Hot-Rolled Flat Bar | Thickness 5–80 mm, Width to 400 mm | AMS 5853 |
| Sheet & Plate | 0.5 – 50 mm | AMS 5525 / ASTM B670 |
| Strip & Wire | 0.05 – 6 mm | AMS 5858 / AMS 5895 |
| Seamless Tube | OD 6–200 mm, WT 1–30 mm | AMS 5589 / ASTM B906 |
Non-standard dimensions and custom forgings (discs, rings, stepped shafts) are produced to order. Contact FUSHUN METAL with your drawing for a mill-direct quotation.
Chemical Composition of A-286 (S66286 / 1.4944) — ASTM A638 Grade 660
| Element | Composition (wt %) | Metallurgical Role |
|---|---|---|
| Iron (Fe) | Balance (~54) | Austenitic matrix base |
| Nickel (Ni) | 24.0 – 27.0 | Austenite stabilizer; high-temp ductility |
| Chromium (Cr) | 13.5 – 16.0 | Oxidation & corrosion resistance |
| Titanium (Ti) | 1.90 – 2.35 | Primary gamma-prime former |
| Molybdenum (Mo) | 1.00 – 1.50 | Solid-solution strengthening; creep resistance |
| Manganese (Mn) | ≤ 2.00 | Deoxidation; hot-workability |
| Silicon (Si) | ≤ 1.00 | Deoxidation |
| Vanadium (V) | 0.10 – 0.50 | Carbide refiner; grain-boundary strength |
| Aluminum (Al) | ≤ 0.35 | Co-precipitant in gamma-prime |
| Boron (B) | 0.001 – 0.010 | Grain-boundary cohesion; notch-rupture life |
| Carbon (C) | ≤ 0.08 | Carbide former (TiC / M₂₃C₆) |
| Phosphorus (P) | ≤ 0.040 | Residual; tightly managed via VIM |
| Sulfur (S) | ≤ 0.030 | Residual; minimized in triple-melt route |
FUSHUN METAL targets mid-range Ti (2.05–2.20%) and B (0.004–0.007%) to maximize the aging response window while meeting both ASTM A638 and the tighter EN 10269 limits. VIM chemistries with VAR refinement routinely achieve sulfur below 0.005%.
Mechanical & Physical Properties of A-286 (S66286 / 1.4944)
The aging cycle (718°C / 16 h, air cool) precipitates coherent gamma-prime and raises strength substantially over the solution-annealed baseline. Two solution-treatment routes are commonly specified: Route A (899°C/2 h + age) maximizes room-temperature tensile ductility; Route B (982°C/1 h + age) maximizes creep-rupture life.
| Condition | Tensile (MPa) | Yield 0.2% (MPa) | Elong. (%) | Hardness (BHN) |
|---|---|---|---|---|
| ASTM A638 Grade 660, Bar ≤160 mm, Aged | ≥ 895 | ≥ 585 | ≥ 15 | 248 – 341 |
| Forged Bar D ≤300 mm, Aged | 900 – 1200 | ≥ 600 | ≥ 16 | 248 – 341 |
| AMS 5737 Sheet/Strip, Aged | 900 – 1150 | ≥ 600 | ≥ 15 | — |
| Typical, Solution-Annealed Only | ~620 – 760 | ~275 – 380 | ~35 – 45 | ≤ 200 |
| Physical Property | Value at 20°C |
|---|---|
| Density | 7.92 g/cm³ |
| Melting Range | 1364 – 1424°C |
| Elastic Modulus | 199 GPa |
| CTE (20–300°C) | 17.0 μm/m·K |
| Thermal Conductivity (100°C) | 13.8 W/(m·K) |
| Electrical Resistivity | 91 μΩ·cm |
FUSHUN METAL’s in-house tensile and hardness testing laboratory certifies every heat lot to the applicable ASTM/AMS specification. Elevated-temperature tensile data at 540°C, 650°C, and 700°C, plus 1000-hour stress-rupture curves, are provided on request. Charpy impact values at both ambient and cryogenic (-196°C) temperature are included in the standard test report package. All mechanical certification is traceable to our ISO 9001 and AS9120B accredited quality management system.
