Type A-286 (UNS S66286)
Description
A-286 is a Ni-Cr austenitic precipitation-hardened iron-based steel that is one of the original superalloys. It has been used for applications requiring high strength and corrosion resistance up to 1,300°F (704°C), and for cryogenic applications. Its relatively low alloy content and low-cost formulation make it an excellent choice for many applications. A-286 alloy is typically produced by vacuum induction melting (VIM), followed by vacuum arc (VAR) or electroslag (ESR) remelting. Applications include jet engine, supercharger, and missile components including: wheels and blades, casings, afterburner and sound suppressor parts, fuel nozzles, fasteners, extrusion tooling and miscellaneous hardware. This alloy is designated Grade or Type 660 in several specifications.
Chemical Composition
Chemical Composition (wt%) limits as specified in ASTM A638 and ASME SA638*
| Carbon | 0.08 | Silicon | 1.00 |
| Chromium | 13.50-16.00 | Phosphorus | 0.040 |
| Nickel | 24.00-27.00 | Sulfur | 0.030 |
| Molybdenum | 1.00-1.50 | Aluminum | 0.35 |
| Titanium | 1.90-2.35 | Vanadium | 0.10-0.50 |
| Manganese | 2.00 | Boron | 0.0010-0.010 |
*Maximum, unless range is indicated
Physical Properties
Physical properties for A-286
| Density, lb/in3 | 0.287 |
| Modulus of Elasticity, psi | 29.1x 106 |
| Coefficient of Thermal Expansion, 68-212˚F, /˚F | 9.2 x 10-6 |
| Thermal Conductivity, Btu/ft hr ˚F | 8.7 |
| Specific Heat, Btu/lb ˚F | 0.10 |
| Electrical Resistivity, Microhm-in | 35.8 |
Mechanical Properties
Mechanical property requirements for heat treated product as specified in ASTM A638 and ASME SA638
| Yield Strength, min. (ksi) | 85 |
| Tensile Strength, min. (ksi) | 130 |
| Elongation, min. (%) | 40 |
Standards
Typical standards for A-286
| ASTM A453 |
| ASTM A638 |
| ASME A638 |
| AMS 5731 |
| AMS 5732 |
| AMS 5734 |
| AMS 5737 |