


Alloy L-605 (also referenced as HAYNES® 25) is the strongest of the fabricable cobalt alloys, useful for continuous service to 1800°F. Because of its long and widespread use, this alloy has been the subject of many investigations to determine its properties over a wide range of conditions, thus making it an unusually well characterized material. When exposed for prolonged periods at intermediate temperatures, alloy L-605 exhibits a loss of room temperature ductility in much the same fashion as other superalloys, such as alloy X or alloy 625.
L-605 is welded using gas tungsten arc, gas metal arc, shielded metal arc, electron beam and resistance welding. Submerged arc welding is not recommended. Use good joint fit-up, minimum restraint, low interpass temperature and cool rapidly from welding. For maximum ductility, fabricated components should be annealed 2150-2250°F, rapid cool.
HAYNES® 25, L-605 Alloy
Alloy L-605 Sheet, Alloy L-605 Coil, Alloy L-605 Welding Products
UNS R30605, Werkstoff 2.4964, Nr./EN 2.4964, AMS 5537, AMS 5796, GE B50A460
| Cr | Ni | Co | W | C | Fe | Mn | Si | P | S | |
|---|---|---|---|---|---|---|---|---|---|---|
| MIN | 19.0 | 9.0 | - | 14.0 | 0.05 | - | 1.0 | - | - | - |
| MAX | 21.0 | 11.0 | Balance | 16.0 | 0.15 | 3.0 | 2.0 | 0.4 | 0.04 | 0.03 |
Density: 0.330 lb/in3
Melting Range: 2425-2570°F
| Temperature, °F | 70 | 800 | 1000 | 1200 | 1400 | 1600 | 1800 |
| Coefficient* of Thermal Expansion, in/in°F x 10-6 |
- | 7.8 | 8.0 | 8.2 | 8.6 | 9.1 | 9.4 |
| Thermal Conductivity Btu • ft/ft2 • hr • °F |
- | 10.0 | 11.2 | 12.5 | 13.7 | 15.2 | 16.7 |
| Modulus of Elasticity Dynamic, psi x 106 | 33 | 28 | 27 | 26 | 24 | 23 | 21 |
* 70°F to indicated temperature.
Representative Tensile Properties, Sheet
| Temperature, °F | 70 | 1200 | 1400 | 1600 | 1800 |
| Ultimate Tensile Strength, ksi | 146 | 108 | 93 | 60 | 34 |
| 0.2% Yield Strength, ksi | 69 | 48 | 41 | 36 | 18 |
| Elongation, % | 51 | 60 | 42 | 45 | 32 |
Typical Stress-Rupture Strength
| Temperature, °F | 1200 | 1400 | 1500 | 1600 | 1700 | 1800 |
| 100 Hours, ksi | 69 | 36 | 25 | 18 | 12 | 7 |
| 1,000 Hours, ksi | 57 | 26 | 18 | 12 | 7 | 4 |
Haynes 25® is a Trademark of Haynes International