Alloy L605 (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 L605 exhibits a loss of room temperature ductility in much the same fashion as other superalloys, such as alloy X or alloy 625.

L605 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.
Chemistry

	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

Specifications
AMS 5537, AMS 5796
EN 2.4964
GE B50A460, UNS R30605
Werkstoff 2.4964
Inventory
L605 Coil, L605 Sheet, L605 Weld Wire
Common Trade Names
HAYNES® 25, L-605 Alloy
Features
• Outstanding high temperature strength
• Oxidation resistant to 1800° F
• Galling resistant
• Resistant to marine environments, acids and body fluids
Applications
• Gas turbine engine components such as combustion chambers and afterburners
• High temperature ball bearings and bearing races
• Springs
• Heart valves
Physical Properties
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.
Mechanical Properties
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®