UNS R30816 (formerly Grade 671) Cobalt
Cobalt Alloys
Property Overview
Density9.1g/cm³
Elastic Modulus210GPa
Tensile Strength1020MPa
Yield Strength460MPa
Brinell Hardness280HB
Maximum Service TemperatureUnknown
Chemical Composition
C
0.32 to 0.42%
CR
19 to 21%
NI
19 to 21%
MO
3.5 to 4.5%
MN
1.0 to 2.0%
SI
0 to 1.0%
P
0 to 0.040%
S
0 to 0.030%
NB
3.5 to 4.5%
CO
40 to 49.8%
W
3.5 to 4.5%
TA
3.5 to 4.5%
FE
0 to 5.0%
Mechanical
Elastic (Young's, Tensile) Modulus
210 GPa
Elongation at Break
23 %
Fatigue Strength
250 MPa
Poisson's Ratio
0.3
Reduction in Area
22 %
Shear Modulus
81 GPa
Tensile Strength: Ultimate (UTS)
1020 MPa
Tensile Strength: Yield (Proof)
460 MPa
Hardness
Brinell Hardness
280
Physical
Density
9.1 g/cm 3
Thermal
Latent Heat of Fusion
300 J/g
Melting Completion (Liquidus)
1540 °C
Melting Onset (Solidus)
1460 °C
Specific Heat Capacity
420 J/kg-K
Thermal Conductivity
13 W/m-K
Thermal Diffusivity
3.3 mm 2 /s
Thermal Expansion
12 µm/m-K
Thermal Shock Resistance
28 points
Calculated
Resilience: Ultimate (Unit Rupture Work)
190 MJ/m 3
Resilience: Unit (Modulus of Resilience)
510 kJ/m 3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
22 points
Strength to Weight: Axial
31 points
Strength to Weight: Bending
25 points
Environmental
Embodied Carbon
20 kg CO 2 /kg material
Embodied Energy
320 MJ/kg
Embodied Energy
320 MJ/kg 140 x 10 3 BTU/lb
Embodied Water
440 L/kg
Embodied Water
440 L/kg 52 gal/lb
Registered Designations & Aliases
R30816UNS R30816 (formerly Grade 671) Cobaltformerly Grade 671
Standards
ASTM B639 ASTM B639: Standard Specification for Precipitation Hardening Cobalt-Containing Alloys (UNS R30155 and UNS R30816) Rod, Bar, Forgings, and Forging Stock for High-Temperature Service