UNS R30155 (formerly Grade 661) Iron-Cobalt Alloy
Austenitic & General Stainless Steels
Property Overview
Density8.5g/cm³
Elastic Modulus210GPa
Tensile Strength850MPa
Yield Strength390MPa
Brinell Hardness220HB
Maximum Service Temperature1100°C
Chemical Composition
C
0.080 to 0.16%
CR
20 to 22.5%
NI
19 to 21%
MO
2.5 to 3.5%
MN
1.0 to 2.0%
SI
0 to 1.0%
N
0 to 0.2%
P
0 to 0.040%
S
0 to 0.030%
NB
0.75 to 1.3%
CO
18.5 to 21%
W
2.0 to 3.0%
TA
0.75 to 1.3%
FE
24.3 to 36.2%
Mechanical
Elastic (Young's, Tensile) Modulus
210 GPa
Elongation at Break
34 %
Fatigue Strength
310 MPa
Poisson's Ratio
0.29
Reduction in Area
34 %
Shear Modulus
81 GPa
Shear Strength
570 MPa
Tensile Strength: Ultimate (UTS)
850 MPa
Tensile Strength: Yield (Proof)
390 MPa
Hardness
Brinell Hardness
220
Physical
Density
8.5 g/cm 3
Thermal
Latent Heat of Fusion
300 J/g
Maximum Temperature: Corrosion
570 °C
Maximum Temperature: Mechanical
1100 °C
Melting Completion (Liquidus)
1470 °C
Melting Onset (Solidus)
1420 °C
Specific Heat Capacity
450 J/kg-K
Thermal Conductivity
12 W/m-K
Thermal Diffusivity
3.2 mm 2 /s
Thermal Expansion
14 µm/m-K
Thermal Shock Resistance
21 points
Calculated
PREN (Pitting Resistance)
37
Resilience: Ultimate (Unit Rupture Work)
230 MJ/m 3
Resilience: Unit (Modulus of Resilience)
370 kJ/m 3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
23 points
Strength to Weight: Axial
28 points
Strength to Weight: Bending
24 points
Environmental
Base Metal Price
80 % relative
Embodied Carbon
9.7 kg CO 2 /kg material
Embodied Energy
150 MJ/kg
Embodied Energy
150 MJ/kg 63 x 10 3 BTU/lb
Embodied Water
300 L/kg
Embodied Water
300 L/kg 36 gal/lb
Registered Designations & Aliases
R30155UNS R30155 (formerly Grade 661) Iron-Cobalt Alloyformerly Grade 661
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
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 Machining of Stainless Steels and Super Alloys: Traditional and Nontraditional Techniques, Helmi A. Youssef, 2016