R30008 Cobalt vs. ACI-ASTM CB7Cu-2 Steel
R30008 cobalt belongs to the cobalt alloys classification, while ACI-ASTM CB7Cu-2 steel belongs to the iron alloys. They have a modest 34% of their average alloy composition in common, which, by itself, doesn't mean much. There are 23 material properties with values for both materials. Properties with values for just one material (7, in this case) are not shown.
For each property being compared, the top bar is R30008 cobalt and the bottom bar is ACI-ASTM CB7Cu-2 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 210 | |
| 190 |
| Elongation at Break, % | 1.1 to 73 | |
| 5.7 to 11 |
| Fatigue Strength, MPa | 320 to 530 | |
| 420 to 590 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Shear Modulus, GPa | 83 | |
| 75 |
| Tensile Strength: Ultimate (UTS), MPa | 950 to 1700 | |
| 960 to 1350 |
| Tensile Strength: Yield (Proof), MPa | 500 to 1080 | |
| 760 to 1180 |
Thermal Properties
| Latent Heat of Fusion, J/g | 320 | |
| 280 |
| Melting Completion (Liquidus), °C | 1400 | |
| 1430 |
| Melting Onset (Solidus), °C | 1330 | |
| 1380 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 480 |
| Thermal Expansion, µm/m-K | 13 | |
| 11 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 95 | |
| 13 |
| Density, g/cm3 | 8.4 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 8.1 | |
| 2.6 |
| Embodied Energy, MJ/kg | 110 | |
| 38 |
| Embodied Water, L/kg | 400 | |
| 130 |
Common Calculations
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 590 to 2720 | |
| 1510 to 3600 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 25 |
| Strength to Weight: Axial, points | 31 to 56 | |
| 34 to 48 |
| Strength to Weight: Bending, points | 25 to 37 | |
| 28 to 35 |
| Thermal Shock Resistance, points | 25 to 44 | |
| 32 to 45 |
Alloy Composition
| Boron (B), % | 0 to 0.0010 | |
| 0 |
| Carbon (C), % | 0 to 0.15 | |
| 0 to 0.070 |
| Chromium (Cr), % | 18.5 to 21.5 | |
| 14 to 15.5 |
| Cobalt (Co), % | 39 to 42 | |
| 0 |
| Copper (Cu), % | 0 | |
| 2.5 to 3.2 |
| Iron (Fe), % | 7.6 to 20 | |
| 73.6 to 79 |
| Manganese (Mn), % | 1.0 to 2.0 | |
| 0 to 0.7 |
| Molybdenum (Mo), % | 6.5 to 7.5 | |
| 0 |
| Nickel (Ni), % | 15 to 18 | |
| 4.5 to 5.5 |
| Niobium (Nb), % | 0 | |
| 0 to 0.35 |
| Nitrogen (N), % | 0 | |
| 0 to 0.050 |
| Phosphorus (P), % | 0 to 0.015 | |
| 0 to 0.035 |
| Silicon (Si), % | 0 to 1.2 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 to 0.015 | |
| 0 to 0.030 |