R30008 Cobalt vs. SAE-AISI 8645 Steel
R30008 cobalt belongs to the cobalt alloys classification, while SAE-AISI 8645 steel belongs to the iron alloys. There are 23 material properties with values for both materials. Properties with values for just one material (8, in this case) are not shown.
For each property being compared, the top bar is R30008 cobalt and the bottom bar is SAE-AISI 8645 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 210 | |
| 190 |
| Elongation at Break, % | 1.1 to 73 | |
| 12 to 23 |
| Fatigue Strength, MPa | 320 to 530 | |
| 280 to 350 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 83 | |
| 73 |
| Tensile Strength: Ultimate (UTS), MPa | 950 to 1700 | |
| 600 to 670 |
| Tensile Strength: Yield (Proof), MPa | 500 to 1080 | |
| 390 to 560 |
Thermal Properties
| Latent Heat of Fusion, J/g | 320 | |
| 250 |
| Melting Completion (Liquidus), °C | 1400 | |
| 1460 |
| Melting Onset (Solidus), °C | 1330 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 470 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 95 | |
| 2.6 |
| Density, g/cm3 | 8.4 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 8.1 | |
| 1.5 |
| Embodied Energy, MJ/kg | 110 | |
| 20 |
| Embodied Water, L/kg | 400 | |
| 50 |
Common Calculations
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 590 to 2720 | |
| 420 to 840 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 31 to 56 | |
| 21 to 24 |
| Strength to Weight: Bending, points | 25 to 37 | |
| 20 to 22 |
| Thermal Shock Resistance, points | 25 to 44 | |
| 18 to 20 |
Alloy Composition
| Boron (B), % | 0 to 0.0010 | |
| 0 |
| Carbon (C), % | 0 to 0.15 | |
| 0.43 to 0.48 |
| Chromium (Cr), % | 18.5 to 21.5 | |
| 0.4 to 0.6 |
| Cobalt (Co), % | 39 to 42 | |
| 0 |
| Iron (Fe), % | 7.6 to 20 | |
| 96.5 to 97.7 |
| Manganese (Mn), % | 1.0 to 2.0 | |
| 0.75 to 1.0 |
| Molybdenum (Mo), % | 6.5 to 7.5 | |
| 0.15 to 0.25 |
| Nickel (Ni), % | 15 to 18 | |
| 0.4 to 0.7 |
| Phosphorus (P), % | 0 to 0.015 | |
| 0 to 0.035 |
| Silicon (Si), % | 0 to 1.2 | |
| 0.15 to 0.35 |
| Sulfur (S), % | 0 to 0.015 | |
| 0 to 0.040 |