R31538 Cobalt vs. SAE-AISI T8 Steel
R31538 cobalt belongs to the cobalt alloys classification, while SAE-AISI T8 steel belongs to the iron alloys. There are 20 material properties with values for both materials. Properties with values for just one material (11, in this case) are not shown.
For each property being compared, the top bar is R31538 cobalt and the bottom bar is SAE-AISI T8 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 220 | |
| 200 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 86 | |
| 78 |
| Tensile Strength: Ultimate (UTS), MPa | 1020 to 1360 | |
| 780 to 2140 |
Thermal Properties
| Latent Heat of Fusion, J/g | 320 | |
| 250 |
| Melting Completion (Liquidus), °C | 1360 | |
| 1730 |
| Melting Onset (Solidus), °C | 1290 | |
| 1670 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 420 |
| Thermal Conductivity, W/m-K | 13 | |
| 18 |
| Thermal Expansion, µm/m-K | 13 | |
| 12 |
Otherwise Unclassified Properties
| Density, g/cm3 | 8.4 | |
| 9.0 |
| Embodied Carbon, kg CO2/kg material | 8.1 | |
| 10 |
| Embodied Energy, MJ/kg | 110 | |
| 160 |
| Embodied Water, L/kg | 530 | |
| 120 |
Common Calculations
| Stiffness to Weight: Axial, points | 15 | |
| 12 |
| Stiffness to Weight: Bending, points | 24 | |
| 22 |
| Strength to Weight: Axial, points | 34 to 45 | |
| 24 to 66 |
| Strength to Weight: Bending, points | 27 to 32 | |
| 21 to 41 |
| Thermal Diffusivity, mm2/s | 3.5 | |
| 4.8 |
| Thermal Shock Resistance, points | 25 to 33 | |
| 24 to 66 |
Alloy Composition
| Carbon (C), % | 0.15 to 0.35 | |
| 0.75 to 0.85 |
| Chromium (Cr), % | 26 to 30 | |
| 3.8 to 4.5 |
| Cobalt (Co), % | 58.7 to 68.9 | |
| 4.3 to 5.8 |
| Copper (Cu), % | 0 | |
| 0 to 0.25 |
| Iron (Fe), % | 0 to 0.75 | |
| 69.3 to 75.4 |
| Manganese (Mn), % | 0 to 1.0 | |
| 0.2 to 0.4 |
| Molybdenum (Mo), % | 5.0 to 7.0 | |
| 0.4 to 1.0 |
| Nickel (Ni), % | 0 to 1.0 | |
| 0 to 0.3 |
| Nitrogen (N), % | 0 to 0.25 | |
| 0 |
| Phosphorus (P), % | 0 | |
| 0 to 0.030 |
| Silicon (Si), % | 0 to 1.0 | |
| 0.2 to 0.4 |
| Sulfur (S), % | 0 | |
| 0 to 0.030 |
| Tungsten (W), % | 0 | |
| 13.3 to 14.8 |
| Vanadium (V), % | 0 | |
| 1.8 to 2.4 |