R30155 Cobalt vs. SAE-AISI A8 Steel
Both R30155 cobalt and SAE-AISI A8 steel are iron alloys. They have a modest 39% of their average alloy composition in common, which, by itself, doesn't mean much. There are 22 material properties with values for both materials. Properties with values for just one material (12, in this case) are not shown.
For each property being compared, the top bar is R30155 cobalt and the bottom bar is SAE-AISI A8 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 210 | |
| 190 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 81 | |
| 74 |
| Tensile Strength: Ultimate (UTS), MPa | 850 | |
| 700 to 1920 |
Thermal Properties
| Latent Heat of Fusion, J/g | 300 | |
| 270 |
| Melting Completion (Liquidus), °C | 1470 | |
| 1480 |
| Melting Onset (Solidus), °C | 1420 | |
| 1430 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 470 |
| Thermal Conductivity, W/m-K | 12 | |
| 37 |
| Thermal Expansion, µm/m-K | 14 | |
| 12 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 80 | |
| 8.5 |
| Density, g/cm3 | 8.5 | |
| 7.9 |
| Embodied Carbon, kg CO2/kg material | 9.7 | |
| 2.3 |
| Embodied Energy, MJ/kg | 150 | |
| 31 |
| Embodied Water, L/kg | 300 | |
| 73 |
Common Calculations
| PREN (Pitting Resistance) | 37 | |
| 12 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 23 | |
| 24 |
| Strength to Weight: Axial, points | 28 | |
| 25 to 68 |
| Strength to Weight: Bending, points | 24 | |
| 22 to 44 |
| Thermal Diffusivity, mm2/s | 3.2 | |
| 9.9 |
| Thermal Shock Resistance, points | 21 | |
| 22 to 62 |
Alloy Composition
| Carbon (C), % | 0.080 to 0.16 | |
| 0.5 to 0.6 |
| Chromium (Cr), % | 20 to 22.5 | |
| 4.8 to 5.5 |
| Cobalt (Co), % | 18.5 to 21 | |
| 0 |
| Copper (Cu), % | 0 | |
| 0 to 0.25 |
| Iron (Fe), % | 24.3 to 36.2 | |
| 88.5 to 91.9 |
| Manganese (Mn), % | 1.0 to 2.0 | |
| 0 to 0.5 |
| Molybdenum (Mo), % | 2.5 to 3.5 | |
| 1.2 to 1.7 |
| Nickel (Ni), % | 19 to 21 | |
| 0 to 0.3 |
| Niobium (Nb), % | 0.75 to 1.3 | |
| 0 |
| Nitrogen (N), % | 0 to 0.2 | |
| 0 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.030 |
| Silicon (Si), % | 0 to 1.0 | |
| 0.75 to 1.1 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.030 |
| Tantalum (Ta), % | 0.75 to 1.3 | |
| 0 |
| Tungsten (W), % | 2.0 to 3.0 | |
| 1.0 to 1.5 |