R30816 Cobalt vs. SAE-AISI 4320 Steel
R30816 cobalt belongs to the cobalt alloys classification, while SAE-AISI 4320 steel belongs to the iron alloys. There are 26 material properties with values for both materials. Properties with values for just one material (6, in this case) are not shown.
For each property being compared, the top bar is R30816 cobalt and the bottom bar is SAE-AISI 4320 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 280 | |
| 160 to 240 |
| Elastic (Young's, Tensile) Modulus, GPa | 210 | |
| 190 |
| Elongation at Break, % | 23 | |
| 21 to 29 |
| Fatigue Strength, MPa | 250 | |
| 320 |
| Poisson's Ratio | 0.3 | |
| 0.29 |
| Shear Modulus, GPa | 81 | |
| 73 |
| Tensile Strength: Ultimate (UTS), MPa | 1020 | |
| 570 to 790 |
| Tensile Strength: Yield (Proof), MPa | 460 | |
| 430 to 460 |
Thermal Properties
| Latent Heat of Fusion, J/g | 300 | |
| 250 |
| Melting Completion (Liquidus), °C | 1540 | |
| 1460 |
| Melting Onset (Solidus), °C | 1460 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 420 | |
| 470 |
| Thermal Conductivity, W/m-K | 13 | |
| 46 |
| Thermal Expansion, µm/m-K | 12 | |
| 11 |
Otherwise Unclassified Properties
| Density, g/cm3 | 9.1 | |
| 7.9 |
| Embodied Carbon, kg CO2/kg material | 20 | |
| 1.7 |
| Embodied Energy, MJ/kg | 320 | |
| 22 |
| Embodied Water, L/kg | 440 | |
| 52 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 190 | |
| 140 to 150 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 510 | |
| 480 to 560 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 22 | |
| 24 |
| Strength to Weight: Axial, points | 31 | |
| 20 to 28 |
| Strength to Weight: Bending, points | 25 | |
| 19 to 24 |
| Thermal Diffusivity, mm2/s | 3.3 | |
| 13 |
| Thermal Shock Resistance, points | 28 | |
| 19 to 27 |
Alloy Composition
| Carbon (C), % | 0.32 to 0.42 | |
| 0.17 to 0.22 |
| Chromium (Cr), % | 19 to 21 | |
| 0.4 to 0.6 |
| Cobalt (Co), % | 40 to 49.8 | |
| 0 |
| Iron (Fe), % | 0 to 5.0 | |
| 95.8 to 97 |
| Manganese (Mn), % | 1.0 to 2.0 | |
| 0.45 to 0.65 |
| Molybdenum (Mo), % | 3.5 to 4.5 | |
| 0.2 to 0.3 |
| Nickel (Ni), % | 19 to 21 | |
| 1.7 to 2.0 |
| Niobium (Nb), % | 3.5 to 4.5 | |
| 0 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.035 |
| Silicon (Si), % | 0 to 1.0 | |
| 0.15 to 0.35 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.040 |
| Tantalum (Ta), % | 3.5 to 4.5 | |
| 0 |
| Tungsten (W), % | 3.5 to 4.5 | |
| 0 |