R30816 Cobalt vs. AISI 440B Stainless Steel
R30816 cobalt belongs to the cobalt alloys classification, while AISI 440B stainless steel belongs to the iron alloys. They have a modest 21% of their average alloy composition in common, which, by itself, doesn't mean much. There are 24 material properties with values for both materials. Properties with values for just one material (10, in this case) are not shown.
For each property being compared, the top bar is R30816 cobalt and the bottom bar is AISI 440B stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 210 | |
| 200 |
| Elongation at Break, % | 23 | |
| 3.0 to 18 |
| Fatigue Strength, MPa | 250 | |
| 260 to 850 |
| Poisson's Ratio | 0.3 | |
| 0.28 |
| Shear Modulus, GPa | 81 | |
| 77 |
| Tensile Strength: Ultimate (UTS), MPa | 1020 | |
| 740 to 1930 |
| Tensile Strength: Yield (Proof), MPa | 460 | |
| 430 to 1860 |
Thermal Properties
| Latent Heat of Fusion, J/g | 300 | |
| 280 |
| Melting Completion (Liquidus), °C | 1540 | |
| 1480 |
| Melting Onset (Solidus), °C | 1460 | |
| 1370 |
| Specific Heat Capacity, J/kg-K | 420 | |
| 480 |
| Thermal Conductivity, W/m-K | 13 | |
| 23 |
| Thermal Expansion, µm/m-K | 12 | |
| 10 |
Otherwise Unclassified Properties
| Density, g/cm3 | 9.1 | |
| 7.7 |
| Embodied Carbon, kg CO2/kg material | 20 | |
| 2.2 |
| Embodied Energy, MJ/kg | 320 | |
| 31 |
| Embodied Water, L/kg | 440 | |
| 120 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 190 | |
| 57 to 110 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 22 | |
| 25 |
| Strength to Weight: Axial, points | 31 | |
| 27 to 70 |
| Strength to Weight: Bending, points | 25 | |
| 24 to 45 |
| Thermal Diffusivity, mm2/s | 3.3 | |
| 6.1 |
| Thermal Shock Resistance, points | 28 | |
| 27 to 70 |
Alloy Composition
| Carbon (C), % | 0.32 to 0.42 | |
| 0.75 to 1.0 |
| Chromium (Cr), % | 19 to 21 | |
| 16 to 18 |
| Cobalt (Co), % | 40 to 49.8 | |
| 0 |
| Iron (Fe), % | 0 to 5.0 | |
| 78.2 to 83.3 |
| Manganese (Mn), % | 1.0 to 2.0 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 3.5 to 4.5 | |
| 0 to 0.75 |
| Nickel (Ni), % | 19 to 21 | |
| 0 |
| Niobium (Nb), % | 3.5 to 4.5 | |
| 0 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.015 |
| Tantalum (Ta), % | 3.5 to 4.5 | |
| 0 |
| Tungsten (W), % | 3.5 to 4.5 | |
| 0 |