R30816 Cobalt vs. AISI 431 Stainless Steel
R30816 cobalt belongs to the cobalt alloys classification, while AISI 431 stainless steel belongs to the iron alloys. They have a modest 22% of their average alloy composition in common, which, by itself, doesn't mean much. There are 26 material properties with values for both materials. Properties with values for just one material (9, in this case) are not shown.
For each property being compared, the top bar is R30816 cobalt and the bottom bar is AISI 431 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 280 | |
| 250 |
| Elastic (Young's, Tensile) Modulus, GPa | 210 | |
| 200 |
| Elongation at Break, % | 23 | |
| 15 to 17 |
| Fatigue Strength, MPa | 250 | |
| 430 to 610 |
| Poisson's Ratio | 0.3 | |
| 0.28 |
| Shear Modulus, GPa | 81 | |
| 77 |
| Tensile Strength: Ultimate (UTS), MPa | 1020 | |
| 890 to 1380 |
| Tensile Strength: Yield (Proof), MPa | 460 | |
| 710 to 1040 |
Thermal Properties
| Latent Heat of Fusion, J/g | 300 | |
| 280 |
| Melting Completion (Liquidus), °C | 1540 | |
| 1510 |
| Melting Onset (Solidus), °C | 1460 | |
| 1450 |
| Specific Heat Capacity, J/kg-K | 420 | |
| 480 |
| Thermal Conductivity, W/m-K | 13 | |
| 26 |
| Thermal Expansion, µm/m-K | 12 | |
| 12 |
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 | |
| 140 to 180 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 510 | |
| 1270 to 2770 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 22 | |
| 25 |
| Strength to Weight: Axial, points | 31 | |
| 32 to 50 |
| Strength to Weight: Bending, points | 25 | |
| 27 to 36 |
| Thermal Diffusivity, mm2/s | 3.3 | |
| 7.0 |
| Thermal Shock Resistance, points | 28 | |
| 28 to 43 |
Alloy Composition
| Carbon (C), % | 0.32 to 0.42 | |
| 0 to 0.2 |
| Chromium (Cr), % | 19 to 21 | |
| 15 to 17 |
| Cobalt (Co), % | 40 to 49.8 | |
| 0 |
| Iron (Fe), % | 0 to 5.0 | |
| 78.2 to 83.8 |
| Manganese (Mn), % | 1.0 to 2.0 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 3.5 to 4.5 | |
| 0 |
| Nickel (Ni), % | 19 to 21 | |
| 1.3 to 2.5 |
| 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 0.030 |
| Tantalum (Ta), % | 3.5 to 4.5 | |
| 0 |
| Tungsten (W), % | 3.5 to 4.5 | |
| 0 |