R30021 Cobalt vs. AISI 205 Stainless Steel
R30021 cobalt belongs to the cobalt alloys classification, while AISI 205 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 23 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 R30021 cobalt and the bottom bar is AISI 205 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 220 | |
| 200 |
| Elongation at Break, % | 9.0 | |
| 11 to 51 |
| Fatigue Strength, MPa | 250 | |
| 410 to 640 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Shear Modulus, GPa | 86 | |
| 77 |
| Tensile Strength: Ultimate (UTS), MPa | 700 | |
| 800 to 1430 |
| Tensile Strength: Yield (Proof), MPa | 500 | |
| 450 to 1100 |
Thermal Properties
| Latent Heat of Fusion, J/g | 330 | |
| 280 |
| Melting Completion (Liquidus), °C | 1350 | |
| 1380 |
| Melting Onset (Solidus), °C | 1190 | |
| 1340 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 480 |
| Thermal Expansion, µm/m-K | 11 | |
| 18 |
Otherwise Unclassified Properties
| Density, g/cm3 | 8.4 | |
| 7.6 |
| Embodied Carbon, kg CO2/kg material | 8.0 | |
| 2.6 |
| Embodied Energy, MJ/kg | 110 | |
| 37 |
| Embodied Water, L/kg | 520 | |
| 150 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 57 | |
| 150 to 430 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 570 | |
| 510 to 3060 |
| Stiffness to Weight: Axial, points | 15 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 26 |
| Strength to Weight: Axial, points | 23 | |
| 29 to 52 |
| Strength to Weight: Bending, points | 21 | |
| 25 to 37 |
| Thermal Shock Resistance, points | 21 | |
| 16 to 29 |
Alloy Composition
| Carbon (C), % | 0.2 to 0.35 | |
| 0.12 to 0.25 |
| Chromium (Cr), % | 26 to 29 | |
| 16.5 to 18.5 |
| Cobalt (Co), % | 61.7 to 67.3 | |
| 0 |
| Iron (Fe), % | 0 to 3.0 | |
| 62.6 to 68.1 |
| Manganese (Mn), % | 0 | |
| 14 to 15.5 |
| Molybdenum (Mo), % | 4.5 to 6.0 | |
| 0 |
| Nickel (Ni), % | 2.0 to 3.0 | |
| 1.0 to 1.7 |
| Nitrogen (N), % | 0 | |
| 0.32 to 0.4 |
| Phosphorus (P), % | 0 | |
| 0 to 0.060 |
| Silicon (Si), % | 0 to 1.5 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 | |
| 0 to 0.030 |