R31539 Cobalt vs. EN 1.7221 Steel
R31539 cobalt belongs to the cobalt alloys classification, while EN 1.7221 steel belongs to the iron alloys. There are 27 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 R31539 cobalt and the bottom bar is EN 1.7221 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 220 | |
| 190 |
| Elongation at Break, % | 13 to 22 | |
| 11 to 17 |
| Fatigue Strength, MPa | 310 to 480 | |
| 290 to 390 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 86 | |
| 73 |
| Tensile Strength: Ultimate (UTS), MPa | 1000 to 1340 | |
| 650 to 780 |
| Tensile Strength: Yield (Proof), MPa | 590 to 940 | |
| 430 to 630 |
Thermal Properties
| Latent Heat of Fusion, J/g | 320 | |
| 250 |
| Melting Completion (Liquidus), °C | 1360 | |
| 1460 |
| Melting Onset (Solidus), °C | 1290 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 470 |
| Thermal Conductivity, W/m-K | 13 | |
| 44 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 2.0 | |
| 7.3 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.1 | |
| 8.4 |
Otherwise Unclassified Properties
| Density, g/cm3 | 8.4 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 8.2 | |
| 1.5 |
| Embodied Energy, MJ/kg | 110 | |
| 20 |
| Embodied Water, L/kg | 530 | |
| 51 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 140 to 190 | |
| 83 to 98 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 780 to 2000 | |
| 490 to 1050 |
| Stiffness to Weight: Axial, points | 15 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 33 to 44 | |
| 23 to 27 |
| Strength to Weight: Bending, points | 27 to 32 | |
| 21 to 24 |
| Thermal Diffusivity, mm2/s | 3.5 | |
| 12 |
| Thermal Shock Resistance, points | 24 to 32 | |
| 19 to 23 |
Alloy Composition
| Aluminum (Al), % | 0.3 to 1.0 | |
| 0 |
| Carbon (C), % | 0 to 0.14 | |
| 0.22 to 0.29 |
| Chromium (Cr), % | 26 to 30 | |
| 0.8 to 1.2 |
| Cobalt (Co), % | 57.7 to 68.7 | |
| 0 |
| Iron (Fe), % | 0 to 0.75 | |
| 96.8 to 98.3 |
| Lanthanum (La), % | 0.030 to 0.2 | |
| 0 |
| Manganese (Mn), % | 0 to 1.0 | |
| 0.5 to 0.8 |
| Molybdenum (Mo), % | 5.0 to 7.0 | |
| 0.15 to 0.3 |
| Nickel (Ni), % | 0 to 1.0 | |
| 0 |
| Nitrogen (N), % | 0 to 0.25 | |
| 0 |
| Phosphorus (P), % | 0 | |
| 0 to 0.025 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 0.6 |
| Sulfur (S), % | 0 | |
| 0 to 0.030 |