Annealed R31539 Cobalt vs. Annealed R31538 Cobalt
Both annealed R31539 cobalt and annealed R31538 cobalt are cobalt alloys. Both are furnished in the annealed condition. Their average alloy composition is basically identical.
For each property being compared, the top bar is annealed R31539 cobalt and the bottom bar is annealed R31538 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 220 | |
| 220 |
| Elongation at Break, % | 22 | |
| 23 |
| Fatigue Strength, MPa | 310 | |
| 310 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Reduction in Area, % | 23 | |
| 22 |
| Rockwell C Hardness | 25 | |
| 25 |
| Shear Modulus, GPa | 86 | |
| 86 |
| Tensile Strength: Ultimate (UTS), MPa | 1000 | |
| 1020 |
| Tensile Strength: Yield (Proof), MPa | 590 | |
| 580 |
Thermal Properties
| Latent Heat of Fusion, J/g | 320 | |
| 320 |
| Melting Completion (Liquidus), °C | 1360 | |
| 1360 |
| Melting Onset (Solidus), °C | 1290 | |
| 1290 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 450 |
| Thermal Conductivity, W/m-K | 13 | |
| 13 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 2.0 | |
| 2.0 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.1 | |
| 2.1 |
Otherwise Unclassified Properties
| Density, g/cm3 | 8.4 | |
| 8.4 |
| Embodied Carbon, kg CO2/kg material | 8.2 | |
| 8.1 |
| Embodied Energy, MJ/kg | 110 | |
| 110 |
| Embodied Water, L/kg | 530 | |
| 530 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 190 | |
| 200 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 780 | |
| 750 |
| Stiffness to Weight: Axial, points | 15 | |
| 15 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 33 | |
| 34 |
| Strength to Weight: Bending, points | 27 | |
| 27 |
| Thermal Diffusivity, mm2/s | 3.5 | |
| 3.5 |
| Thermal Shock Resistance, points | 24 | |
| 25 |
Alloy Composition
| Aluminum (Al), % | 0.3 to 1.0 | |
| 0 |
| Carbon (C), % | 0 to 0.14 | |
| 0.15 to 0.35 |
| Chromium (Cr), % | 26 to 30 | |
| 26 to 30 |
| Cobalt (Co), % | 57.7 to 68.7 | |
| 58.7 to 68.9 |
| Iron (Fe), % | 0 to 0.75 | |
| 0 to 0.75 |
| Lanthanum (La), % | 0.030 to 0.2 | |
| 0 |
| Manganese (Mn), % | 0 to 1.0 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 5.0 to 7.0 | |
| 5.0 to 7.0 |
| Nickel (Ni), % | 0 to 1.0 | |
| 0 to 1.0 |
| Nitrogen (N), % | 0 to 0.25 | |
| 0 to 0.25 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 1.0 |