R31538 Cobalt vs. S20910 Stainless Steel
R31538 cobalt belongs to the cobalt alloys classification, while S20910 stainless steel belongs to the iron alloys. They have a modest 26% 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 R31538 cobalt and the bottom bar is S20910 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 220 | |
| 200 |
| Elongation at Break, % | 13 to 23 | |
| 14 to 39 |
| Fatigue Strength, MPa | 310 to 480 | |
| 310 to 460 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Reduction in Area, % | 13 to 22 | |
| 56 to 62 |
| Shear Modulus, GPa | 86 | |
| 79 |
| Tensile Strength: Ultimate (UTS), MPa | 1020 to 1360 | |
| 780 to 940 |
| Tensile Strength: Yield (Proof), MPa | 580 to 930 | |
| 430 to 810 |
Thermal Properties
| Latent Heat of Fusion, J/g | 320 | |
| 300 |
| Melting Completion (Liquidus), °C | 1360 | |
| 1420 |
| Melting Onset (Solidus), °C | 1290 | |
| 1380 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 480 |
| Thermal Conductivity, W/m-K | 13 | |
| 13 |
| Thermal Expansion, µm/m-K | 13 | |
| 16 |
Otherwise Unclassified Properties
| Density, g/cm3 | 8.4 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 8.1 | |
| 4.8 |
| Embodied Energy, MJ/kg | 110 | |
| 68 |
| Embodied Water, L/kg | 530 | |
| 180 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 140 to 200 | |
| 120 to 260 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 750 to 1920 | |
| 460 to 1640 |
| Stiffness to Weight: Axial, points | 15 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 25 |
| Strength to Weight: Axial, points | 34 to 45 | |
| 28 to 33 |
| Strength to Weight: Bending, points | 27 to 32 | |
| 24 to 27 |
| Thermal Diffusivity, mm2/s | 3.5 | |
| 3.6 |
| Thermal Shock Resistance, points | 25 to 33 | |
| 17 to 21 |
Alloy Composition
| Carbon (C), % | 0.15 to 0.35 | |
| 0 to 0.060 |
| Chromium (Cr), % | 26 to 30 | |
| 20.5 to 23.5 |
| Cobalt (Co), % | 58.7 to 68.9 | |
| 0 |
| Iron (Fe), % | 0 to 0.75 | |
| 52.1 to 62.1 |
| Manganese (Mn), % | 0 to 1.0 | |
| 4.0 to 6.0 |
| Molybdenum (Mo), % | 5.0 to 7.0 | |
| 1.5 to 3.0 |
| Nickel (Ni), % | 0 to 1.0 | |
| 11.5 to 13.5 |
| Niobium (Nb), % | 0 | |
| 0.1 to 0.3 |
| Nitrogen (N), % | 0 to 0.25 | |
| 0.2 to 0.4 |
| Phosphorus (P), % | 0 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 0.75 |
| Sulfur (S), % | 0 | |
| 0 to 0.030 |
| Vanadium (V), % | 0 | |
| 0.1 to 0.3 |