R31538 Cobalt vs. S45000 Stainless Steel
R31538 cobalt belongs to the cobalt alloys classification, while S45000 stainless steel belongs to the iron alloys. There are 29 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 R31538 cobalt and the bottom bar is S45000 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 220 | |
| 200 |
| Elongation at Break, % | 13 to 23 | |
| 6.8 to 14 |
| Fatigue Strength, MPa | 310 to 480 | |
| 330 to 650 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Reduction in Area, % | 13 to 22 | |
| 22 to 50 |
| Rockwell C Hardness | 25 to 35 | |
| 28 to 44 |
| Shear Modulus, GPa | 86 | |
| 76 |
| Tensile Strength: Ultimate (UTS), MPa | 1020 to 1360 | |
| 980 to 1410 |
| Tensile Strength: Yield (Proof), MPa | 580 to 930 | |
| 580 to 1310 |
Thermal Properties
| Latent Heat of Fusion, J/g | 320 | |
| 280 |
| Melting Completion (Liquidus), °C | 1360 | |
| 1440 |
| Melting Onset (Solidus), °C | 1290 | |
| 1390 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 480 |
| Thermal Conductivity, W/m-K | 13 | |
| 17 |
| Thermal Expansion, µm/m-K | 13 | |
| 11 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 2.0 | |
| 2.2 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.1 | |
| 2.5 |
Otherwise Unclassified Properties
| Density, g/cm3 | 8.4 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 8.1 | |
| 2.8 |
| Embodied Energy, MJ/kg | 110 | |
| 39 |
| Embodied Water, L/kg | 530 | |
| 130 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 140 to 200 | |
| 94 to 160 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 750 to 1920 | |
| 850 to 4400 |
| Stiffness to Weight: Axial, points | 15 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 25 |
| Strength to Weight: Axial, points | 34 to 45 | |
| 35 to 50 |
| Strength to Weight: Bending, points | 27 to 32 | |
| 28 to 36 |
| Thermal Diffusivity, mm2/s | 3.5 | |
| 4.5 |
| Thermal Shock Resistance, points | 25 to 33 | |
| 33 to 47 |
Alloy Composition
| Carbon (C), % | 0.15 to 0.35 | |
| 0 to 0.050 |
| Chromium (Cr), % | 26 to 30 | |
| 14 to 16 |
| Cobalt (Co), % | 58.7 to 68.9 | |
| 0 |
| Copper (Cu), % | 0 | |
| 1.3 to 1.8 |
| Iron (Fe), % | 0 to 0.75 | |
| 72.1 to 79.3 |
| Manganese (Mn), % | 0 to 1.0 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 5.0 to 7.0 | |
| 0.5 to 1.0 |
| Nickel (Ni), % | 0 to 1.0 | |
| 5.0 to 7.0 |
| Nitrogen (N), % | 0 to 0.25 | |
| 0 |
| Phosphorus (P), % | 0 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 | |
| 0 to 0.030 |