R31538 Cobalt vs. S45500 Stainless Steel
R31538 cobalt belongs to the cobalt alloys classification, while S45500 stainless steel belongs to the iron alloys. There are 24 material properties with values for both materials. Properties with values for just one material (11, in this case) are not shown.
For each property being compared, the top bar is R31538 cobalt and the bottom bar is S45500 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 220 | |
| 190 |
| Elongation at Break, % | 13 to 23 | |
| 3.4 to 11 |
| Fatigue Strength, MPa | 310 to 480 | |
| 570 to 890 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Reduction in Area, % | 13 to 22 | |
| 34 to 45 |
| Rockwell C Hardness | 25 to 35 | |
| 32 to 54 |
| Shear Modulus, GPa | 86 | |
| 75 |
| Tensile Strength: Ultimate (UTS), MPa | 1020 to 1360 | |
| 1370 to 1850 |
| Tensile Strength: Yield (Proof), MPa | 580 to 930 | |
| 1240 to 1700 |
Thermal Properties
| Latent Heat of Fusion, J/g | 320 | |
| 270 |
| Melting Completion (Liquidus), °C | 1360 | |
| 1440 |
| Melting Onset (Solidus), °C | 1290 | |
| 1400 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 470 |
| Thermal Expansion, µm/m-K | 13 | |
| 11 |
Otherwise Unclassified Properties
| Density, g/cm3 | 8.4 | |
| 7.9 |
| Embodied Carbon, kg CO2/kg material | 8.1 | |
| 3.8 |
| Embodied Energy, MJ/kg | 110 | |
| 57 |
| Embodied Water, L/kg | 530 | |
| 120 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 140 to 200 | |
| 45 to 190 |
| Stiffness to Weight: Axial, points | 15 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 34 to 45 | |
| 48 to 65 |
| Strength to Weight: Bending, points | 27 to 32 | |
| 35 to 42 |
| Thermal Shock Resistance, points | 25 to 33 | |
| 48 to 64 |
Alloy Composition
| Carbon (C), % | 0.15 to 0.35 | |
| 0 to 0.050 |
| Chromium (Cr), % | 26 to 30 | |
| 11 to 12.5 |
| Cobalt (Co), % | 58.7 to 68.9 | |
| 0 |
| Copper (Cu), % | 0 | |
| 1.5 to 2.5 |
| Iron (Fe), % | 0 to 0.75 | |
| 71.5 to 79.2 |
| Manganese (Mn), % | 0 to 1.0 | |
| 0 to 0.5 |
| Molybdenum (Mo), % | 5.0 to 7.0 | |
| 0 to 0.5 |
| Nickel (Ni), % | 0 to 1.0 | |
| 7.5 to 9.5 |
| Niobium (Nb), % | 0 | |
| 0 to 0.5 |
| Nitrogen (N), % | 0 to 0.25 | |
| 0 |
| Phosphorus (P), % | 0 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 0.5 |
| Sulfur (S), % | 0 | |
| 0 to 0.030 |
| Tantalum (Ta), % | 0 | |
| 0 to 0.5 |
| Titanium (Ti), % | 0 | |
| 0.8 to 1.4 |