R31538 Cobalt vs. AWS E33-31
R31538 cobalt belongs to the cobalt alloys classification, while AWS E33-31 belongs to the iron alloys. They have a modest 31% of their average alloy composition in common, which, by itself, doesn't mean much. There are 19 material properties with values for both materials. Properties with values for just one material (12, in this case) are not shown.
For each property being compared, the top bar is R31538 cobalt and the bottom bar is AWS E33-31.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 220 | |
| 210 |
| Elongation at Break, % | 13 to 23 | |
| 29 |
| Poisson's Ratio | 0.29 | |
| 0.27 |
| Shear Modulus, GPa | 86 | |
| 81 |
| Tensile Strength: Ultimate (UTS), MPa | 1020 to 1360 | |
| 810 |
Thermal Properties
| Latent Heat of Fusion, J/g | 320 | |
| 320 |
| Melting Completion (Liquidus), °C | 1360 | |
| 1380 |
| Melting Onset (Solidus), °C | 1290 | |
| 1330 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 480 |
| Thermal Expansion, µm/m-K | 13 | |
| 14 |
Otherwise Unclassified Properties
| Density, g/cm3 | 8.4 | |
| 7.9 |
| Embodied Carbon, kg CO2/kg material | 8.1 | |
| 6.0 |
| Embodied Energy, MJ/kg | 110 | |
| 86 |
| Embodied Water, L/kg | 530 | |
| 260 |
Common Calculations
| Stiffness to Weight: Axial, points | 15 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 25 |
| Strength to Weight: Axial, points | 34 to 45 | |
| 28 |
| Strength to Weight: Bending, points | 27 to 32 | |
| 24 |
| Thermal Shock Resistance, points | 25 to 33 | |
| 19 |
Alloy Composition
| Carbon (C), % | 0.15 to 0.35 | |
| 0 to 0.030 |
| Chromium (Cr), % | 26 to 30 | |
| 31 to 35 |
| Cobalt (Co), % | 58.7 to 68.9 | |
| 0 |
| Copper (Cu), % | 0 | |
| 0.4 to 0.8 |
| Iron (Fe), % | 0 to 0.75 | |
| 24.7 to 34.8 |
| Manganese (Mn), % | 0 to 1.0 | |
| 2.5 to 4.0 |
| Molybdenum (Mo), % | 5.0 to 7.0 | |
| 1.0 to 2.0 |
| Nickel (Ni), % | 0 to 1.0 | |
| 30 to 32 |
| Nitrogen (N), % | 0 to 0.25 | |
| 0.3 to 0.5 |
| Phosphorus (P), % | 0 | |
| 0 to 0.020 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 0.9 |
| Sulfur (S), % | 0 | |
| 0 to 0.010 |