AWS E312 vs. R30021 Cobalt
AWS E312 belongs to the iron alloys classification, while R30021 cobalt belongs to the cobalt alloys. They have a modest 32% 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 AWS E312 and the bottom bar is R30021 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 220 |
| Elongation at Break, % | 25 | |
| 9.0 |
| Poisson's Ratio | 0.27 | |
| 0.29 |
| Shear Modulus, GPa | 80 | |
| 86 |
| Tensile Strength: Ultimate (UTS), MPa | 740 | |
| 700 |
Thermal Properties
| Latent Heat of Fusion, J/g | 310 | |
| 330 |
| Melting Completion (Liquidus), °C | 1410 | |
| 1350 |
| Melting Onset (Solidus), °C | 1360 | |
| 1190 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 450 |
| Thermal Expansion, µm/m-K | 15 | |
| 11 |
Otherwise Unclassified Properties
| Density, g/cm3 | 7.7 | |
| 8.4 |
| Embodied Carbon, kg CO2/kg material | 3.6 | |
| 8.0 |
| Embodied Energy, MJ/kg | 52 | |
| 110 |
| Embodied Water, L/kg | 200 | |
| 520 |
Common Calculations
| Stiffness to Weight: Axial, points | 15 | |
| 15 |
| Stiffness to Weight: Bending, points | 25 | |
| 24 |
| Strength to Weight: Axial, points | 27 | |
| 23 |
| Strength to Weight: Bending, points | 24 | |
| 21 |
| Thermal Shock Resistance, points | 18 | |
| 21 |
Alloy Composition
| Carbon (C), % | 0 to 0.15 | |
| 0.2 to 0.35 |
| Chromium (Cr), % | 28 to 32 | |
| 26 to 29 |
| Cobalt (Co), % | 0 | |
| 61.7 to 67.3 |
| Copper (Cu), % | 0 to 0.75 | |
| 0 |
| Iron (Fe), % | 52.3 to 63.5 | |
| 0 to 3.0 |
| Manganese (Mn), % | 0.5 to 2.5 | |
| 0 |
| Molybdenum (Mo), % | 0 to 0.75 | |
| 4.5 to 6.0 |
| Nickel (Ni), % | 8.0 to 10.5 | |
| 2.0 to 3.0 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 1.5 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 |