SAE-AISI D7 Steel vs. R31539 Cobalt
SAE-AISI D7 steel belongs to the iron alloys classification, while R31539 cobalt belongs to the cobalt alloys. There are 20 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 SAE-AISI D7 steel and the bottom bar is R31539 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 220 |
| Poisson's Ratio | 0.28 | |
| 0.29 |
| Shear Modulus, GPa | 73 | |
| 86 |
| Tensile Strength: Ultimate (UTS), MPa | 800 to 2120 | |
| 1000 to 1340 |
Thermal Properties
| Latent Heat of Fusion, J/g | 270 | |
| 320 |
| Melting Completion (Liquidus), °C | 1440 | |
| 1360 |
| Melting Onset (Solidus), °C | 1400 | |
| 1290 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 450 |
| Thermal Conductivity, W/m-K | 27 | |
| 13 |
| Thermal Expansion, µm/m-K | 11 | |
| 13 |
Otherwise Unclassified Properties
| Density, g/cm3 | 7.6 | |
| 8.4 |
| Embodied Carbon, kg CO2/kg material | 11 | |
| 8.2 |
| Embodied Energy, MJ/kg | 180 | |
| 110 |
| Embodied Water, L/kg | 130 | |
| 530 |
Common Calculations
| Stiffness to Weight: Axial, points | 14 | |
| 15 |
| Stiffness to Weight: Bending, points | 25 | |
| 24 |
| Strength to Weight: Axial, points | 29 to 78 | |
| 33 to 44 |
| Strength to Weight: Bending, points | 25 to 48 | |
| 27 to 32 |
| Thermal Diffusivity, mm2/s | 7.4 | |
| 3.5 |
| Thermal Shock Resistance, points | 27 to 72 | |
| 24 to 32 |
Alloy Composition
| Aluminum (Al), % | 0 | |
| 0.3 to 1.0 |
| Carbon (C), % | 2.2 to 2.5 | |
| 0 to 0.14 |
| Chromium (Cr), % | 11.5 to 13.5 | |
| 26 to 30 |
| Cobalt (Co), % | 0 | |
| 57.7 to 68.7 |
| Copper (Cu), % | 0 to 0.25 | |
| 0 |
| Iron (Fe), % | 76.6 to 81.9 | |
| 0 to 0.75 |
| Lanthanum (La), % | 0 | |
| 0.030 to 0.2 |
| Manganese (Mn), % | 0 to 0.6 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 0.7 to 1.2 | |
| 5.0 to 7.0 |
| Nickel (Ni), % | 0 to 0.3 | |
| 0 to 1.0 |
| Nitrogen (N), % | 0 | |
| 0 to 0.25 |
| Phosphorus (P), % | 0 to 0.030 | |
| 0 |
| Silicon (Si), % | 0 to 0.6 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 |
| Vanadium (V), % | 3.8 to 4.4 | |
| 0 |