R30155 Cobalt vs. EN 1.7221 Steel
Both R30155 cobalt and EN 1.7221 steel are iron alloys. They have a modest 33% of their average alloy composition in common, which, by itself, doesn't mean much. There are 28 material properties with values for both materials. Properties with values for just one material (7, in this case) are not shown.
For each property being compared, the top bar is R30155 cobalt and the bottom bar is EN 1.7221 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 220 | |
| 200 to 230 |
| Elastic (Young's, Tensile) Modulus, GPa | 210 | |
| 190 |
| Elongation at Break, % | 34 | |
| 11 to 17 |
| Fatigue Strength, MPa | 310 | |
| 290 to 390 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 81 | |
| 73 |
| Tensile Strength: Ultimate (UTS), MPa | 850 | |
| 650 to 780 |
| Tensile Strength: Yield (Proof), MPa | 390 | |
| 430 to 630 |
Thermal Properties
| Latent Heat of Fusion, J/g | 300 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 1100 | |
| 420 |
| Melting Completion (Liquidus), °C | 1470 | |
| 1460 |
| Melting Onset (Solidus), °C | 1420 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 470 |
| Thermal Conductivity, W/m-K | 12 | |
| 44 |
| Thermal Expansion, µm/m-K | 14 | |
| 13 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 80 | |
| 2.4 |
| Density, g/cm3 | 8.5 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 9.7 | |
| 1.5 |
| Embodied Energy, MJ/kg | 150 | |
| 20 |
| Embodied Water, L/kg | 300 | |
| 51 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 230 | |
| 83 to 98 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 370 | |
| 490 to 1050 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 23 | |
| 24 |
| Strength to Weight: Axial, points | 28 | |
| 23 to 27 |
| Strength to Weight: Bending, points | 24 | |
| 21 to 24 |
| Thermal Diffusivity, mm2/s | 3.2 | |
| 12 |
| Thermal Shock Resistance, points | 21 | |
| 19 to 23 |
Alloy Composition
| Carbon (C), % | 0.080 to 0.16 | |
| 0.22 to 0.29 |
| Chromium (Cr), % | 20 to 22.5 | |
| 0.8 to 1.2 |
| Cobalt (Co), % | 18.5 to 21 | |
| 0 |
| Iron (Fe), % | 24.3 to 36.2 | |
| 96.8 to 98.3 |
| Manganese (Mn), % | 1.0 to 2.0 | |
| 0.5 to 0.8 |
| Molybdenum (Mo), % | 2.5 to 3.5 | |
| 0.15 to 0.3 |
| Nickel (Ni), % | 19 to 21 | |
| 0 |
| Niobium (Nb), % | 0.75 to 1.3 | |
| 0 |
| Nitrogen (N), % | 0 to 0.2 | |
| 0 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.025 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 0.6 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.030 |
| Tantalum (Ta), % | 0.75 to 1.3 | |
| 0 |
| Tungsten (W), % | 2.0 to 3.0 | |
| 0 |