R30155 Cobalt vs. EN 1.7725 Steel
Both R30155 cobalt and EN 1.7725 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 29 material properties with values for both materials. Properties with values for just one material (6, in this case) are not shown.
For each property being compared, the top bar is R30155 cobalt and the bottom bar is EN 1.7725 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 220 | |
| 250 to 300 |
| Elastic (Young's, Tensile) Modulus, GPa | 210 | |
| 190 |
| Elongation at Break, % | 34 | |
| 14 |
| Fatigue Strength, MPa | 310 | |
| 390 to 550 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 81 | |
| 73 |
| Tensile Strength: Ultimate (UTS), MPa | 850 | |
| 830 to 1000 |
| Tensile Strength: Yield (Proof), MPa | 390 | |
| 610 to 860 |
Thermal Properties
| Latent Heat of Fusion, J/g | 300 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 1100 | |
| 440 |
| 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 | |
| 39 |
| Thermal Expansion, µm/m-K | 14 | |
| 13 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 80 | |
| 2.9 |
| Density, g/cm3 | 8.5 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 9.7 | |
| 1.8 |
| Embodied Energy, MJ/kg | 150 | |
| 24 |
| Embodied Water, L/kg | 300 | |
| 54 |
Common Calculations
| PREN (Pitting Resistance) | 37 | |
| 2.8 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 230 | |
| 110 to 130 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 370 | |
| 980 to 1940 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 23 | |
| 24 |
| Strength to Weight: Axial, points | 28 | |
| 29 to 35 |
| Strength to Weight: Bending, points | 24 | |
| 25 to 28 |
| Thermal Diffusivity, mm2/s | 3.2 | |
| 11 |
| Thermal Shock Resistance, points | 21 | |
| 24 to 29 |
Alloy Composition
| Carbon (C), % | 0.080 to 0.16 | |
| 0.27 to 0.34 |
| Chromium (Cr), % | 20 to 22.5 | |
| 1.3 to 1.7 |
| Cobalt (Co), % | 18.5 to 21 | |
| 0 |
| Iron (Fe), % | 24.3 to 36.2 | |
| 95.7 to 97.5 |
| Manganese (Mn), % | 1.0 to 2.0 | |
| 0.6 to 1.0 |
| Molybdenum (Mo), % | 2.5 to 3.5 | |
| 0.3 to 0.5 |
| 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 |
| Vanadium (V), % | 0 | |
| 0.050 to 0.15 |