R30155 Cobalt vs. ASTM A387 Grade 2 Steel
Both R30155 cobalt and ASTM A387 grade 2 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 30 material properties with values for both materials. Properties with values for just one material (4, in this case) are not shown.
For each property being compared, the top bar is R30155 cobalt and the bottom bar is ASTM A387 grade 2 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 220 | |
| 140 to 170 |
| Elastic (Young's, Tensile) Modulus, GPa | 210 | |
| 190 |
| Elongation at Break, % | 34 | |
| 25 |
| Fatigue Strength, MPa | 310 | |
| 190 to 250 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 81 | |
| 73 |
| Shear Strength, MPa | 570 | |
| 300 to 350 |
| Tensile Strength: Ultimate (UTS), MPa | 850 | |
| 470 to 550 |
| Tensile Strength: Yield (Proof), MPa | 390 | |
| 260 to 350 |
Thermal Properties
| Latent Heat of Fusion, J/g | 300 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 1100 | |
| 420 |
| Melting Completion (Liquidus), °C | 1470 | |
| 1470 |
| Melting Onset (Solidus), °C | 1420 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 470 |
| Thermal Conductivity, W/m-K | 12 | |
| 45 |
| Thermal Expansion, µm/m-K | 14 | |
| 13 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 80 | |
| 2.6 |
| Density, g/cm3 | 8.5 | |
| 7.9 |
| Embodied Carbon, kg CO2/kg material | 9.7 | |
| 1.6 |
| Embodied Energy, MJ/kg | 150 | |
| 20 |
| Embodied Water, L/kg | 300 | |
| 50 |
Common Calculations
| PREN (Pitting Resistance) | 37 | |
| 2.4 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 230 | |
| 98 to 120 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 370 | |
| 180 to 320 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 23 | |
| 24 |
| Strength to Weight: Axial, points | 28 | |
| 16 to 20 |
| Strength to Weight: Bending, points | 24 | |
| 17 to 19 |
| Thermal Diffusivity, mm2/s | 3.2 | |
| 12 |
| Thermal Shock Resistance, points | 21 | |
| 14 to 16 |
Alloy Composition
| Carbon (C), % | 0.080 to 0.16 | |
| 0.050 to 0.21 |
| Chromium (Cr), % | 20 to 22.5 | |
| 0.5 to 0.8 |
| Cobalt (Co), % | 18.5 to 21 | |
| 0 |
| Iron (Fe), % | 24.3 to 36.2 | |
| 97.1 to 98.3 |
| Manganese (Mn), % | 1.0 to 2.0 | |
| 0.55 to 0.8 |
| Molybdenum (Mo), % | 2.5 to 3.5 | |
| 0.45 to 0.6 |
| 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 | |
| 0.15 to 0.4 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.025 |
| Tantalum (Ta), % | 0.75 to 1.3 | |
| 0 |
| Tungsten (W), % | 2.0 to 3.0 | |
| 0 |