R30155 Cobalt vs. SAE-AISI 4028 Steel
Both R30155 cobalt and SAE-AISI 4028 steel are iron alloys. They have a modest 32% 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 (5, in this case) are not shown.
For each property being compared, the top bar is R30155 cobalt and the bottom bar is SAE-AISI 4028 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 220 | |
| 150 to 190 |
| Elastic (Young's, Tensile) Modulus, GPa | 210 | |
| 190 |
| Elongation at Break, % | 34 | |
| 14 to 23 |
| Fatigue Strength, MPa | 310 | |
| 180 to 330 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 81 | |
| 73 |
| Shear Strength, MPa | 570 | |
| 310 to 380 |
| Tensile Strength: Ultimate (UTS), MPa | 850 | |
| 490 to 630 |
| Tensile Strength: Yield (Proof), MPa | 390 | |
| 260 to 520 |
Thermal Properties
| Latent Heat of Fusion, J/g | 300 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 1100 | |
| 400 |
| 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 | |
| 49 |
| Thermal Expansion, µm/m-K | 14 | |
| 12 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 80 | |
| 2.1 |
| Density, g/cm3 | 8.5 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 9.7 | |
| 1.5 |
| Embodied Energy, MJ/kg | 150 | |
| 19 |
| Embodied Water, L/kg | 300 | |
| 47 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 230 | |
| 81 to 95 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 370 | |
| 180 to 720 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 23 | |
| 24 |
| Strength to Weight: Axial, points | 28 | |
| 17 to 22 |
| Strength to Weight: Bending, points | 24 | |
| 18 to 21 |
| Thermal Diffusivity, mm2/s | 3.2 | |
| 13 |
| Thermal Shock Resistance, points | 21 | |
| 16 to 20 |
Alloy Composition
| Carbon (C), % | 0.080 to 0.16 | |
| 0.25 to 0.3 |
| Chromium (Cr), % | 20 to 22.5 | |
| 0 |
| Cobalt (Co), % | 18.5 to 21 | |
| 0 |
| Iron (Fe), % | 24.3 to 36.2 | |
| 98.1 to 98.7 |
| Manganese (Mn), % | 1.0 to 2.0 | |
| 0.7 to 0.9 |
| Molybdenum (Mo), % | 2.5 to 3.5 | |
| 0.2 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 0.035 |
| Silicon (Si), % | 0 to 1.0 | |
| 0.15 to 0.35 |
| Sulfur (S), % | 0 to 0.030 | |
| 0.035 to 0.050 |
| Tantalum (Ta), % | 0.75 to 1.3 | |
| 0 |
| Tungsten (W), % | 2.0 to 3.0 | |
| 0 |