SAE-AISI 1021 Steel vs. R30155 Cobalt
Both SAE-AISI 1021 steel and R30155 cobalt are iron alloys. They have a modest 31% 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 SAE-AISI 1021 steel and the bottom bar is R30155 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 130 to 150 | |
| 220 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 210 |
| Elongation at Break, % | 17 to 27 | |
| 34 |
| Fatigue Strength, MPa | 190 to 300 | |
| 310 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Reduction in Area, % | 46 to 54 | |
| 34 |
| Shear Modulus, GPa | 73 | |
| 81 |
| Shear Strength, MPa | 310 to 320 | |
| 570 |
| Tensile Strength: Ultimate (UTS), MPa | 480 to 530 | |
| 850 |
| Tensile Strength: Yield (Proof), MPa | 260 to 450 | |
| 390 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 300 |
| Maximum Temperature: Mechanical, °C | 400 | |
| 1100 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1470 |
| Melting Onset (Solidus), °C | 1420 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 450 |
| Thermal Conductivity, W/m-K | 52 | |
| 12 |
| Thermal Expansion, µm/m-K | 12 | |
| 14 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 1.8 | |
| 80 |
| Density, g/cm3 | 7.9 | |
| 8.5 |
| Embodied Carbon, kg CO2/kg material | 1.4 | |
| 9.7 |
| Embodied Energy, MJ/kg | 18 | |
| 150 |
| Embodied Water, L/kg | 46 | |
| 300 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 84 to 110 | |
| 230 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 180 to 530 | |
| 370 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 23 |
| Strength to Weight: Axial, points | 17 to 19 | |
| 28 |
| Strength to Weight: Bending, points | 17 to 18 | |
| 24 |
| Thermal Diffusivity, mm2/s | 14 | |
| 3.2 |
| Thermal Shock Resistance, points | 15 to 17 | |
| 21 |
Alloy Composition
| Carbon (C), % | 0.18 to 0.23 | |
| 0.080 to 0.16 |
| Chromium (Cr), % | 0 | |
| 20 to 22.5 |
| Cobalt (Co), % | 0 | |
| 18.5 to 21 |
| Iron (Fe), % | 98.8 to 99.22 | |
| 24.3 to 36.2 |
| Manganese (Mn), % | 0.6 to 0.9 | |
| 1.0 to 2.0 |
| Molybdenum (Mo), % | 0 | |
| 2.5 to 3.5 |
| Nickel (Ni), % | 0 | |
| 19 to 21 |
| Niobium (Nb), % | 0 | |
| 0.75 to 1.3 |
| Nitrogen (N), % | 0 | |
| 0 to 0.2 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 to 0.050 | |
| 0 to 0.030 |
| Tantalum (Ta), % | 0 | |
| 0.75 to 1.3 |
| Tungsten (W), % | 0 | |
| 2.0 to 3.0 |