R30155 Cobalt vs. ASTM A227 Spring Steel
Both R30155 cobalt and ASTM A227 spring steel are iron alloys. They have a modest 31% 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 (6, in this case) are not shown.
For each property being compared, the top bar is R30155 cobalt and the bottom bar is ASTM A227 spring steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 220 | |
| 500 to 640 |
| Elastic (Young's, Tensile) Modulus, GPa | 210 | |
| 190 |
| Elongation at Break, % | 34 | |
| 12 |
| Fatigue Strength, MPa | 310 | |
| 900 to 1160 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 81 | |
| 72 |
| Shear Strength, MPa | 570 | |
| 1030 to 1330 |
| Tensile Strength: Ultimate (UTS), MPa | 850 | |
| 1720 to 2220 |
| Tensile Strength: Yield (Proof), MPa | 390 | |
| 1430 to 1850 |
Thermal Properties
| Latent Heat of Fusion, J/g | 300 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 1100 | |
| 400 |
| Melting Completion (Liquidus), °C | 1470 | |
| 1450 |
| Melting Onset (Solidus), °C | 1420 | |
| 1410 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 470 |
| Thermal Conductivity, W/m-K | 12 | |
| 52 |
| Thermal Expansion, µm/m-K | 14 | |
| 12 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 80 | |
| 1.8 |
| Density, g/cm3 | 8.5 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 9.7 | |
| 1.4 |
| Embodied Energy, MJ/kg | 150 | |
| 19 |
| Embodied Water, L/kg | 300 | |
| 46 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 230 | |
| 200 to 260 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 23 | |
| 24 |
| Strength to Weight: Axial, points | 28 | |
| 61 to 79 |
| Strength to Weight: Bending, points | 24 | |
| 41 to 48 |
| Thermal Diffusivity, mm2/s | 3.2 | |
| 14 |
| Thermal Shock Resistance, points | 21 | |
| 55 to 71 |
Alloy Composition
| Carbon (C), % | 0.080 to 0.16 | |
| 0.45 to 0.85 |
| Chromium (Cr), % | 20 to 22.5 | |
| 0 |
| Cobalt (Co), % | 18.5 to 21 | |
| 0 |
| Iron (Fe), % | 24.3 to 36.2 | |
| 97.4 to 99.1 |
| Manganese (Mn), % | 1.0 to 2.0 | |
| 0.3 to 1.3 |
| Molybdenum (Mo), % | 2.5 to 3.5 | |
| 0 |
| 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 0.040 |
| Silicon (Si), % | 0 to 1.0 | |
| 0.15 to 0.35 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.050 |
| Tantalum (Ta), % | 0.75 to 1.3 | |
| 0 |
| Tungsten (W), % | 2.0 to 3.0 | |
| 0 |