ASTM A229 Spring Steel vs. R30155 Cobalt
Both ASTM A229 spring 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 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 ASTM A229 spring steel and the bottom bar is R30155 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 490 to 550 | |
| 220 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 210 |
| Elongation at Break, % | 14 | |
| 34 |
| Fatigue Strength, MPa | 710 to 790 | |
| 310 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 72 | |
| 81 |
| Shear Strength, MPa | 1020 to 1140 | |
| 570 |
| Tensile Strength: Ultimate (UTS), MPa | 1690 to 1890 | |
| 850 |
| Tensile Strength: Yield (Proof), MPa | 1100 to 1230 | |
| 390 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 300 |
| Maximum Temperature: Mechanical, °C | 400 | |
| 1100 |
| Melting Completion (Liquidus), °C | 1450 | |
| 1470 |
| Melting Onset (Solidus), °C | 1410 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 450 |
| Thermal Conductivity, W/m-K | 50 | |
| 12 |
| Thermal Expansion, µm/m-K | 12 | |
| 14 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 1.8 | |
| 80 |
| Density, g/cm3 | 7.8 | |
| 8.5 |
| Embodied Carbon, kg CO2/kg material | 1.4 | |
| 9.7 |
| Embodied Energy, MJ/kg | 19 | |
| 150 |
| Embodied Water, L/kg | 46 | |
| 300 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 200 to 230 | |
| 230 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 3260 to 4080 | |
| 370 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 23 |
| Strength to Weight: Axial, points | 60 to 67 | |
| 28 |
| Strength to Weight: Bending, points | 40 to 43 | |
| 24 |
| Thermal Diffusivity, mm2/s | 14 | |
| 3.2 |
| Thermal Shock Resistance, points | 54 to 60 | |
| 21 |
Alloy Composition
| Carbon (C), % | 0.55 to 0.85 | |
| 0.080 to 0.16 |
| Chromium (Cr), % | 0 | |
| 20 to 22.5 |
| Cobalt (Co), % | 0 | |
| 18.5 to 21 |
| Iron (Fe), % | 97.5 to 99 | |
| 24.3 to 36.2 |
| Manganese (Mn), % | 0.3 to 1.2 | |
| 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), % | 0.15 to 0.35 | |
| 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 |