ASTM A372 Grade M Steel vs. R30155 Cobalt
Both ASTM A372 grade M steel and R30155 cobalt are iron alloys. They have a modest 36% 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 ASTM A372 grade M steel and the bottom bar is R30155 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 240 to 280 | |
| 220 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 210 |
| Elongation at Break, % | 18 to 21 | |
| 34 |
| Fatigue Strength, MPa | 450 to 520 | |
| 310 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 73 | |
| 81 |
| Shear Strength, MPa | 510 to 570 | |
| 570 |
| Tensile Strength: Ultimate (UTS), MPa | 810 to 910 | |
| 850 |
| Tensile Strength: Yield (Proof), MPa | 660 to 770 | |
| 390 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 300 |
| Maximum Temperature: Mechanical, °C | 450 | |
| 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 | 46 | |
| 12 |
| Thermal Expansion, µm/m-K | 13 | |
| 14 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 5.0 | |
| 80 |
| Density, g/cm3 | 7.9 | |
| 8.5 |
| Embodied Carbon, kg CO2/kg material | 2.0 | |
| 9.7 |
| Embodied Energy, MJ/kg | 27 | |
| 150 |
| Embodied Water, L/kg | 61 | |
| 300 |
Common Calculations
| PREN (Pitting Resistance) | 3.4 | |
| 37 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 160 | |
| 230 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 1140 to 1580 | |
| 370 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 23 |
| Strength to Weight: Axial, points | 29 to 32 | |
| 28 |
| Strength to Weight: Bending, points | 24 to 27 | |
| 24 |
| Thermal Diffusivity, mm2/s | 12 | |
| 3.2 |
| Thermal Shock Resistance, points | 24 to 27 | |
| 21 |
Alloy Composition
| Carbon (C), % | 0 to 0.23 | |
| 0.080 to 0.16 |
| Chromium (Cr), % | 1.5 to 2.0 | |
| 20 to 22.5 |
| Cobalt (Co), % | 0 | |
| 18.5 to 21 |
| Iron (Fe), % | 92.5 to 95.1 | |
| 24.3 to 36.2 |
| Manganese (Mn), % | 0.2 to 0.4 | |
| 1.0 to 2.0 |
| Molybdenum (Mo), % | 0.4 to 0.6 | |
| 2.5 to 3.5 |
| Nickel (Ni), % | 2.8 to 3.9 | |
| 19 to 21 |
| Niobium (Nb), % | 0 | |
| 0.75 to 1.3 |
| Nitrogen (N), % | 0 | |
| 0 to 0.2 |
| Phosphorus (P), % | 0 to 0.015 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 0.3 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 to 0.010 | |
| 0 to 0.030 |
| Tantalum (Ta), % | 0 | |
| 0.75 to 1.3 |
| Tungsten (W), % | 0 | |
| 2.0 to 3.0 |
| Vanadium (V), % | 0 to 0.080 | |
| 0 |