R30155 Cobalt vs. S20910 Stainless Steel
Both R30155 cobalt and S20910 stainless steel are iron alloys. They have 68% of their average alloy composition in common.
For each property being compared, the top bar is R30155 cobalt and the bottom bar is S20910 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 220 | |
| 230 to 290 |
| Elastic (Young's, Tensile) Modulus, GPa | 210 | |
| 200 |
| Elongation at Break, % | 34 | |
| 14 to 39 |
| Fatigue Strength, MPa | 310 | |
| 310 to 460 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Reduction in Area, % | 34 | |
| 56 to 62 |
| Shear Modulus, GPa | 81 | |
| 79 |
| Shear Strength, MPa | 570 | |
| 500 to 570 |
| Tensile Strength: Ultimate (UTS), MPa | 850 | |
| 780 to 940 |
| Tensile Strength: Yield (Proof), MPa | 390 | |
| 430 to 810 |
Thermal Properties
| Latent Heat of Fusion, J/g | 300 | |
| 300 |
| Maximum Temperature: Corrosion, °C | 570 | |
| 460 |
| Maximum Temperature: Mechanical, °C | 1100 | |
| 1080 |
| Melting Completion (Liquidus), °C | 1470 | |
| 1420 |
| Melting Onset (Solidus), °C | 1420 | |
| 1380 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 480 |
| Thermal Conductivity, W/m-K | 12 | |
| 13 |
| Thermal Expansion, µm/m-K | 14 | |
| 16 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 80 | |
| 22 |
| Density, g/cm3 | 8.5 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 9.7 | |
| 4.8 |
| Embodied Energy, MJ/kg | 150 | |
| 68 |
| Embodied Water, L/kg | 300 | |
| 180 |
Common Calculations
| PREN (Pitting Resistance) | 37 | |
| 34 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 230 | |
| 120 to 260 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 370 | |
| 460 to 1640 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 23 | |
| 25 |
| Strength to Weight: Axial, points | 28 | |
| 28 to 33 |
| Strength to Weight: Bending, points | 24 | |
| 24 to 27 |
| Thermal Diffusivity, mm2/s | 3.2 | |
| 3.6 |
| Thermal Shock Resistance, points | 21 | |
| 17 to 21 |
Alloy Composition
| Carbon (C), % | 0.080 to 0.16 | |
| 0 to 0.060 |
| Chromium (Cr), % | 20 to 22.5 | |
| 20.5 to 23.5 |
| Cobalt (Co), % | 18.5 to 21 | |
| 0 |
| Iron (Fe), % | 24.3 to 36.2 | |
| 52.1 to 62.1 |
| Manganese (Mn), % | 1.0 to 2.0 | |
| 4.0 to 6.0 |
| Molybdenum (Mo), % | 2.5 to 3.5 | |
| 1.5 to 3.0 |
| Nickel (Ni), % | 19 to 21 | |
| 11.5 to 13.5 |
| Niobium (Nb), % | 0.75 to 1.3 | |
| 0.1 to 0.3 |
| Nitrogen (N), % | 0 to 0.2 | |
| 0.2 to 0.4 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 0.75 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.030 |
| Tantalum (Ta), % | 0.75 to 1.3 | |
| 0 |
| Tungsten (W), % | 2.0 to 3.0 | |
| 0 |
| Vanadium (V), % | 0 | |
| 0.1 to 0.3 |