R30155 Cobalt vs. S21800 Stainless Steel
Both R30155 cobalt and S21800 stainless steel are iron alloys. They have 58% of their average alloy composition in common. There are 30 material properties with values for both materials. Properties with values for just one material (3, in this case) are not shown.
For each property being compared, the top bar is R30155 cobalt and the bottom bar is S21800 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 220 | |
| 210 |
| Elastic (Young's, Tensile) Modulus, GPa | 210 | |
| 190 |
| Elongation at Break, % | 34 | |
| 40 |
| Fatigue Strength, MPa | 310 | |
| 330 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Reduction in Area, % | 34 | |
| 62 |
| Shear Modulus, GPa | 81 | |
| 75 |
| Shear Strength, MPa | 570 | |
| 510 |
| Tensile Strength: Ultimate (UTS), MPa | 850 | |
| 740 |
| Tensile Strength: Yield (Proof), MPa | 390 | |
| 390 |
Thermal Properties
| Latent Heat of Fusion, J/g | 300 | |
| 340 |
| Maximum Temperature: Corrosion, °C | 570 | |
| 410 |
| Maximum Temperature: Mechanical, °C | 1100 | |
| 900 |
| Melting Completion (Liquidus), °C | 1470 | |
| 1360 |
| Melting Onset (Solidus), °C | 1420 | |
| 1310 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 500 |
| Thermal Expansion, µm/m-K | 14 | |
| 16 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 80 | |
| 15 |
| Density, g/cm3 | 8.5 | |
| 7.5 |
| Embodied Carbon, kg CO2/kg material | 9.7 | |
| 3.1 |
| Embodied Energy, MJ/kg | 150 | |
| 45 |
| Embodied Water, L/kg | 300 | |
| 150 |
Common Calculations
| PREN (Pitting Resistance) | 37 | |
| 19 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 230 | |
| 250 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 370 | |
| 390 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 23 | |
| 26 |
| Strength to Weight: Axial, points | 28 | |
| 27 |
| Strength to Weight: Bending, points | 24 | |
| 24 |
| Thermal Shock Resistance, points | 21 | |
| 17 |
Alloy Composition
| Carbon (C), % | 0.080 to 0.16 | |
| 0 to 0.1 |
| Chromium (Cr), % | 20 to 22.5 | |
| 16 to 18 |
| Cobalt (Co), % | 18.5 to 21 | |
| 0 |
| Iron (Fe), % | 24.3 to 36.2 | |
| 59.1 to 65.4 |
| Manganese (Mn), % | 1.0 to 2.0 | |
| 7.0 to 9.0 |
| Molybdenum (Mo), % | 2.5 to 3.5 | |
| 0 |
| Nickel (Ni), % | 19 to 21 | |
| 8.0 to 9.0 |
| Niobium (Nb), % | 0.75 to 1.3 | |
| 0 |
| Nitrogen (N), % | 0 to 0.2 | |
| 0.080 to 0.18 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.060 |
| Silicon (Si), % | 0 to 1.0 | |
| 3.5 to 4.5 |
| 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 |