R30008 Cobalt vs. AISI 321 Stainless Steel
R30008 cobalt belongs to the cobalt alloys classification, while AISI 321 stainless steel belongs to the iron alloys. They have 44% of their average alloy composition in common. There are 23 material properties with values for both materials. Properties with values for just one material (10, in this case) are not shown.
For each property being compared, the top bar is R30008 cobalt and the bottom bar is AISI 321 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 210 | |
| 200 |
| Elongation at Break, % | 1.1 to 73 | |
| 34 to 50 |
| Fatigue Strength, MPa | 320 to 530 | |
| 220 to 270 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Shear Modulus, GPa | 83 | |
| 77 |
| Tensile Strength: Ultimate (UTS), MPa | 950 to 1700 | |
| 590 to 690 |
| Tensile Strength: Yield (Proof), MPa | 500 to 1080 | |
| 220 to 350 |
Thermal Properties
| Latent Heat of Fusion, J/g | 320 | |
| 290 |
| Melting Completion (Liquidus), °C | 1400 | |
| 1430 |
| Melting Onset (Solidus), °C | 1330 | |
| 1400 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 480 |
| Thermal Expansion, µm/m-K | 13 | |
| 17 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 95 | |
| 16 |
| Density, g/cm3 | 8.4 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 8.1 | |
| 3.2 |
| Embodied Energy, MJ/kg | 110 | |
| 45 |
| Embodied Water, L/kg | 400 | |
| 140 |
Common Calculations
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 590 to 2720 | |
| 130 to 310 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 25 |
| Strength to Weight: Axial, points | 31 to 56 | |
| 21 to 25 |
| Strength to Weight: Bending, points | 25 to 37 | |
| 20 to 22 |
| Thermal Shock Resistance, points | 25 to 44 | |
| 13 to 15 |
Alloy Composition
| Boron (B), % | 0 to 0.0010 | |
| 0 |
| Carbon (C), % | 0 to 0.15 | |
| 0 to 0.080 |
| Chromium (Cr), % | 18.5 to 21.5 | |
| 17 to 19 |
| Cobalt (Co), % | 39 to 42 | |
| 0 |
| Iron (Fe), % | 7.6 to 20 | |
| 65.3 to 74 |
| Manganese (Mn), % | 1.0 to 2.0 | |
| 0 to 2.0 |
| Molybdenum (Mo), % | 6.5 to 7.5 | |
| 0 |
| Nickel (Ni), % | 15 to 18 | |
| 9.0 to 12 |
| Nitrogen (N), % | 0 | |
| 0 to 0.1 |
| Phosphorus (P), % | 0 to 0.015 | |
| 0 to 0.045 |
| Silicon (Si), % | 0 to 1.2 | |
| 0 to 0.75 |
| Sulfur (S), % | 0 to 0.015 | |
| 0 to 0.030 |
| Titanium (Ti), % | 0 | |
| 0 to 0.7 |