AISI 321 Stainless Steel vs. R30012 Cobalt
AISI 321 stainless steel belongs to the iron alloys classification, while R30012 cobalt belongs to the cobalt alloys. They have a modest 21% of their average alloy composition in common, which, by itself, doesn't mean much. There are 27 material properties with values for both materials. Properties with values for just one material (8, in this case) are not shown.
For each property being compared, the top bar is AISI 321 stainless steel and the bottom bar is R30012 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
Elastic (Young's, Tensile) Modulus, GPa | 200 | |
220 |
Elongation at Break, % | 34 to 50 | |
1.0 |
Fatigue Strength, MPa | 220 to 270 | |
320 |
Poisson's Ratio | 0.28 | |
0.28 |
Shear Modulus, GPa | 77 | |
86 |
Tensile Strength: Ultimate (UTS), MPa | 590 to 690 | |
830 |
Tensile Strength: Yield (Proof), MPa | 220 to 350 | |
650 |
Thermal Properties
Latent Heat of Fusion, J/g | 290 | |
320 |
Melting Completion (Liquidus), °C | 1430 | |
1470 |
Melting Onset (Solidus), °C | 1400 | |
1280 |
Specific Heat Capacity, J/kg-K | 480 | |
440 |
Thermal Conductivity, W/m-K | 16 | |
15 |
Thermal Expansion, µm/m-K | 17 | |
12 |
Electrical Properties
Electrical Conductivity: Equal Volume, % IACS | 2.4 | |
1.8 |
Electrical Conductivity: Equal Weight (Specific), % IACS | 2.7 | |
1.8 |
Otherwise Unclassified Properties
Density, g/cm3 | 7.8 | |
8.8 |
Embodied Carbon, kg CO2/kg material | 3.2 | |
8.3 |
Embodied Energy, MJ/kg | 45 | |
120 |
Embodied Water, L/kg | 140 | |
480 |
Common Calculations
Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 190 to 230 | |
7.7 |
Resilience: Unit (Modulus of Resilience), kJ/m3 | 130 to 310 | |
960 |
Stiffness to Weight: Axial, points | 14 | |
14 |
Stiffness to Weight: Bending, points | 25 | |
23 |
Strength to Weight: Axial, points | 21 to 25 | |
26 |
Strength to Weight: Bending, points | 20 to 22 | |
22 |
Thermal Diffusivity, mm2/s | 4.1 | |
3.8 |
Thermal Shock Resistance, points | 13 to 15 | |
23 |
Alloy Composition
Carbon (C), % | 0 to 0.080 | |
1.4 to 2.0 |
Chromium (Cr), % | 17 to 19 | |
27 to 32 |
Cobalt (Co), % | 0 | |
47.5 to 64.1 |
Iron (Fe), % | 65.3 to 74 | |
0 to 3.0 |
Manganese (Mn), % | 0 to 2.0 | |
0 |
Molybdenum (Mo), % | 0 | |
0 to 1.0 |
Nickel (Ni), % | 9.0 to 12 | |
0 to 3.0 |
Nitrogen (N), % | 0 to 0.1 | |
0 |
Phosphorus (P), % | 0 to 0.045 | |
0 |
Silicon (Si), % | 0 to 0.75 | |
0 to 2.0 |
Sulfur (S), % | 0 to 0.030 | |
0 |
Titanium (Ti), % | 0 to 0.7 | |
0 |
Tungsten (W), % | 0 | |
7.5 to 9.5 |