AISI 309 Stainless Steel vs. R31537 Cobalt
AISI 309 stainless steel belongs to the iron alloys classification, while R31537 cobalt belongs to the cobalt alloys. They have a modest 25% 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 (9, in this case) are not shown.
For each property being compared, the top bar is AISI 309 stainless steel and the bottom bar is R31537 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
Elastic (Young's, Tensile) Modulus, GPa | 200 | |
220 |
Elongation at Break, % | 34 to 47 | |
14 to 23 |
Fatigue Strength, MPa | 250 to 280 | |
310 to 480 |
Poisson's Ratio | 0.27 | |
0.29 |
Shear Modulus, GPa | 78 | |
87 |
Tensile Strength: Ultimate (UTS), MPa | 600 to 710 | |
1000 to 1340 |
Tensile Strength: Yield (Proof), MPa | 260 to 350 | |
590 to 940 |
Thermal Properties
Latent Heat of Fusion, J/g | 290 | |
320 |
Melting Completion (Liquidus), °C | 1450 | |
1360 |
Melting Onset (Solidus), °C | 1400 | |
1290 |
Specific Heat Capacity, J/kg-K | 480 | |
450 |
Thermal Conductivity, W/m-K | 16 | |
13 |
Thermal Expansion, µm/m-K | 15 | |
13 |
Electrical Properties
Electrical Conductivity: Equal Volume, % IACS | 2.2 | |
2.0 |
Electrical Conductivity: Equal Weight (Specific), % IACS | 2.5 | |
2.1 |
Otherwise Unclassified Properties
Density, g/cm3 | 7.8 | |
8.4 |
Embodied Carbon, kg CO2/kg material | 3.6 | |
8.1 |
Embodied Energy, MJ/kg | 51 | |
110 |
Embodied Water, L/kg | 170 | |
530 |
Common Calculations
Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 200 to 230 | |
140 to 200 |
Resilience: Unit (Modulus of Resilience), kJ/m3 | 170 to 310 | |
780 to 1990 |
Stiffness to Weight: Axial, points | 14 | |
15 |
Stiffness to Weight: Bending, points | 25 | |
24 |
Strength to Weight: Axial, points | 21 to 25 | |
33 to 44 |
Strength to Weight: Bending, points | 20 to 23 | |
26 to 32 |
Thermal Diffusivity, mm2/s | 4.3 | |
3.4 |
Thermal Shock Resistance, points | 14 to 16 | |
24 to 32 |
Alloy Composition
Carbon (C), % | 0 to 0.2 | |
0 to 0.14 |
Chromium (Cr), % | 22 to 24 | |
26 to 30 |
Cobalt (Co), % | 0 | |
58.9 to 69 |
Iron (Fe), % | 58 to 66 | |
0 to 0.75 |
Manganese (Mn), % | 0 to 2.0 | |
0 to 1.0 |
Molybdenum (Mo), % | 0 | |
5.0 to 7.0 |
Nickel (Ni), % | 12 to 15 | |
0 to 1.0 |
Nitrogen (N), % | 0 | |
0 to 0.25 |
Phosphorus (P), % | 0 to 0.045 | |
0 |
Silicon (Si), % | 0 to 0.75 | |
0 to 1.0 |
Sulfur (S), % | 0 to 0.030 | |
0 |