AISI 420 Stainless Steel vs. R30155 Cobalt
Both AISI 420 stainless steel and R30155 cobalt are iron alloys. They have 45% of their average alloy composition in common. There are 31 material properties with values for both materials. Properties with values for just one material (4, in this case) are not shown.
For each property being compared, the top bar is AISI 420 stainless steel and the bottom bar is R30155 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 190 | |
| 220 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 210 |
| Elongation at Break, % | 8.0 to 15 | |
| 34 |
| Fatigue Strength, MPa | 220 to 670 | |
| 310 |
| Poisson's Ratio | 0.28 | |
| 0.29 |
| Shear Modulus, GPa | 76 | |
| 81 |
| Shear Strength, MPa | 420 to 1010 | |
| 570 |
| Tensile Strength: Ultimate (UTS), MPa | 690 to 1720 | |
| 850 |
| Tensile Strength: Yield (Proof), MPa | 380 to 1310 | |
| 390 |
Thermal Properties
| Latent Heat of Fusion, J/g | 280 | |
| 300 |
| Maximum Temperature: Corrosion, °C | 390 | |
| 570 |
| Maximum Temperature: Mechanical, °C | 620 | |
| 1100 |
| Melting Completion (Liquidus), °C | 1510 | |
| 1470 |
| Melting Onset (Solidus), °C | 1450 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 450 |
| Thermal Conductivity, W/m-K | 27 | |
| 12 |
| Thermal Expansion, µm/m-K | 10 | |
| 14 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 7.5 | |
| 80 |
| Density, g/cm3 | 7.7 | |
| 8.5 |
| Embodied Carbon, kg CO2/kg material | 2.0 | |
| 9.7 |
| Embodied Energy, MJ/kg | 28 | |
| 150 |
| Embodied Water, L/kg | 100 | |
| 300 |
Common Calculations
| PREN (Pitting Resistance) | 14 | |
| 37 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 88 to 130 | |
| 230 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 380 to 4410 | |
| 370 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 25 | |
| 23 |
| Strength to Weight: Axial, points | 25 to 62 | |
| 28 |
| Strength to Weight: Bending, points | 22 to 41 | |
| 24 |
| Thermal Diffusivity, mm2/s | 7.3 | |
| 3.2 |
| Thermal Shock Resistance, points | 25 to 62 | |
| 21 |
Alloy Composition
| Carbon (C), % | 0.15 to 0.4 | |
| 0.080 to 0.16 |
| Chromium (Cr), % | 12 to 14 | |
| 20 to 22.5 |
| Cobalt (Co), % | 0 | |
| 18.5 to 21 |
| Iron (Fe), % | 82.3 to 87.9 | |
| 24.3 to 36.2 |
| Manganese (Mn), % | 0 to 1.0 | |
| 1.0 to 2.0 |
| Molybdenum (Mo), % | 0 to 0.5 | |
| 2.5 to 3.5 |
| Nickel (Ni), % | 0 to 0.75 | |
| 19 to 21 |
| Niobium (Nb), % | 0 | |
| 0.75 to 1.3 |
| Nitrogen (N), % | 0 | |
| 0 to 0.2 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.030 |
| Tantalum (Ta), % | 0 | |
| 0.75 to 1.3 |
| Tungsten (W), % | 0 | |
| 2.0 to 3.0 |