SAE-AISI 4320 Steel vs. Austempered Cast Iron
Both SAE-AISI 4320 steel and austempered cast iron are iron alloys. They have a moderately high 94% of their average alloy composition in common. There are 26 material properties with values for both materials. Properties with values for just one material (5, in this case) are not shown.
For each property being compared, the top bar is SAE-AISI 4320 steel and the bottom bar is austempered cast iron.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 160 to 240 | |
| 270 to 490 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 180 |
| Elongation at Break, % | 21 to 29 | |
| 1.1 to 13 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 73 | |
| 62 to 69 |
| Tensile Strength: Ultimate (UTS), MPa | 570 to 790 | |
| 860 to 1800 |
| Tensile Strength: Yield (Proof), MPa | 430 to 460 | |
| 560 to 1460 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 280 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1380 |
| Melting Onset (Solidus), °C | 1420 | |
| 1340 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 490 |
| Thermal Conductivity, W/m-K | 46 | |
| 42 |
| Thermal Expansion, µm/m-K | 11 | |
| 13 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 3.4 | |
| 2.9 |
| Density, g/cm3 | 7.9 | |
| 7.5 |
| Embodied Carbon, kg CO2/kg material | 1.7 | |
| 1.8 |
| Embodied Energy, MJ/kg | 22 | |
| 25 |
| Embodied Water, L/kg | 52 | |
| 48 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 140 to 150 | |
| 19 to 95 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 480 to 560 | |
| 880 to 3970 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 25 |
| Strength to Weight: Axial, points | 20 to 28 | |
| 32 to 66 |
| Strength to Weight: Bending, points | 19 to 24 | |
| 27 to 44 |
| Thermal Diffusivity, mm2/s | 13 | |
| 11 |
| Thermal Shock Resistance, points | 19 to 27 | |
| 25 to 53 |
Alloy Composition
| Aluminum (Al), % | 0 | |
| 0 to 0.050 |
| Arsenic (As), % | 0 | |
| 0 to 0.020 |
| Carbon (C), % | 0.17 to 0.22 | |
| 3.4 to 3.8 |
| Chromium (Cr), % | 0.4 to 0.6 | |
| 0 to 0.1 |
| Copper (Cu), % | 0 | |
| 0 to 0.8 |
| Iron (Fe), % | 95.8 to 97 | |
| 89.6 to 94 |
| Magnesium (Mg), % | 0 | |
| 0 to 0.040 |
| Manganese (Mn), % | 0.45 to 0.65 | |
| 0.3 to 0.4 |
| Molybdenum (Mo), % | 0.2 to 0.3 | |
| 0 to 0.3 |
| Nickel (Ni), % | 1.7 to 2.0 | |
| 0 to 2.0 |
| Phosphorus (P), % | 0 to 0.035 | |
| 0 to 0.040 |
| Selenium (Se), % | 0 | |
| 0 to 0.030 |
| Silicon (Si), % | 0.15 to 0.35 | |
| 2.3 to 2.7 |
| Sulfur (S), % | 0 to 0.040 | |
| 0 to 0.020 |
| Tin (Sn), % | 0 | |
| 0 to 0.020 |
| Vanadium (V), % | 0 | |
| 0 to 0.1 |