Austempered Cast Iron vs. SAE-AISI 8740 Steel
Both austempered cast iron and SAE-AISI 8740 steel 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 austempered cast iron and the bottom bar is SAE-AISI 8740 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 270 to 490 | |
| 170 to 200 |
| Elastic (Young's, Tensile) Modulus, GPa | 180 | |
| 190 |
| Elongation at Break, % | 1.1 to 13 | |
| 11 to 23 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 62 to 69 | |
| 73 |
| Tensile Strength: Ultimate (UTS), MPa | 860 to 1800 | |
| 580 to 670 |
| Tensile Strength: Yield (Proof), MPa | 560 to 1460 | |
| 380 to 570 |
Thermal Properties
| Latent Heat of Fusion, J/g | 280 | |
| 250 |
| Melting Completion (Liquidus), °C | 1380 | |
| 1460 |
| Melting Onset (Solidus), °C | 1340 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 490 | |
| 470 |
| Thermal Conductivity, W/m-K | 42 | |
| 39 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 2.9 | |
| 2.6 |
| Density, g/cm3 | 7.5 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 1.8 | |
| 1.5 |
| Embodied Energy, MJ/kg | 25 | |
| 20 |
| Embodied Water, L/kg | 48 | |
| 50 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 19 to 95 | |
| 71 to 120 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 880 to 3970 | |
| 390 to 850 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 25 | |
| 24 |
| Strength to Weight: Axial, points | 32 to 66 | |
| 20 to 24 |
| Strength to Weight: Bending, points | 27 to 44 | |
| 20 to 22 |
| Thermal Diffusivity, mm2/s | 11 | |
| 10 |
| Thermal Shock Resistance, points | 25 to 53 | |
| 17 to 20 |
Alloy Composition
| Aluminum (Al), % | 0 to 0.050 | |
| 0 |
| Arsenic (As), % | 0 to 0.020 | |
| 0 |
| Carbon (C), % | 3.4 to 3.8 | |
| 0.38 to 0.43 |
| Chromium (Cr), % | 0 to 0.1 | |
| 0.4 to 0.6 |
| Copper (Cu), % | 0 to 0.8 | |
| 0 |
| Iron (Fe), % | 89.6 to 94 | |
| 96.5 to 97.7 |
| Magnesium (Mg), % | 0 to 0.040 | |
| 0 |
| Manganese (Mn), % | 0.3 to 0.4 | |
| 0.75 to 1.0 |
| Molybdenum (Mo), % | 0 to 0.3 | |
| 0.2 to 0.3 |
| Nickel (Ni), % | 0 to 2.0 | |
| 0.4 to 0.7 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.035 |
| Selenium (Se), % | 0 to 0.030 | |
| 0 |
| Silicon (Si), % | 2.3 to 2.7 | |
| 0.15 to 0.35 |
| Sulfur (S), % | 0 to 0.020 | |
| 0 to 0.040 |
| Tin (Sn), % | 0 to 0.020 | |
| 0 |
| Vanadium (V), % | 0 to 0.1 | |
| 0 |