Austempered Cast Iron vs. ASTM A231 Spring Steel
Both austempered cast iron and ASTM A231 spring steel are iron alloys. They have a moderately high 93% of their average alloy composition in common. There are 25 material properties with values for both materials. Properties with values for just one material (7, in this case) are not shown.
For each property being compared, the top bar is austempered cast iron and the bottom bar is ASTM A231 spring steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 270 to 490 | |
| 540 |
| Elastic (Young's, Tensile) Modulus, GPa | 180 | |
| 190 |
| Elongation at Break, % | 1.1 to 13 | |
| 14 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 62 to 69 | |
| 73 |
| Tensile Strength: Ultimate (UTS), MPa | 860 to 1800 | |
| 1790 |
| Tensile Strength: Yield (Proof), MPa | 560 to 1460 | |
| 1570 |
Thermal Properties
| Latent Heat of Fusion, J/g | 280 | |
| 250 |
| Melting Completion (Liquidus), °C | 1380 | |
| 1460 |
| Melting Onset (Solidus), °C | 1340 | |
| 1410 |
| Specific Heat Capacity, J/kg-K | 490 | |
| 470 |
| Thermal Conductivity, W/m-K | 42 | |
| 52 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 2.9 | |
| 2.3 |
| Density, g/cm3 | 7.5 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 1.8 | |
| 2.0 |
| Embodied Energy, MJ/kg | 25 | |
| 28 |
| Embodied Water, L/kg | 48 | |
| 51 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 19 to 95 | |
| 230 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 25 | |
| 24 |
| Strength to Weight: Axial, points | 32 to 66 | |
| 64 |
| Strength to Weight: Bending, points | 27 to 44 | |
| 42 |
| Thermal Diffusivity, mm2/s | 11 | |
| 14 |
| Thermal Shock Resistance, points | 25 to 53 | |
| 53 |
Alloy Composition
| Aluminum (Al), % | 0 to 0.050 | |
| 0 |
| Arsenic (As), % | 0 to 0.020 | |
| 0 |
| Carbon (C), % | 3.4 to 3.8 | |
| 0.48 to 0.53 |
| Chromium (Cr), % | 0 to 0.1 | |
| 0.8 to 1.1 |
| Copper (Cu), % | 0 to 0.8 | |
| 0 |
| Iron (Fe), % | 89.6 to 94 | |
| 96.7 to 97.7 |
| Magnesium (Mg), % | 0 to 0.040 | |
| 0 |
| Manganese (Mn), % | 0.3 to 0.4 | |
| 0.7 to 0.9 |
| Molybdenum (Mo), % | 0 to 0.3 | |
| 0 |
| Nickel (Ni), % | 0 to 2.0 | |
| 0 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.040 |
| 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 | |
| 0.15 to 0.3 |