ACI-ASTM CF8 Steel vs. ACI-ASTM CK20 Steel
Both ACI-ASTM CF8 steel and ACI-ASTM CK20 steel are iron alloys. Both are furnished in the heat treated (HT) condition. They have 83% of their average alloy composition in common.
For each property being compared, the top bar is ACI-ASTM CF8 steel and the bottom bar is ACI-ASTM CK20 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 140 | |
| 150 |
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 200 |
| Elongation at Break, % | 55 | |
| 37 |
| Fatigue Strength, MPa | 260 | |
| 220 |
| Poisson's Ratio | 0.28 | |
| 0.28 |
| Shear Modulus, GPa | 77 | |
| 78 |
| Tensile Strength: Ultimate (UTS), MPa | 540 | |
| 530 |
| Tensile Strength: Yield (Proof), MPa | 260 | |
| 260 |
Thermal Properties
| Latent Heat of Fusion, J/g | 300 | |
| 310 |
| Maximum Temperature: Corrosion, °C | 420 | |
| 440 |
| Maximum Temperature: Mechanical, °C | 980 | |
| 1100 |
| Melting Completion (Liquidus), °C | 1420 | |
| 1400 |
| Melting Onset (Solidus), °C | 1430 | |
| 1430 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 480 |
| Thermal Conductivity, W/m-K | 16 | |
| 14 |
| Thermal Expansion, µm/m-K | 15 | |
| 15 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 2.0 | |
| 2.0 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.3 | |
| 2.3 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 16 | |
| 25 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 3.1 | |
| 4.4 |
| Embodied Energy, MJ/kg | 44 | |
| 62 |
| Embodied Water, L/kg | 150 | |
| 190 |
Common Calculations
| PREN (Pitting Resistance) | 20 | |
| 26 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 240 | |
| 160 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 160 | |
| 170 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 25 | |
| 25 |
| Strength to Weight: Axial, points | 19 | |
| 19 |
| Strength to Weight: Bending, points | 19 | |
| 19 |
| Thermal Diffusivity, mm2/s | 4.3 | |
| 3.7 |
| Thermal Shock Resistance, points | 13 | |
| 13 |
Alloy Composition
| Carbon (C), % | 0 to 0.080 | |
| 0 to 0.2 |
| Chromium (Cr), % | 18 to 21 | |
| 23 to 27 |
| Iron (Fe), % | 63.8 to 74 | |
| 46.7 to 58 |
| Manganese (Mn), % | 0 to 1.5 | |
| 0 to 2.0 |
| Molybdenum (Mo), % | 0 to 0.5 | |
| 0 to 0.5 |
| Nickel (Ni), % | 8.0 to 11 | |
| 19 to 22 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 2.0 | |
| 0 to 2.0 |
| Sulfur (S), % | 0 to 0.040 | |
| 0 to 0.040 |