ASTM Grade HH Steel vs. ACI-ASTM CF20 Steel
Both ASTM grade HH steel and ACI-ASTM CF20 steel are iron alloys. They have 90% of their average alloy composition in common.
For each property being compared, the top bar is ASTM grade HH steel and the bottom bar is ACI-ASTM CF20 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 170 | |
| 160 |
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 200 |
| Elongation at Break, % | 11 | |
| 50 |
| Fatigue Strength, MPa | 150 | |
| 240 |
| Poisson's Ratio | 0.27 | |
| 0.28 |
| Shear Modulus, GPa | 79 | |
| 77 |
| Tensile Strength: Ultimate (UTS), MPa | 580 | |
| 530 |
| Tensile Strength: Yield (Proof), MPa | 270 | |
| 250 |
Thermal Properties
| Latent Heat of Fusion, J/g | 310 | |
| 300 |
| Maximum Temperature: Corrosion, °C | 440 | |
| 420 |
| Maximum Temperature: Mechanical, °C | 1100 | |
| 970 |
| Melting Completion (Liquidus), °C | 1400 | |
| 1420 |
| Melting Onset (Solidus), °C | 1360 | |
| 1410 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 480 |
| Thermal Conductivity, W/m-K | 14 | |
| 16 |
| Thermal Expansion, µm/m-K | 17 | |
| 17 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 2.1 | |
| 2.0 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.4 | |
| 2.3 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 20 | |
| 16 |
| Density, g/cm3 | 7.7 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 3.7 | |
| 3.1 |
| Embodied Energy, MJ/kg | 53 | |
| 44 |
| Embodied Water, L/kg | 180 | |
| 150 |
Common Calculations
| PREN (Pitting Resistance) | 27 | |
| 20 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 53 | |
| 220 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 190 | |
| 160 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 25 | |
| 25 |
| Strength to Weight: Axial, points | 21 | |
| 19 |
| Strength to Weight: Bending, points | 20 | |
| 19 |
| Thermal Diffusivity, mm2/s | 3.8 | |
| 4.3 |
| Thermal Shock Resistance, points | 12 | |
| 11 |
Alloy Composition
| Carbon (C), % | 0.2 to 0.5 | |
| 0 to 0.2 |
| Chromium (Cr), % | 24 to 28 | |
| 18 to 21 |
| Iron (Fe), % | 52.9 to 64.8 | |
| 64.2 to 74 |
| Manganese (Mn), % | 0 to 2.0 | |
| 0 to 1.5 |
| Molybdenum (Mo), % | 0 to 0.5 | |
| 0 |
| Nickel (Ni), % | 11 to 14 | |
| 8.0 to 11 |
| 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 |