ASTM Grade HP Steel vs. ASTM A231 Spring Steel
Both ASTM grade HP steel and ASTM A231 spring steel are iron alloys. They have a modest 38% of their average alloy composition in common, which, by itself, doesn't mean much. There are 27 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 ASTM grade HP steel and the bottom bar is ASTM A231 spring steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 140 | |
| 540 |
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 190 |
| Elongation at Break, % | 5.1 | |
| 14 |
| Fatigue Strength, MPa | 130 | |
| 1000 |
| Poisson's Ratio | 0.28 | |
| 0.29 |
| Shear Modulus, GPa | 78 | |
| 73 |
| Tensile Strength: Ultimate (UTS), MPa | 490 | |
| 1790 |
| Tensile Strength: Yield (Proof), MPa | 260 | |
| 1570 |
Thermal Properties
| Latent Heat of Fusion, J/g | 320 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 1100 | |
| 420 |
| Melting Completion (Liquidus), °C | 1370 | |
| 1460 |
| Melting Onset (Solidus), °C | 1330 | |
| 1410 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 470 |
| Thermal Conductivity, W/m-K | 12 | |
| 52 |
| Thermal Expansion, µm/m-K | 16 | |
| 13 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 34 | |
| 2.3 |
| Density, g/cm3 | 7.9 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 5.8 | |
| 2.0 |
| Embodied Energy, MJ/kg | 82 | |
| 28 |
| Embodied Water, L/kg | 220 | |
| 51 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 21 | |
| 230 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 25 | |
| 24 |
| Strength to Weight: Axial, points | 17 | |
| 64 |
| Strength to Weight: Bending, points | 17 | |
| 42 |
| Thermal Diffusivity, mm2/s | 3.2 | |
| 14 |
| Thermal Shock Resistance, points | 11 | |
| 53 |
Alloy Composition
| Carbon (C), % | 0.35 to 0.75 | |
| 0.48 to 0.53 |
| Chromium (Cr), % | 24 to 28 | |
| 0.8 to 1.1 |
| Iron (Fe), % | 29.2 to 42.7 | |
| 96.7 to 97.7 |
| Manganese (Mn), % | 0 to 2.0 | |
| 0.7 to 0.9 |
| Molybdenum (Mo), % | 0 to 0.5 | |
| 0 |
| Nickel (Ni), % | 33 to 37 | |
| 0 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 2.5 | |
| 0.15 to 0.35 |
| Sulfur (S), % | 0 to 0.040 | |
| 0 to 0.040 |
| Vanadium (V), % | 0 | |
| 0.15 to 0.3 |