Grade 31 Titanium vs. ASTM Grade HI Steel
Grade 31 titanium belongs to the titanium alloys classification, while ASTM grade HI steel belongs to the iron alloys. There are 28 material properties with values for both materials. Properties with values for just one material (6, in this case) are not shown.
For each property being compared, the top bar is grade 31 titanium and the bottom bar is ASTM grade HI steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 110 | |
| 200 |
| Elongation at Break, % | 20 | |
| 11 |
| Fatigue Strength, MPa | 300 | |
| 150 |
| Poisson's Ratio | 0.32 | |
| 0.27 |
| Shear Modulus, GPa | 41 | |
| 79 |
| Tensile Strength: Ultimate (UTS), MPa | 510 | |
| 550 |
| Tensile Strength: Yield (Proof), MPa | 450 | |
| 270 |
Thermal Properties
| Latent Heat of Fusion, J/g | 420 | |
| 310 |
| Maximum Temperature: Mechanical, °C | 320 | |
| 1100 |
| Melting Completion (Liquidus), °C | 1660 | |
| 1400 |
| Melting Onset (Solidus), °C | 1610 | |
| 1350 |
| Specific Heat Capacity, J/kg-K | 540 | |
| 490 |
| Thermal Conductivity, W/m-K | 21 | |
| 15 |
| Thermal Expansion, µm/m-K | 8.7 | |
| 17 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 3.4 | |
| 2.1 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 6.9 | |
| 2.4 |
Otherwise Unclassified Properties
| Density, g/cm3 | 4.5 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 36 | |
| 4.1 |
| Embodied Energy, MJ/kg | 600 | |
| 59 |
| Embodied Water, L/kg | 230 | |
| 200 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 99 | |
| 52 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 940 | |
| 180 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 35 | |
| 25 |
| Strength to Weight: Axial, points | 32 | |
| 20 |
| Strength to Weight: Bending, points | 32 | |
| 19 |
| Thermal Diffusivity, mm2/s | 8.5 | |
| 3.9 |
| Thermal Shock Resistance, points | 39 | |
| 12 |
Alloy Composition
| Carbon (C), % | 0 to 0.080 | |
| 0.2 to 0.5 |
| Chromium (Cr), % | 0 | |
| 26 to 30 |
| Cobalt (Co), % | 0.2 to 0.8 | |
| 0 |
| Hydrogen (H), % | 0 to 0.015 | |
| 0 |
| Iron (Fe), % | 0 to 0.3 | |
| 46.9 to 59.8 |
| Manganese (Mn), % | 0 | |
| 0 to 2.0 |
| Molybdenum (Mo), % | 0 | |
| 0 to 0.5 |
| Nickel (Ni), % | 0 | |
| 14 to 18 |
| Nitrogen (N), % | 0 to 0.050 | |
| 0 |
| Oxygen (O), % | 0 to 0.35 | |
| 0 |
| Palladium (Pd), % | 0.040 to 0.080 | |
| 0 |
| Phosphorus (P), % | 0 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 | |
| 0 to 2.0 |
| Sulfur (S), % | 0 | |
| 0 to 0.040 |
| Titanium (Ti), % | 97.9 to 99.76 | |
| 0 |
| Residuals, % | 0 to 0.4 | |
| 0 |