ASTM A387 Grade 91 Class 2 vs. AWS E33-31
Both ASTM A387 grade 91 class 2 and AWS E33-31 are iron alloys. They have 41% of their average alloy composition in common. There are 21 material properties with values for both materials. Properties with values for just one material (11, in this case) are not shown.
For each property being compared, the top bar is ASTM A387 grade 91 class 2 and the bottom bar is AWS E33-31.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 210 |
| Elongation at Break, % | 20 | |
| 29 |
| Poisson's Ratio | 0.28 | |
| 0.27 |
| Shear Modulus, GPa | 75 | |
| 81 |
| Tensile Strength: Ultimate (UTS), MPa | 670 | |
| 810 |
Thermal Properties
| Latent Heat of Fusion, J/g | 270 | |
| 320 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1380 |
| Melting Onset (Solidus), °C | 1420 | |
| 1330 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 480 |
| Thermal Expansion, µm/m-K | 13 | |
| 14 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 7.0 | |
| 36 |
| Density, g/cm3 | 7.8 | |
| 7.9 |
| Embodied Carbon, kg CO2/kg material | 2.6 | |
| 6.0 |
| Embodied Energy, MJ/kg | 37 | |
| 86 |
| Embodied Water, L/kg | 88 | |
| 260 |
Common Calculations
| PREN (Pitting Resistance) | 13 | |
| 44 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 25 | |
| 25 |
| Strength to Weight: Axial, points | 24 | |
| 28 |
| Strength to Weight: Bending, points | 22 | |
| 24 |
| Thermal Shock Resistance, points | 19 | |
| 19 |
Alloy Composition
| Aluminum (Al), % | 0 to 0.020 | |
| 0 |
| Carbon (C), % | 0.080 to 0.12 | |
| 0 to 0.030 |
| Chromium (Cr), % | 8.0 to 9.5 | |
| 31 to 35 |
| Copper (Cu), % | 0 | |
| 0.4 to 0.8 |
| Iron (Fe), % | 87.3 to 90.3 | |
| 24.7 to 34.8 |
| Manganese (Mn), % | 0.3 to 0.6 | |
| 2.5 to 4.0 |
| Molybdenum (Mo), % | 0.85 to 1.1 | |
| 1.0 to 2.0 |
| Nickel (Ni), % | 0 to 0.4 | |
| 30 to 32 |
| Niobium (Nb), % | 0.060 to 0.1 | |
| 0 |
| Nitrogen (N), % | 0.030 to 0.070 | |
| 0.3 to 0.5 |
| Phosphorus (P), % | 0 to 0.020 | |
| 0 to 0.020 |
| Silicon (Si), % | 0.2 to 0.5 | |
| 0 to 0.9 |
| Sulfur (S), % | 0 to 0.010 | |
| 0 to 0.010 |
| Titanium (Ti), % | 0 to 0.010 | |
| 0 |
| Vanadium (V), % | 0.18 to 0.25 | |
| 0 |
| Zirconium (Zr), % | 0 to 0.010 | |
| 0 |