ASTM A387 Grade 91 Class 2 vs. SAE-AISI 8620 Steel
Both ASTM A387 grade 91 class 2 and SAE-AISI 8620 steel are iron alloys. They have a moderately high 91% of their average alloy composition in common. There are 31 material properties with values for both materials. Properties with values for just one material (1, 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 SAE-AISI 8620 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 200 | |
| 150 to 210 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 20 | |
| 13 to 31 |
| Fatigue Strength, MPa | 330 | |
| 270 to 360 |
| Poisson's Ratio | 0.28 | |
| 0.29 |
| Shear Modulus, GPa | 75 | |
| 73 |
| Shear Strength, MPa | 420 | |
| 340 to 420 |
| Tensile Strength: Ultimate (UTS), MPa | 670 | |
| 520 to 690 |
| Tensile Strength: Yield (Proof), MPa | 470 | |
| 360 to 570 |
Thermal Properties
| Latent Heat of Fusion, J/g | 270 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 600 | |
| 410 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1460 |
| Melting Onset (Solidus), °C | 1420 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 470 |
| Thermal Conductivity, W/m-K | 26 | |
| 39 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 8.9 | |
| 7.3 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 10 | |
| 8.3 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 7.0 | |
| 2.6 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 2.6 | |
| 1.5 |
| Embodied Energy, MJ/kg | 37 | |
| 20 |
| Embodied Water, L/kg | 88 | |
| 50 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 120 | |
| 86 to 150 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 580 | |
| 340 to 880 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 25 | |
| 24 |
| Strength to Weight: Axial, points | 24 | |
| 18 to 24 |
| Strength to Weight: Bending, points | 22 | |
| 18 to 22 |
| Thermal Diffusivity, mm2/s | 6.9 | |
| 10 |
| Thermal Shock Resistance, points | 19 | |
| 15 to 20 |
Alloy Composition
| Aluminum (Al), % | 0 to 0.020 | |
| 0 |
| Carbon (C), % | 0.080 to 0.12 | |
| 0.18 to 0.23 |
| Chromium (Cr), % | 8.0 to 9.5 | |
| 0.4 to 0.6 |
| Iron (Fe), % | 87.3 to 90.3 | |
| 96.9 to 98 |
| Manganese (Mn), % | 0.3 to 0.6 | |
| 0.7 to 0.9 |
| Molybdenum (Mo), % | 0.85 to 1.1 | |
| 0.15 to 0.25 |
| Nickel (Ni), % | 0 to 0.4 | |
| 0.4 to 0.7 |
| Niobium (Nb), % | 0.060 to 0.1 | |
| 0 |
| Nitrogen (N), % | 0.030 to 0.070 | |
| 0 |
| Phosphorus (P), % | 0 to 0.020 | |
| 0 to 0.035 |
| Silicon (Si), % | 0.2 to 0.5 | |
| 0.15 to 0.35 |
| Sulfur (S), % | 0 to 0.010 | |
| 0 to 0.040 |
| Titanium (Ti), % | 0 to 0.010 | |
| 0 |
| Vanadium (V), % | 0.18 to 0.25 | |
| 0 |
| Zirconium (Zr), % | 0 to 0.010 | |
| 0 |