ASTM A387 Grade 91 Class 2 vs. AISI 204 Stainless Steel
Both ASTM A387 grade 91 class 2 and AISI 204 stainless steel are iron alloys. They have 83% of their average alloy composition in common. There are 32 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 AISI 204 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 200 | |
| 210 to 330 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 200 |
| Elongation at Break, % | 20 | |
| 23 to 39 |
| Fatigue Strength, MPa | 330 | |
| 320 to 720 |
| Poisson's Ratio | 0.28 | |
| 0.28 |
| Shear Modulus, GPa | 75 | |
| 77 |
| Shear Strength, MPa | 420 | |
| 500 to 700 |
| Tensile Strength: Ultimate (UTS), MPa | 670 | |
| 730 to 1100 |
| Tensile Strength: Yield (Proof), MPa | 470 | |
| 380 to 1080 |
Thermal Properties
| Latent Heat of Fusion, J/g | 270 | |
| 280 |
| Maximum Temperature: Mechanical, °C | 600 | |
| 850 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1410 |
| Melting Onset (Solidus), °C | 1420 | |
| 1370 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 480 |
| Thermal Conductivity, W/m-K | 26 | |
| 15 |
| Thermal Expansion, µm/m-K | 13 | |
| 17 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 8.9 | |
| 2.4 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 10 | |
| 2.9 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 7.0 | |
| 10 |
| Density, g/cm3 | 7.8 | |
| 7.7 |
| Embodied Carbon, kg CO2/kg material | 2.6 | |
| 2.4 |
| Embodied Energy, MJ/kg | 37 | |
| 35 |
| Embodied Water, L/kg | 88 | |
| 130 |
Common Calculations
| PREN (Pitting Resistance) | 13 | |
| 20 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 120 | |
| 240 to 250 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 580 | |
| 360 to 2940 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 25 | |
| 25 |
| Strength to Weight: Axial, points | 24 | |
| 27 to 40 |
| Strength to Weight: Bending, points | 22 | |
| 24 to 31 |
| Thermal Diffusivity, mm2/s | 6.9 | |
| 4.1 |
| Thermal Shock Resistance, points | 19 | |
| 16 to 24 |
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 | |
| 15 to 17 |
| Iron (Fe), % | 87.3 to 90.3 | |
| 69.6 to 76.4 |
| Manganese (Mn), % | 0.3 to 0.6 | |
| 7.0 to 9.0 |
| Molybdenum (Mo), % | 0.85 to 1.1 | |
| 0 |
| Nickel (Ni), % | 0 to 0.4 | |
| 1.5 to 3.0 |
| Niobium (Nb), % | 0.060 to 0.1 | |
| 0 |
| Nitrogen (N), % | 0.030 to 0.070 | |
| 0.15 to 0.3 |
| Phosphorus (P), % | 0 to 0.020 | |
| 0 to 0.040 |
| Silicon (Si), % | 0.2 to 0.5 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 to 0.010 | |
| 0 to 0.030 |
| Titanium (Ti), % | 0 to 0.010 | |
| 0 |
| Vanadium (V), % | 0.18 to 0.25 | |
| 0 |
| Zirconium (Zr), % | 0 to 0.010 | |
| 0 |