ASTM A182 Grade F122 (K91271) Steel
ASTM A182 grade F122 is an alloy steel formulated for primary forming into wrought products. Cited properties are appropriate for the normalized and tempered condition. F122 is the ASTM designation for this material. K91271 is the UNS number.
It has the lowest thermal conductivity among wrought alloy steels in the same category. In addition, it has a very high base cost and a very high electrical conductivity.
The graph bars on the material properties cards below compare ASTM A182 grade F122 to: wrought alloy steels in the same category (top), all iron alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Brinell Hardness
220
Elastic (Young's, Tensile) Modulus
190 GPa 28 x 106 psi
Elongation at Break
23 %
Fatigue Strength
320 MPa 46 x 103 psi
Poisson's Ratio
0.28
Reduction in Area
45 %
Shear Modulus
76 GPa 11 x 106 psi
Shear Strength
450 MPa 65 x 103 psi
Tensile Strength: Ultimate (UTS)
710 MPa 100 x 103 psi
Tensile Strength: Yield (Proof)
450 MPa 65 x 103 psi
Thermal Properties
Latent Heat of Fusion
270 J/g
Maximum Temperature: Mechanical
600 °C 1110 °F
Melting Completion (Liquidus)
1490 °C 2710 °F
Melting Onset (Solidus)
1440 °C 2630 °F
Specific Heat Capacity
470 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
24 W/m-K 14 BTU/h-ft-°F
Thermal Expansion
13 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
10 % IACS
Electrical Conductivity: Equal Weight (Specific)
12 % IACS
Otherwise Unclassified Properties
Base Metal Price
12 % relative
Density
8.0 g/cm3 500 lb/ft3
Embodied Carbon
3.0 kg CO2/kg material
Embodied Energy
44 MJ/kg 19 x 103 BTU/lb
Embodied Water
100 L/kg 12 gal/lb
Common Calculations
PREN (Pitting Resistance)
17
Resilience: Ultimate (Unit Rupture Work)
140 MJ/m3
Resilience: Unit (Modulus of Resilience)
520 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
25 points
Strength to Weight: Bending
22 points
Thermal Diffusivity
6.4 mm2/s
Thermal Shock Resistance
19 points
Alloy Composition
Among alloy steels, the composition of ASTM A182 grade F122 is notable for including tungsten (W) and zirconium (Zr). Tungsten interacts with other alloying elements to a greater extent than usual, which makes it hard to broadly characterize its effects. Zirconium is used to improve ductility.
| Fe | 81.3 to 87.7 | |
| Cr | 10 to 11.5 | |
| W | 1.5 to 2.5 | |
| Cu | 0.3 to 1.7 | |
| Mo | 0.25 to 0.6 | |
| Mn | 0 to 0.7 | |
| Si | 0 to 0.5 | |
| Ni | 0 to 0.5 | |
| V | 0.15 to 0.3 | |
| C | 0.070 to 0.14 | |
| N | 0.040 to 0.1 | |
| Nb | 0.040 to 0.1 | |
| Al | 0 to 0.020 | |
| P | 0 to 0.020 | |
| S | 0 to 0.010 | |
| Ti | 0 to 0.010 | |
| Zr | 0 to 0.010 | |
| B | 0 to 0.0050 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM A182: Standard Specification for Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service