ASTM A369 Grade FP2 Cr-Mo Steel
ASTM A369 grade FP2 is an alloy steel formulated for primary forming into wrought products. Cited properties are appropriate for the stress relieved condition.
It has a very low tensile strength among wrought alloy steels in the same category. In addition, it has a moderately low embodied energy and a moderately low electrical conductivity.
The graph bars on the material properties cards below compare ASTM A369 grade FP2 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
130
Elastic (Young's, Tensile) Modulus
190 GPa 27 x 106 psi
Elongation at Break
20 %
Fatigue Strength
160 MPa 24 x 103 psi
Poisson's Ratio
0.29
Shear Modulus
73 GPa 11 x 106 psi
Shear Strength
270 MPa 39 x 103 psi
Tensile Strength: Ultimate (UTS)
430 MPa 63 x 103 psi
Tensile Strength: Yield (Proof)
240 MPa 34 x 103 psi
Thermal Properties
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
420 °C 790 °F
Melting Completion (Liquidus)
1470 °C 2670 °F
Melting Onset (Solidus)
1430 °C 2600 °F
Specific Heat Capacity
470 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
49 W/m-K 28 BTU/h-ft-°F
Thermal Expansion
13 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.2 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.2 % IACS
Otherwise Unclassified Properties
Base Metal Price
2.6 % relative
Density
7.9 g/cm3 490 lb/ft3
Embodied Carbon
1.6 kg CO2/kg material
Embodied Energy
20 MJ/kg 8.8 x 103 BTU/lb
Embodied Water
50 L/kg 6.0 gal/lb
Common Calculations
PREN (Pitting Resistance)
2.5
Resilience: Ultimate (Unit Rupture Work)
75 MJ/m3
Resilience: Unit (Modulus of Resilience)
150 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
15 points
Strength to Weight: Bending
16 points
Thermal Diffusivity
13 mm2/s
Thermal Shock Resistance
13 points
Alloy Composition
Among alloy steels, the composition of ASTM A369 grade FP2 is notable for containing comparatively high amounts of chromium (Cr) and molybdenum (Mo). Chromium is used to improve corrosion resistance and most mechanical properties (particularly at higher temperatures). Molybdenum is used to facilitate tempering. In addition, it offers modest bonuses to a wide range of material properties.
| Fe | 97.4 to 98.6 | |
| Cr | 0.5 to 0.81 | |
| Mo | 0.44 to 0.65 | |
| Mn | 0.3 to 0.61 | |
| Si | 0.1 to 0.3 | |
| C | 0.1 to 0.2 | |
| P | 0 to 0.025 | |
| S | 0 to 0.025 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM A369: Standard Specification for Carbon and Ferritic Alloy Steel Forged and Bored Pipe for High-Temperature Service