Steel A369 FP2-ANN (Annealed)
Heat-treated state · default condition
ASTM A369 FP2
Standard stocked condition for FP2 forged-and-bored pipe: softest, best machinability and bending, meets 380/205 MPa minimums.
Values for the ANN condition
Other A369 FP2 tempers and conditions
A369 FP2 is listed in 2 conditions; see the grade overview at A369 FP2.
- ANN
- N+T
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ANNDefaultThis page Annealed | Standard stocked condition for FP2 forged-and-bored pipe: softest, best machinability and bending, meets 380/205 MPa minimums. | 255 | 450 | 34 | 131 HB | — |
Normalized and tempered | Pick for higher strength and better toughness/creep consistency in thicker forged pipe and for code work needing N+T documentation. | 320 | 500 | 28 | 155 HB | — |
What is A369 FP2-ANN?
A369 FP2-ANN is A369 FP2 heat treated to ANN — standard stocked condition for FP2 forged-and-bored pipe: softest, best machinability and bending, meets 380/205 MPa minimums. A369 FP2-ANN has a yield strength of 255 MPa (37 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 93% of steel grades. Elongation at break is 34% and the elastic modulus is 205 GPa (29.7 Msi). A369 FP2-ANN has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,490°C (2,714 °F).
Advantages
- Ductile — tolerates forming and impact — 34%, better than 97% of steel grades
- High service temperature — 540°C (1,004 °F), better than 93% of steel grades
- Good corrosion resistance — 22/100, better than 90% of steel grades
- Easy to machine — 62/100, better than 89% of steel grades
- Readily welded — 72/100, better than 75% of steel grades
Limitations
- Low strength — 255 MPa (37 ksi), worse than 93% of steel grades
A369 FP2-ANN properties
Typical room-temperature values for A369 FP2-ANN; 12 are specific to this condition. Other listed values are A369 FP2 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
A369 FP2-ANN has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,490°C (2,714 °F).
Mechanical14
A369 FP2-ANN has a yield strength of 255 MPa (37 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 93% of steel grades. Elongation at break is 34% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
A369 FP2-ANN is rated for continuous service to 540°C (1,004 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical2
A369 FP2-ANN has an electrical resistivity of 2.2×10⁻⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is poor (22/100), better than 90% of steel grades.
Sustainability4
Producing a kilogram of A369 FP2-ANN takes about 26 MJ of energy and emits 2 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 30%.
Manufacturability7
A369 FP2-ANN's machinability is good (62/100, better than 89% of steel grades); weldability very good (72/100); formability good (60/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with A369 FP2-ANN
Is A369 FP2 easy to machine?
Machines like annealed low-alloy steel at ~60 % of AISI 1212; use rigid setups and positive-rake carbide for boring long pipe sections.
Can A369 FP2 be welded?
Weldable by SMAW/GTAW with matching 1.25Cr-0.5Mo or 0.5Cr-0.5Mo filler; preheat 150–200 °C and PWHT at 675–730 °C to avoid hard HAZ and hydrogen cracking.
Can A369 FP2 be formed, bent or molded?
Hot bend/form at 900–1050 °C followed by re-annealing or N+T; cold bending is possible for thin walls but springback and residual stress are high.
What surface finishes work on A369 FP2?
No anodizing; protect with phosphate + high-temperature aluminium paint, aluminizing or insulation-compatible coatings, since bare surfaces oxidize above ~450 °C.
A369 FP2 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C | 0.1 – 0.2 | 0.15 |
| Mn | 0.3 – 0.61 | 0.45 |
| Si | 0.1 – 0.3 | 0.2 |
| Cr | 0.5 – 0.81 | 0.65 |
| Mo | 0.44 – 0.65 | 0.55 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
A369 FP2-ANN — frequently asked
What is A369 FP2-ANN used for?
A369 FP2-ANN is typically used for moderate-temperature steam piping, header fittings, boiler feed and connecting piping, forged pipe couplings and nozzles, refinery low-severity hot process lines and turbine auxiliary steam lines. In short: leanest Cr-Mo pipe grade; best-machining A369 grade; easiest-welding Cr-Mo pipe.
What is the yield strength of A369 FP2-ANN?
A369 FP2-ANN has a typical yield strength of 255 MPa (37 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 93% of steel grades. Strength varies by condition: see the 2 listed tempers.
Is A369 FP2-ANN easy to machine?
Reasonably — machinability is rated good (62/100, better than 89% of steel grades). Machines like annealed low-alloy steel at ~60 % of AISI 1212; use rigid setups and positive-rake carbide for boring long pipe sections.
Can A369 FP2-ANN be welded?
Yes — weldability is rated very good (72/100). Weldable by SMAW/GTAW with matching 1.25Cr-0.5Mo or 0.5Cr-0.5Mo filler; preheat 150–200 °C and PWHT at 675–730 °C to avoid hard HAZ and hydrogen cracking.
What surface finishes work on A369 FP2-ANN?
No anodizing; protect with phosphate + high-temperature aluminium paint, aluminizing or insulation-compatible coatings, since bare surfaces oxidize above ~450 °C.
Can A369 FP2-ANN be formed, bent or molded?
Hot bend/form at 900–1050 °C followed by re-annealing or N+T; cold bending is possible for thin walls but springback and residual stress are high.
What is the maximum service temperature of A369 FP2-ANN?
A369 FP2-ANN is rated for continuous use to about 540°C (1,004 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM A369/A369M — Carbon and Ferritic Alloy Steel Forged and Bored Pipe for High-Temperature Service — ASTM International (2018)
- ASTM A335/A335M — Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service (grade P2) — ASTM International (2022)
- ASME BPVC Section II Part D — Properties (Metric) — ASME (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.13C — Corrosion: Environments and Industries — ASM International (2006)
- GB/T 5310 / GB/T 3077 (12CrMo, 15CrMo ) (2017)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.