Steel A182 F122
ASTM A182 F122 · UNS K91271
ASTM A182 F122 (UNS K91271) is an advanced 11Cr-2W-Cu-V-Nb-N martensitic creep-strength-enhanced forging steel developed for ultra-supercritical boiler and steam-piping components.
Reference datasheet — A182 F122 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the N+T condition
A182 F122 tempers and conditions
A182 F122 is supplied in 5 conditions, soft to hard. N+T is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Subcritical/soft annealed (≈760–800 °C, slow cool) for machining or… | Non-code intermediate condition supplied for heavy machining or cold sizing; must be re-normalized and tempered before service. | 420 | 620 | 26 | 11 HRC | 3 % IACS |
Normalized and tempered, then post-weld heat treated 740–780 °C | Condition of the finished welded assembly; slightly softer than the as-tempered forging and the basis for weldment creep assessment. | 460 | 655 | 24 | 15 HRC | 2.9 % IACS |
Normalized plus double temper | Used when maximum toughness and full hardness compliance (<250 HBW) are needed on thick sections or after repair welding. | 465 | 660 | 25 | 15 HRC | 2.9 % IACS |
N+TDefault Normalized and tempered | Standard supply condition for all ASTM A182 F122 forgings, flanges, valve bodies and fittings in USC steam service. | 490 | 690 | 23 | 18 HRC | — |
Austenitized 1040–1090 °C with accelerated (liquid/forced-air) cooling,… | Chosen for heavy-section forgings where air cooling cannot ensure full martensite through-thickness; gives the same tempered properties with better core uniformity. | 510 | 710 | 22 | 20 HRC | — |
What is A182 F122?
ASTM A182 F122 (UNS K91271) is an advanced 11Cr-2W-Cu-V-Nb-N martensitic creep-strength-enhanced forging steel developed for ultra-supercritical boiler and steam-piping components. Normalized and tempered it provides 490 MPa yield, 690 MPa tensile, 23 % elongation and about 215 HB (18 HRC), with service to 620 °C and the highest creep rupture strength of the Cr-Mo forging family here. Trade-offs are difficult machining (score 40), demanding welding with mandatory 740–780 °C PWHT and Type IV HAZ creep weakness (weldability 40), and modest corrosion resistance (35) despite the 11 % Cr. Where 620 °C creep strength is not required, F11 or F12 forgings are simpler to fabricate. A182 F122 has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 93% of steel grades. It melts at 1,420°C (2,588 °F). A182 F122 has a yield strength of 490 MPa (71.1 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 61% of steel grades. Elongation at break is 23% and the elastic modulus is 213 GPa (30.9 Msi).
What is A182 F122 used for?
- Ultra-supercritical boiler flanges
- High-temperature steam headers
- Valve bodies
Advantages
- High service temperature — 620°C (1,148 °F), better than 99% of steel grades
- Good corrosion resistance — 35/100, better than 97% of steel grades
Limitations
- Low electrical conductivity — 2.9 % IACS, worse than 93% of steel grades
- Poor heat conductor — 26 W/m·K (15 BTU/hr·ft·°F), worse than 87% of steel grades
- High embodied carbon — 2.6 kg CO₂/kg, worse than 87% of steel grades
- Difficult to machine — 40/100, worse than 77% of steel grades
A182 F122 properties
Typical room-temperature values for A182 F122-N+T; bars are the position among steel grades.
Physical3
A182 F122 has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 93% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
A182 F122 has a yield strength of 490 MPa (71.1 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 61% of steel grades. Elongation at break is 23% and the elastic modulus is 213 GPa (30.9 Msi).
Thermal6
A182 F122 is rated for continuous service to 620°C (1,148 °F). It conducts heat at 26 W/m·K (15 BTU/hr·ft·°F), worse than 87% of steel grades. Thermal expansion is 10.5 µm/m·K (5.83 µin/in·°F).
Electrical3
A182 F122 conducts electricity at 2.9 % IACS, worse than 93% of steel grades.
Chemical & Environmental3
Corrosion resistance is fair (35/100), better than 97% of steel grades.
Sustainability4
Producing a kilogram of A182 F122 takes about 34 MJ of energy and emits 2.6 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 30%.
Manufacturability8
A182 F122's machinability is fair (40/100, worse than 77% of steel grades); weldability fair (40/100); formability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. A182 F122 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with A182 F122
Is A182 F122 easy to machine?
Machine in the tempered (≈215 HB) condition with rigid setups, coated carbide, moderate speed and heavy feed; the work-hardening martensite dulls edges so avoid dwelling and keep coolant flooded.
Can A182 F122 be welded?
Weld with matching 9-12Cr filler (e.g. W-modified E911/P122 consumables), 200–250 °C preheat, interpass ≤350 °C, hydrogen control, cool to ~100 °C before a mandatory 740–780 °C PWHT; expect Type IV creep weakness in the fine-grained HAZ.
Can A182 F122 be formed, bent or molded?
Hot forge 1150–950 °C and always re-normalize and temper afterwards; cold forming is essentially limited to minor straightening because of the low ductility and high springback.
A182 F122 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 | 0.07 – 0.14 | 0.11 |
| Mn | ≤ 0.7 | 0.55 |
| P | ≤ 0.02 | — |
| S | ≤ 0.01 | — |
| Si | ≤ 0.5 | 0.25 |
| Ni | ≤ 0.5 | 0.25 |
| Cr | 10 – 11.5 | 10.8 |
| Mo | 0.25 – 0.6 | 0.4 |
| Wsolid-solution creep strengthener | 1.5 – 2.5 | 1.9 |
| Cufine Cu precipitates | 0.3 – 1.7 | 1 |
| V | 0.15 – 0.3 | 0.2 |
| NbCb in ASTM text | 0.04 – 0.1 | 0.06 |
| NMX nitride former | 0.04 – 0.1 | 0.06 |
| B | 5×10⁻⁴ – 0.01 | 0 |
| Alsoluble Al limited to protect N | ≤ 0.02 | — |
| Ti | ≤ 0.01 | — |
| Zr | ≤ 0.01 | — |
| Fe | balance | — |
What surface finishes work on A182 F122?
Not stainless — shot-blast plus preservation oil or paint for storage; for wet steam/water-side duty consider chromizing, aluminizing or a weld overlay rather than relying on the 11Cr base metal.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel A182 F122 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- K91271
How much does A182 F122 cost?
A182 F122 is a premium-cost steel ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
A182 F122 — frequently asked
What is A182 F122 used for?
A182 F122 is typically used for ultra-supercritical boiler flanges, high-temperature steam headers and valve bodies. In short: highest creep strength here; 620 °C USC steam service; hardest to weld and machine.
What is the yield strength of A182 F122?
A182 F122 has a typical yield strength of 490 MPa (71.1 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 61% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is A182 F122 easy to machine?
Not especially — machinability is rated fair (40/100, worse than 77% of steel grades). Machine in the tempered (≈215 HB) condition with rigid setups, coated carbide, moderate speed and heavy feed; the work-hardening martensite dulls edges so avoid dwelling and keep coolant flooded.
Can A182 F122 be welded?
With care — weldability is rated fair (40/100). Weld with matching 9-12Cr filler (e.g. W-modified E911/P122 consumables), 200–250 °C preheat, interpass ≤350 °C, hydrogen control, cool to ~100 °C before a mandatory 740–780 °C PWHT; expect Type IV creep weakness in the fine-grained HAZ.
What surface finishes work on A182 F122?
Not stainless — shot-blast plus preservation oil or paint for storage; for wet steam/water-side duty consider chromizing, aluminizing or a weld overlay rather than relying on the 11Cr base metal.
Can A182 F122 be formed, bent or molded?
Hot forge 1150–950 °C and always re-normalize and temper afterwards; cold forming is essentially limited to minor straightening because of the low ductility and high springback.
What is the maximum service temperature of A182 F122?
A182 F122 is rated for continuous use to about 620°C (1,148 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between A182 F122 N+T and A182 F122-SA?
N+T is the default condition — standard supply condition for all ASTM A182 F122 forgings, flanges, valve bodies and fittings in USC steam service. SA: non-code intermediate condition supplied for heavy machining or cold sizing; must be re-normalized and tempered before service. Yield strength is 490 MPa in N+T versus 420 MPa in SA.
How much does A182 F122 cost?
A182 F122 is a premium-cost steel ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM A182/A182M — Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Fittings, Valves and Parts (Grade F122) — ASTM International (2024)
- ASME BPVC Section II Part D — Allowable stresses and physical properties for 11Cr-2W-0.4Mo-1Cu-V-Nb (P122) — ASME (2023)
- ASTM A213/A335 Grades T122/P122 (companion tube and pipe grades) — ASTM International (2023)
- HCM12A (11Cr-2W-Cu-V-Nb) boiler steel technical data — Nippon Steel / Mitsubishi Heavy Industries (2015)
- NIMS Creep Data Sheet — high-Cr ferritic heat-resisting steels — National Institute for Materials Science, Japan (2014)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.