Steel A182 F911
ASTM A182 F911 · UNS K91061
Modified 9Cr-1Mo-V-Nb (Grade 91) martensitic forging steel offering high creep-rupture strength for high-temperature power plant flanges, valves and reactor internals; forging counterpart of A335 P91 pipe.
Reference datasheet — A182 F911 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 F911 tempers and conditions
A182 F911 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 |
|---|---|---|---|---|---|---|
Annealed | Soft condition used to ease heavy machining of large forgings before the final normalize-and-temper cycle. | 380 | 600 | 26 | 185 HB | — |
N&T double-tempered | Second temper used after weld repair or when a softer, tougher forging with guaranteed ≤ 248 HB is specified. | 480 | 665 | 24 | 15 HRC | 2.9 % IACS |
N+TDefault Normalized and tempered | Standard delivery condition for all A182 F911 flanges, valve bodies and fittings; gives the code-qualified creep strength. | 510 | 700 | 22 | 20 HRC | — |
Quenched and tempered | Accelerated/liquid quench used on thick valve bodies and large flanges to guarantee full martensite through-section before tempering. | 540 | 730 | 21 | 22 HRC | 2.9 % IACS |
As-Forged | Rough forging supplied before normalizing/tempering — only for further heat treatment and machining allowance. | 650 | 900 | 15 | 34 HRC | 2.8 % IACS |
What is A182 F911?
Modified 9Cr-1Mo-V-Nb (Grade 91) martensitic forging steel offering high creep-rupture strength for high-temperature power plant flanges, valves and reactor internals; forging counterpart of A335 P91 pipe. A182 F911 has a density of 7.77 g/cm³ (0.281 lb/in³), lighter than 92% of steel grades. It melts at 1,420°C (2,588 °F). A182 F911 has a yield strength of 510 MPa (74 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 65% of steel grades. Elongation at break is 22% and the elastic modulus is 215 GPa (31.2 Msi).
What is A182 F911 used for?
- Power plant steam header flanges
- Valve bodies for high-temperature steam
- Reactor internals
Advantages
- High service temperature — 620°C (1,148 °F), better than 99% of steel grades
- Good corrosion resistance — 33/100, better than 97% of steel grades
- Tough — resists crack growth — 130 MPa·√m (118.3 ksi·√in), better than 89% 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 F911 properties
Typical room-temperature values for A182 F911-N+T; bars are the position among steel grades.
Physical3
A182 F911 has a density of 7.77 g/cm³ (0.281 lb/in³), lighter than 92% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
A182 F911 has a yield strength of 510 MPa (74 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 65% of steel grades. Elongation at break is 22% and the elastic modulus is 215 GPa (31.2 Msi).
Thermal6
A182 F911 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 10.9 µm/m·K (6.06 µin/in·°F).
Electrical3
A182 F911 conducts electricity at 2.9 % IACS, worse than 93% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (33/100), better than 97% of steel grades.
Sustainability4
Producing a kilogram of A182 F911 takes about 34 MJ of energy and emits 2.6 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 25%.
Manufacturability6
A182 F911'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 F911 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with A182 F911
Is A182 F911 easy to machine?
Machine in the annealed or freshly tempered state with rigid setups, sharp coated carbide and generous coolant; the V/Nb carbonitrides are abrasive and work-hardening is noticeable at low feeds.
Can A182 F911 be welded?
GTAW root + SMAW/SAW fill with matching 9Cr-1Mo-W-V consumables, preheat/interpass 200–300 °C, cool to ~100 °C before mandatory PWHT at 750–770 °C; avoid over-temper and control Type IV HAZ creep damage.
Can A182 F911 be formed, bent or molded?
Hot forge from about 1150–1200 °C, finish above 900 °C, then always re-normalize and temper; cold forming is essentially limited to light straightening.
A182 F911 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 | 0.09 – 0.13 | 0.11 |
| Mn | 0.3 – 0.6 | 0.45 |
| P | ≤ 0.02 | — |
| S | ≤ 0.01 | — |
| Si | 0.1 – 0.5 | 0.25 |
| Cr | 8.5 – 9.5 | 9 |
| Mo | 0.9 – 1.1 | 1 |
| Wtungsten strengthening distinguishes 911 from Grade 91 | 0.9 – 1.1 | 1 |
| V | 0.18 – 0.25 | 0.21 |
| NbCb | 0.06 – 0.1 | 0.07 |
| N | 0.04 – 0.09 | 0.06 |
| B | 3×10⁻⁴ – 0.01 | 0 |
| Ni | ≤ 0.4 | — |
| Al | ≤ 0.02 | — |
| Ti | ≤ 0.01 | — |
| Zr | ≤ 0.01 | — |
| Fe | balance | — |
What surface finishes work on A182 F911?
No anodizing; use shot blast + high-temperature aluminium or silicone paint, or aluminide/thermal-spray coatings for steam-side oxidation and outdoor storage protection.
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 F911 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- K91061
- ASTM
- A335 P91
How much does A182 F911 cost?
A182 F911 is a high-cost steel ($$$$), pricier than about 78% 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 F911 — frequently asked
What is A182 F911 used for?
A182 F911 is typically used for power plant steam header flanges, valve bodies for high-temperature steam and reactor internals. In short: creep-strength 9Cr forging grade; 620 °C steam service; mandatory PWHT after welding.
What is the yield strength of A182 F911?
A182 F911 has a typical yield strength of 510 MPa (74 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 65% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is A182 F911 easy to machine?
Not especially — machinability is rated fair (40/100, worse than 77% of steel grades). Machine in the annealed or freshly tempered state with rigid setups, sharp coated carbide and generous coolant; the V/Nb carbonitrides are abrasive and work-hardening is noticeable at low feeds.
Can A182 F911 be welded?
With care — weldability is rated fair (40/100). GTAW root + SMAW/SAW fill with matching 9Cr-1Mo-W-V consumables, preheat/interpass 200–300 °C, cool to ~100 °C before mandatory PWHT at 750–770 °C; avoid over-temper and control Type IV HAZ creep damage.
What surface finishes work on A182 F911?
No anodizing; use shot blast + high-temperature aluminium or silicone paint, or aluminide/thermal-spray coatings for steam-side oxidation and outdoor storage protection.
Can A182 F911 be formed, bent or molded?
Hot forge from about 1150–1200 °C, finish above 900 °C, then always re-normalize and temper; cold forming is essentially limited to light straightening.
What is the maximum service temperature of A182 F911?
A182 F911 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 F911 N+T and A182 F911-AF?
N+T is the default condition — standard delivery condition for all A182 F911 flanges, valve bodies and fittings; gives the code-qualified creep strength. AF: rough forging supplied before normalizing/tempering — only for further heat treatment and machining allowance. Yield strength is 510 MPa in N+T versus 650 MPa in AF.
How much does A182 F911 cost?
A182 F911 is a high-cost steel ($$$$), pricier than about 78% 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 for High-Temperature Service (Grade F911) — ASTM International (2022)
- ASTM A335/A335M — Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service (Grade P911) — ASTM International (2022)
- EN 10216-2 — Seamless steel tubes for pressure purposes, X11CrMoWVNb9-1-1 (1.4905) — CEN (2020)
- ECCC Data Sheet — Creep rupture data for E911 (9Cr-1Mo-1W-V-Nb) — European Creep Collaborative Committee (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.