Steel A182 F92 SUBANN
Heat-treated state
ASTM A182 F92 · UNS K92460
SUBANN = sub-critical annealed
Interim soft condition for rough machining of large forgings; must be re-normalized/tempered before code service.
Values for the SUBANN condition
Other A182 F92 tempers and conditions
A182 F92 is listed in 5 conditions; see the grade overview at A182 F92.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SUBANNThis page Sub-critical annealed | Interim soft condition for rough machining of large forgings; must be re-normalized/tempered before code service. | 400 | 630 | 26 | 185 HB | 3 % IACS |
N+T + simulated post-weld heat treatment | Order this when the forging will see field PWHT cycles and design must use post-PWHT (slightly softened) properties. | 480 | 670 | 24 | 15 HRC | 2.9 % IACS |
N+TDefault Normalized and tempered | Standard ASME/ASTM code condition for F92 flanges, valve bodies and fittings in USC steam service. | 520 | 710 | 22 | 20 HRC | — |
Quenched and tempered | Chosen for heavy-section forgings where still-air normalizing cannot guarantee full martensite through-thickness. | 560 | 745 | 21 | 22 HRC | 2.9 % IACS |
As-forged | Only an intermediate stage — untempered martensite is hard and brittle and is never acceptable for pressure service. | 900 | 1,200 | 10 | 41 HRC | 2.7 % IACS |
What is A182 F92 SUBANN?
A182 F92 SUBANN is A182 F92 heat treated to SUBANN — interim soft condition for rough machining of large forgings; must be re-normalized/tempered before code service. A182 F92 SUBANN has a yield strength of 400 MPa (58 ksi) and a tensile strength of 630 MPa (91.4 ksi) — weaker than 60% of steel grades. Elongation at break is 26% and the elastic modulus is 216 GPa (31.3 Msi). A182 F92 SUBANN has a density of 7.78 g/cm³ (0.281 lb/in³), lighter than 91% of steel grades. It melts at 1,420°C (2,588 °F). N+T is the default condition FabDigit quotes; SUBANN is available on request or by drawing note.
Advantages
- Good corrosion resistance — 30/100, better than 95% of steel grades
- Tough — resists crack growth — 135 MPa·√m (122.9 ksi·√in), better than 93% of steel grades
- High service temperature — 500°C (932 °F), better than 90% of steel grades
- Ductile — tolerates forming and impact — 26%, better than 82% of steel grades
Limitations
- Low electrical conductivity — 3 % IACS, worse than 91% of steel grades
- High embodied carbon — 2.6 kg CO₂/kg, worse than 87% of steel grades
- Poor heat conductor — 28 W/m·K (16.2 BTU/hr·ft·°F), worse than 85% of steel grades
A182 F92 SUBANN properties
Typical room-temperature values for A182 F92 SUBANN; 22 are specific to this condition. Other listed values are A182 F92 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
A182 F92 SUBANN has a density of 7.78 g/cm³ (0.281 lb/in³), lighter than 91% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
A182 F92 SUBANN has a yield strength of 400 MPa (58 ksi) and a tensile strength of 630 MPa (91.4 ksi) — weaker than 60% of steel grades. Elongation at break is 26% and the elastic modulus is 216 GPa (31.3 Msi).
Thermal6
A182 F92 SUBANN is rated for continuous service to 500°C (932 °F). It conducts heat at 28 W/m·K (16.2 BTU/hr·ft·°F), worse than 85% of steel grades. Thermal expansion is 10.8 µm/m·K (6 µin/in·°F).
Electrical3
A182 F92 SUBANN conducts electricity at 3 % IACS, worse than 91% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (30/100), better than 95% of steel grades.
Sustainability4
Producing a kilogram of A182 F92 SUBANN takes about 34 MJ of energy and emits 2.6 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
A182 F92 SUBANN's machinability is fair (50/100, worse than 53% of steel grades); weldability fair (45/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with A182 F92 SUBANN
Is A182 F92 easy to machine?
Machine in the N+T condition at ~200–230 HB with rigid setups, sharp coated carbide, moderate speed and heavy positive feed; the fine carbides are abrasive and work-hardening is mild but tool wear is high.
Can A182 F92 be welded?
GTAW/SMAW/SAW with matching Grade 92 consumables, 200–300 °C preheat and interpass ≤300 °C, cool to ~80–100 °C before a mandatory 755–780 °C PWHT; avoid excessive heat input to limit Type IV creep cracking in the fine-grained HAZ.
Can A182 F92 be formed, bent or molded?
Hot forge at 1100–1200 °C finishing above ~950 °C, then full re-normalize and temper; cold forming is essentially impractical.
What surface finishes work on A182 F92?
Not corrosion-resistant — protect with high-temperature paint, aluminizing, chromizing or thermal-spray coatings; no anodizing, and any coating bake must stay below the tempering temperature.
A182 F92 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 – 0.13 | 0.11 |
| Mn | 0.3 – 0.6 | 0.45 |
| P | ≤ 0.02 | 0.01 |
| S | ≤ 0.01 | 0 |
| Si | ≤ 0.5 | 0.25 |
| Cr | 8.5 – 9.5 | 9 |
| Wsolid-solution and Laves-phase strengthening | 1.5 – 2 | 1.75 |
| Mo | 0.3 – 0.6 | 0.45 |
| VMX carbonitride former | 0.15 – 0.25 | 0.2 |
| Nblisted as Cb in ASTM | 0.04 – 0.09 | 0.06 |
| N | 0.03 – 0.07 | 0.05 |
| Bstabilizes M23C6 | 0 – 0.01 | 0 |
| Ni | ≤ 0.4 | 0.15 |
| Alsoluble Al limit | ≤ 0.02 | 0.01 |
| Ti | ≤ 0.01 | 0 |
| Zr | ≤ 0.01 | 0 |
| Fe | balance | — |
A182 F92 SUBANN — frequently asked
What is A182 F92 SUBANN used for?
A182 F92 SUBANN is typically used for ultra-supercritical boiler flanges, high-temperature steam valve bodies and header forgings. In short: highest-strength 9Cr forging grade; ultra-supercritical steam service; mandatory post-weld heat treatment.
What is the yield strength of A182 F92 SUBANN?
A182 F92 SUBANN has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 630 MPa (91.4 ksi) — weaker than 60% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is A182 F92 SUBANN easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machine in the N+T condition at ~200–230 HB with rigid setups, sharp coated carbide, moderate speed and heavy positive feed; the fine carbides are abrasive and work-hardening is mild but tool wear is high.
Can A182 F92 SUBANN be welded?
With care — weldability is rated fair (45/100). GTAW/SMAW/SAW with matching Grade 92 consumables, 200–300 °C preheat and interpass ≤300 °C, cool to ~80–100 °C before a mandatory 755–780 °C PWHT; avoid excessive heat input to limit Type IV creep cracking in the fine-grained HAZ.
What surface finishes work on A182 F92 SUBANN?
Not corrosion-resistant — protect with high-temperature paint, aluminizing, chromizing or thermal-spray coatings; no anodizing, and any coating bake must stay below the tempering temperature.
Can A182 F92 SUBANN be formed, bent or molded?
Hot forge at 1100–1200 °C finishing above ~950 °C, then full re-normalize and temper; cold forming is essentially impractical.
What is the maximum service temperature of A182 F92 SUBANN?
A182 F92 SUBANN is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between A182 F92 N+T and A182 F92-AF?
N+T is the default condition — standard ASME/ASTM code condition for F92 flanges, valve bodies and fittings in USC steam service. AF: only an intermediate stage — untempered martensite is hard and brittle and is never acceptable for pressure service. Yield strength is 520 MPa in N+T versus 900 MPa in AF.
Sources
- ASTM A182/A182M — Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Fittings, Valves and Parts for High-Temperature Service (Grade F92) — ASTM International (2024)
- ASTM A335/A335M — Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service (Grade P92) — ASTM International (2022)
- ASME BPVC Section II Part D — Properties (Metric): allowable stresses, E, α, k for 9Cr-2W steels — ASME (2023)
- EN 10222-2 / EN 10216-2 X10CrWMoVNb9-2 (1.4901) — CEN (2020)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- NIMS Creep Data Sheets, ASME Grade 92 (9Cr-0.5Mo-1.8W-V-Nb) steel — NIMS (2014)
- Vallourec / Nippon Steel Grade 92 (P92/T92) product literature — Vallourec; Nippon Steel (2021)
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.