Steel A182 F3VCb
ASTM A182 F3VCb · UNS K31390
ASTM A182 F3VCb (UNS K31390) is a niobium- and vanadium-modified 2.25Cr-1Mo low-alloy forging steel developed for heavy-section elevated-temperature pressure equipment.
Reference datasheet — A182 F3VCb 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 QT condition
A182 F3VCb tempers and conditions
A182 F3VCb is supplied in 5 conditions, soft to hard. QT 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 | Non-code intermediate condition for rough machining or repair of large forgings before final quench and temper. | 350 | 550 | 25 | 170 HB | 7.8 % IACS |
normalized and tempered | Used for lighter sections or where full quench hardenability is not needed; slightly lower strength and toughness than Q&T. | 470 | 620 | 23 | 12 HRC | 7.8 % IACS |
Q&T + simulated PWHT (min/max soak, e.g. 705 °C × 20–40 h) | Test-coupon condition required by API 934-A for heavy-wall reactor forgings; properties after full fabrication PWHT cycles. | 480 | 620 | 23 | 12 HRC | 7.8 % IACS |
Q&T + step-cooled | Step-cooled test condition used to verify the J-factor/X-bar temper-embrittlement resistance of the heat; strength unchanged, toughness transition shift measured. | 500 | 640 | 22 | 14 HRC | 7.8 % IACS |
QTDefault Quenched and tempered | Standard code-supply condition for heavy hydroprocessing reactor and pressure-vessel forgings. | 515 | 655 | 22 | 200 HB | — |
What is A182 F3VCb?
ASTM A182 F3VCb (UNS K31390) is a niobium- and vanadium-modified 2.25Cr-1Mo low-alloy forging steel developed for heavy-section elevated-temperature pressure equipment. Engineers specify it for hydroprocessing reactor and heavy pressure vessel forgings because the Nb/V additions raise creep and tempering resistance over plain 2.25Cr-1Mo; in the quenched-and-tempered default condition it provides 515 MPa yield, 655 MPa tensile, 22% elongation, about 200 HB and service to 540 °C. It is available in QT, NT, QT-SPWHT, QT-SC and annealed conditions, but demands strict low-hydrogen welding with mandatory 690–710 °C PWHT and J-factor/X-bar control, has no inherent corrosion resistance, and is not a cold-forming grade. A182 F3VCb has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F). A182 F3VCb has a yield strength of 515 MPa (74.7 ksi) and a tensile strength of 655 MPa (95 ksi) — stronger than 66% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi).
What is A182 F3VCb used for?
- Hydroprocessing reactor forgings
- Heavy pressure vessel components
- Heavy-wall reactor shell courses
- Reactor closure flanges
- Hydrocracker nozzle forgings
- Thick-section high-temperature piping forgings
Advantages
- Tough — resists crack growth — 180 MPa·√m (163.8 ksi·√in), better than 99% of steel grades
- High service temperature — 540°C (1,004 °F), better than 93% of steel grades
- Good corrosion resistance — 25/100, better than 92% of steel grades
Limitations
- Poor heat conductor — 35 W/m·K (20.2 BTU/hr·ft·°F), worse than 75% of steel grades
A182 F3VCb properties
Typical room-temperature values for A182 F3VCb-QT; bars are the position among steel grades.
Physical3
A182 F3VCb has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F).
Mechanical15
A182 F3VCb has a yield strength of 515 MPa (74.7 ksi) and a tensile strength of 655 MPa (95 ksi) — stronger than 66% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
A182 F3VCb is rated for continuous service to 540°C (1,004 °F). It conducts heat at 35 W/m·K (20.2 BTU/hr·ft·°F), worse than 75% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical2
A182 F3VCb has an electrical resistivity of 2.2×10⁻⁷ Ω·m.
Chemical & Environmental2
Corrosion resistance is poor (25/100), better than 92% of steel grades.
Sustainability4
Producing a kilogram of A182 F3VCb takes about 32 MJ of energy and emits 2.3 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 25%.
Manufacturability8
A182 F3VCb's machinability is fair (45/100, worse than 65% of steel grades); weldability fair (45/100); formability poor (30/100).
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 F3VCb is highlighted; hover a dot for its name, or open the interactive family chart.
Working with A182 F3VCb
Is A182 F3VCb easy to machine?
Machines like Q&T 4140 at ~200 HB — rigid setups, carbide inserts, 60–120 m/min; leave stock for final PWHT distortion on heavy forgings.
Can A182 F3VCb be welded?
SAW/SMAW with matching 3Cr-1Mo-V filler, 200–250 °C preheat/interpass, strict low-hydrogen control, DHT after welding and mandatory 690–710 °C PWHT; check J-factor and weld X-bar limits.
Can A182 F3VCb be formed, bent or molded?
Supplied hot-forged from ingot with controlled finish temperature; not a cold-forming grade — reheat above 950 °C for any shaping.
A182 F3VCb 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 – 0.15 | 0.13 |
| Mn | 0.3 – 0.6 | 0.45 |
| Pkept low for temper-embrittlement control (J-factor) | ≤ 0.02 | 0.01 |
| S | ≤ 0.01 | 0 |
| Silow Si limits X-bar embrittlement | ≤ 0.1 | 0.06 |
| Ni | ≤ 0.25 | 0.15 |
| Cr | 2.7 – 3.3 | 3 |
| Mo | 0.9 – 1.1 | 1 |
| V | 0.2 – 0.3 | 0.25 |
| Nblisted as Cb in ASTM | 0.02 – 0.07 | 0.04 |
| Cacalcium treatment for inclusion shape control | 5×10⁻⁴ – 0.02 | 0 |
| Ti | ≤ 0.03 | 0.01 |
| B | ≤ 0 | 5×10⁻⁴ |
| Cu | ≤ 0.25 | 0.1 |
| Fe | balance | — |
What surface finishes work on A182 F3VCb?
Internal surfaces normally clad with 309L/347 stainless weld overlay; external surfaces shot-blasted and coated with high-temperature aluminum/silicone paint under insulation.
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 F3VCb in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- K31390
How much does A182 F3VCb cost?
A182 F3VCb 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 F3VCb — frequently asked
What is A182 F3VCb used for?
A182 F3VCb is typically used for hydroprocessing reactor forgings, heavy pressure vessel components, heavy-wall reactor shell courses, reactor closure flanges, hydrocracker nozzle forgings and thick-section high-temperature piping forgings. In short: strongest 2.25Cr-1Mo forging; hydrogen-service reactor grade; 540 °C service temperature.
What is the yield strength of A182 F3VCb?
A182 F3VCb has a typical yield strength of 515 MPa (74.7 ksi) and a tensile strength of 655 MPa (95 ksi) — stronger than 66% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is A182 F3VCb easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machines like Q&T 4140 at ~200 HB — rigid setups, carbide inserts, 60–120 m/min; leave stock for final PWHT distortion on heavy forgings.
Can A182 F3VCb be welded?
With care — weldability is rated fair (45/100). SAW/SMAW with matching 3Cr-1Mo-V filler, 200–250 °C preheat/interpass, strict low-hydrogen control, DHT after welding and mandatory 690–710 °C PWHT; check J-factor and weld X-bar limits.
What surface finishes work on A182 F3VCb?
Internal surfaces normally clad with 309L/347 stainless weld overlay; external surfaces shot-blasted and coated with high-temperature aluminum/silicone paint under insulation.
Can A182 F3VCb be formed, bent or molded?
Supplied hot-forged from ingot with controlled finish temperature; not a cold-forming grade — reheat above 950 °C for any shaping.
What is the maximum service temperature of A182 F3VCb?
A182 F3VCb 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.
What is the difference between A182 F3VCb-QT and A182 F3VCb-ANN?
QT is the default condition — standard code-supply condition for heavy hydroprocessing reactor and pressure-vessel forgings. ANN: non-code intermediate condition for rough machining or repair of large forgings before final quench and temper. Yield strength is 515 MPa in QT versus 350 MPa in ANN.
How much does A182 F3VCb cost?
A182 F3VCb 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 for High-Temperature Service — ASTM International (2023)
- ASME BPVC Section II Part D — Properties (Metric) — ASME (2023)
- API RP 934-A — Materials and Fabrication of 2¼Cr-1Mo, 2¼Cr-1Mo-¼V, 3Cr-1Mo and 3Cr-1Mo-¼V Steel Heavy Wall Pressure Vessels — API (2019)
- API RP 941 — Steels for Hydrogen Service at Elevated Temperatures — API (2016)
- 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.