Steel A182 F3VCb-NT
Heat-treated state
ASTM A182 F3VCb · UNS K31390
Used for lighter sections or where full quench hardenability is not needed; slightly lower strength and toughness than Q&T.
Values for the NT condition
Other A182 F3VCb tempers and conditions
A182 F3VCb is listed in 5 conditions; see the grade overview at A182 F3VCb.
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 |
NTThis page 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-NT?
A182 F3VCb-NT is A182 F3VCb heat treated to NT — used for lighter sections or where full quench hardenability is not needed; slightly lower strength and toughness than Q&T. A182 F3VCb-NT has a yield strength of 470 MPa (68.2 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 57% of steel grades. Elongation at break is 23% and the elastic modulus is 210 GPa (30.5 Msi). A182 F3VCb-NT 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). QT is the default condition FabDigit quotes; NT is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 150 MPa·√m (136.5 ksi·√in), better than 96% 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-NT properties
Typical room-temperature values for A182 F3VCb-NT; 23 are specific to this condition. Other listed values are A182 F3VCb reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
A182 F3VCb-NT 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-NT has a yield strength of 470 MPa (68.2 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 57% of steel grades. Elongation at break is 23% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
A182 F3VCb-NT 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-NT 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-NT 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-NT's machinability is fair (48/100, worse than 57% of steel grades); weldability fair (45/100); formability poor (32/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with A182 F3VCb-NT
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.
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.
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 | — |
A182 F3VCb-NT — frequently asked
What is A182 F3VCb-NT used for?
A182 F3VCb-NT 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-NT?
A182 F3VCb-NT has a typical yield strength of 470 MPa (68.2 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 57% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is A182 F3VCb-NT easy to machine?
Reasonably — machinability is rated fair (48/100, worse than 57% 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-NT 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-NT?
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-NT 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-NT?
A182 F3VCb-NT 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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.