Steel A182 F12 Cl.2 Q+T
Heat-treated state
ASTM A182 F12 Cl.2 · UNS K11564
Q+T = quenched and tempered
Used for heavy-wall valve bodies and thick forgings where through-thickness strength and low-temperature toughness must be maximised.
Values for the Q+T condition
Other A182 F12 Cl.2 tempers and conditions
A182 F12 Cl.2 is listed in 3 conditions; see the grade overview at A182 F12 Cl.2.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Choose when maximum machinability and dimensional stability of thick forgings matter and Cl.2 strength minima can still be met in the section size. | 300 | 510 | 29 | 155 HB | 8 % IACS |
N+TDefault Normalized and tempered | Standard supply condition for F12 Cl.2 forgings, flanges and fittings; best balance of strength, toughness and creep behaviour. | 335 | 545 | 26 | 175 HB | — |
Q+TThis page Quenched and tempered | Used for heavy-wall valve bodies and thick forgings where through-thickness strength and low-temperature toughness must be maximised. | 400 | 585 | 24 | 190 HB | 8 % IACS |
What is A182 F12 Cl.2 Q+T?
A182 F12 Cl.2 Q+T is A182 F12 Cl.2 heat treated to Q+T — used for heavy-wall valve bodies and thick forgings where through-thickness strength and low-temperature toughness must be maximised. A182 F12 Cl.2 Q+T has a yield strength of 400 MPa (58 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 60% of steel grades. Elongation at break is 24% and the elastic modulus is 207 GPa (30 Msi). A182 F12 Cl.2 Q+T has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). N+T is the default condition FabDigit quotes; Q+T is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 155 MPa·√m (141.1 ksi·√in), better than 97% of steel grades
- High service temperature — 550°C (1,022 °F), better than 95% of steel grades
A182 F12 Cl.2 Q+T properties
Typical room-temperature values for A182 F12 Cl.2 Q+T; 22 are specific to this condition. Other listed values are A182 F12 Cl.2 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
A182 F12 Cl.2 Q+T has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
A182 F12 Cl.2 Q+T has a yield strength of 400 MPa (58 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 60% of steel grades. Elongation at break is 24% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
A182 F12 Cl.2 Q+T is rated for continuous service to 550°C (1,022 °F). It conducts heat at 41 W/m·K (23.7 BTU/hr·ft·°F), worse than 62% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
A182 F12 Cl.2 Q+T conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (16/100), better than 79% of steel grades.
Sustainability4
Producing a kilogram of A182 F12 Cl.2 Q+T takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability7
A182 F12 Cl.2 Q+T's machinability is fair (50/100, worse than 53% of steel grades); weldability good (58/100); formability fair (42/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with A182 F12 Cl.2 Q+T
Is A182 F12 Cl.2 easy to machine?
Machines like annealed 4130-class Cr-Mo steel (~60 % of AISI 1212); use rigid setups, carbide tooling and moderate speeds — normalized-and-tempered stock produces tough, stringy chips.
Can A182 F12 Cl.2 be welded?
Weld with matching E8018-B2/ER80S-B2 consumables, 150–250 °C preheat and interpass control, plus PWHT at 675–730 °C to avoid hard HAZ and hydrogen cracking.
Can A182 F12 Cl.2 be formed, bent or molded?
Hot forge at 1050–1200 °C and finish above 900 °C, then normalize-and-temper; cold forming is limited and should be followed by stress relief.
What surface finishes work on A182 F12 Cl.2?
No natural corrosion resistance — shot blast and apply zinc-rich primer/paint, aluminizing or hot-dip coating for outdoor and insulated-line service (CUI risk).
A182 F12 Cl.2 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 |
|---|---|---|
| Chigher than Cl.1 (0.05–0.15) to reach Cl.2 strength | 0.1 – 0.2 | 0.15 |
| Mn | 0.3 – 0.8 | 0.55 |
| P | ≤ 0.04 | — |
| S | ≤ 0.04 | — |
| Si | 0.1 – 0.6 | 0.3 |
| Cr | 0.8 – 1.25 | 1 |
| Mo | 0.44 – 0.65 | 0.52 |
| Fe | balance | — |
A182 F12 Cl.2 Q+T — frequently asked
What is A182 F12 Cl.2 Q+T used for?
A182 F12 Cl.2 Q+T is typically used for high-pressure boiler flanges, steam turbine casings and valve bodies. In short: stronger F12 class; normalized-and-tempered 1Cr-0.5Mo; 550 °C pressure service.
What is the yield strength of A182 F12 Cl.2 Q+T?
A182 F12 Cl.2 Q+T has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 60% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is A182 F12 Cl.2 Q+T easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machines like annealed 4130-class Cr-Mo steel (~60 % of AISI 1212); use rigid setups, carbide tooling and moderate speeds — normalized-and-tempered stock produces tough, stringy chips.
Can A182 F12 Cl.2 Q+T be welded?
Yes — weldability is rated good (58/100). Weld with matching E8018-B2/ER80S-B2 consumables, 150–250 °C preheat and interpass control, plus PWHT at 675–730 °C to avoid hard HAZ and hydrogen cracking.
What surface finishes work on A182 F12 Cl.2 Q+T?
No natural corrosion resistance — shot blast and apply zinc-rich primer/paint, aluminizing or hot-dip coating for outdoor and insulated-line service (CUI risk).
Can A182 F12 Cl.2 Q+T be formed, bent or molded?
Hot forge at 1050–1200 °C and finish above 900 °C, then normalize-and-temper; cold forming is limited and should be followed by stress relief.
What is the maximum service temperature of A182 F12 Cl.2 Q+T?
A182 F12 Cl.2 Q+T is rated for continuous use to about 550°C (1,022 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between A182 F12 Cl.2 N+T and A182 F12 Cl.2-ANN?
N+T is the default condition — standard supply condition for F12 Cl.2 forgings, flanges and fittings; best balance of strength, toughness and creep behaviour. ANN: choose when maximum machinability and dimensional stability of thick forgings matter and Cl.2 strength minima can still be met in the section size. Yield strength is 335 MPa in N+T versus 300 MPa in ANN.
Sources
- ASTM A182/A182M — Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Fittings, Valves and Parts — ASTM International (2023)
- ASTM A335/A335M — Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service (Grade P12) — ASTM International (2023)
- ASME BPVC Section II Part D — Material Properties (Metric) — ASME (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- API RP 941 — Steels for Hydrogen Service at Elevated Temperatures — API (2016)
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.