Steel 12Cr1MoV · heat-treated state
Steel 12Cr1MoV-QT
Properties of the QT condition, compared with the other 12Cr1MoV tempers.
Pick oil quenching plus a 680–720 °C temper for high-temperature bolts and turbine fasteners needing 560 MPa yield and 215 HB; elongation falls to 18% and service is limited to 550 °C.
What is 12Cr1MoV-QT?
12Cr1MoV-QT is 12Cr1MoV heat treated to QT — pick oil quenching plus a 680–720 °C temper for high-temperature bolts and turbine fasteners needing 560 MPa yield and 215 HB; elongation falls to 18% and service is limited to 550 °C. 12Cr1MoV-QT has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 73% of steel grades. Elongation at break is 18% and the elastic modulus is 212 GPa (30.7 Msi). 12Cr1MoV-QT has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,490°C (2,714 °F). N&T is the default condition FabDigit quotes; QT is available on request or by drawing note.
Advantages
- High service temperature — 550°C (1,022 °F), better than 94% of steel grades
- Good corrosion resistance — 22/100, better than 89% of steel grades
12Cr1MoV-QT properties
Typical room-temperature values for 12Cr1MoV-QT — 10 properties are specific to this condition; the rest are grade-level values shared by every 12Cr1MoV temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
12Cr1MoV-QT has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,490°C (2,714 °F).
Mechanical16
12Cr1MoV-QT has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 73% of steel grades. Elongation at break is 18% and the elastic modulus is 212 GPa (30.7 Msi).
Thermal6
12Cr1MoV-QT is rated for continuous service to 550°C (1,022 °F). It conducts heat at 38 W/m·K (22 BTU/hr·ft·°F), worse than 68% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical2
12Cr1MoV-QT has an electrical resistivity of 2.2×10⁻⁷ Ω·m.
Chemical & Environmental2
Corrosion resistance is poor (22/100), better than 89% of steel grades.
Sustainability4
Producing a kilogram of 12Cr1MoV-QT takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 55% of steel grades. Typical recycled content is 30%.
Manufacturability7
12Cr1MoV-QT's machinability is good (55/100, better than 62% of steel grades); weldability good (55/100); formability fair (50/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 12Cr1MoV tempers and conditions
12Cr1MoV is also supplied in 5 other conditions. The full side-by-side table is on the 12Cr1MoV overview.
- N&TDefaultChoose the roughly 970 °C normalize plus 730–750 °C temper for boiler tubes, main steam lines and high-temperature bolts; 285 MPa yield with rupture strength and toughness balanced to 580 °C.285 MPa yield · 160 HB
- QTPick oil quenching plus a 680–720 °C temper for high-temperature bolts and turbine fasteners needing 560 MPa yield and 215 HB; elongation falls to 18% and service is limited to 550 °C.560 MPa yield · 19 HRC
- AOrder the roughly 900 °C slow-cooled annealed bar or forging at 145 HB for rough machining and cold forming, then normalize and temper before service.245 MPa yield · 145 HB
Working with 12Cr1MoV-QT
Is 12Cr1MoV easy to machine?
In the normalized-and-tempered condition it machines normally with carbide tooling at about 55 % of the 1212 rate: low to moderate speeds, heavier feeds and generous coolant. Tool wear rises sharply in the quenched-and-tempered condition.
Can 12Cr1MoV be welded?
Weldable but classed as restricted-weldability steel: use Cr-Mo-V consumables of the R31 / R317 type for TIG or SMAW, preheat 250–300 °C, hold interpass temperature at or above preheat, and temper at 720–750 °C after welding for hydrogen removal and stress relief.
Can 12Cr1MoV be formed, bent or molded?
Hot form (tube bending, forging) between 1150 °C and 850 °C and always re-normalize and temper afterwards. Keep cold bend radii large and stress-relieve after cold deformation.
What surface finishes work on 12Cr1MoV?
Anodizing does not apply. Piping is normally blasted and then coated with high-temperature protective paint or aluminized; fasteners can be phosphated or zinc plated, with a 200 °C bake after plating to avoid hydrogen embrittlement.
12Cr1MoV 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 |
|---|---|---|
| CGB/T 5310 / GB/T 3077 | 0.08 – 0.15 | 0.12 |
| Si | 0.17 – 0.37 | 0.27 |
| Mn | 0.4 – 0.7 | 0.55 |
| Cr | 0.9 – 1.2 | 1.05 |
| Mo | 0.25 – 0.35 | 0.3 |
| VVC precipitation strengthening; raises creep-rupture strength | 0.15 – 0.3 | 0.22 |
| P≤ 0.025 for tube (grade G) | ≤ 0.03 | — |
| S≤ 0.010 for tube (grade G) | ≤ 0.01 | — |
| Niresidual element | ≤ 0.3 | — |
| Curesidual element | ≤ 0.2 | — |
| Fe | balance | — |
12Cr1MoV-QT — frequently asked
What is 12Cr1MoV-QT used for?
12Cr1MoV-QT is typically used for superheater and reheater tubes, high-pressure steam piping, hot petrochemical piping, hydrocracker unit components, boiler headers and manifolds and high-temperature flanges and fittings. In short: heat-resistant alloy pipe.
What is the yield strength of 12Cr1MoV-QT?
12Cr1MoV-QT has a typical yield strength of 560 MPa (81.2 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 73% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is 12Cr1MoV-QT easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). In the normalized-and-tempered condition it machines normally with carbide tooling at about 55 % of the 1212 rate: low to moderate speeds, heavier feeds and generous coolant. Tool wear rises sharply in the quenched-and-tempered condition.
Can 12Cr1MoV-QT be welded?
Yes — weldability is rated good (55/100). Weldable but classed as restricted-weldability steel: use Cr-Mo-V consumables of the R31 / R317 type for TIG or SMAW, preheat 250–300 °C, hold interpass temperature at or above preheat, and temper at 720–750 °C after welding for hydrogen removal and stress relief.
What surface finishes work on 12Cr1MoV-QT?
Anodizing does not apply. Piping is normally blasted and then coated with high-temperature protective paint or aluminized; fasteners can be phosphated or zinc plated, with a 200 °C bake after plating to avoid hydrogen embrittlement.
Can 12Cr1MoV-QT be formed, bent or molded?
Hot form (tube bending, forging) between 1150 °C and 850 °C and always re-normalize and temper afterwards. Keep cold bend radii large and stress-relieve after cold deformation.
What is the maximum service temperature of 12Cr1MoV-QT?
12Cr1MoV-QT 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 12Cr1MoV N&T and 12Cr1MoV-QT?
N&T is the default condition — choose the roughly 970 °C normalize plus 730–750 °C temper for boiler tubes, main steam lines and high-temperature bolts; 285 MPa yield with rupture strength and toughness balanced to 580 °C. QT: pick oil quenching plus a 680–720 °C temper for high-temperature bolts and turbine fasteners needing 560 MPa yield and 215 HB; elongation falls to 18% and service is limited to 550 °C. Yield strength is 285 MPa in N&T versus 560 MPa in QT.
Can FabDigit make parts in 12Cr1MoV-QT?
Yes — 12Cr1MoV-QT is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASME BPVC Section II Part D — Properties (Cr-Mo steels) — ASME (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — 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.