Steel 25Cr2MoVA · heat-treated state · default condition
Steel 25Cr2MoVA Q&T
Properties of the Q&T condition, compared with the other 25Cr2MoVA tempers.
Standard delivered condition for high-temperature bolting, studs and valve spindles; meets GB/T 3077 property table.
What is 25Cr2MoVA Q&T?
25Cr2MoVA Q&T is 25Cr2MoVA heat treated to Q&T — standard delivered condition for high-temperature bolting, studs and valve spindles; meets GB/T 3077 property table. 25Cr2MoVA Q&T has a yield strength of 850 MPa (123 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 88% of steel grades. Elongation at break is 16% and the elastic modulus is 210 GPa (30.5 Msi). 25Cr2MoVA Q&T has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Advantages
- High service temperature — 520°C (968 °F), better than 92% of steel grades
- High strength — 850 MPa (123 ksi), better than 88% of steel grades
25Cr2MoVA Q&T properties
Typical room-temperature values for 25Cr2MoVA Q&T — 14 properties are specific to this condition; the rest are grade-level values shared by every 25Cr2MoVA temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
25Cr2MoVA Q&T has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
25Cr2MoVA Q&T has a yield strength of 850 MPa (123 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 88% of steel grades. Elongation at break is 16% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
25Cr2MoVA Q&T is rated for continuous service to 520°C (968 °F). It conducts heat at 38 W/m·K (22 BTU/hr·ft·°F), worse than 68% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
25Cr2MoVA Q&T conducts electricity at 7.5 % IACS, worse than 68% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (15/100), better than 75% of steel grades.
Sustainability4
Producing a kilogram of 25Cr2MoVA Q&T takes about 34 MJ of energy and emits 2.4 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 30%.
Manufacturability8
25Cr2MoVA Q&T's machinability is fair (42/100, worse than 72% of steel grades); weldability poor (32/100); formability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 25Cr2MoVA tempers and conditions
25Cr2MoVA is also supplied in 7 other conditions. The full side-by-side table is on the 25Cr2MoVA overview.
- Q&TDefaultStandard delivered condition for high-temperature bolting, studs and valve spindles; meets GB/T 3077 property table.850 MPa yield · 31 HRC
- Q&T 34-38 HRCPick when maximum bolt preload or shaft strength is wanted and service temperature stays below ~450 °C.1,000 MPa yield · 36 HRC
- QT+NitridedChoose for valve spindles, gears and wear surfaces needing a hard, seizure-resistant case on a tough 30 HRC core.850 MPa yield · 31 HRC
- Q&T 28-32 HRCHardness-controlled temper for pressure-boundary studs where relaxation resistance and toughness matter more than peak strength.800 MPa yield · 30 HRC
- ASoftest condition for rough machining, deep-hole drilling and thread rolling before final Q&T.450 MPa yield · 220 HB
Working with 25Cr2MoVA Q&T
Is 25Cr2MoVA easy to machine?
Rough machine annealed (≤241 HB) and finish after Q&T at 28–35 HRC with coated carbide, rigid setups and moderate speeds; thread rolling before tempering gives the best fatigue life.
Can 25Cr2MoVA be welded?
Weld only when unavoidable — preheat 250–350 °C, use matched Cr-Mo-V or 2.25Cr-1Mo filler, low hydrogen, and PWHT/temper at 680–700 °C to avoid cold cracking.
Can 25Cr2MoVA be formed, bent or molded?
Forge 1150→850 °C with slow cooling then anneal; cold bending is impractical in the Q&T state.
What surface finishes work on 25Cr2MoVA?
Phosphate, black oxide or Zn-Ni/aluminium-flake coatings for atmospheric use; gas or ion nitriding at 520–560 °C gives an 800–1000 HV case — avoid electroplating above 1000 MPa without hydrogen bake-out.
25Cr2MoVA 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 | 0.22 – 0.29 | 0.26 |
| Si | 0.17 – 0.37 | 0.27 |
| Mn | 0.4 – 0.7 | 0.55 |
| Cr | 1.5 – 1.8 | 1.65 |
| Mo | 0.25 – 0.35 | 0.3 |
| V | 0.15 – 0.3 | 0.22 |
| Niresidual | ≤ 0.3 | — |
| Curesidual | ≤ 0.2 | — |
| Phigh-quality steel grade A limit | ≤ 0.03 | — |
| Shigh-quality steel grade A limit | ≤ 0.03 | — |
| Fe | balance | — |
25Cr2MoVA Q&T — frequently asked
What is 25Cr2MoVA Q&T used for?
25Cr2MoVA Q&T is typically used for steam turbine bolting and studs, high-pressure valve stems, high-temperature flange fasteners, nitrided shafts and spindles, boiler superheater components and hot petrochemical piping fittings. In short: high-strength aerospace bar.
What is the yield strength of 25Cr2MoVA Q&T?
25Cr2MoVA Q&T has a typical yield strength of 850 MPa (123 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 88% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 25Cr2MoVA Q&T easy to machine?
Not especially — machinability is rated fair (42/100, worse than 72% of steel grades). Rough machine annealed (≤241 HB) and finish after Q&T at 28–35 HRC with coated carbide, rigid setups and moderate speeds; thread rolling before tempering gives the best fatigue life.
Can 25Cr2MoVA Q&T be welded?
Not readily — weldability is rated poor (32/100). Weld only when unavoidable — preheat 250–350 °C, use matched Cr-Mo-V or 2.25Cr-1Mo filler, low hydrogen, and PWHT/temper at 680–700 °C to avoid cold cracking.
What surface finishes work on 25Cr2MoVA Q&T?
Phosphate, black oxide or Zn-Ni/aluminium-flake coatings for atmospheric use; gas or ion nitriding at 520–560 °C gives an 800–1000 HV case — avoid electroplating above 1000 MPa without hydrogen bake-out.
Can 25Cr2MoVA Q&T be formed, bent or molded?
Forge 1150→850 °C with slow cooling then anneal; cold bending is impractical in the Q&T state.
What is the maximum service temperature of 25Cr2MoVA Q&T?
25Cr2MoVA Q&T is rated for continuous use to about 520°C (968 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 25Cr2MoVA Q&T and 25Cr2MoVA-A?
Q&T is the default condition — standard delivered condition for high-temperature bolting, studs and valve spindles; meets GB/T 3077 property table. A: softest condition for rough machining, deep-hole drilling and thread rolling before final Q&T. Yield strength is 850 MPa in Q&T versus 450 MPa in A.
Can FabDigit make parts in 25Cr2MoVA Q&T?
Yes — 25Cr2MoVA Q&T 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
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 19: Fatigue and Fracture — ASM International (1996)
- ASTM A193/A193M (B16 Cr-Mo-V bolting, comparison grade) — ASTM International (2023)
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.