Steel 25Cr2MoVA · finish state
Steel 25Cr2MoVA QT+Nitrided
Properties of the QT+Nitrided condition, compared with the other 25Cr2MoVA tempers.
Choose for valve spindles, gears and wear surfaces needing a hard, seizure-resistant case on a tough 30 HRC core.
What is 25Cr2MoVA QT+Nitrided?
25Cr2MoVA QT+Nitrided is 25Cr2MoVA supplied in the QT+Nitrided condition — choose for valve spindles, gears and wear surfaces needing a hard, seizure-resistant case on a tough 30 HRC core. 25Cr2MoVA QT+Nitrided 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 14% and the elastic modulus is 210 GPa (30.5 Msi). 25Cr2MoVA QT+Nitrided 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). Q&T is the default condition FabDigit quotes; QT+Nitrided is available on request or by drawing note.
Advantages
- Good corrosion resistance — 25/100, better than 91% of steel grades
- High service temperature — 500°C (932 °F), better than 90% of steel grades
- High strength — 850 MPa (123 ksi), better than 88% of steel grades
Limitations
- Difficult to machine — 10/100, worse than 100% of steel grades
- Limited ductility — 14%, worse than 75% of steel grades
25Cr2MoVA QT+Nitrided properties
Typical room-temperature values for 25Cr2MoVA QT+Nitrided — 9 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 QT+Nitrided 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 QT+Nitrided 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 14% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
25Cr2MoVA QT+Nitrided is rated for continuous service to 500°C (932 °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 QT+Nitrided conducts electricity at 7.5 % IACS, worse than 68% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (25/100), better than 91% of steel grades.
Sustainability4
Producing a kilogram of 25Cr2MoVA QT+Nitrided 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 QT+Nitrided's machinability is not recommended (10/100, worse than 100% of steel grades); weldability poor (32/100); formability poor (25/100).
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 QT+Nitrided
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 QT+Nitrided — frequently asked
What is 25Cr2MoVA QT+Nitrided used for?
25Cr2MoVA QT+Nitrided 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 QT+Nitrided?
25Cr2MoVA QT+Nitrided 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 QT+Nitrided easy to machine?
Not especially — machinability is rated not recommended (10/100, worse than 100% 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 QT+Nitrided 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 QT+Nitrided?
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 QT+Nitrided 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 QT+Nitrided?
25Cr2MoVA QT+Nitrided is rated for continuous use to about 500°C (932 °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 QT+Nitrided?
Yes — 25Cr2MoVA QT+Nitrided 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.