Steel 7CrMoVTiB10-10 N+T
Heat-treated state · default condition
EN 7CrMoVTiB10-10 · ASTM A213 T24
N+T = normalized and tempered
Standard delivery condition for T24 / 7CrMoVTiB10-10 seamless boiler tubes and headers.
Values for the N+T condition
Other 7CrMoVTiB10-10 tempers and conditions
7CrMoVTiB10-10 is listed in 4 conditions; see the grade overview at 7CrMoVTiB10-10.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softened condition for heavy machining, cold bending or intermediate processing; must be re-normalized/tempered before service. | 340 | 520 | 28 | 165 HB | 8.2 % IACS |
N+TDefaultThis page Normalized and tempered | Standard delivery condition for T24 / 7CrMoVTiB10-10 seamless boiler tubes and headers. | 520 | 640 | 23 | 205 HB | — |
Cold drawn tube, then normalized and tempered | Cold-drawn small-diameter waterwall tubing given the full N&T cycle for close dimensional tolerance with code-compliant properties. | 530 | 650 | 22 | 17 HRC | 7.8 % IACS |
Quenched and tempered | Used for heavy-wall headers and forgings where a fully bainitic through-section structure and the upper strength band are wanted. | 570 | 700 | 20 | 225 HB | — |
What is 7CrMoVTiB10-10 N+T?
7CrMoVTiB10-10 N+T is 7CrMoVTiB10-10 heat treated to N+T — standard delivery condition for T24 / 7CrMoVTiB10-10 seamless boiler tubes and headers. 7CrMoVTiB10-10 N+T has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 640 MPa (92.8 ksi) — stronger than 67% of steel grades. Elongation at break is 23% and the elastic modulus is 213 GPa (30.9 Msi). 7CrMoVTiB10-10 N+T has a density of 7.84 g/cm³ (0.283 lb/in³), lighter than 78% of steel grades. It melts at 1,450°C (2,642 °F).
Advantages
- High service temperature — 560°C (1,040 °F), better than 96% of steel grades
- Good corrosion resistance — 22/100, better than 90% of steel grades
- Tough — resists crack growth — 130 MPa·√m (118.3 ksi·√in), better than 89% of steel grades
7CrMoVTiB10-10 N+T properties
Typical room-temperature values for 7CrMoVTiB10-10 N+T; 11 are specific to this condition. Other listed values are 7CrMoVTiB10-10 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
7CrMoVTiB10-10 N+T has a density of 7.84 g/cm³ (0.283 lb/in³), lighter than 78% of steel grades. It melts at 1,450°C (2,642 °F).
Mechanical15
7CrMoVTiB10-10 N+T has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 640 MPa (92.8 ksi) — stronger than 67% of steel grades. Elongation at break is 23% and the elastic modulus is 213 GPa (30.9 Msi).
Thermal6
7CrMoVTiB10-10 N+T is rated for continuous service to 560°C (1,040 °F). It conducts heat at 36 W/m·K (20.8 BTU/hr·ft·°F), worse than 73% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical2
7CrMoVTiB10-10 N+T has an electrical resistivity of 2.2×10⁻⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is poor (22/100), better than 90% of steel grades.
Sustainability4
Producing a kilogram of 7CrMoVTiB10-10 N+T takes about 32 MJ of energy and emits 2.4 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 25%.
Manufacturability7
7CrMoVTiB10-10 N+T's machinability is fair (45/100, worse than 65% of steel grades); weldability good (55/100); formability fair (50/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 7CrMoVTiB10-10 N+T
Is 7CrMoVTiB10-10 easy to machine?
Machines like normalized 2.25Cr-1Mo at ~55 % of 1212; use rigid setups, carbide inserts and moderate speeds — bainitic structure work-hardens the cut surface.
Can 7CrMoVTiB10-10 be welded?
GTAW root/SMAW-SAW fill with matching T24 consumables; keep hydrogen low, preheat 150–250 °C, and apply PWHT ~730–750 °C unless a qualified no-PWHT procedure exists — HAZ hardness above ~350 HV invites hydrogen and stress-corrosion cracking in service.
Can 7CrMoVTiB10-10 be formed, bent or molded?
Hot form 900–1050 °C followed by re-normalizing and tempering; cold bending of tube is possible at generous radii but demands a restoration heat treatment for code service.
What surface finishes work on 7CrMoVTiB10-10?
Supplied descaled/pickled or shot-blasted; not corrosion resistant at ambient — protect stored tube with oil or coating and use aluminising/coatings for fireside protection.
7CrMoVTiB10-10 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 |
|---|---|---|
| Clow carbon for weldability | 0.05 – 0.1 | 0.07 |
| Si | 0.15 – 0.45 | 0.3 |
| Mn | 0.3 – 0.7 | 0.5 |
| P | ≤ 0.02 | — |
| S | ≤ 0.01 | — |
| Cr | 2.2 – 2.6 | 2.4 |
| Mo | 0.9 – 1.1 | 1 |
| VMX carbonitride strengthening | 0.2 – 0.3 | 0.25 |
| Tities up N, protects B | 0.05 – 0.1 | 0.07 |
| Bhardenability / creep | 0 – 0.01 | 0 |
| N | ≤ 0.01 | — |
| Almax, total | ≤ 0.02 | — |
| Nbresidual, max | ≤ 0.05 | — |
| Fe | balance | — |
7CrMoVTiB10-10 N+T — frequently asked
What is 7CrMoVTiB10-10 N+T used for?
7CrMoVTiB10-10 N+T is typically used for supercritical boiler tubes, waterwall and membrane wall panels, superheater tubing, boiler headers, once-through steam generator tubing and economizer tube banks. In short: high creep strength P22 variant; supercritical waterwall tube grade; thinner walls than P22.
What is the yield strength of 7CrMoVTiB10-10 N+T?
7CrMoVTiB10-10 N+T has a typical yield strength of 520 MPa (75.4 ksi) and a tensile strength of 640 MPa (92.8 ksi) — stronger than 67% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is 7CrMoVTiB10-10 N+T easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machines like normalized 2.25Cr-1Mo at ~55 % of 1212; use rigid setups, carbide inserts and moderate speeds — bainitic structure work-hardens the cut surface.
Can 7CrMoVTiB10-10 N+T be welded?
Yes — weldability is rated good (55/100). GTAW root/SMAW-SAW fill with matching T24 consumables; keep hydrogen low, preheat 150–250 °C, and apply PWHT ~730–750 °C unless a qualified no-PWHT procedure exists — HAZ hardness above ~350 HV invites hydrogen and stress-corrosion cracking in service.
What surface finishes work on 7CrMoVTiB10-10 N+T?
Supplied descaled/pickled or shot-blasted; not corrosion resistant at ambient — protect stored tube with oil or coating and use aluminising/coatings for fireside protection.
Can 7CrMoVTiB10-10 N+T be formed, bent or molded?
Hot form 900–1050 °C followed by re-normalizing and tempering; cold bending of tube is possible at generous radii but demands a restoration heat treatment for code service.
What is the maximum service temperature of 7CrMoVTiB10-10 N+T?
7CrMoVTiB10-10 N+T is rated for continuous use to about 560°C (1,040 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 7CrMoVTiB10-10 N+T and 7CrMoVTiB10-10-A?
N+T is the default condition — standard delivery condition for T24 / 7CrMoVTiB10-10 seamless boiler tubes and headers. A: softened condition for heavy machining, cold bending or intermediate processing; must be re-normalized/tempered before service. Yield strength is 520 MPa in N+T versus 340 MPa in A.
Sources
- EN 10216-2 Seamless steel tubes for pressure purposes — alloy steel tubes with specified elevated temperature properties — CEN (2020)
- ASTM A213/A213M Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes (Grade T24) — ASTM International (2022)
- VdTÜV-Werkstoffblatt 533 — 7CrMoVTiB10-10 (1.7378) — VdTÜV (2015)
- Seamless boiler tube grade T24 / 7CrMoVTiB10-10 data sheet — Vallourec / Mannesmann (2018)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (Cr-Mo steels) — ASM International (1990)
- ASME BPVC Section II Part D — physical property tables, 2.25Cr-1Mo group — ASME (2021)
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.