X10CrMoVNb9-1 (P91)
X10CrMoVNb9-1 – short P91 – is a high-temperature 9 % chromium steel for modern power plants with the highest steam parameters (up to ~620 °C).
Application & properties
X10CrMoVNb9-1 – short P91 – is a high-temperature 9 % chromium steel for modern power plants with the highest steam parameters (up to ~620 °C).
- Main-steam and live-steam lines
- Superheaters and headers in high-performance boilers
- Power plant new-build and retrofit
Chemical composition
Typical values in wt.-% per EN standard (heat analysis).
| Element | Content (%) |
|---|---|
| C | 0.08–0.12 |
| Si | 0.20–0.50 |
| Mn | 0.30–0.60 |
| Cr | 8.00–9.50 |
| Mo | 0.85–1.05 |
| V | 0.18–0.25 |
| Nb | 0.06–0.10 |
| N | 0.03–0.07 |
Mechanical properties
Typical values at room temperature per EN standard.
| Property | Value |
|---|---|
| Yield strength Rp0.2 | ≥ 450 MPa |
| Tensile strength Rm | 630–830 MPa |
| Elongation A | ≥ 19 % |
| Impact energy KV | ≥ 40 J |
Standards, equivalents & product forms
| Topic | Detail |
|---|---|
| Standards | EN 10216-2 |
| ASME/ASTM equivalent | = ASTM A335 P91 · A182 F91 |
| Material no. | 1.4903 |
| Short name / aka | P91 · A335 P91 |
We supply X10CrMoVNb9-1 (P91) as pipes, flanges and fittings – seamless or welded, on request with an EN 10204 3.1 / 3.2 mill certificate.
Frequently asked questions about X10CrMoVNb9-1 (P91)
What does P91 stand for?
P91 is the common ASTM short designation for the high-temperature steel X10CrMoVNb9-1 (1.4903).
Why P91 instead of 10CrMo9-10?
P91 withstands higher temperatures and pressures (up to ~620 °C) and allows thinner walls – ideal for modern high-performance boilers.
Is P91 demanding to process?
Yes – precisely controlled preheating and post-weld heat treatment are mandatory.
Request X10CrMoVNb9-1 (P91)?
Grade, standard, size, pressure rating and quantity are enough – on request with an EN 10204 3.1 / 3.2 mill certificate. Your quote usually the same day.
All data are typical values per the relevant EN standards for first orientation – without warranty. The applicable standard and the mill certificate of the delivery are decisive.