1.4903, 1.4901, P91, P92, F91, F92 - boiler steel

High-alloy boiler steel X10CrMoVNb9-1, 1.4903, X10CrWMoVNb9-2, 1.4901, P91, P92 used in the power industry in the form of pipes, sheets, forgings and bars according to EN 10216-2, EN 10088-1, EN 10302.

Standard Steel Grade
Chemical Composition %
C: Mn: Si: P: S: Cr: Ni: Mo: V: Nb: Ti: Al: N: W: W: B: Cu:
EN X10CrMoVNb9-1 - 1.4903 - LW 1.4904 - 10CrMoVNb
0.08 - 0.12 0.3 - 0.6 0.2 - 0.5 <0.02 <0.005 8:0 - 9.5 <0.4 0.85 - 1.05 0.18 - 0.25 0.06 - 0.10 <0.01 <0.02 0.03 - 0.07 - <0.01 - <0.3
EN X10CrWMoVNb9-2 - 1.4901
0.07 - 0.13 0.3 - 0.6 <0.5 <0.02 <0.001 8.5 - 9.5 <0.4 0.3 - 0.6 0.15 - 0.25 0.04 - 0.09 <0.01 <0.02 0.03 - 0.07 1.5 - 2.0 <0.01 0.001 - 0.006 -
ASTM
ASME
UNS
A 182 Grade F911 - A 213 Grade T911 - SA 335 Grade P911 - K91061
0.09 - 0.13 0.3 - 0.6 0.1 - 0.5 <0.02 <0.01 8.5 - 9.5 <0.4 0.9 - 1.1 0.18 - 0.25 0.06 - 0.10 <0.01 <0.02 0.04 - 0.09 0.9 - 1.1 <0.01 0.0003 - 0.0060 -
ASTM
ASME
UNS
A 335 Grade P91 - SA 355 Grade P91 - K91560
0.08 - 0.12 0.3 - 0.6 0.2 - 0.5 <0.02 <0.001 8:0 - 9.5 <0.4 0.85 - 1.05 0.18 - 0.25 0.06 - 0.10 <0.01 <0.02 0.03 - 0.07 - <0.01 - -
ASTM
ASME
A 387 Grade 91 - SA 387 Grade 91
0.06 - 0.15 0.25 - 0.66 0.18 - 0.56 <0.025 <0.012 7.9 - 9.6 <0.43 0.8 - 1.1 0.16 - 0.27 0.05 - 0.11 <0.01 <0.02 0.025 - 0.080 - <0.01 - -
ASTM
ASME
UNS
A 335 Grade P92 - SA 182 F92 - A 182 Grade F92 - K92460 - A213 T92
0.07 - 0.13 0.3 - 0.6 <0.5 <0.020 <0.010 8.5 - 9.5 <0.4 0.3 - 0.6 0.15 - 0.25 0.04 - 0.09 <0.01 <0.02 0.03 - 0.07 1.5 - 2.0 <0.01 0.001 - 0.006 -
ASTM
ASME
UNS
K90901 - 9Cr1Mo - A 182 F91 - SA 182 Grade F91 - A 213 T91 - SA 213 grade T91
0.07 - 0.14 0.3 - 0.6 0.2 - 0.5 <0.020 <0.010 8.0 - 9.5 <0.4 0.85 - 1.05 0.18 - 0.25 0.06 - 0.10 <0.01 <0.02 0.03 - 0.07 - <0.01 - -

X10CrMoVNb9-1, 1.4903 - Boiler steel

X10CrMoVNb9-1 and equivalent P91 / T91, F91 are high-alloy species designed to work at elevated temperatures with a martensitic structure. The most common ones in the form of seamless pipes, bars, sheets or forged elements are used in the production of installations, pipelines, boilers and other components of power equipment operating at temperatures of 540-580C.

X10CrMoVNb9-1 steel is becoming more and more popular due to much better mechanical properties, resistance to creep, corrosion, impact resistance and thermal fatigue. In contrast to the well-known, proven boiler species, 1.4903 should be classified as high-alloyed heat-resistant boiler steel due to the increased content of Chromium, Molybdenum, and small amounts of Vanadium and Niobium.

It's price in relation to standard grades such as 14MoV6-3 is certainly higher, however, along with the price, the length of service life and higher material durability also increases.

1.4901 / X10CrWMoVNb9-2 / 92 is an improved version of the P91 / T91 / F91 material with a 2% addition of Tungsten, a slightly increased amount of Chromium, and a reduced content of Molybdenum, characterized by a creep resistance at temperatures of up to 600C higher by about 1/3. The material has even higher corrosion resistance and weldability. It is used at the highest operating temperatures up to 650C.

Grade 91/92 - Steel used for production of boiler components with supercritical and ultra-critical parameters - jackets, connectors for steam superheater outlet chambers, superheated steam superheaters, turbine shaft parts, chambers and pipelines for fresh and superheated steam, superheater coils, steam collectors, outlet collectors, fittings and sleeves for the installation of boilers, connectors, pipelines of modern power units operating at temperatures of approximately 550-640C and steam pressures of approx. 18-30 MPa.

General properties of X10CrMoVNb9-1, 1.4903:

  • Tensile strength, Rm: 620 - 850 MPa
  • The yield point, Re: > 450 MPa
  • Elongation, A: >20%
  • Modulus of elasticity E = 218 GPa
  • Thermal conductivity, λ: 14 W * m-1 * K-1
  • Linear expansion coefficient, α: 10,9 * 10-6 K-1

X10CrMoVNb9-1, 1.4903 - mechanical properties for pipes in the +NT condition

  • Tensile strength, Rm: 630 - 830 MPa
  • The yield point, Re: > 450 MPa
  • Longitudinal samples
    • Elongation, A: >19%
    • Impact resistance, KV20℃: > 40J
  • Transverse samples
    • Elongation, A: >17%
    • Impact resistance, KV20℃: > 27J
Mechanical properties Operating temperatures
100℃ 150℃ 200℃ 250 - 205℃ 300℃ 350℃ 400℃ 450℃ 500℃ 550℃ 600℃
The yield point, Rp0,2 (MPa) >410 >395 >380 >370 >360 >350 >340 >320 >300 >270 >215

Mechanical properties for flat products X10CrMoVNb9-1, 1.4903

  • In the +NT delivery condition
    • Tensile strength, Rm: 550 - 760 MPa
    • The yield point, Re: > 435 MPa
    • Elongation, A: >18%
    • Impact resistance, KV20℃: > 40J
    • Impact resistance, KV0℃: > 34J
    • Impact resistance, KV-20℃: > 27J
  • In the +QT delivery condition
    • Tensile strength, Rm: 520 - 700 MPa
    • The yield point, Re: > 435 MPa
    • Elongation, A: >18%
    • Impact resistance, KV20℃: > 40J
    • Impact resistance, KV0℃: > 34J
    • Impact resistance, KV-20℃: > 27J

Mechanical properties for forgings X10CrMoVNb9-1, 1.4903

  • Tensile strength, Rm: 630 - 730 MPa
  • The yield point, Rp0,2: > 450 MPa
  • Impact resistance and elongation - longitudinal samples
    • KV0℃: > 40J
    • A: > 19%
  • Impact resistance and elongation - transverse samples
    • KV0℃: > 27J
    • A: > 17%

Heat treatment - process and temperature

  • Normalizing at 1040 - 1100 ℃ with cooling in air or oil
  • Tempering at a temperature of 730 - 780 ℃ with cooling in the air

Substitutes, equivalents and other species designations

1.4903
A 1017 Grade 911
SA 1017 Grade 911
A 234 Grade WP91
SA 234 Grade WP91
A 336 Grade F91
SA 336 Grade F91
A 336 Grade F911
SA 336 Grade F911
A 336 Grade FP91
SA 369 Grade FP91
A 387 Grade 91
SA 387 Grade 91
UNS K91560
9Cr1Mo
UNS K90901
A1012 T91
A182 F91
A200 T91
A213 T91
A831 T91
SA199 T91
SA213 T91
A1012 T911
A182 F911
A213 T911
A335 Grade P911
SA182 F911
SA213 T911
SA335 Grade P911
UNS K91560
9Cr-1Mo-V-Cb-N
A335 Grade P91
A691 Grade 91
SA335 Grade P91
SA691 Grade 91
10CrMoVNb
10Cr9Mo1VNbN
S31108
10Ch9MFB
10Kh9MFB
10Х9МФБ
1.4901
X10CrWMoVNb9-2
A1012 T92
A182 F92
K92460
SA182 F92
SA213 T92
SA335 Grade P92
Stal P91
Stal P92
Grade P91
Grade P92

Need help? Contact us!

Call or send a message, and our representative
will contact you within 24 hours!

We use cookies
In order to properly operate the Website and for statistical purposes, and if you consent, also to personalize advertising, remarketing and retargeting. If you want to learn more, read on privacy and cookies policy. You can specify the detailed configuration by clicking the button below "Settings".
Cookie preferences
We use cookies

In order to properly operate the Website and for statistical purposes, and if you consent, also to personalize advertising, remarketing and retargeting. If you want to learn more, read on privacy and cookies policy.

More information

If you have any questions about our cookie policy, please ask contact.