1.4903 is a high-temperature resistant, martensitic (structure of heat-treatable material used) high-alloyed chromium-molybdenum-steel, which is used for mixed-pressure turbine elements by improved properties compared with common steel (10CrMo9-10). With its higher amount of chrome and molybdenum together with nitrogen (0,03-0,07%) and vanadium (> 0,18 %) it is possible to substitute nickel it still work at more than 500°C in permanent load.
EN 1.4903 stainless steel is a martensitic stainless steel formulated for primary forming into wrought products. 1.4903 is the EN numeric designation for this material. X10CrMoVNb9-1 is the EN chemical designation.
Among wrought stainless steels, the composition of EN 1.4903 stainless steel is notable for including vanadium (V) and aluminum (Al). Vanadium has a strong hardening effect, but this effect is particularly sensitive to the type of tempering. Aluminum is used to improve oxidation resistance. It can also enhance the effects of heat treatment.
1.4903 is defined with the material designation type F91 according to ASTM Standard.
A387 Gr91, T91, 1.4903, 1.4901, P91, P92, F91, F92, X10CrMoVNb9-1 and equivalent P91 / T91, F91 are high alloy types, designed to use martensite structure at high temperature. The most common forms of seamless tubes, bars, sheets or forgings are used to produce devices, pipes, boilers and other parts of power equipment operating at temperatures of 540-580C. X10CrMoVNb9-1 steel is becoming more and more popular due to better mechanical properties, creep resistance, corrosion resistance, impact resistance and thermal fatigue. Compared with the well-known and proven boiler varieties, 1.4903 should be classified as a high-alloy heat-resistant boiler steel because of the increased content of chromium, molybdenum and a small amount of vanadium and niobium. Compared with the standard grade, the price such as 14MoV6-3 is of course higher, but as the price increases, the service life and higher material durability also increase. 1.4901/X10CrWMoVNb9-2/92 is an improved version of P91/T91/F91 material, with an added percentage of 2 tungsten, the content of chromium is slightly increased, and the content of molybdenum is reduced. It is characterized by high creep resistance at temperatures up to 600C About 1/3. The material has higher corrosion resistance and weldability. It is used for the maximum operating temperature of 650C. Class 91/92-Steel used for the production of boiler components with supercritical and supercritical parameters-jackets, connectors for steam superheater outlet chambers, superheated steam superheaters, turboshaft components, and piping for fresh and superheated steam in the chamber , Superheater coils, steam collectors, outlet collectors, fittings and sleeves for installing boilers, connectors, operating at a temperature of about 550-640C and steam pressure of about 18-30 MPa.
EN 10302: 2008 Creep resisting steels, nickel and cobalt alloys
EN 10028-2: 2009 Flat products made of steels for pressure purposes. Non-alloy and alloy steels with specified elevated temperature properties
EN 10222-2: 2000 Steel forgings for pressure purposes. Ferritic and martensitic steels with specified elevated temperature properties
EN 10216-2: 2014 Seamless steel tubes for pressure purposes. Technical delivery conditions. Non-alloy and alloy steel tubes with specified elevated temperature properties
EN 10253-2: 2007 Butt-welding pipe fittings. Non alloy and ferritic alloy steels with specific inspection requirements
EN 10088-1: 2005 Stainless steels. List of stainless steels
| Grade | Chemical Composition WT % | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| C | Mn | Si | P | S | Cr | Ni | Mo | V | Nb | Ti | Al | N | W | W | B | Cu | |
| X10CrMoVNb9-1, 1.4903 | 0.08 - 0.12 | 0.3 - 0.6 | 0.2 - 0.5 | Max 0.02 | Max 0.005 | 8:0 - 9.5 | Max 0.4 | 0.85 - 1.05 | 0.18 - 0.25 | 0.06 - 0.10 | Max 0.01 | Max 0.02 | 0.03 - 0.07 | - | Max 0.01 | - | Max 0.3 |
| X10CrWMoVNb9-2, 1.4901 | 0.07 - 0.13 | 0.3 - 0.6 | Max 0.5 | Max 0.02 | Max 0.001 | 8.5 - 9.5 | Max 0.4 | 0.3 - 0.6 | 0.15 - 0.25 | 0.04 - 0.09 | Max 0.01 | Max 0.02 | 0.03 - 0.07 | 1.5 - 2.0 | Max 0.01 | 0.001 - 0.006 | - |
| 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 | Max 0.02 | Max 0.01 | 8.5 - 9.5 | Max 0.4 | 0.9 - 1.1 | 0.18 - 0.25 | 0.06 - 0.10 | Max 0.01 | Max 0.02 | 0.04 - 0.09 | 0.9 - 1.1 | Max 0.01 | 0.0003 - 0.0060 | - |
| A 335 Grade P91, SA 355 Grade P91, K91560 | 0.08 - 0.12 | 0.3 - 0.6 | 0.2 - 0.5 | Max 0.02 | Max 0.001 | 8:0 - 9.5 | Max 0.4 | 0.85 - 1.05 | 0.18 - 0.25 | 0.06 - 0.10 | Max 0.01 | Max 0.02 | 0.03 - 0.07 | - | Max 0.01 | - | - |
| A 387 Grade 91, SA 387 Grade 91 | 0.06 - 0.15 | 0.25 - 0.66 | 0.18 - 0.56 | Max 0.025 | Max 0.012 | 7.9 - 9.6 | Max 0.43 | 0.8 - 1.1 | 0.16 - 0.27 | 0.05 - 0.11 | Max 0.01 | Max 0.02 | 0.025 - 0.080 | - | Max 0.01 | - | - |
| A 335 Grade P92, SA 182 F92, A 182 Grade F92, K92460, A213 T92 | 0.07 - 0.13 | 0.3 - 0.6 | Max 0.5 | Max 0.020 | Max 0.010 | 8.5 - 9.5 | Max 0.4 | 0.3 - 0.6 | 0.15 - 0.25 | 0.04 - 0.09 | Max 0.01 | Max 0.02 | 0.03 - 0.07 | 1.5 - 2.0 | Max 0.01 | 0.001 - 0.006 | - |
| 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 | Max 0.020 | Max 0.010 | 8.0 - 9.5 | Max 0.4 | 0.85 - 1.05 | 0.18 - 0.25 | 0.06 - 0.10 | Max 0.01 | Max 0.02 | 0.03 - 0.07 | - | Max 0.01 | - | - |
Tensile strength, Rm: 630 - 830 MPa
Yield point, Re: > 450 MPa
Elongation, A: >19%
Impact, KV20℃: > 40J
Delivery condition: +NT
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
Delivery condition: +QT
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
| Density (kg/dm3) | 7,75 |
| Electrical resistivity at 20°C (Ω mm2 /m) | 0,50 |
| Thermal conductivity at 20°C (W/m K) | 26 |
| Thermal conductivity at 500°C (W/m K) | 30 |
| Specific heat capacity at 20°C (J/kg K) | 430 |
| Specific heat capacity at 500°C (J/kg K) | 680 |
| Modulus of Elasticity at 20°C (GPa) | 218 |
| Modulus of Elasticity at 500°C (GPa) | 180 |
The heat treatment that apply to 1.4903 steel is solution annealing: Heat to 1040 to 1100°C and subsequent cooling by oil quenching. Tempering temperature and time at temperature primarily depend on desired final hardness (730-780°C mostly). Before welding on bigger section thickness it is recommend, too.
| Temperature | Cooling | |
| Hot forming | 1200°C - 1100°C | Air |
| Heat treatment | ||
| Quenched and Tempered (+QT) | 1040°C - 1100°C | Oil |
| 730°C - 780°C (>1h dwell time) |
good
Cold formingnot common
Cold upsettingnot common
Free-form and drop forgingis possible
Machiningpossible
| Grade | Shape | Dimensionmm | Qty.kg |
|---|---|---|---|
| Gr.91, P91, T91, F91 | Plate | T.8mm - 50mm | 68235 |
Steel grade
Special steel