A387 Gr91, T91, 1.4903, 1.4901, P91, P92, F91, F92


high-temperature resistant for pressure vessels and boiler steel A387 Gr91, T91, X10CrMoVNb9-1, 1.4903, X10CrWMoVNb9-2, 1.4901, P91, P92 used in the power industry in the form of Plate, Sheet, pipe, forgings and bars according to ASTM A387, A335, EN 10216-2, EN 10088-1, EN 10302.ASTM A182 (F91) | ASTM A336 | UNS K90901

A387 Gr91, T91, 1.4903, 1.4901, P91, P92, F91, F92 - Introduction and Application

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



A387 Gr91, T91, 1.4903, 1.4901, P91, P92, F91, F92 - Chemical composition WT %

GradeChemical Composition WT %
CMnSiPSCrNiMoVNbTiAlNWWBCu
X10CrMoVNb9-1, 1.49030.08 - 0.120.3 - 0.60.2 - 0.5Max 0.02Max 0.0058:0 - 9.5Max 0.40.85 - 1.050.18 - 0.250.06 - 0.10Max 0.01Max 0.020.03 - 0.07-Max 0.01-Max 0.3
X10CrWMoVNb9-2, 1.49010.07 - 0.130.3 - 0.6Max 0.5Max 0.02Max 0.0018.5 - 9.5Max 0.40.3 - 0.60.15 - 0.250.04 - 0.09Max 0.01Max 0.020.03 - 0.071.5 - 2.0Max 0.010.001 - 0.006-
A 182 Grade F911, A 213 Grade T911, SA 335 Grade P911, K910610.09 - 0.130.3 - 0.60.1 - 0.5Max 0.02Max 0.018.5 - 9.5Max 0.40.9 - 1.10.18 - 0.250.06 - 0.10Max 0.01Max 0.020.04 - 0.090.9 - 1.1Max 0.010.0003 - 0.0060-
A 335 Grade P91, SA 355 Grade P91, K915600.08 - 0.120.3 - 0.60.2 - 0.5Max 0.02Max 0.0018:0 - 9.5Max 0.40.85 - 1.050.18 - 0.250.06 - 0.10Max 0.01Max 0.020.03 - 0.07-Max 0.01--
A 387 Grade 91, SA 387 Grade 910.06 - 0.150.25 - 0.660.18 - 0.56Max 0.025Max 0.0127.9 - 9.6Max 0.430.8 - 1.10.16 - 0.270.05 - 0.11Max 0.01Max 0.020.025 - 0.080-Max 0.01--
A 335 Grade P92, SA 182 F92, A 182 Grade F92, K92460, A213 T920.07 - 0.130.3 - 0.6Max 0.5Max 0.020Max 0.0108.5 - 9.5Max 0.40.3 - 0.60.15 - 0.250.04 - 0.09Max 0.01Max 0.020.03 - 0.071.5 - 2.0Max 0.010.001 - 0.006-
K90901, 9Cr1Mo, A 182 F91, SA 182 Grade F91, A 213 T91, SA 213 grade T910.07 - 0.140.3 - 0.60.2 - 0.5Max 0.020Max 0.0108.0 - 9.5Max 0.40.85 - 1.050.18 - 0.250.06 - 0.10Max 0.01Max 0.020.03 - 0.07-Max 0.01--

Mechanical Property of A387 Gr91, T91, 1.4903, 1.4901, P91, P92, F91, F92

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



Physical Property of A387 Gr91, T91, 1.4903, 1.4901, P91, P92, F91, F92

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

Heat Treatment of A387 Gr91, T91, 1.4903, 1.4901, P91, P92, F91, F92

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.

TemperatureCooling
Hot forming1200°C - 1100°CAir
Heat treatment

Quenched and Tempered (+QT)1040°C - 1100°COil

730°C - 780°C (>1h dwell time)

Welding of A387 Gr91, T91, 1.4903, 1.4901, P91, P92, F91, F92

good


Machining of A387 Gr91, T91, 1.4903, 1.4901, P91, P92, F91, F92

Cold formingnot common

Cold upsettingnot common

Free-form and drop forgingis possible

Machiningpossible



Equivalent grades of A387 Gr91, T91, 1.4903, 1.4901, P91, P92, F91, F92

A387 Gr91, Grade 91, P91, T91, 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.

A387 Gr91, T91, 1.4903, 1.4901, P91, P92, F91, F92 Boiler steel stock list

Grade Shape Dimensionmm Qty.kg
Gr.91, P91, T91, F91 Plate T.8mm - 50mm 68235