18H11MNFB (EP291, 2H11MFBN)

High-loaded parts, turbine blades.

highly loaded parts for steam and gas turbines, long operating at temperatures up to 600 ° C.; martensitic steel grade

Classification

Country Section Category
CIS, Russia, Ukraine Heat resistant steels and alloys Heat resistant high alloy steel

Chemical composition

Standard Fe, % Si, % Mn, % Cr, % Ni, % V, % P, % C, % S, % Nb, % Mo, %
GOST 5632-72 83.685–87.55 < 0.6 0.6–1 10–11.5 0.5–1 0.2–0.4 < 0.03 0.15–0.21 < 0.025 0.2–0.45 0.8–1.1

Information on suppliers

Physical characteristics

Temperature, °C $$E\cdot 10^{9}$$, $$MPa$$ $$\alpha\cdot 10^{6}$$, $$K^{-1}$$ $$\varkappa$$, $$\frac{W}{m\cdot K}$$ $$\rho$$, $$\frac{kg}{m^3}$$ $$c\cdot 10^{-3}$$, $$\frac{J}{kg\cdot K}$$
20 228 7850
100 222 10.3 21.4 0.485
200 213 10.6 25.1 0.53
300 205 10.8 25.9 0.59
400 193 11.3 26.3 0.667
500 180 11.7 27.2 0.77
600 11.8 28 0.9
700 12
800 12.4

Mechanical properties at 20 °C

Rolling Standard Size, mm Tension Classifiers $$\sigma _{U}$$, $$MPa$$ $$\sigma_{P}$$, $$MPa$$ $$\epsilon_L$$, % $$\psi$$, % $$KCU\cdot 10^{3}$$, $$\frac{J}{m^2}$$ Treatment
Rod GOST 5949-75 740 590–735 15 50 590 Hardening of 1080-1130 ° C, air Accommodation 660-770 ° C, air
Rod GOST 18968-73 740 590–735 15 50 590 Normalized and tempered

Brinell hardness number

Rolling Standard Classifiers Value, HBW
Rod GOST 5949-75 annealing 225
Rod GOST 18968-73 normalization, average vacation 229–269

Technological Properties

Weldability
Difficult to weld

Analogues

Standards

Standard Description
GOST 5632-72

Description of chemical elements

Element Units of measurement Description
Fe % Iron
Si % Silicon
Mn % Manganese
Cr % Chrome
Ni % Nickel
V % Vanadium
P % Phosphorus
C % Carbon
S % Sulfur
Nb % Niobium
Mo % Molybdenum

Description of physical characteristics

Parameter Units of measurement Description
$$E\cdot 10^{9}$$ $$MPa$$ Elastic modulus
$$\alpha\cdot 10^{6}$$ $$K^{-1}$$ Coefficient of thermal (linear) expansion (range 20°C–T)
$$\varkappa$$ $$\frac{W}{m\cdot K}$$ Coefficient of thermal conductivity (the heat capacity of the material)
$$\rho$$ $$\frac{kg}{m^3}$$ The density of the material
$$c\cdot 10^{-3}$$ $$\frac{J}{kg\cdot K}$$ The specific heat of the material (range 20°C–T)

Description of mechanical properties

Parameter Units of measurement Description
$$\sigma _{U}$$ $$MPa$$ Ultimate tensile strength
$$\sigma_{P}$$ $$MPa$$ Proportionality limit
$$\epsilon_L$$ % Elongation at break (longitudinal)
$$\psi$$ % Reduction in cross section on fracture
$$KCU\cdot 10^{3}$$ $$\frac{J}{m^2}$$ Impact toughness

Designation of types of weldability

Parameter Units of measurement Description
no limits Welding is performed without heating and without subsequent heat treatment
Boundedly welded Welding is possible with heating up to 100–120 °C and subsequent heat treatment
Difficult to weld For obtaining quality welded joints, additional operations are required: heating up to 200–300 °C for welding, heat treatment after welding — annealing
Not applicable for welded structures