Steel 18KH11MNFB (ЭП291)
Designation
| Name |
The value |
| Designation GOST Cyrillic |
18Х11МНФБ |
| Designation GOST Latin |
18X11MHFB |
| Transliteration |
18H11MNFB |
| The chemical elements |
18Cr11MoНVNb |
| Name |
The value |
| Designation GOST Cyrillic |
ЭП291 |
| Designation GOST Latin |
EP291 |
| Transliteration |
EhP291 |
| The chemical elements |
- |
Description
Steel 18KH11MNFB used: for the production of highly loaded parts; steam turbine blades operating at temperatures up to +580 °C and gas turbines; parts of valves, forgings, discs, rotors for steam and gas turbines, continuously operating at temperatures up to +600 °C.
Note
Steel heat-resistant martensitic class.
The recommended maximum operating temperature for a very long time — up to +600 °C.
The temperature of beginning of intensive scaling in air +750 °C.
Standards
| Name |
Code |
Standards |
| Classification, nomenclature and general norms |
В30 |
GOST 5632-72 |
| Sectional and shaped rolling |
В32 |
GOST 5949-75, GOST 18968-73, GOST 19442-74, TU 14-1-792-73, TU 14-11-245-88 |
| Bulls. Blanks. Slabs |
В31 |
OST 108.020.03-82, OST 3-1686-90 |
| Metal forming. Forgings |
В03 |
TU 0306.018-80 |
Chemical composition
| Standard |
C |
S |
P |
Mn |
Cr |
Si |
Ni |
Fe |
Cu |
V |
Ti |
Mo |
Nb |
W |
| GOST 5632-72 |
0.15-0.21 |
≤0.025 |
≤0.03 |
0.6-1 |
10-11.5 |
≤0.6 |
0.5-1 |
The rest |
≤0.3 |
0.2-0.4 |
≤0.2 |
0.8-1.1 |
0.2-0.45 |
≤0.2 |
Fe is the basis.
Mechanical characteristics
| Section, mm |
sT|s0,2, MPa |
σB, MPa |
d5, % |
y, % |
kJ/m2, кДж/м2 |
Brinell hardness number, MPa |
| Bars and strip hot rolled and forged GOST 18968-73. Normalization or annealing at 1000-1050 °C, cooling in air or in oil + Leave in 660-770 °C, air cooling |
|
590-735 |
≥740 |
≥15 |
≥50 |
≥588 |
229-269 |
| Bars hot rolled and forged according to GOST 5949-75. Annealing in air or in oil with 1080-1130 °C to + Leave in 660-770 °C, air cooling |
|
590-735 |
≥740 |
≥15 |
≥50 |
≥588 |
- |
| Contoured rods (g/K, x/K and x/t for steam turbine blades; x/a and x/t for coupling blades of steam turbines) according to GOST 19442-74. Annealing in air or in oil with 1080-1130 °C to + Leave in 660-770 °C, air cooling (specified strength) |
|
588-735 |
735-931 |
≥15 |
≥50 |
≥588 |
229-255 |
Description mechanical marks
| Name |
Description |
| Section |
Section |
| sT|s0,2 |
Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2% |
| σB |
Limit short-term strength |
| d5 |
Elongation after rupture |
| y |
The relative narrowing |
| kJ/m2 |
Toughness |
Physical characteristics
| Temperature |
Е, ГПа |
r, кг/м3 |
l, Вт/(м · °С) |
a, 10-6 1/°С |
С, Дж/(кг · °С) |
| 20 |
228 |
7850 |
- |
- |
- |
| 100 |
222 |
- |
214 |
103 |
485 |
| 200 |
213 |
- |
251 |
106 |
530 |
| 300 |
205 |
- |
259 |
108 |
590 |
| 400 |
193 |
- |
263 |
113 |
667 |
| 500 |
180 |
- |
272 |
117 |
770 |
| 600 |
- |
- |
280 |
118 |
900 |
| 700 |
- |
- |
- |
120 |
- |
| 800 |
- |
- |
- |
124 |
- |
A description of the physical symbols
| Name |
Description |
| Е |
The normal elasticity modulus |
| r |
Density |
| l |
Coefficient of thermal conductivity |
| R |
UD. the resistivity |
Technological properties
| Name |
The value |
| Weldability |
difficult weldability |
