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 rules	В30	GOST 5632-72
Bars and shapes	В32	GOST 5949-75, GOST 18968-73, GOST 19442-74, TU 14-1-792-73, TU 14-11-245-88
Blanks. Of the workpiece. Slabs	В31	OST 108.020.03-82, OST 3-1686-90
Processing of metals by pressure. 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	Rest	≤0.3	0.2-0.4	≤0.2	0.8-1.1	0.2-0.45	≤0.2

Fe is the basis.

Mechanical properties

Section, mm	s_T\|s_0,2, MPa	σ_U, MPa	d₅, %	y, %	KCU, kJ/m²	HB, 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
s_T\|s_0,2	Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2%
σ_U	Limit short-term strength
d₅	Elongation after rupture
y	The relative narrowing
KCU	Toughness
HB	Brinell hardness number

Physical characteristics

Temperature	Е, HPa	r, kg/m³	l, W/(m · °C)	a, 10^-6 1/°C	С, J/(kg · °C)
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

Steel 18KH11MNFB (ЭП291)

Designation

Description