18KH12VMBFR steel is used: for the production of forgings, steam turbine blades, pipes and fasteners for long service life at temperatures up to +620 °C; for the manufacture by cold machining and hot forming fasteners turbines and flange connections, steam pipes and fittings, operating at a steam temperature 500−580 °C.

Note

Martensite steel-ferritic class.
The recommended maximum operating temperature for a very long time +500 °C. the Temperature of beginning of intensive scaling in air +750 °C.

Standards

Name	Code	Standards
Bars and shapes	В22	GOST 1133-71, GOST 2590-2006, GOST 2591-2006
Classification, nomenclature and General rules	В30	GOST 5632-72
Bars and shapes	В32	GOST 5949-75, TU 14-1-552-72, TU 14-11-245-88
Blanks. Of the workpiece. Slabs	В31	OST 3-1686-90

Chemical composition

Standard	C	S	P	Mn	Cr	Si	Ni	Fe	Cu	V	B	Ti	Mo	Nb	W
GOST 5632-72	0.15-0.22	≤0.025	≤0.03	≤0.5	11-13	≤0.5	≤0.6	Rest	≤0.3	0.15-0.18	≤0.003	≤0.2	0.4-0.6	0.2-0.4	0.4-0.7
TU 14-1-552-72	0.15-0.22	≤0.025	≤0.03	≤0.5	11-13	≤0.5	≤0.6	Rest	≤0.3	0.15-0.18	≤0.003	≤0.2	0.4-0.6	0.2-0.4	0.4-0.7

Fe is the basis.
According to TU 14-1-552-72, the chemical composition is given for steel grade 18Х12ВМБФР-Ш (ЭИ993-Ш).

Mechanical properties

Section, mm	s_T\|s_0,2, MPa	σ_U, MPa	d₅, %	y, %	KCU, kJ/m²
Bars hot rolled and forged (12-180 mm) square and round. Quenching in oil with 1030-1050 °C to + Leave at 680-720 °C, air cooling
	≥670	≥780	≥12	≥45	≥590
Bars hot rolled and forged according to GOST 5949-75. Quenching in oil from 1050-1150 °C + Vacation at 650-700 °C , cooling in air or in oil
	≥490	≥740	≥12	≥45	≥392
Pipe. Normalization at 1050 °C, air cooling + Vacation at 750 °C (extract 3 hours), air cooling
21927	≥590	≥750	≥15	≥43	≥400
306	≥640	≥820	≥17	≥56	≥900

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

Physical characteristics

Temperature	Е, HPa	r, kg/m³	l, W/(m · °C)	a, 10^-6 1/°C
20	228	7850	276	-
200	215	-	24	1113
300	209	-	251	1142
400	195	-	263	118
500	188	-	272	12
600	173	-	28	125
700	155	-	289	1265
100	-	-	218	1115
800	-	-	-	116

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	does not apply to welded structures

Steel 18KH12VMBFR (ЭИ993)

Designation

Description