Steel 40KH15N7G7F2MS (ЭИ388)

Designation

Name	The value
Designation GOST Cyrillic	40Х15Н7Г7Ф2МС
Designation GOST Latin	40X15H7G7F2MC
Transliteration	40H15N7G7F2MS
By chemical elements	40Cr15Н7Mn7V2MoС

Name	The value
Designation GOST Cyrillic	ЭИ388
Designation GOST Latin	EI388
Transliteration	EhI388
By chemical elements	-

Description

40KH15N7G7F2MS steel is used: for the manufacture of gas turbine blades and fasteners that have an expiration date at a temperature of 650 °C.

Note

Steel alloy heat-resistant, precipitation hardening, austenitic.
The recommended maximum operating temperature for a limited period of work +650 °C.
The temperature of beginning of intensive scaling in air +800 °C.

Standards

Name	Code	Standards
Sheets and strips	В23	GOST 103-2006
Bars and shapes	В22	GOST 1133-71, GOST 2590-2006, GOST 2591-2006, GOST 2879-2006
Sheets and strips	В33	GOST 4405-75
Classification, nomenclature and General rules	В30	GOST 5632-72
Bars and shapes	В32	GOST 5949-75, GOST 7417-75, GOST 8559-75, GOST 8560-78, GOST 14955-77, TU 14-1-1763-76, TU 14-1-714-73, TU 14-11-245-88
Blanks. Of the workpiece. Slabs	В21	OST 1 90176-75
Blanks. Of the workpiece. Slabs	В31	OST 3-1686-90

Chemical composition

Standard	C	S	P	Mn	Cr	Si	Ni	Fe	Cu	V	Ti	Mo	W
GOST 5632-72	0.38-0.47	≤0.02	≤0.035	6-8	14-16	0.9-1.4	6-8	Rest	≤0.3	1.5-1.9	≤0.2	0.65-0.95	≤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 hot rolled and forged according to GOST 5949-75. Quenching in water or air with 1170-1190 °C + Aging at 780-820 °C (8-10 h exposure), air cooling
	≥590	≥880	≥15	≥15	≥294	-
Rolled steel. Quenching in water from 1180 °C (aging for 1 h) + Quenching in air from 1,000 °C (aging for 1 h), air cooling
-	≥480	≥940	≥30	≥28	-	-
Rolled steel. Quenching in water from 1180 °C (aging for 1 h) + Quenching in air from 1,000 °C (aging for 1 h), cooling air (indicated temperature and time of heat exposure)
-	≥510	≥930	≥22	≥18	≥24	-
Forming at OST 1 90176-75. Quenching in water or air with 1170-1190 °C (exposure 30-45 min) + Aging at 780-820 °C (8-10 h exposure), air cooling
	-	≥883	≥15	≥15	-	255-341
Rolled steel. Quenching in water from 1180 °C (aging for 1 h) + Quenching in air from 1,000 °C (aging for 1 h), air cooling
-	≥360	≥640	≥16	≥24	-	-
Rolled steel. Quenching in water from 1180 °C (aging for 1 h) + Quenching in air from 1,000 °C (aging for 1 h), cooling air (indicated temperature and time of heat exposure)
-	≥470	≥810	≥18	≥15	≥20	-
Rolled steel. Quenching in water or air with 1170-1190 °C + Ageing at 800 °C (8-10 h exposure), air cooling
-	≥600	≥1000	≥15	≥15	-	-
Rolled steel. Quenching in water from 1180 °C (aging for 1 h) + Quenching in air from 1,000 °C (aging for 1 h), cooling air (indicated temperature and time of heat exposure)
-	≥490	≥880	≥19	≥17	≥20	-
Rolled steel. Quenching in water or air with 1170-1190 °C + Ageing at 800 °C (8-10 h exposure), air cooling
-	≥550	≥810	≥13	≥26	-	-
-	≥540	≥780	≥12	≥23	-	-
-	-	≥700	≥12	≥23	-	-
-	≥500	≥640	≥9	≥23	-	-
-	≥430	≥520	≥8	≥23	-	-
-	≥280	≥380	≥8	≥17	-	-
-	-	≥250	≥7	≥18	-	-
-	-	≥160	≥6	≥21	-	-

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
20	185	7800	-	-
200	187	7720	16	177
300	157	7680	18	184
400	147	7630	20	191
500	147	7580	22	205
600	147	7530	24	205
700	118	-	26	-
800	118	-	-	208
100	-	7770	14	17

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
The temperature of forging	Start - 1160 °C, the end - 1000 °C.