Name	The value
Name	The value
Designation GOST Cyrillic	16Х2Н3МФБАЮ
Designation GOST Latin	16X2H3MFBAJu
Transliteration	16H2N3MFBAYu
By chemical elements	16Cr2Н3MoVNbNAl

Name	The value
Name	The value
Designation GOST Cyrillic	16Х2Н3МФАБ
Designation GOST Latin	16X2H3MFAB
Transliteration	16H2N3MFAB
By chemical elements	16Cr2Н3MoVNNb

Name	The value
Name	The value
Designation GOST Cyrillic	ВКС7
Designation GOST Latin	BKC7
Transliteration	VKS7
By chemical elements	WCoС7

Description

16Х2Н3МФБАЮ steel is used: for the manufacture of forgings of various parts of the aviation and transport machine-building; heavy duty gears; nitride of parts for the aircraft industry.

Note

Alloyed construction steel of the martensitic class.
Case hardening steel hardening chemical-thermal treatment.

Standards

Name	Code	Standards
Name	Code	Standards
Classification, nomenclature and General rules	В20	OST 1 90005-91
Bars and shapes	В32	TU 14-1-4483-88

Chemical composition

Standard	C	S	P	Mn	Cr	Si	Ni	Fe	N	V	Mo	Nb
Standard	C	S	P	Mn	Cr	Si	Ni	Fe	N	V	Mo	Nb
TU 14-1-4483-88	0.14-0.18	≤0.015	≤0.025	0.3-0.6	1.8-2.2	0.17-0.37	2.7-3	Rest	0.01-0.03	0.1-0.3	0.4-0.6	0.05-0.15

Fe is the basis.
According to TU 14-1-4483-88 the chemical composition is given for steel grade 16Х2Н3МФАБ-Ш (ВКС7-Ш). Deviations in the mass fraction of elements are permissible in accordance with clause 2.4 of Table 3 of GOST 4543. Titanium in an amount not exceeding 0.050% is introduced into steel by calculation and chemical analysis is not determined. The mass fraction of copper should not exceed 0.25%, tungsten - 0.20%. The mass fraction of aluminum in the metal of the ESR should not exceed 0.050%.

Mechanical properties

Section, mm	s_T\|s_0,2, MPa	σ_U, MPa	d₅, %	y, %	KCU, kJ/m²	HB, MPa	HRC
Section, mm	s_T\|s_0,2, MPa	σ_U, MPa	d₅, %	y, %	KCU, kJ/m²	HB, MPa	HRC
Gradation of performance properties of the finished heat-treated parts for OST 1 90005-91
-	-	1040-1270	-	-	-	302-363	33-39
-	-	-	-	-	-	321-429	33-42.5
-	-	-	-	-	-	302-388	28-39
Bars hot rolled on the other 14-1-4483-88. Quenching in oil from 860±10 °C + Vacation at 200±10 °C, air cooling
	≥1080	≥1270	≥9	≥45	≥490	302-415	-

Description mechanical marks

Name	Description
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
HRC	Rockwell hardness (indenter diamond spheroconical)

Technological properties

Name	The value
Name	The value
Macrostructure and pollution	The macrostructure of the steel on the other 14-1-4483-88 when checking in the fracture and lateral etched templeto should not have voids, traces of shrinkage, blistering, delamination, cracks, foreign metal and slag inclusions and placenow and defects of fracture, as listed in Annex 4 to GOST 10243. The degree of development of the Central porosity, point heterogeneity and phase separation of the square should not exceed the first score of the scales GOST 10243, layer-by-layer crystallization and light strip (circuit) - the third-score scales GOST 10243.
Microstructure	In hot-rolled steel on the other 14-1-4483-88 is the determination of the austenitic grain size, which should not be larger than 6 dial numbers according to GOST 5639.
Particularities of production of goods	Hot rolled steel on the other 14-1-4483-88 designed for cold machining, comes in heat-treated (annealed with a temperature of 670±20 °C) hardness Brinell indentation diameter not less than 3.5 mm. Steel for hot forming (forging, stamping, etc.) is supplied in heat-treated (annealed with a temperature of 800-900 °C).

Steel 16Х2Н3МФБАЮ (16Х2Н3МФАБ; ВКС7)

Designation