20KH2N4A steel is used: for the manufacture of gear, shaft-sestina, fingers, solid-rolled rings, case hardening, critical, highly loaded parts, which are requirements of high strength, ductility and toughness of core and high surface hardness, working under shock loads and at low temperatures.

Note

The high quality stainless steel construction.

Standards

Name	Code	Standards
Sheets and strips	В23	GOST 103-2006
Bars and shapes	В32	GOST 1051-73, GOST 4543-71, GOST 7417-75, GOST 8559-75, GOST 8560-78, GOST 14955-77, TU 3-173-83, TU 14-1-1433-75, TU 14-1-1732-76, TU 14-1-1885-85, TU 14-1-2118-77, TU 1-83-77-90, TU 14-11-245-88, TU 14-1-1271-75, TU 14-136-367-2008
Bars and shapes	В22	GOST 1133-71, GOST 8319.0-75, GOST 2590-2006, GOST 2591-2006, GOST 2879-2006
Blanks. Of the workpiece. Slabs	В31	OST 3-1686-90, TU 14-1-4944-90

Chemical composition

Standard	C	S	P	Mn	Cr	Si	Ni	Fe	Cu	V	Ti	Mo	W
TU 14-1-1885-85	0.16-0.22	≤0.015	≤0.025	0.3-0.6	1.25-1.65	0.17-0.37	3.25-3.65	Rest	≤0.25	-	-	-	-
GOST 4543-71	0.16-0.22	≤0.025	≤0.025	0.3-0.6	1.25-1.65	0.17-0.37	3.25-3.65	Rest	≤0.3	≤0.05	≤0.03	≤0.15	≤0.2

Fe is the basis.
GOST 4543-71 regulates the content of high-quality steel: P≤0,025%; S≤0.015%; Сu≤0.25%.
According to TU 14-1-1885-85 the chemical composition is given for steel grade 20Х2Н4А-ВД. To ensure the required grain size, it is allowed to introduce vanadium in the steel smelting at the rate of its content in steel no more than 0.10%, the content of which in steel is not determined. The presence of tungsten to 0.20%, molybdenum to 0.15%, titanium to 0.030% is not a defect. The allowable variation in manganese content in steel is ± 0.010%.

Mechanical properties

Section, mm	t отпуска, °C	s_T\|s_0,2, MPa	σ_U, MPa	d₅, %	y, %	KCU, kJ/m²	HB, MPa	HRC
Quenching in oil from 860 °C + quenching in oil from 780 °C to + vacation at 180 °C, cooling in air or in oil
≤15	-	≥1080	≥1270	≥9	≥45	≥765	-	-
Hardening + Vacation
120-160	-	≥760	≥880	≥12	≥50	-	≥262	-
Quenching in oil from 840 °C to + Vacation
-	200	≥1360	≥1500	≥7	≥56	-	-	-
A specimen of 10 mm diameter, 50 mm length, forged and annealed. The rate of deformation of 5 mm/min strain Rate of 0.002 1/s.
-	-	≥63	≥120	≥56	≥78	-	-	-
Rods made of steel 20KH2N4A on the other 14-1-1885-85. Quenching in oil with 850-870 °C + Quenching in oil with 770-790 °C + Vacation at 180 °C, cooling in air or in oil. In the graph KCU KCU values are shown along the fiber/KCU across the grain
Образец 15х15	-	≥1080	≥1270	≥9	≥45	≥784	363-444	-
Hardening + Vacation
15-30	-	≥820	≥940	≥12	≥50	-	≥277	-
Quenching in oil from 840 °C to + Vacation
-	300	≥1280	≥1400	≥7	≥60	-	-	-
A specimen of 10 mm diameter, 50 mm length, forged and annealed. The rate of deformation of 5 mm/min strain Rate of 0.002 1/s.
-	-	≥45	≥56	≥64	≥95	-	-	-
Cementation at 900-920 °C, air cooling + tempering in oil 780-810 °C + vacation at 180-200 °C, air cooling
20-50	-	≥1050	≥1220	≥12	≥45	≥1158	360	57-64
Hardening + Vacation
160-200	-	≥740	≥860	≥12	≥50	-	≥262	-
Quenching in oil from 840 °C to + Vacation
-	400	≥1140	≥1300	≥7	≥63	-	-	-
A specimen of 10 mm diameter, 50 mm length, forged and annealed. The rate of deformation of 5 mm/min strain Rate of 0.002 1/s.
-	-	≥36	≥56	≥58	≥100	-	-	-
Cementation at 920-950 °C + normalization at 900-920 °C, cooling in air or quenching in oil with 880-920 °C + vacation at 630-660 °C, air cooling. Quenching in oil 780-820 °C + vacation at 150-200 °C air cooling
150	-	≥830	≥1080	≥9	≥35	≥765	321-420	57-64
Hardening + Vacation
200-240	-	≥720	≥860	≥12	≥50	-	≥255	-
Quenching in oil from 840 °C to + Vacation
-	500	≥970	≥1170	≥10	≥67	-	-	-
A specimen of 10 mm diameter, 50 mm length, forged and annealed. The rate of deformation of 5 mm/min strain Rate of 0.002 1/s.
-	-	≥22	≥37	≥63	≥100	-	-	-
Hardening + Vacation
30-50	-	≥820	≥940	≥12	≥50	-	≥277	-
Quenching in oil from 840 °C to + Vacation
-	600	≥790	≥1000	≥11	≥72	-	-	-
A specimen of 10 mm diameter, 50 mm length, forged and annealed. The rate of deformation of 5 mm/min strain Rate of 0.002 1/s.
-	-	≥20	≥27	≥59	≥100	-	-	-
Hardening + Vacation
50-80	-	≥820	≥940	≥12	≥50	-	≥269	-
A specimen of 10 mm diameter, 50 mm length, forged and annealed. The rate of deformation of 5 mm/min strain Rate of 0.002 1/s.
-	-	≥16	≥26	≥65	≥100	-	-	-
Hardening + Vacation
80-120	-	≥780	≥900	≥12	≥50	-	≥262	-
A specimen of 10 mm diameter, 50 mm length, forged and annealed. The rate of deformation of 5 mm/min strain Rate of 0.002 1/s.
-	-	≥16	≥22	≥71	≥100	-	-	-

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
HRC	Rockwell hardness (indenter diamond spheroconical)

Physical characteristics

Temperature	Е, HPa	r, kg/m³	l, W/(m · °C)
0	203	7850	-
20	203	7850	-
100	-	-	24

A description of the physical symbols

Name	Description
Е	The normal elasticity modulus
G	Modulus of elasticity shear torsion
r	Density
l	Coefficient of thermal conductivity
R	UD. the resistivity

Technological properties

Name	The value
Weldability	difficult weldability. Welding methods: SMAW, ADS submerged arc, electroslag welding. Necessary preheating and subsequent heat treatment.
Склонность к отпускной хрупкости	malosana
The temperature of forging	Start - 1200 °C, the end - of 800 °C. the cross Sections up to 100 mm are cooled in air, 101-350 mm - in the pit.
Flock-sensitive sensitivity	sensitive
Machinability	After normalization and tempering at HB 259 blower SB=880 MPa Kn TV.SPL.=0.72 Kn b.St.=0.63[100]
Macrostructure and pollution	Macrostructure of steel when testing for the breaks in the longitudinal direction and transverse templeto selected from rolled, should not have shrinkage, porosity, bubbles, cracks, delamination, inclusions and placenow and defects of fracture, listed in Annex 3 GOST 10243. The Central porosity, point heterogeneity and phase separation in the square should not exceed 1 points; layer-by-layer crystallization and the bright loop - 3 points reference scales GOST 10243. All other defects under GOST 10243, are not allowed. Pollution steel non-metallic inclusions should be according to the average score is not higher (in points): oxides of point 1,5, 2,0 stroke oxides, silicates fragile 1,0, 1,0 silicates plastic, silicates, non-deformed 2,5, 2,5 sulfides, nitrides stroke and point 1,0.

Steel 20KH2N4A

Designation

Description