Steel 20KH2N4A

Designation

Name The value
Designation GOST Cyrillic 20Х2Н4А
Designation GOST Latin 20X2H4A
Transliteration 20H2N4A
By chemical elements 20Cr2Н4

Description

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 sT|s0,2, MPa σU, 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
sT|s0,2 Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2%
σU 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.