Steel 20KHN4FA

Designation

Name The value
Designation GOST Cyrillic 20ХН4ФА
Designation GOST Latin 20XH4FA
Transliteration 20HN4FA
By chemical elements 20CrН4V

Description

Steel 20KHN4FA used: for the manufacture of intake valves, bolts, pins and other critical parts operating in corrosive environment at elevated temperatures (300−400 °C).

Note

Structural steel high-quality romancelatina.

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 14-1-2118-77, TU 14-11-245-88, 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 14-1-2677-79, TU 14-1-4944-90, TU 14-1-4797-90

Chemical composition

Standard C S P Mn Cr Si Ni Fe Cu V Ti Mo W
GOST 4543-71 0.17-0.24 ≤0.025 ≤0.025 0.25-0.55 0.7-1.1 0.17-0.37 3.75-4.15 Rest ≤0.3 0.1-0.18 ≤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%.

Mechanical properties

Section, mm t отпуска, °C sT|s0,2, MPa σU, MPa d5, % d10 y, % KCU, kJ/m2
Quenching in oil from 850 °C + vacation at 630 °C, cooling in water
≤25 - 685 880 12 - 50 961
Quenching in water from 870 °C to + vacation, cooling in oil
- 200 1200 1500 12 - 58 883
Samples with a cross section of 10 mm. Quenching in oil from 850 °C + vacation at 580 °C
- - 740 890 - 15 64 520
Quenching in water from 870 °C to + vacation, cooling in oil
- 400 1150 1300 13 - 62 883
Samples with a cross section of 10 mm. Quenching in oil from 850 °C + vacation at 580 °C
- - 710 830 - 13 64 618
Quenching in water from 870 °C to + vacation, cooling in oil
- 600 990 1040 16 - 65 1177
Samples with a cross section of 10 mm. Quenching in oil from 850 °C + vacation at 580 °C
- - - 830 - 12 63 549
- - 670 820 - 12 61 971
- - 590 700 - 12 70 903
- - 445 580 - 11 57 804
- - 205 360 - 13 50 1020

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
d10 Elongation after rupture
y The relative narrowing
KCU Toughness

Physical characteristics

Temperature l, W/(m · °C) R, Mr. · m a, 10-6 1/°C
100 38 470 117
200 38 480 127
700 29 1020 -
20 - 360 -

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 does not apply to welded structures.
Склонность к отпускной хрупкости tend [81]
The temperature of forging Start - 1200 °C, the end - of 800 °C. Sections over 40 mm are cooled slowly.
Flock-sensitive sensitivity sensitive [81]