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] |
