20HN4FA
intake valves, bolts, studs and other critical parts, operating in corrosive environments at elevated temperatures (300 to 400 ° C).
Classification
| Country |
Section |
Category |
| CIS, Russia, Ukraine |
Structural steel |
Alloyed structural steel |
Chemical composition
| Standard |
Fe, % |
Si, % |
Mn, % |
Cr, % |
Cu, % |
Ni, % |
V, % |
P, % |
C, % |
S, % |
|---|
| GOST 4543-71 |
93.06–94.86 |
0.17–0.37 |
0.25–0.55 |
0.7–1.1 |
< 0.3 |
3.75–4.15 |
0.1–0.18 |
< 0.025 |
0.17–0.24 |
< 0.025 |
Information on suppliers
Physical characteristics
| Temperature, °C |
$$\alpha\cdot 10^{6}$$, $$K^{-1}$$ |
$$\varkappa$$, $$\frac{W}{m\cdot K}$$ |
$$R\cdot 10^{-6}$$, $$\Omega\cdot m$$ |
|---|
| 20 |
|
|
0.36 |
| 100 |
11.7 |
38 |
0.41 |
| 200 |
12.7 |
38 |
0.48 |
| 300 |
13.7 |
37 |
0.56 |
| 400 |
|
35 |
0.64 |
| 500 |
|
34 |
0.72 |
| 600 |
15.4 |
31 |
|
| 700 |
|
29 |
1.02 |
| 800 |
|
28 |
1.12 |
| 900 |
|
27 |
1.18 |
Mechanical properties at 20 °C
| Rolling |
Standard |
Size, mm |
Tension |
Classifiers |
$$\sigma _{U}$$, $$MPa$$ |
$$\sigma_{P}$$, $$MPa$$ |
$$\epsilon_L$$, % |
$$\psi$$, % |
$$KCU\cdot 10^{3}$$, $$\frac{J}{m^2}$$ |
Treatment |
|---|
| Rod |
GOST 4543-71 |
25 |
|
|
880 |
685 |
12 |
50 |
980 |
Hardening and tempering |
Brinell hardness number
| Rolling |
Standard |
Classifiers |
Value, HBW |
| Alloy |
GOST 4543-71 |
annealing |
269 |
Technological Properties
| Weldability |
Flake Susceptibility |
Propensity to temper brittleness |
|---|
| Not applicable for welded structures |
sensitive |
inclined |
Critical point temperatures
| Ac1, K |
Ac3(Acm), K |
Mn, K |
|---|
| 710 |
750 |
310 |
Analogues
Standards
Description of chemical elements
| Element |
Units of measurement |
Description |
| Fe |
% |
Iron |
| Si |
% |
Silicon |
| Mn |
% |
Manganese |
| Cr |
% |
Chrome |
| Cu |
% |
Copper |
| Ni |
% |
Nickel |
| V |
% |
Vanadium |
| P |
% |
Phosphorus |
| C |
% |
Carbon |
| S |
% |
Sulfur |
Description of physical characteristics
| Parameter |
Units of measurement |
Description |
| $$\alpha\cdot 10^{6}$$ |
$$K^{-1}$$ |
Coefficient of thermal (linear) expansion (range 20°C–T) |
| $$\varkappa$$ |
$$\frac{W}{m\cdot K}$$ |
Coefficient of thermal conductivity (the heat capacity of the material) |
| $$R\cdot 10^{-6}$$ |
$$\Omega\cdot m$$ |
Electrical resistivity |
Description of mechanical properties
| Parameter |
Units of measurement |
Description |
| $$\sigma _{U}$$ |
$$MPa$$ |
Ultimate tensile strength |
| $$\sigma_{P}$$ |
$$MPa$$ |
Proportionality limit |
| $$\epsilon_L$$ |
% |
Elongation at break (longitudinal) |
| $$\psi$$ |
% |
Reduction in cross section on fracture |
| $$KCU\cdot 10^{3}$$ |
$$\frac{J}{m^2}$$ |
Impact toughness |
Designation of types of weldability
| Parameter |
Units of measurement |
Description |
| no limits |
|
Welding is performed without heating and without subsequent heat treatment |
| Boundedly welded |
|
Welding is possible with heating up to 100–120 °C and subsequent heat treatment |
| Difficult to weld |
|
For obtaining quality welded joints, additional operations are required: heating up to 200–300 °C for welding, heat treatment after welding — annealing |
| Not applicable for welded structures |
|
|
Description of temperatures of critical points
| Parameter |
Units of measurement |
Description |
| Ac1 |
K |
|
| Ac3(Acm) |
K |
|
| Mn |
K |
|