30X
Fasteners for operation at temperatures above 400 deg.
Classification
Country |
Section |
Category |
CIS, Russia, Ukraine |
Structural steel |
Alloyed structural steel |
Chemical composition
Standard |
Fe, % |
Si, % |
Mn, % |
Cr, % |
Cu, % |
Ni, % |
P, % |
C, % |
S, % |
GOST 4543-71 |
96.74–98.29 |
0.17–0.37 |
0.5–0.8 |
0.8–1.1 |
< 0.3 |
< 0.3 |
< 0.035 |
0.24–0.32 |
< 0.035 |
Information on suppliers
Physical characteristics
Temperature, °C |
$$E\cdot 10^{9}$$, $$MPa$$ |
$$\alpha\cdot 10^{6}$$, $$K^{-1}$$ |
$$\varkappa$$, $$\frac{W}{m\cdot K}$$ |
$$\rho$$, $$\frac{kg}{m^3}$$ |
$$c\cdot 10^{-3}$$, $$\frac{J}{kg\cdot K}$$ |
$$R\cdot 10^{-6}$$, $$\Omega\cdot m$$ |
20 |
208 |
|
|
7820 |
|
0.21 |
100 |
211 |
12.4 |
46.5 |
7800 |
0.482 |
0.259 |
200 |
|
12.9 |
44.4 |
7770 |
0.496 |
0.33 |
300 |
197 |
13.3 |
42.3 |
7740 |
0.513 |
0.417 |
400 |
|
13.8 |
38.5 |
7700 |
0.532 |
0.517 |
500 |
175 |
14.1 |
35.6 |
7670 |
0.555 |
0.636 |
600 |
|
14.5 |
31.9 |
7630 |
0.583 |
0.778 |
700 |
|
14.8 |
28.8 |
7590 |
0.62 |
0.934 |
800 |
|
|
26 |
7610 |
0.703 |
1.106 |
900 |
|
|
26.7 |
7560 |
0.687 |
1.146 |
1100 |
|
|
|
7470 |
0.67 |
1.205 |
1200 |
|
|
|
7430 |
0.67 |
1.23 |
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 |
Alloy |
GOST 4543-71 |
|
|
|
880 |
685 |
12 |
45 |
690 |
Hardening and tempering |
Brinell hardness number
Technological Properties
Weldability |
Flake Susceptibility |
Propensity to temper brittleness |
Boundedly welded |
sensitive |
inclined |
Critical point temperatures
Ac1, K |
Ac3(Acm), K |
Ar1, K |
740 |
815 |
670 |
Analogues
Standards
Description of chemical elements
Element |
Units of measurement |
Description |
Fe |
% |
Iron |
Si |
% |
Silicon |
Mn |
% |
Manganese |
Cr |
% |
Chrome |
Cu |
% |
Copper |
Ni |
% |
Nickel |
P |
% |
Phosphorus |
C |
% |
Carbon |
S |
% |
Sulfur |
Description of physical characteristics
Parameter |
Units of measurement |
Description |
$$E\cdot 10^{9}$$ |
$$MPa$$ |
Elastic modulus |
$$\alpha\cdot 10^{6}$$ |
$$K^{-1}$$ |
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) |
$$\rho$$ |
$$\frac{kg}{m^3}$$ |
The density of the material |
$$c\cdot 10^{-3}$$ |
$$\frac{J}{kg\cdot K}$$ |
The specific heat of the material (range 20°C–T) |
$$R\cdot 10^{-6}$$ |
$$\Omega\cdot m$$ |
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 |
|
Ar1 |
K |
|