25H2M1F (EI723)
bolts, flat springs, nuts and other fasteners with a working temperature of 520−540 deg.
Classification
| Country |
Section |
Category |
| CIS, Russia, Ukraine |
Heat resistant steels and alloys |
Heat-resistant relaxation-resistant steel |
Chemical composition
| Standard |
Fe, % |
Si, % |
Mn, % |
Cr, % |
Cu, % |
Ni, % |
V, % |
P, % |
C, % |
S, % |
Mo, % |
|---|
| TU 14-1-552-72 |
93.935–95.91 |
0.17–0.37 |
0.4–0.7 |
2.1–2.6 |
< 0.2 |
< 0.25 |
0.3–0.5 |
< 0.03 |
0.22–0.29 |
< 0.025 |
0.9–1.1 |
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 |
223 |
|
|
7800 |
|
0.27 |
| 100 |
218 |
12.5 |
32.7 |
7780 |
0.536 |
0.36 |
| 200 |
213 |
12.9 |
31.8 |
7750 |
0.574 |
0.42 |
| 300 |
207 |
13.3 |
30.1 |
7720 |
0.599 |
0.5 |
| 400 |
200 |
13.7 |
28.5 |
7680 |
0.632 |
0.59 |
| 500 |
192 |
14 |
28.1 |
7650 |
0.674 |
0.71 |
| 600 |
183 |
14.7 |
26.4 |
7600 |
0.733 |
0.84 |
| 700 |
175 |
|
|
|
|
0.97 |
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 |
|
25 |
Longitudinal |
|
900 |
750 |
10 |
40 |
300 |
Normalization of 1030-1060 ° C, and Holidays 680-720 ° C, air |
Brinell hardness number
| Rolling |
Standard |
Classifiers |
Value, HBW |
| Alloy |
|
Hardening, average vacation |
235–277 |
Technological Properties
| Weldability |
|---|
| Not applicable for welded structures |
Critical point temperatures
| Ac1, K |
Ac3(Acm), K |
Ar3(Arcm), K |
Ar1, K |
|---|
| 780 |
870 |
790 |
700 |
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 |
| Mo |
% |
Molybdenum |
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 |
|
| Ar3(Arcm) |
K |
|
| Ar1 |
K |
|