18K
parts and fittings for boilers, vessels working under pressure at normal, low and high temperatures.
Classification
| Country |
Section |
Category |
| CIS, Russia, Ukraine |
Structural steel |
Carbonaceous quality structural steel |
Chemical composition
| Standard |
Fe, % |
Si, % |
Mn, % |
Cr, % |
Cu, % |
Ni, % |
As, % |
P, % |
C, % |
S, % |
|---|
| GOST 5520-79 |
97.5–99.14 |
0.17–0.37 |
0.55–0.85 |
< 0.3 |
< 0.3 |
< 0.3 |
< 0.08 |
< 0.04 |
0.14–0.22 |
< 0.04 |
Information on suppliers
Mechanical properties at 20 °C
| Rolling |
Standard |
Size, mm |
Tension |
Classifiers |
$$\sigma _{U}$$, $$MPa$$ |
$$\sigma_{P}$$, $$MPa$$ |
$$\epsilon_L$$, % |
$$KCU\cdot 10^{3}$$, $$\frac{J}{m^2}$$ |
Treatment |
|---|
| Sheet |
GOST 5520-79 |
|
|
|
430–520 |
255–275 |
20 |
590 |
|
Technological Properties
Analogues
Standards
Description of chemical elements
| Element |
Units of measurement |
Description |
| Fe |
% |
Iron |
| Si |
% |
Silicon |
| Mn |
% |
Manganese |
| Cr |
% |
Chrome |
| Cu |
% |
Copper |
| Ni |
% |
Nickel |
| As |
% |
Arsenic |
| P |
% |
Phosphorus |
| C |
% |
Carbon |
| S |
% |
Sulfur |
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) |
| $$KCU\cdot 10^{3}$$ |
$$\frac{J}{m^2}$$ |
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 |
|
|