20K

flanges, bottoms, one-piece and welded drum boilers, coupling halves, housing units and other details Boiler and vessels working under pressure and at temperatures up to 450 ° C.

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 97.75–99.34 0.15–0.3 0.35–0.65 < 0.3 < 0.3 < 0.3 < 0.08 < 0.04 0.16–0.24 < 0.04

Information on suppliers

Physical characteristics

Temperature, °C $$E\cdot 10^{9}$$, $$MPa$$ $$\alpha\cdot 10^{6}$$, $$K^{-1}$$ $$\varkappa$$, $$\frac{W}{m\cdot K}$$ $$\rho$$, $$\frac{kg}{m^3}$$ $$c\cdot 10^{-3}$$, $$\frac{J}{kg\cdot K}$$ $$R\cdot 10^{-6}$$, $$\Omega\cdot m$$
20 211 7870 0.482 0.2
100 208 51 7840 0.486 0.219
200 205 12 49 7810 0.498 0.292
300 200 12.8 46 7780 0.514 0.381
400 191 13.2 42 7740 0.533 0.487
500 180 13.6 39 7710 0.555 0.601
600 165 13.85 36 7670 0.584 0.758
700 7630 0.636 0.925
800 7640 0.703 1.094
900 7610 0.703 1.135
1000 7550 0.695 1.167
1100 7490 0.691 1.194
1200 0.687 1.219

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 5520-79 400–510 225–245 23–25 490–590

Technological Properties

Weldability Flake Susceptibility Propensity to temper brittleness
no limits not sensitive not inclined

Critical point temperatures

Ac1, K Ac3(Acm), K Ar3(Arcm), K Ar1, K
724 845 817 682

Analogues

USA Germany
K02801 1.0425 (P265GH)

Standards

Standard Description
GOST 5520-79

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 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)
$$KCU\cdot 10^{3}$$ $$\frac{J}{m^2}$$ 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