20HN

gears, bushings, fingers, fasteners and other details that are required to increased viscosity and mild hardenability.

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 96.18–97.81 0.17–0.37 0.4–0.7 0.45–0.75 < 0.3 1–1.4 < 0.035 0.17–0.23 < 0.035

Information on suppliers

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 15 780 590 14 50 780 Hardening and tempering

Brinell hardness number

Rolling Standard Classifiers Value, HBW
Alloy GOST 4543-71 annealing 197

Technological Properties

Weldability Flake Susceptibility Propensity to temper brittleness
Boundedly welded sensitive inclined

Critical point temperatures

Ac1, K Ac3(Acm), K Ar3(Arcm), K Ar1, K Mn, K
735 805 790 660 410

Analogues

USA
3120

Standards

Standard Description
GOST 4543-71

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 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
Mn K