12Kh2N4A (EI83, 2Х2Н4А-SH)

Gears, shafts, rollers, piston pins and other large special responsibility carburized parts, which are requirements of high strength, ductility and toughness of the core and surface hardness, operating under the influence of shock loads or at low temperatures down to -120 ° C.

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 93.23–94.94 0.17–0.37 0.3–0.6 1.25–1.65 < 0.3 3.25–3.65 < 0.025 0.09–0.15 < 0.025

Information on suppliers

Physical characteristics

Temperature, °C $$E\cdot 10^{9}$$, $$MPa$$ $$\alpha\cdot 10^{6}$$, $$K^{-1}$$ $$\varkappa$$, $$\frac{W}{m\cdot K}$$ $$\rho$$, $$\frac{kg}{m^3}$$
20 200 7840
100 11 25 7820
200 12
300 13 7760
400 14.7 19 7710
500 15.3
600 15.6 7630

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
Round GOST 4543-71 15 1130 930 10 50 880 Hardening and tempering

Brinell hardness number

Rolling Standard Classifiers Value, HBW
Alloy GOST 4543-71 annealing 269

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
745 800 675 625 438

Analogues

USA Germany
G33106 1.5752 (14NiCr14)

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 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

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