20HF (20HFA)

for medium-sized parts subjected to carburizing and hardening with low release (gears, piston pins, distribution rollers, plungers, copiers)

Classification

Country Section Category
CIS, Russia, Ukraine Structural steel Alloyed structural steel

Chemical composition

Standard Fe, % Si, % Mn, % Cr, % Cu, % Ni, % V, % P, % C, % S, %
GOST 10702-78 96.8–98.43 < 0.2 0.5–0.8 0.8–1.1 < 0.3 < 0.3 0.1–0.2 < 0.035 0.17–0.23 < 0.035

Information on suppliers

Physical characteristics

Temperature, °C $$\alpha\cdot 10^{6}$$, $$K^{-1}$$
100 12
200 12.5
400 13
500 13.7

Brinell hardness number

Rolling Standard Classifiers Value, HBW
annealing, hot rolling 170

Technological Properties

Flake Susceptibility Propensity to temper brittleness
insensitive loathsome

Critical point temperatures

Ac1, K Ac3(Acm), K
768 840

Analogues

Germany USA
22CrV4 6120

Standards

Standard Description
GOST 10702-78

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

Description of physical characteristics

Parameter Units of measurement Description
$$\alpha\cdot 10^{6}$$ $$K^{-1}$$ Coefficient of thermal (linear) expansion (range 20°C–T)

Description of temperatures of critical points

Parameter Units of measurement Description
Ac1 K
Ac3(Acm) K