25G

After improvement — rivet-duty; after carburizing or cyanide — piston pins, friction discs, finger springs, cam rollers, bolts, nuts, screws, gears, worms and other parts with high surface hardness and wear resistance; without heat treatment — welded sub-frame, shoes, scarves, fittings, bushings.

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 97.36–98.91 0.17–0.37 0.7–1 < 0.3 < 0.3 < 0.3 < 0.035 0.22–0.3 < 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
Workpiece GOST 4543-71 < 25 500 300 22 50 880 Tempering 880 ° C, the water, leave 560 ° C, air

Brinell hardness number

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

Critical point temperatures

Ac1, K Ac3(Acm), K
723 820

Analogues

USA Germany
1026 1.1155 (GS-Ck25)

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

Description of temperatures of critical points

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