Steel 25G (25Г2)

Designation

Name The value
Designation GOST Cyrillic 25Г
Designation GOST Latin 25G
Transliteration 25G
By chemical elements 25Mn
Name The value
Designation GOST Cyrillic 25Г2
Designation GOST Latin 25G2
Transliteration 25G2
By chemical elements 25Mn2

Description

Steel 25G used: for the manufacture of rivets of responsible use (after improvements), piston pins, friction discs, finger springs, Cam rollers, bolts, nuts, screws, gears, worms, and other parts with high hardness and wear resistance of the surface (after cementation, or cyanidation); welded sub frames, shoes, scarves, fittings, bushings (without heat treatment); collectors of marine water-tube boilers (article 25Г2).

Note

Structural steel high-quality manganese.

Standards

Name Code Standards
Bars and shapes В32 GOST 4543-71, GOST 14955-77, GOST 1050-2013, TU 14-1-2118-77, TU 14-1-670-73, TU 14-11-245-88, TU 14-1-1271-75, TU 14-1-5228-93, TU 14-136-367-2008
Bars and shapes В22 GOST 8319.0-75
Blanks. Of the workpiece. Slabs В31 OST 3-1686-90, TU 14-1-4944-90
Ship's machinery and boilers Д44 OST 5-4197-76

Chemical composition

Standard C S P Mn Cr Si Ni Fe Cu V Ti Mo W
GOST 4543-71 0.22-0.3 ≤0.035 ≤0.035 0.7-1 ≤0.3 0.17-0.37 ≤0.3 Rest ≤0.3 ≤0.05 ≤0.03 ≤0.15 ≤0.2
Fe is the basis.
According to GOST 4543-71 the chemical composition is given for steel grade 25G. The content in high-quality steel is regulated: P≤0,025%; S≤0.025%; Сu≤0.30%; in high-grade steel: P≤0,025%; S≤0.015%; Сu≤0.25%.

Mechanical properties

Section, mm sT|s0,2, MPa σU, MPa d5, % y, %
Rolled steel. Quenching in water from 880 °C to + Vacation at 560 °C, air cooling
25 ≥300 ≥500 ≥22 ≥50

Description mechanical marks

Name Description
sT|s0,2 Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2%
σU Limit short-term strength
d5 Elongation after rupture
y The relative narrowing