Steel 25ХНТЦ

Designation

Name The value
Designation GOST Cyrillic 25ХНТЦ
Designation GOST Latin 25XHTTs
Transliteration 25HNTTs
By chemical elements 25CrНTiZn

Description

25ХНТЦ steel is used: for the manufacture of loaded and heavily loaded parts of General machinery (gear, shaft gear) by hot forging and subsequent machining with the use of nitrocarburizing.

Note

Hereditary fine-grained steel.

Standards

Name Code Standards
Bars and shapes В32 TU 14-1-1552-76

Chemical composition

Standard C S P Mn Cr Si Ni Fe Ti Zr
TU 14-1-1552-76 0.22-0.28 ≤0.03 ≤0.03 0.3-0.6 0.9-1.2 0.17-0.37 0.8-1.1 Rest 0.04-0.08 0.04-0.08
Fe is the basis.
According to TU 14-1-1552-76, with the observance of all other requirements of technical specifications, the following deviations in chemical composition are allowed: for carbon ± 0.010%, for chromium ± 0.050%, for titanium -0.010 / + 0.020%, for zirconium -0.010 / + 0.020 %. The silicon content is up to 0.50%. Before the introduction into the steel of alloys containing titanium and zirconium, steel is deoxidized by aluminum.

Mechanical properties

Section, mm sT|s0,2, MPa σU, MPa d5, % y, % KCU, kJ/m2
Hot rolled long products (up to 150 mm) TU 14-1-1552-76. The first quenching in oil at 880 °C + Second quenching in oil from 860 °C to + Vacation at 200 °C, air cooling (longitudinal samples)
≥1167 ≥1422 ≥10 ≥50 ≥785

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
KCU Toughness

Technological properties

Name The value
Microstructure Steel on the other 14-1-1552-76 is controlled by the amount of the austenitic grain, which should be no larger than 6 numbers according to GOST 5639.
Particularities of production of goods Bars on the other 14-1-1552-76 supplied without annealing.
Features of heat treatment For parts subjected to nitrocarburizing, apply direct quenching from 830-860 °C with cooling in a cold (30-75 °C) or hot (160-190 °C) oil.