Steel 18KHG

Designation

Name The value
Designation GOST Cyrillic 18ХГ
Designation GOST Latin 18XG
Transliteration 18HG
By chemical elements 18CrMn

Description

18KHG steel is used: for the production of carburized parts of small sections, working on friction; details of pipeline valves are designed to cut non-aggressive media (water, steam, air, nitrogen, inert gases, fuel oil, oil, oil distillers, diesel fuel, diesel oil, crude oil and petroleum products); tubes for plants of chemical and petrochemical plants with nominal pressure PN=19.6−98 MPa (200−1000 kgf/cm2). Details of pipe fittings are made of rolled, forged blanks and forgings (requires heat treatment: quenching in oil and tempering in air or in oil).

Note

Steel structural quality chromatorgraphy.

Standards

Name Code Standards
Sheets and strips В23 GOST 103-2006
Bars and shapes В22 GOST 1133-71, GOST 8319.0-75, GOST 2590-2006, GOST 2591-2006, GOST 2879-2006
Bars and shapes В32 GOST 4543-71, GOST 7417-75, GOST 8560-78, GOST 14955-77, TU 14-1-2118-77, TU 14-11-245-88, TU 14-1-1271-75, TU 14-1-5228-93, TU 14-136-367-2008
Blanks. Of the workpiece. Slabs В31 OST 3-1686-90, TU 14-1-4944-90
Classification, nomenclature and General rules В30 OST 64-155-75
Thermal and thermochemical treatment of metals В04 ST ЦКБА 026-2005
Steel pipes and fittings to them В62 TU 14-3-251-74
Tape В34 TU 14-4-795-77

Chemical composition

Standard C S P Mn Cr Si Ni Fe Cu V Ti Mo W
GOST 4543-71 0.15-0.21 ≤0.035 ≤0.035 0.9-1.2 0.9-1.2 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 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 t отпуска, °C sT|s0,2, MPa σU, MPa d5, % y, % KCU, kJ/m2 HB, MPa
Blank pieces of pipe armature at ST CKBA 026-2005. Quenching in oil with 865-895 °C (exposure for 2.5-4.0 hours depending on thickness and weight of the workpiece) + Vacation, air cooling or oil (longitudinal samples)
≤15 200-220 ≥735 ≥880 ≥10 ≥40 - 277-321
≤80 650-700 ≥440 ≥635 ≥16 ≥45 ≥588 197-235

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
HB Brinell hardness number

Technological properties

Name The value
Склонность к отпускной хрупкости Inclined.
Flock-sensitive sensitivity Sensitive.