Steel 18KH3MV (ЭИ578)

Designation

Name The value
Designation GOST Cyrillic 18Х3МВ
Designation GOST Latin 18X3MB
Transliteration 18H3MV
By chemical elements 18Cr3MoW
Name The value
Designation GOST Cyrillic ЭИ578
Designation GOST Latin EI578
Transliteration EhI578
By chemical elements -

Description

18KH3MV steel is used: for the production of pipes hydrogenation facilities; details of pipes and valves with quenching in oil and tempering to the air; tubes for plants of chemical and petrochemical plants with nominal pressure PN=19.6−98 MPa (200−1000 kgf/cm2), operating at temperatures up to 450−500 °C.

Note

Steel pearlitic class.
Temperature intense scaling +600 °C.

Standards

Name Code Standards
Sheets and strips В23 GOST 103-2006
Bars and shapes В22 GOST 1133-71, GOST 2590-2006, GOST 2591-2006
Sheets and strips В33 GOST 4405-75
Bars and shapes В32 GOST 7417-75, GOST 8559-75, GOST 8560-78, GOST 14955-77, GOST 20072-74, TU 14-11-245-88
Processing of metals by pressure. Forgings В03 OST 26-01-135-81
Thermal and thermochemical treatment of metals В04 ST ЦКБА 026-2005
Steel pipes and fittings to them В62 TU 14-3Р-251-2007, TU 14-3-251-74, TU 14-3-463-2005

Chemical composition

Standard C S P Mn Cr Si Ni Fe Cu V Ti Mo W
TU 14-3-251-74 0.15-0.2 ≤0.025 ≤0.03 0.25-0.5 2.5-3 0.17-0.37 ≤0.3 Rest - 0.05-0.15 - 0.5-0.7 0.5-0.8
GOST 20072-74 0.15-0.2 ≤0.025 ≤0.03 0.25-0.5 2.5-3 0.17-0.37 ≤0.3 Rest ≤0.2 0.05-0.15 ≤0.03 0.5-0.7 0.5-0.8
Fe is the basis.
According to GOST 20072-74, when steel is scrap-process, the content of Cu ≤ 0.30%. The presence of titanium is up to 0.030%. When smelting steel by the method of electroslag remelting, the mass fraction of sulfur should not be more than 0.015%.

Mechanical properties

Section, mm sT|s0,2, MPa σU, MPa d5, % y, % KCU, kJ/m2 HB, MPa
Blank pieces of pipe fittings. Quenching in air or oil from 950-970 °C (exposure for 2.5-4.5 hours depending on the thickness and weight of the workpiece) + Vacation at 680-730 °C , air cooling
≤100 ≥440 ≥590 ≥15 ≥45 ≥588 197-235
Bars of ≤60 mm. Quenching in oil from 950-970 °C + Vacation at 660-680 °C , air cooling
15 ≥440 ≥640 ≥18 - ≥1180 -
Seamless pipes for chemical and petrochemical industries in the state of delivery (indicate the cutting direction of sample)
- ≥441 ≥637 ≥16 - ≥1078 197-241
- ≥441 ≥637 ≥18 - ≥1180 197-241

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