Steel 18KH3MV (ЭИ578)
Designation
| Name |
The value |
| Designation GOST Cyrillic |
18Х3МВ |
| Designation GOST Latin |
18X3MB |
| Transliteration |
18H3MV |
| The chemical elements |
18Cr3MoW |
| Name |
The value |
| Designation GOST Cyrillic |
ЭИ578 |
| Designation GOST Latin |
EI578 |
| Transliteration |
EhI578 |
| The 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 stripes |
В23 |
GOST 103-2006 |
| Sectional and shaped rolling |
В22 |
GOST 1133-71, GOST 2590-2006, GOST 2591-2006 |
| Sheets and stripes |
В33 |
GOST 4405-75 |
| Sectional and shaped rolling |
В32 |
GOST 7417-75, GOST 8559-75, GOST 8560-78, GOST 14955-77, GOST 20072-74, TU 14-11-245-88 |
| Metal forming. Forgings |
В03 |
OST 26-01-135-81 |
| Thermal and thermochemical treatment of metals |
В04 |
ST ЦКБА 026-2005 |
| Pipes steel and connecting parts 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 |
The 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 |
The 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 characteristics
| Section, mm |
sT|s0,2, MPa |
σB, MPa |
d5, % |
y, % |
kJ/m2, кДж/м2 |
Brinell hardness number, 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 |
| Section |
Section |
| sT|s0,2 |
Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2% |
| σB |
Limit short-term strength |
| d5 |
Elongation after rupture |
| y |
The relative narrowing |
| kJ/m2 |
Toughness |
