Steel 12KH8VF (1Х8ВФ)
Designation
| Name |
The value |
| Designation GOST Cyrillic |
12Х8ВФ |
| Designation GOST Latin |
12X8BF |
| Transliteration |
12H8VF |
| The chemical elements |
12Cr8WV |
| Name |
The value |
| Designation GOST Cyrillic |
1Х8ВФ |
| Designation GOST Latin |
1X8BF |
| Transliteration |
1H8VF |
| The chemical elements |
1Cr8WV |
Description
12KH8VF steel is used: for the manufacture of pipes of furnaces; apparatus and communication refineries are continuously operating at temperatures up to +500 °C; tubes for plants of chemical and petrochemical plants with nominal pressure PN=19.6−98 MPa (200−1000 kgf/cm2); of billets intended for production of tubes of the cracking units of oil refining.
Note
Steel martensitic class.
Temperature intense scaling +650 °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 |
| Pipes steel and connecting parts to them |
В62 |
GOST 550-75, TU 14-3-251-74, TU 14-3-457-76, TU 14-3-463-2005 |
| 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 |
| Bulls. Blanks. Slabs |
В31 |
TU 14-1-583-73 |
Chemical composition
| Standard |
C |
S |
P |
Mn |
Cr |
Si |
Ni |
Fe |
Cu |
V |
Ti |
Mo |
W |
| GOST 20072-74 |
0.08-0.15 |
≤0.025 |
≤0.03 |
≤0.5 |
7-8.5 |
≤0.6 |
≤0.6 |
The rest |
≤0.2 |
0.3-0.5 |
≤0.03 |
≤0.2 |
0.6-1 |
| TU 14-3-251-74 |
0.08-0.15 |
≤0.025 |
≤0.03 |
≤0.5 |
7-8.5 |
≤0.6 |
≤0.6 |
The rest |
- |
0.3-0.5 |
- |
- |
0.6-1 |
Fe is the basis.
According to GOST 20072-74, when steel is scrap-process, the content of Cu ≤ 0.30%. When smelting steel by the method of electroslag remelting, the mass fraction of sulfur should not be more than 0.015%. The presence of molybdenum up to 0.20% and titanium up to 0.030% is allowed.
According to TU 14-1-583-73, the chemical composition is given for steel grade 12X8VF. In the finished rolled products, deviations in chemical composition are allowed in accordance with GOST 20072.
Mechanical characteristics
| Section, mm |
sT|s0,2, MPa |
σB, MPa |
d5, % |
d10 |
y, % |
kJ/m2, кДж/м2 |
Brinell hardness number, MPa |
| Rolled steel. Annealing at 840-860 °C, cooling with the furnace |
|
≥165 |
≥300 |
≥22 |
- |
≥50 |
≥980 |
≤217 |
| Tubular billet on the other 14-1-583-73 after annealing |
|
≥165 |
≥390 |
≥22 |
- |
≥50 |
≥981 |
≤170 |
| Seamless hot deformed tubes, heat-treated in the delivery condition according to GOST 550-75 |
|
≥167 |
≥392 |
≥22 |
- |
≥50 |
≥980 |
≤170 |
| Pipe kiln and communication in the delivery condition on the other 14-3-457-76 (impact strength is specified for tubes with wall thickness ≥ 12 mm and is determined for longitudinal samples) |
|
≥216 |
≥392 |
≥22 |
≥18 |
≥50 |
≥980 |
≤170 |
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 |
| d10 |
Elongation after rupture |
| y |
The relative narrowing |
| kJ/m2 |
Toughness |
Technological properties
| Name |
The value |
| Macrostructure and contamination |
The macrostructure of billets, check for the etched cross templeto should not have shrinkage looseness, bubbles, delaminations, voids, cracks, inclusions and placenow visible without using the magnifying devices. The defects allowed on a point inhomogeneity, the Central porosity and segregation must not exceed 2 points (for each species), subcortical bubbles at 1 point at a depth of less than 2 mm. |
