Designation
| Name |
The value |
| Designation GOST Cyrillic |
28Г2СФБ |
| Designation GOST Latin |
28G2CFB |
| Transliteration |
28G2SFB |
| By chemical elements |
28Mn2СVNb |
| Name |
The value |
| Designation GOST Cyrillic |
28Г2СФБД |
| Designation GOST Latin |
28G2CFBD |
| Transliteration |
28G2SFBD |
| By chemical elements |
28Mn2СVNbCu |
Description
28Г2СФБ steel is used: for the production of billets intended for the subsequent manufacture of casing and drill pipe.
Standards
| Name |
Code |
Standards |
| Blanks. Of the workpiece. Slabs |
В31 |
TU 14-1-2727-79 |
Chemical composition
| Standard |
C |
S |
P |
Mn |
Si |
Fe |
V |
Nb |
| TU 14-1-2727-79 |
0.26-0.32 |
≤0.035 |
≤0.035 |
1.3-1.6 |
0.4-0.6 |
Rest |
0.06-0.12 |
0.01-0.04 |
Fe is the basis.
According to TU 14-1-2727-79 for the grade 28G2SFB grade steel the following deviations in the mass fraction of elements are allowed: for carbon ± 0.010%, for manganese ± 0.050%, for silicon ± 0.050%, for vanadium +0.020%. The content of residual copper, nickel and chromium should comply with GOST 4543.
Mechanical properties
| Section, mm |
sT|s0,2, MPa |
σU, MPa |
d5, % |
y, % |
KCU, kJ/m2 |
| Tubular billet on the other 14-1-2727-79. Normalizing, air cooling |
|
≥539 |
≥736 |
≥12 |
≥40 |
≥382 |
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 |
| Macrostructure and pollution |
The macrostructure of billets on the other 14-1-2727-79 when checking for cross etched templeto should not have shrinkage porosity, bubbles, cracks, inclusions, inversions, crust and placenow visible without using the magnifying devices. The defects allowed must not exceed the scores: - Central porosity ≤ 2.0 points; - point nonuniformity ≤ 2.0 points; - exudation square ≤ 2.0 points; - subcortical bubbles are not allowed. Contamination of billets non-metallic inclusions shall not exceed the maximum score: - sulphides - 5 points; - for oxides and silicates (OS,CX,SP) - 5 points. |
