Designation
| Name |
The value |
| Designation GOST Cyrillic |
21Н5А |
| Designation GOST Latin |
21H5A |
| Transliteration |
21N5A |
| By chemical elements |
21Н5 |
| Name |
The value |
| Designation GOST Cyrillic |
ЭИ56 |
| Designation GOST Latin |
EI56 |
| Transliteration |
EhI56 |
| By chemical elements |
- |
Description
21Н5А steel is used: for the production of long products and forgings intended for fabrication of various critical stressed parts of power plant engineering.
Standards
| Name |
Code |
Standards |
| Bars and shapes |
В22 |
GOST 1133-71, GOST 2590-2006, GOST 2591-2006, GOST 2879-2006 |
| Bars and shapes |
В32 |
GOST 7417-75, GOST 8559-75, GOST 8560-78, TU 14-1-2765-79, TU 14-1-950-74 |
| Blanks. Of the workpiece. Slabs |
В21 |
OST 14-13-75 |
| Blanks. Of the workpiece. Slabs |
В31 |
TU 1-92-156-90 |
Chemical composition
| Standard |
C |
S |
P |
Mn |
Cr |
Si |
Ni |
Fe |
Cu |
V |
Ti |
Mo |
W |
| TU 14-1-2765-79 |
0.18-0.25 |
≤0.025 |
≤0.025 |
0.3-0.6 |
≤0.3 |
0.17-0.37 |
4.5-5 |
Rest |
0.25 |
≤0.05 |
≤0.03 |
≤0.15 |
≤0.2 |
Fe is the basis.
According to TU 14-1-2765-79 the chemical composition is given for steel grade 21N5A-III.
Mechanical properties
| Section, mm |
sT|s0,2, MPa |
σU, MPa |
d5, % |
y, % |
KCU, kJ/m2 |
HB, MPa |
| Bars hot rolled, forged and calibrated. Quenching in oil with 760-800 °C + Vacation at 150-170 °C, air cooling |
|
≥932 |
≥1177 |
≥9 |
≥40 |
≥490 |
363-444 |
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 |
