Designation
| Name |
The value |
| Designation GOST Cyrillic |
20ХМ |
| Designation GOST Latin |
20XM |
| Transliteration |
20HM |
| By chemical elements |
20CrMo |
Description
20KHM steel is used: for the manufacture of gear wheels gear boxes.
Note
Structural steel high-quality chrome-molybdenum.
Standards
| Name |
Code |
Standards |
| Bars and shapes |
В32 |
GOST 4543-71, GOST 14955-77, TU 14-1-2118-77, TU 14-11-245-88, TU 14-1-5228-93, TU 14-136-367-2008 |
| Bars and shapes |
В22 |
GOST 8319.0-75 |
| Blanks. Of the workpiece. Slabs |
В31 |
OST 3-1686-90, TU 14-1-4944-90 |
| Processing of metals by pressure. Forgings |
В03 |
OST 5Р.9125-84, ST ЦКБА 010-2004 |
Chemical composition
| Standard |
C |
S |
P |
Mn |
Cr |
Si |
Ni |
Fe |
Cu |
V |
Ti |
Mo |
W |
| GOST 4543-71 |
0.15-0.25 |
≤0.035 |
≤0.035 |
0.4-0.7 |
0.8-1.1 |
0.17-0.37 |
≤0.3 |
Rest |
≤0.3 |
≤0.05 |
≤0.03 |
0.15-0.25 |
≤0.2 |
Fe is the basis.
According to GOST 4543-71 the content in high-quality steel is regulated: P≤0,025%; S≤0.025%; Сu≤0.30%; in high-grade steel: P≤0,025%; S≤0.015%; Сu≤0.25%.
Mechanical properties
| Section, mm |
sT|s0,2, MPa |
σU, MPa |
d5, % |
y, % |
| Quenching in oil at 880 °C + vacation at 500 °C |
| ≤15 |
600 |
800 |
12 |
50 |
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 |
