Steel 55KH
Designation
| Name |
The value |
| Designation GOST Cyrillic |
55Х |
| Designation GOST Latin |
55X |
| Transliteration |
55H |
| The chemical elements |
55Cr |
Description
55KH steel is used: for the manufacture of a compound of the axes of the backup rolls for cold rolling of metals; work rolls Blumenhof, rollable, billet, rail and structural steel, heavy section, medium section and light section mills and work rolls of sheet mills for hot rolling of metals; gear shafts, gears and other stressed parts exposed to abrasion, but working without significant impact.
Standards
| Name |
Code |
Standards |
| Metal forming. Forgings |
В03 |
GOST 8479-70, TU 108-11-905-87 |
Chemical composition
| Standard |
C |
S |
P |
Mn |
Cr |
Si |
Ni |
|
0.5-0.6 |
≤0.04 |
≤0.04 |
0.35-0.65 |
1-1.3 |
0.17-0.37 |
≤0.5 |
Mechanical characteristics
| Section, mm |
sT|s0,2, MPa |
σB, MPa |
d5, % |
y, % |
kJ/m2, кДж/м2 |
Brinell hardness number, MPa |
| Quenching in oil from 820-840 °C + Vacation at 560-630 °C, cooling in furnace or in air |
| ≤100 |
≥640 |
≥840 |
≥12 |
≥40 |
- |
255-322 |
| Superheat temperature of 1220 °C, exposure 15 min moving Speed of the grips of the testing machine 150 mm/min. |
| - |
- |
≥190 |
≥52 |
≥65 |
- |
- |
| Quenching in oil from 820-840 °C + Vacation at 560-630 °C, cooling in furnace or in air |
| 101-300 |
≥540 |
≥780 |
≥10 |
≥35 |
- |
240-302 |
| Superheat temperature of 1220 °C, exposure 15 min moving Speed of the grips of the testing machine 150 mm/min. |
| - |
- |
≥115 |
≥56 |
≥80 |
- |
- |
| Quenching in oil from 820-840 °C + Vacation at 560-630 °C, cooling in furnace or in air |
| 301-500 |
≥490 |
≥730 |
≥8 |
≥30 |
- |
240-300 |
| Superheat temperature of 1220 °C, exposure 15 min moving Speed of the grips of the testing machine 150 mm/min. |
| - |
- |
≥78 |
≥83 |
≥99 |
- |
- |
| Normalization at 840-860 °C, air cooling + Vacation at 580-630 °C, air cooling or pecii |
| 301-500 |
≥340 |
≥640 |
≥8 |
≥30 |
- |
210-240 |
| Superheat temperature of 1220 °C, exposure 15 min moving Speed of the grips of the testing machine 150 mm/min. |
| - |
- |
≥54 |
≥89 |
≥100 |
- |
- |
| The forging temperature of 1210 °C, exposure time 10 h of Isothermal annealing. Normalization. High vacation. |
| 480 |
≥380 |
≥780 |
≥13 |
≥22 |
≥210 |
- |
| Superheat temperature of 1220 °C, exposure 15 min moving Speed of the grips of the testing machine 150 mm/min. |
| - |
- |
≥40 |
≥99 |
≥100 |
- |
- |
| The forging temperature of 1210 °C, exposure time 10 h of Isothermal annealing. Normalization. High vacation. |
| 670 |
≥360 |
≥760 |
≥10 |
≥17 |
≥200 |
- |
| Superheat temperature of 1220 °C, exposure 15 min moving Speed of the grips of the testing machine 150 mm/min. |
| - |
- |
≥27 |
- |
≥100 |
- |
- |
| The forging temperature of 1210 °C, exposure time 10 h of Isothermal annealing. Normalization. High vacation. |
| 960 |
≥340 |
≥750 |
≥9 |
≥15 |
≥180 |
- |
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 |
Technological properties
| Name |
The value |
| Weldability |
Steel difficult weldability. Welding methods: SMAW, essential heating and subsequent heat treatment. The CCC, the necessary subsequent heat treatment. |
| Propensity to temper brittleness |
Inclined. |
| Forging temperature |
Beginning - 1220 °C, the end - of 800 °C. the cross Sections up to 200 mm are cooled in air, 200-350 mm in the pit. |
| Flock-sensitive sensitivity |
Sensitive. |
