Steel 74 (M74)
A4 steel
Steel 76F
76KhSF steel
Steel 76C (M76C)
78KhSF steel
Steel 90AF (E90AF)
Steel A1 (A0)
A2 steel
A3 steel
Steel 76VT (M76VT)
Steel wheel 1
Steel wheel 2
Steel wheel 3
Steel M75
Steel H50
OS Steel
PT70 steel
T60 steel
Steel 70 (M70)
Steel 2
Steel 3
3Gps steel
Steel 4
Steel 54 (M54)
5Gps steel
Steel 63 (K63)
Steel 68 (M68)
76T steel
Steel 73B (M73B)
Steel 73T (M73T)
Steel 73C (M73C)
Steel 74 (M74)
Steel 74T (M74T)
Steel 74C (M74C)
Steel 76 (M76)
Steel 76B (M76B)
Designation
| Name | The value |
|---|---|
| Designation GOST Cyrillic | 74 |
| Designation GOST Latin | 74 |
| Transliteration | 74 |
| The chemical elements | 74 |
| Name | The value |
|---|---|
| Designation GOST Cyrillic | М74 |
| Designation GOST Latin | M74 |
| Transliteration | M74 |
| The chemical elements | Mo74 |
Description
74 steel is used: for the manufacture of railway rails P50.
Note
M74 — steel open-hearth rail.
Allowed production of rails P50 of the oxygen-Converter steel when you stop the purge of iron in the carbon content not less than 0.60%. Thus in the designation of steel grades the letter «M» is replaced by letter «K» — К74.
Standards
| Name | Code | Standards |
|---|---|---|
| Rails. Lining. Lining. Crutches | В42 | GOST 7174-75, GOST 18267-82, GOST 24182-80 |
Chemical composition
| Standard | C | S | P | Mn | Si | Fe |
|---|---|---|---|---|---|---|
| GOST 24182-80 | 0.69-0.8 | ≤0.045 | ≤0.035 | 0.75-1.05 | 0.18-0.4 | The rest |
Fe is the basis.
In rails made of Kerch ores, the content of phosphorus is not more than 0.040%, sulfur is not more than 0.050%, arsenic is not more than 0.15%.
The rails of Group II must be made of calm open-hearth steel, deoxidized with aluminum or manganese-aluminum alloy.
In rails made of Kerch ores, the content of phosphorus is not more than 0.040%, sulfur is not more than 0.050%, arsenic is not more than 0.15%.
The rails of Group II must be made of calm open-hearth steel, deoxidized with aluminum or manganese-aluminum alloy.
Mechanical characteristics
| Section, mm | sT|s0,2, MPa | σB, MPa | d5, % | y, % | kJ/m2, кДж/м2 | Brinell hardness number, MPa |
|---|---|---|---|---|---|---|
| The mechanical properties of rails type R50 GOST 18267-82. Bulk quenching in oil + Furnace vacation | ||||||
| ≥794 | ≥1176 | ≥6 | ≥25 | ≥245 | 341-388 | |
| Mechanical properties of steel for rails type R50 GOST 24182-80 on delivery | ||||||
| - | ≥860 | ≥5 | - | - | - | |
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 |
