Steel 74Ц (М74Ц)

Designation

Name The value
Designation GOST Cyrillic 74Ц
Designation GOST Latin 74Ts
Transliteration 74Ts
By chemical elements 74Zn
Name The value
Designation GOST Cyrillic М74Ц
Designation GOST Latin M74Ts
Transliteration M74Ts
By chemical elements Mo74Zn

Description

74Ц steel is used: for the manufacture of railway rails P50.

Note

Steel open-hearth rail with Zirconia.
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» — К74Ц.

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 Zr
GOST 24182-80 0.69-0.8 ≤0.045 ≤0.035 0.75-1.05 0.18-0.4 Rest 0.001-0.05
Fe is the basis.
According to GOST 24182-80, the zirconium content in the range from 0.001% to 0.01% in steel is determined from the calculation of its input of not less than 80 grams per ton of liquid steel.
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 I must be made of calm open-hearth steel, deoxidized in the ladle by complex deoxidizers without the use of aluminum or other deoxidizers, which form harmful non-metallic inclusions in steel.

Mechanical properties

Section, mm sT|s0,2, MPa σU, MPa d5, % y, % KCU, kJ/m2 HB, 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
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