Steel 74T (М74Т)

Designation

Name	The value
Designation GOST Cyrillic	74Т
Designation GOST Latin	74T
Transliteration	74T
By chemical elements	74Ti

Name	The value
Designation GOST Cyrillic	М74Т
Designation GOST Latin	M74T
Transliteration	M74T
By chemical elements	Mo74Ti

Description

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

Note

М74Т — steel open-hearth rail with titanium.
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» — К74Т.

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	Ti
GOST 24182-80	0.69-0.8	≤0.045	≤0.035	0.75-1.05	0.18-0.4	Rest	0.007-0.025

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 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	s_T\|s_0,2, MPa	σ_U, 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
s_T\|s_0,2	Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2%
σ_U	Limit short-term strength
d₅	Elongation after rupture
y	The relative narrowing
KCU	Toughness
HB	Brinell hardness number