Steel 78ХСФ

Designation

Name	The value
Designation GOST Cyrillic	78ХСФ
Designation GOST Latin	78XCF
Transliteration	78HSF
By chemical elements	78CrСV

Description

78ХСФ steel is used: for the manufacture of railroad rail types R50, R65, R65K and R75 designed for ribbon and continuous Railways and for the production of turnouts.

Note

K78KHSF Converter rail steel.
EH78KHSF — rail electric furnace steel.

Standards

Name	Code	Standards
Rails. Lining. Lining. Crutches	В42	GOST Р 51685-2000

Chemical composition

Standard	C	S	P	Mn	Cr	Si	Fe	Al	V
GOST Р 51685-2000	0.74-0.82	≤0.025	≤0.025	0.75-1.05	0.4-0.6	0.4-0.8	Rest	≤0.005	0.05-0.15

Fe is the basis.
According to GOST R 51685-2000, the mass fraction of residual elements - nickel and copper - not more than 0.15% of each is allowed, with a total mass fraction of these elements not exceeding 0.40%. For a rail type P65K, the mass fraction of carbon should be 0.83-0.87%. At the same time, the numbers in the steel brand were replaced by 85.

Mechanical properties

s_T\|s_0,2, MPa	σ_U, MPa	d₅, %	y, %	KCU, kJ/m²	HB, MPa
Rails under GOST R 51685-2000 (in the delivery condition specified by the category of quality, the hardness is indicated on the surface of rail head)
≥850	≥1290	≥12	≥35	≥147	363-401
-	≥920	≥5	-	-	-
≥800	≥1180	≥8	≥25	≥245	341-401
≥750	≥1100	≥6	≥25	≥147	321-401

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