Steel 25Х2ГНТРА

Designation

Name	The value
Designation GOST Cyrillic	25Х2ГНТРА
Designation GOST Latin	25X2GHTPA
Transliteration	25H2GNTRA
By chemical elements	25Cr2MnНTiB

Description

25Х2ГНТРА steel is used: for the manufacture of beams, bolts, axes, vessels, working under excessive internal pressure; the rims of the driven wheels of the traction gear trains, gear and other upgradeable parts.

Note

Chromatorgraphy high quality high strength alloy steel. Can be used at temperatures up to -80 °C (wall thickness not more than 100 mm).

Standards

Name	Code	Standards
Norms for calculation and design	В02	PI 1.2.053-78
Blanks. Of the workpiece. Slabs	В31	TU 1-92-156-90
Bars and shapes	В32	TU 14-1-1885-85

Chemical composition

Standard	C	S	P	Mn	Cr	Si	Ni	Fe	Cu	B	Ti
TU 14-1-1885-85	0.22-0.29	≤0.015	≤0.025	0.6-1.1	1.3-1.7	0.2-0.5	0.9-1.3	Rest	≤0.25	≤0.005	0.02-0.06

Fe is the basis.
According to TU 14-1-1885-85 the chemical composition is given for steel grade 25Х2ГНТРА-ВД. Boron is driven into the steel by 0.0050% and is not determined by chemical analysis. To ensure the required grain size, it is allowed to introduce vanadium in the steel smelting at the rate of its content in steel no more than 0.10%, the content of which in steel is not determined. The presence of tungsten to 0.20%, molybdenum to 0.15% is not a rejection sign. The allowable deviation in manganese content in steel is + 0.010 / -0.020%, in titanium content +0.040%.

Mechanical properties

Section, mm	s_T\|s_0,2, MPa	σ_U, MPa	d₅, %	y, %	KCU, kJ/m²	HB, MPa
Bars and rods, hot rolled, forged and calibrated. Normalization at 880-920 °C + Quenching in oil 840-860 °C + Vacation at 160-200 °C, air cooling
	≥1175	≥1470	≥10	≥45	≥690	388-515
Bars of steel 25Х2ГНТРА on the other 14-1-1885-85. Normalization at 880-920 °C + Quenching in oil 840-860 °C + Vacation at 160-200 °C, air cooling. In the graph KCU KCU values are shown along the fiber/KCU across the grain
	≥1175	≥1470	≥10	≥45	≥686/-	387-514

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

Technological properties

Name	The value
Macrostructure and pollution	Macrostructure of steel when testing for the breaks in the longitudinal direction and transverse templeto selected from rolled, should not have shrinkage, porosity, bubbles, cracks, delamination, inclusions and placenow and defects of fracture, listed in Annex 3 GOST 10243. The Central porosity, point heterogeneity and phase separation in the square should not exceed 1 points; layer-by-layer crystallization and the bright loop - 3 points reference scales GOST 10243. All other defects under GOST 10243, are not allowed. Pollution steel non-metallic inclusions should be according to the average score is not higher (in points): oxides of point 1,5, 2,0 stroke oxides, silicates fragile 1,0, 1,0 silicates plastic, silicates, non-deformed 2,5, 2,5 sulfides, nitrides stroke and point 1,0.