|Designation GOST Cyrillic||25Х2ГНТРА|
|Designation GOST Latin||25X2GHTPA|
|By chemical elements||25Cr2MnНTiB|
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.
Chromatorgraphy high quality high strength alloy steel. Can be used at temperatures up to -80 °C (wall thickness not more than 100 mm).
|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|
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%.
|Section, mm||sT|s0,2, MPa||σU, 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|
|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|
Description mechanical marks
|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|
|HB||Brinell hardness number|
|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.|