|Designation GOST Cyrillic||30Х2НМА|
|Designation GOST Latin||30X2HMA|
|By chemical elements||30Cr2НMo|
30Х2НМА steel is used: for the manufacture of critical parts of high strength and toughness, working in conditions of alternating loads; power components operating at temperatures up to 500 °C; nitride parts.
Structural alloy steel with reduced Nickel content.
|Bars and shapes||В32||TU 14-1-1885-85, TU 14-1-950-74|
According to TU 14-1-1885-85 the chemical composition is given for steel grade 30Х2НМА-ВД. 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%, titanium to 0.030% is not a rejection sign. In the steel, partial replacement of molybdenum with tungsten is allowed. The total content of molybdenum and tungsten converted to molybdenum from the calculation: three parts by weight of tungsten replace one part by weight of molybdenum, should correspond to the content of molybdenum indicated in the table. In this case, the content of tungsten in steel should not exceed 0.30%. The allowable variation in manganese content in steel is ± 0.010%.
|Section, mm||t отпуска, °C||sT|s0,2, MPa||σU, MPa||d5, %||y, %||KCU, kJ/m2||HB, MPa|
|Bars and strip hot rolled and forged. Quenching in oil with 850-870 °C + vacation, air cooling or oil|
|Bars of steel 30Х2НМА on the other 14-1-1885-85. Quenching in oil with 850-870 °C + Vacation, air cooling or oil. 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|
|Temperature||Е, HPa||r, kg/m3||l, W/(m · °C)||a, 10-6 1/°C|
A description of the physical symbols
|Е||The normal elasticity modulus|
|G||Modulus of elasticity shear torsion|
|l||Coefficient of thermal conductivity|
|R||UD. the resistivity|
|The temperature of forging||The forging temperature of from 850 to 1180 °C.|
|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.|