Designation
| Name |
The value |
| Designation GOST Cyrillic |
14Х2Н3МА |
| Designation GOST Latin |
14X2H3MA |
| Transliteration |
14H2N3MA |
| By chemical elements |
14Cr2Н3Mo |
Description
14Х2Н3МА steel is used: for the manufacture in cemented and improved the condition of critical parts, which are requirements of high strength, toughness and wear resistance; parts exposed to high vibration and dynamic loads; paws and cutter drill bits all sizes with air purge, as well as bits from 151 mm and less, borgonovo by hot forming; drill bits with a diameter of 320 mm or more.
Note
Temperature range of use of steel from -70 °C to +450 °C.
Standards
| Name |
Code |
Standards |
| Bars and shapes |
В32 |
TU 3-26-79, TU 3-27-79, TU 3-850-80, TU 3-938-79 |
Chemical composition
| Standard |
C |
S |
P |
Mn |
Cr |
Si |
Ni |
Fe |
Cu |
Mo |
| TU 3-26-79 |
0.12-0.16 |
≤0.02 |
≤0.02 |
0.3-0.6 |
1.5-1.75 |
0.17-0.37 |
2.75-3.15 |
Rest |
≤0.2 |
0.25-0.35 |
| TU 3-850-80 |
0.12-0.17 |
≤0.015 |
≤0.02 |
0.35-0.65 |
1.5-1.75 |
0.17-0.37 |
2.75-3.15 |
Rest |
≤0.3 |
0.2-0.3 |
| TU 3-938-79 |
0.12-0.17 |
≤0.03 |
≤0.03 |
0.3-0.6 |
1.5-1.75 |
0.17-0.37 |
2.75-3.15 |
Rest |
≤0.3 |
0.2-0.3 |
Fe is the basis.
According to TU 3-26-79 the chemical composition is given for steel grade 14H2N3MA-VD.
According to TU 3-938-79 the chemical composition is given for steel grade 14H2N3MA.
According to TU 3-850-80 the chemical composition is given for steel grade 14H2N3MA. The presence of residual titanium in the steel to 0.030%, tungsten to 0.20% and vanadium to 0.050% is not a defect.
Mechanical properties
| Section, mm |
sT|s0,2, MPa |
σU, MPa |
d5, % |
y, % |
KCU, kJ/m2 |
| Bars hot rolled as supplied on the other 3-850-80. 1-I'm quenching in oil from 890±15 °C + 2 quenching in oil from 775±15 °C + Vacation at 170-220 °C, air cooling (longitudinal samples) |
|
≥882 |
≥980 |
≥9 |
≥45 |
≥882 |
| Bars hot rolled on the other 3-26-79. Quenching in oil at 880 °C + Vacation at 180 °C, air cooling |
| 15 |
≥885 |
≥980 |
≥10 |
≥45 |
≥780 |
Description mechanical marks
| Name |
Description |
| 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 |
| KCU |
Toughness |
Technological properties
| Name |
The value |
| Macrostructure and pollution |
Macrostructure of steel ready rods on the other 3-850-80 checked for breaks and pickled Templeton, must meet the requirements of GOST 4543 and should not have shrinkage, porosity, bubbles, cracks, delamination, inclusions and placenow. Upon detection placenow steel is rejected. Evaluation of the macrostructure of the etched on Templeton is on scales GOST 10243. Permitted: Central porosity; a point inhomogeneity; phase separation squared, General, regional and Pousada liquation not more than 2 points; layer-by-layer crystallization and the light circuit is not more than 3 points. Not allowed subcortical bubbles and intergranular cracks. Steel is controlled on the contamination of non-metallic inclusions, the content of which is determined according to GOST 1778 for 6 samples and should not exceed the contents in points (average/maximum): - FROM Point - 2,0/4,0; - Stroke OS - 3,0/4,0; - Fragile CX - 3,5/4,0; Plastic SP 2,5/4,0; - non-deformable SN - 2,5/4,0; - Sulfides C - 2,5/4,0; Nitrides N - 1,5/2,5. |
| Microstructure |
The austenitic grain size shall be not larger than the number 5 according to GOST 5639. |
| Particularities of production of goods |
Bars hot rolled on the other 3-850-80 are supplied in heat-treated (annealed or vysokoopasnye) with hardness not exceeding 269 HB (indentation diameter not less than 3.7 mm). Hardenability of steel (after normalization at 920±10 °C or quenching from 890±10 °C) - Hardness HRC should be at a distance of 4.5 mm from the end of 37.5÷43,5, and at a distance of 30 mm from the end - 32,0÷41,5. |
