Designation
| Name |
The value |
| Designation GOST Cyrillic |
17Н3МА |
| Designation GOST Latin |
17H3MA |
| Transliteration |
17N3MA |
| By chemical elements |
17Н3Mo |
Description
17Н3МА steel is used: for the production of hot rolled bars used for the manufacture of paws and cutter drill bits all sizes with air purge, as well as bits from 151 mm and less, borgonovo by hot forming.
Standards
| Name |
Code |
Standards |
| Bars and shapes |
В22 |
GOST 2590-2006 |
| Bars and shapes |
В32 |
TU 3-26-79, TU 3-850-80, TU 3-938-79, TU 14-1-4612-89 |
Chemical composition
| Standard |
C |
S |
P |
Mn |
Cr |
Si |
Ni |
Fe |
Cu |
Mo |
O |
| TU 3-850-80 |
0.15-0.2 |
≤0.015 |
≤0.02 |
0.35-0.65 |
≤0.3 |
0.17-0.37 |
3.2-3.8 |
Rest |
≤0.3 |
0.2-0.3 |
- |
| TU 3-938-79 |
0.15-0.2 |
≤0.015 |
≤0.02 |
0.35-0.65 |
≤0.3 |
0.17-0.37 |
3.2-3.8 |
Rest |
≤0.25 |
0.2-0.3 |
- |
| TU 14-1-4612-89 |
0.15-0.2 |
≤0.015 |
≤0.02 |
0.35-0.65 |
≤0.3 |
0.17-0.37 |
3.2-3.8 |
Rest |
≤0.25 |
0.2-0.3 |
≤0.006 |
Fe is the basis.
According to TU 3-938-79, the chemical composition is given for steel grade 17N3MA-III.
TU 14-1-4612-89 chemical composition is given for steel grade 17N3MA-III. Allowable deviations in the chemical composition in the finished rolled product and the mass fraction of residual tungsten, molybdenum, titanium and vanadium - according to GOST 4543.
According to TU 3-850-80 the chemical composition is given for steel grade 17N3MA. 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 |
HB, MPa |
HRC |
| Bars hot rolled as supplied on the other 14-1-4612-89. 1-I'm quenching in oil with 880-900 °C + 2 quenching in oil from 800-820 °C + Vacation at 170-220 °C, air cooling (longitudinal samples) |
| 25 |
≥835 |
≥930 |
≥10 |
≥50 |
≥980 |
≤269 |
- |
| 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 765±15 °C + Vacation at 170-220 °C, air cooling (longitudinal samples) |
|
≥735 |
≥833 |
≥10 |
≥45 |
≥882 |
- |
- |
| Bars hot rolled on the other 3-938-79. 1-I'm quenching in oil with 875-905 °C + 2 quenching in oil with 750-780 °C + Vacation at 170-220 °C, air cooling; for determining the hardenability (HRC): normalization at 910-930 °C + face quenching in water with 850-870 °C (for longitudinal samples; HRC at a distance of 4.5 mm from the end, in brackets, at a distance of 30 mm) |
|
≥833 |
≥931 |
≥10 |
≥50 |
≥980 |
- |
35-40.5 (22-32) |
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 |
| HB |
Brinell hardness number |
| HRC |
Rockwell hardness (indenter diamond spheroconical) |
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 35,0÷40,5, and at a distance of 30 mm from the end - 22÷32. |
